Capel 105 m instruction manual. A practical guide to the use of capillary electrophoresis systems "drops. Preparing to take measurements

Type of equipment: With capillary electrophoresis system

Manufacturer: Lumeks

Series: DROP

Model: "KAPEL-105M"

Warranty for Systems of capillary electrophoresis "KAPEL-105M": 12 months

Purpose of the device:

Systems of capillary electrophoresis "KAPEL-105M" have the most extensive capabilities: autosamplers, liquid cooling of the capillary, spectrophotometric detector, work in automatic mode. These models, along with the possibility of performing conventional measurements, have a wide research potential, primarily due to the easily changeable detection wavelength.

The KAPEL-105M model differs from the KAPEL-104T model by the presence of a spectrophotometric detector.

A deuterium lamp is used as a light source, and a diffraction monochromator with a spectral range of 190-380 nm and a spectral interval width of 20 nm is used as a dispersing element. This range allows you to choose the detection wavelength that is most sensitive to the analytes, which facilitates the development of new methods and, in many cases, reduces the detection limit.

Cooling of the capillary - liquid with setting and control of the temperature of the coolant in the range from -10 ° C to + 30 ° C from the ambient temperature.

Sample injection method - pressure or electrokinetic.

Sample change - automatic with an autosampler for 10 input and 10 output test tubes.

Washing of the capillary - automatic.

"KAPEL-105" is a device with the widest possibilities. It retains the best qualities of previous models - a liquid capillary cooling system, autosamplers, the ability to work in a programmable automatic mode: up to 15 analysis programs are stored in non-volatile memory. Each program can contain up to 60 steps, use loops, and call other programs. Programs can be created on the basis of standard templates, edited and overwritten. The automatic mode frees up the user's time, reduces the likelihood of errors during analysis, and increases the reproducibility of results. Thanks to a deuterium lamp and a monochromator with a diffraction grating, the device can operate in any wavelength range from 190 to 380 nm. All this makes KAPEL-105M an indispensable instrument for research work both in the development of new methods and in analytical practice.

"KAPEL-105M" is by far the most latest model in the series "DROPS". "KAPEL-105M" is fully controlled from a computer using specialized software, which allows additional collection and processing of electrophoretic data. Other distinguishing features of this model are the advanced design of the cassette with a capillary, which allows quick and reliable replacement of the capillary, as well as the ability to record the absorption spectra of the components of the analyzed sample. "KAPEL-105M" is certified for compliance with the requirements of the electrical safety directives of the European Community 73/23/EEC and 89/336/EC.

WORK PROCEDURE

"KAPEL-105M" is fully controlled from a computer using specialized software, which, in addition to controlling the device, allows you to collect and process electrophoretic data.

AREAS OF USE

analysis of environmental objects;

quality control of food products and food raw materials;

quality control of feed, compound feed, raw materials for their production, premixes;

pharmaceuticals;

clinical biochemistry;

forensic examination;

chemical industry.

Examples of using the method in various areas are given in the book "Practical guide to the use of capillary electrophoresis systems" Kapel ". Download the book (1.7 Mb pdf).

Specifications:

Operating wavelength range of detection, nm	from 190 to 380
Limits of permissible absolute error in setting the operating wavelength, nm	±5
Operating voltage range on the capillary, kV	from 1 to 25
Detection limit of benzoic acid (with positive polarity of the high-voltage unit) at a signal-to-noise ratio of 3:1, μg/cm 3 , not more than
Detection limit of chloride ions (with negative polarity of the high-voltage unit) at a signal-to-noise ratio of 3:1, μg/cm 3 , not more than
Limit of permissible relative standard deviation (RMS) of the output signal by peak area, %
Limit of permissible relative standard deviation (RMS) of the output signal for 8 hours of operation, %
Time to establish the operating mode, min, no more
Power supply systems from the network alternating current voltage (220 ±22) V, frequency (50 ±1) Hz.
Power consumption consumed by the system, V×A, not more than:
Overall dimensions (L´W´H), mm, no more	420x570x360
Weight, kg, no more
Terms of Use:
ambient temperature, °C	from 10 to 35
relative humidity (at 25 °C), %, max
atmospheric pressure, kPa	from 84 to 106.7
Mean time between failures, h, not less than	2500
Average service life, years, not less

Contents of delivery:

system of capillary electrophoresis "KAPEL-105M". The delivery set of the device includes: "Kapel" system, specialized Elforan® software, high voltage source with changeable polarity; one cassette with a capillary; spare parts; Eppendorf test tubes; reusable filter nozzle; filters;

a spare cassette with a capillary and/or a special cassette with a capillary (for amino acids and vitamins, bromide and iodide ions), at the request of the Customer;

microdosers for 10-100 and 100-1000 µl and tips for them;

computer with installed OS WINDOWS-2000/XP (at the request of the Customer);

software "MultiChrome", basic version 3.x;

kits for analysis (at the request of the Customer).

*Specifications and scope of delivery of the device may be changed by the manufacturer without prior notice.

Additional information can be obtained by contacting our specialists by calling the numbers listed in the "contacts" section.

We deliver laboratory equipment throughout Russia by courier services and transport companies.

Capillary electrophoresis is an alternative to HPLC and classical gel electrophoresis.

The principle of operation is based on the migration and separation of the components of a liquid mixture in a capillary under the action of an electric field. This method is optimal because minimal cost time for sample preparation, high immunity to foreign impurities in the sample and low cost of analysis.

Areas of use: analysis of environmental objects, quality control of food products and their raw materials, quality control of feed, compound feed, raw materials for their production, pharmaceutical production, clinical biochemistry, chemical industry, forensic examination, doping control system.

Capel 105 M: has broader capabilities and is designed for both routine research and the development of new methods of analysis.

Light source - deuterium lamp;
dispersing element - diffraction monochromator with a spectral range of 190-380 nm;
spectral interval width 20 nm;
fully controlled from a PC using specialized software, which, in addition to controlling the device, allows you to collect and process electrophoretic data;
light source - low pressure mercury lamp with HF excitation;
photometric detector 254 nm;
high-voltage DC unit 1–25 kV, 1 kV steps, polarity changeable
(in manual or automatic mode);
current, μA - 0 - 200;
the ability to set and / or change parameters during the analysis - analysis time, pressure, wavelength;
sample injection hydrodynamic or electrokinetic;
2 autosamplers with a capacity of 10 test tubes per input and output;
flushing at constant pressure ~ 1000 mbar (optional - 2000 mbar);
quartz capillary (length 30–100 cm, inner diameter 50 or 75 µm);
large LCD display;
capillary cooling - liquid with setting and control of coolant temperature;
temperature control of the capillary (relative to the ambient temperature), °С - from -10 to +30;
power consumption, W - 200;
dimensions WxDxH, mm - 500x500x500;
weight, kg - 25.

Delivery

Delivery is carried out throughout Russia and the CIS countries. Self-delivery from a warehouse at the address Moscow region, Mytishchi, 7th Leninsky lane, 13 is possible. Delivery in Moscow and the Moscow region is free of charge.

The price of the goods is indicated from a warehouse in Moscow and does not include delivery costs to other cities.

You can choose a delivery method in your account so that it is automatically indicated when placing all subsequent orders. If you select the option "Transport company of the client's choice", indicate in the comments the transport company with which you prefer to work.

The exact cost of delivery is calculated by the manager upon confirmation of the order, depending on the weight and volume characteristics and range. Goods requiring a special temperature regime are delivered subject to the required conditions. If the order contains precursors, it is necessary to issue an official letter on the release of precursors. (sample letter on release of precursors)

Payment

Company diaem works with legal entities and individuals. After placing an order, the sales assistant will generate an invoice and send it to you by e-mail and on the order page Personal account Online. You can also create an invoice yourself from the Basket by logging in to the site. The invoice is paid through a bank. You can pay for the goods at the checkout diaem or any bank branch.

To receive the goods, it is necessary to provide a power of attorney to the organization, and to receive the goods upon payment individual a passport is required.

Pickup:

Price:
On request

Free shipping

throughout Russia

ANK LLC provides free shipping throughout Russia to most of the devices supplied by the organization. Delivery is carried out by almost any transport company or courier service to the terminal or to the door of the Buyer. Read more in the "Shipping and payment" section.

Low Price Guarantee

for all equipment

Our company guarantees most low price for goods. If you find this product cheaper, we are ready to provide discount and issue an invoice with a lower value. To use this service, you must provide Commercial offer or an invoice from a competing organization.

Manufacturer's Warranty

from 1 year to 5 years

Guarantee period operation of all instruments and equipment supplied by ANK is 1 year(for some devices up to 5 years). During the warranty period, the Buyer has the right to repair the product at the expense of the Manufacturer, subject to compliance with all rules of operation, storage and transportation.

Official dealer

we have certificates

Our organization is official representative(dealer, distributor) on the territory of Russia of all equipment presented on the company's website. We have the relevant documents confirming these powers and have the right to sell the entire line of devices of one or another manufacturer.

ANK is the official dealer

Description of the capillary electrophoresis system "KAPEL-105M"

Equipment type: capillary electrophoresis system

Manufacturer: Lumeks

Series: CAPEL

Model: "KAPEL-105M"

Warranty for capillary electrophoresis systems "KAPEL-105M": 12 months.

Purpose of the device:

Capillary electrophoresis systems "KAPEL-105M" have the widest possibilities: autosamplers, liquid cooling of the capillary, spectrophotometric detector, automatic operation. These models, along with the possibility of performing conventional measurements, have a wide research potential, primarily due to the easily changeable detection wavelength.

The KAPEL-105M model differs from the KAPEL-104T model by the presence of a spectrophotometric detector.

Cooling of the capillary is liquid with setting and control of the coolant temperature in the range from -10°C to +30°C from the ambient temperature.

Sample injection method - pressure or electrokinetic.

Sample change is automatic with an autosampler for 10 input and 10 output tubes.

Capillary flushing is automatic.

"KAPEL-105" is a device with the widest possibilities. It retains the best qualities of previous models - a liquid capillary cooling system, autosamplers, the ability to work in a programmable automatic mode: up to 15 analysis programs are recorded in non-volatile memory. Each program can contain up to 60 steps, use loops, and call other programs. Programs can be created on the basis of standard templates, edited and overwritten. The automatic mode frees up the user's time, reduces the likelihood of errors during analysis, and increases the reproducibility of results. Thanks to a deuterium lamp and a monochromator with a diffraction grating, the device can operate in any wavelength range from 190 to 380 nm. All this makes KAPEL-105M an indispensable instrument for research work both in the development of new methods and in analytical practice.

"KAPEL-105M" is by far the latest model in the "KAPEL" series. "KAPEL-105M" is fully controlled from a computer using specialized software, which allows additional collection and processing of electrophoretic data. Other distinguishing features of this model are the advanced design of the cassette with a capillary, which allows quick and reliable replacement of the capillary, as well as the ability to record the absorption spectra of the components of the analyzed sample. "KAPEL-105M" is certified for compliance with the requirements of the electrical safety directives of the European Community 73/23/EEC and 89/336/EC.

WORK PROCEDURE

"KAPEL-105M" is fully controlled from a computer using specialized software, which, in addition to controlling the device, allows you to collect and process electrophoretic data.

AREAS OF USE

analysis of environmental objects;

quality control of food products and food raw materials;

quality control of feed, compound feed, raw materials for their production, premixes;

pharmaceuticals;

clinical biochemistry;

forensic examination;

chemical industry.

Examples of using the method in various areas are given in the book "Practical guide to the use of capillary electrophoresis systems" Kapel ". Download the book (1.7 Mb pdf).

Specifications:

Operating wavelength range of detection, nm	from 190 to 380
Limits of permissible absolute error in setting the operating wavelength, nm
Operating voltage range on the capillary, kV
Detection limit of benzoic acid (with positive polarity of the high-voltage unit) at a signal-to-noise ratio of 3:1, µg/cm3, not more than
Detection limit of chloride ions (with negative polarity of the high-voltage unit) at a signal-to-noise ratio of 3:1, μg/cm3, not more than
Limit of permissible relative standard deviation (RMS) of the output signal by peak area, %
Limit of permissible relative standard deviation (RMS) of the output signal for 8 hours of operation, %
Time to establish the operating mode, min, no more
Power supply of systems from the alternating current network with voltage (220 ±22) V, frequency (50 ±1) Hz.

SYSTEMS OF CAPILLARY ELECTROPHORESIS "KAPEL®-105M"

State Register of SI RF No. 17727-11
State Register SI RB No. 03 09 0926 12
State Register of SI of Kazakhstan No. KZ.02.03.04489-2012/17727-11
Declaration of Conformity CU RU Д-RU.ME03.B00001
KNO code 03.07.03.00.00
OKP 42 1540
OKPD 33.20.53.145

The main distinguishing feature of the KAPEL-105M model is spectrophotometric detection.

A deuterium lamp is used as a light source, and a diffraction monochromator with a spectral range of 190-380 nm and a spectral interval width of 20 nm is used as a dispersing element. This range makes it possible to select the detection wavelength that is most sensitive to the target components, which facilitates the development of new techniques and, in many cases, reduces the detection limit.

"KAPEL-105M" is fully controlled from a computer using specialized software, which allows additional collection and processing of electrophoretic data.

The KAPEL-105M system uses an improved design of the cassette with a capillary, which makes it possible to replace the capillary even faster and more reliably.

The device has the ability to register the absorption spectra of the components of the analyzed sample.

"KAPEL-105M" is certified for compliance with the requirements of the directives on electrical safety of the European Community 73/23/EEC and 89/336/EC.

Since the 4th quarter of 2014, KAPEL-105M has been supplied with a high voltage source with a switchable polarity, which further simplifies the operation procedure.

Optional capillary flushing at 2 atm. allows to carry out the mode of gel electrophoresis.

At the same time, the best qualities of previous models are preserved in the KAPEL-105M system:

Cooling of the capillary is liquid. The choice of coolant temperature depends on the ambient temperature and is possible in the range from minus 10 ° С to +30 ° С from the ambient temperature, but not lower than +5 ° С and not higher than +50 ° С.
Sample injection method - pressure or electrokinetic.
Autosampler for 10 input and 10 output tubes.
All procedures, from sample injection to capillary flushing, are performed automatically in programming mode, which reduces time and error during analysis and improves the reproducibility of results.

All this makes KAPEL-105M a convenient tool both for research in the development of new methods and in analytical practice.

Areas of use:

analysis of environmental objects;
quality control of food products and food raw materials;
quality control of drinks (alcoholic and non-alcoholic)
quality control of feed, compound feed, raw materials for their production, premixes;
pharmaceuticals;
clinical biochemistry;
forensic examination;
chemical industry.

Installation conditions:

the presence in the laboratory of a centrifuge, microdosers, a bidistillator.

transcript

1 N.V. Komarova Ya.S. Kamentsev PRACTICAL GUIDE TO THE USE OF CAPILLARY ELECTROPHORESIS SYSTEMS "DROPS" St. Petersburg 2008

2 UDC BBK P69 Komarova NV, Kamentsev Ya. S. Practical guidance on the use of capillary electrophoresis systems "CAPEL" Circulation 2000 copies. (additional edition) The book is a practical guide to the use of Capillary capillary electrophoresis systems, the first and only mass-produced devices in Russia for the implementation of various options modern instrumental method of capillary electrophoresis. The material of the book includes the physical and chemical foundations of the method, its analytical capabilities, and a description of the apparatus. Using the methods developed by Lumex specialists as an example, development strategies are described with indication of methodological features and our practical recommendations. A significant place in the manual is given to examples of the use of the capillary electrophoresis method in various fields. Particular attention is paid to the preparation of the capillary and the assessment of its performance. The book was written by leading specialists in capillary electrophoresis at the Lumex Research and Production Company with the involvement of materials developed by users of Capel capillary electrophoresis systems in our country and abroad. The book is intended, first of all, for chemical engineers and laboratory assistants of analytical laboratories who are just starting to study or are already using in their daily practice the devices of the Kapel series and the methods developed for them. It can also be useful to researchers and specialists whose area of interest is separation methods and their application for the analysis of environmental objects, food products, drugs, bioassays, etc.; as well as those who are looking for new areas of application of the method of capillary electrophoresis. Authors: N. V. Komarova, Ya. S. Kamentsev Contents Preface... 3 List of accepted terms and abbreviations... 5 Introduction Chapter 1. Physical and chemical basis of the method of capillary electrophoresis Chapter 2. Main variants of capillary electrophoresis Chapter 3. Equipment General device capillary electrophoresis systems High voltage sources Detectors Data acquisition and processing systems Autosamplers Thermal stabilization systems Chapter 4. Efficiency, sensitivity, resolution and selectivity in capillary electrophoresis Separation efficiency Method sensitivity Resolution and separation selectivity Chapter 5. Processing of results in capillary electrophoresis. Qualitative and quantitative analysis Qualitative analysis. Migration/Retention Characteristics Quantitative Processing of Analysis Results Chapter 6. Objects for Analysis by Capillary Electrophoresis. Sample preparation ISBN LLC "Lumex", 2006 LLC "Veda", 2006 Chapter 7. Fields of application of the method of capillary electrophoresis and examples of the use of CE systems "Capel" Analysis of environmental objects Feed industry Food industry Veterinary medicine Pharmacy Clinical biochemistry Forensic examination Technological tasks Some methodological possibilities Instrument Capabilities...149

3 Capillary electrophoresis system "Kapel" 3 Chapter 8. Some analytical applications of the method of capillary electrophoresis developed by Lumex Analysis of the ionic composition of water Determination of inorganic cations Determination of inorganic anions Simultaneous determination of potassium, sodium, magnesium, calcium cations and chloride and sulfate anions in water environments using the Kapel-103RE electroinjection analyzer Analysis of non-alcoholic, low-alcohol and alcoholic beverages (juices, vodkas, wines and wine materials, beer, brandy, etc.) Determination of caffeine, ascorbic acid, preservatives (sorbic and benzoic acids) and sweeteners (saccharin , aspartame and acesulfame K) Determination of organic acids Determination of synthetic dyes Analysis of herbicides of the classes of phenoxycarboxylic acids and symmetrical triazines Analysis of feed, animal feed, raw materials for their production, premixes Analysis of amino acids Analysis of free forms of water-soluble vitamins Chapter 9. General recommendations for working with capillary electrophoresis systems, possible difficulties and ways to overcome them Preparing the capillary for operation, checking its condition, storage, ways to restore performance, replacement Good laboratory practice B. Testing capillary electrophoresis systems "Kapel": checking the performance of the device, quality control of the preparation of the capillary C. Manual washing of the capillary with a medical syringe to combined methods of separation and analysis capillary electrophoresis. Since 1996, Lumex has been the first and still the only manufacturer of serial capillary electrophoresis systems in the CIS. Following the tradition of offering methodological support for the instrument, the methods for analyzing the cationic and anionic composition of water bodies were the first to be developed. Improving and increasing the potential of Kapel devices, we also did not forget about expanding the scope of this relatively new in the world and absolutely new at that time in Russia instrumental method of analysis. This goal was achieved both in the laboratory of our company and outside it: in the research and production laboratories of organizations that have relied on the CE method and on the equipment manufactured by us. Sufficiently large material was accumulated, which made it possible to evaluate the possibilities of using capillary electrophoresis in various fields. The results obtained in 2001 were presented by us in the collection “The system of capillary electrophoresis. Fundamentals of the method. Equipment. Examples of the use of Capel-103, -104, -105 capillary electrophoresis systems. Over the past five years, Lumeks has significantly expanded the circle of users of Kapel devices, has upgraded the existing model range capillary electrophoresis systems and released new modifications, including computer-controlled ones. We have improved methods for analyzing the ionic composition of water, developed new methods for determining (amino acids, vitamins, organic acids, dyes, etc.), accumulated materials demonstrating the broad analytical capabilities of the method. Of course, all these years we have maintained a close relationship with our colleagues who use Kapel devices to solve routine tasks according to certified methods, as well as for scientific and applied research. At the same time, we understand that both novice analysts and experienced researchers can be Capel users, but all of them, of course, need literature on capillary electrophoresis, which is still unforgivably scarce in Russian. Starting to write this book, the authors set themselves 3 goals. First, we wanted to give an intelligible idea of the scientific foundations of capillary electrophoresis, which would serve as a foundation for understanding the practical problems solved with its help. Secondly, on specific analytical examples, which are based on the methods developed by the company, to demonstrate the strategy for developing each of the analyzes, indicating the methodological features and our practical recommendations. Third, give numerous (but by no means all possible) examples practical use method implemented on systems of capillary electrophoresis "Capel".

4 4 Analytical Instrumentation Firm “Lumex” Capillary electrophoresis system “Kapel” 5 The authors are grateful to their colleagues A. P. Solomonova, A. V. Shiryaev, I. V. Ivanova, V. G. Adamson, and O. V. Morozova ., Gremyakov A.I., Lebedev M.Yu., Shpak A.V., Okun V.M. for their help in preparing chapters 7 and 8. for preparing materials for publication, Burleshina A.V. for careful reading of the materials and comments. We would like to especially thank our colleagues from other organizations who kindly provided their materials for this publication, and wish them further success in advancing the method of capillary electrophoresis. Natalya Viktorovna Komarova Yaroslav Sergeevich Kamentsev List of accepted terms and abbreviated electrophoresis, being a relatively young method of separation and analysis, at first borrowed most of the terms from the closest separation method, HPLC. Over time, taking into account the basic principle of separation in electromigration CE, an own terminological base of the capillary electrophoresis method was formed, which since 2002 has been recommended for use by IUPAC. In this section, we present only those basic terms and abbreviations that will be actively used in this Practical Guide. Due to the fact that the vast majority of publications on CE continue to appear on English language, we will give, along with Russian names, English generally accepted equivalents. Terms Migration time t m (migration time, t m) is the time required for the component to pass the effective length of the capillary (, L eff) from the sample injection zone (the beginning of the capillary) to the detection zone. Electroosmotic flow of an EOP (electroosmotic flow, EOF) is the flow of liquid in a capillary under the action of an applied electric field. The time required for the liquid to overcome the effective length of the capillary due to the emerging EOP is called the EOP time (t EOP, t eof) and is experimentally determined from the electrophoregram (electropherogram) by the time of migration of the neutral component of the EOP marker. The mobility of the image intensifier tube µ eo (electroosmotic mobility, µ eof) is the ratio of the speed of the image intensifier tube to the strength of the electric field. The EOF velocity (electroosmotic velocity, veof) is positive in the direction of liquid movement from the inlet section of the capillary to the detector and negative in the opposite direction. The speed of the image intensifier tube is calculated as: v image intensifier tube = /t image intensifier tube. The electric field strength is the ratio of the applied potential difference (U) to the total length of the capillary (Ltot, Ltot). Thus, the mobility of the image intensifier tube is calculated from the experimental data: µ image tube = L total x /t image tube xu. Traditionally, when calculating mobilities, the length of the capillary is expressed in centimeters, the migration time in seconds, and the potential difference in volts. Note. Migration time as a qualitative analysis parameter is usually expressed in minutes, but for high-speed analyzes, the total time of which does not exceed 2-3 minutes, the migration time is given in seconds. The electrophoretic mobility of a particle µ eff (electrophoretic mobility, µ ep), by analogy with the previous value, is the ratio of the electrophoretic velocity of a particle to the electric field strength and can be calculated: µ eff = L total х /t m хu. In contrast to µ seo, the electrophoretic mobility of a particle cannot be determined directly from the electrophoregram, since the particle migration time t m in

5 6 Analytical Instrumentation Firm “Lumex” Capillary electrophoresis system “Kapel” 7 in this case is the sum of the migration times of the particle itself and the image intensifier tube marker. From the experiment, you can find the so-called total mobility, which is expressed (at a positive image intensifier tube speed): µ total = µ eop + µ eff. Knowing from the experiment µ total and µ eop, one can easily calculate µ eff. Capillary Electrophoresis (CE) is a separation method implemented in capillaries and based on differences in the electrophoretic mobilities of charged particles in both aqueous and non-aqueous buffer electrolytes. Solutions (leading electrolytes, running buffers, background electrolyte, run buffer) may contain additives (for example, macrocycles, organic solvents, polymers, etc.) that can interact with the analyzed particles and change their electrophoretic mobility. Note 1: This method is also known as Capillary Zone Electrophoresis (CZE). Neutral components cannot be separated by this method; they all migrate in the image intensifier zone. Note 2: The use of the term capillary electrophoresis as a general term for all capillary electromigration methods is not recommended because many of these methods (capillary gel electrophoresis, capillary affinity electrophoresis, capillary isoelectric focusing, capillary isotachophoresis, micellar electrokinetic chromatography, microemulsion electrokinetic chromatography, capillary electrochromatography) are based on separation principles different from CE. Micellar Electrokinetic Capillary Chromatography (MECC) is a separation method based on a combination of electrophoretic and chromatographic separation principles. A surfactant is introduced into the buffer solution, which at certain concentrations forms a pseudostationary micellar phase, and the sample components are distributed between this phase and the buffer solution phase according to their hydrophobicity. Note 1: This method is also referred to as Micellar Electrokinetic Chromatography (MEKC). Note 2. The migration time of the micelles (t mc) is experimentally determined as the migration time of the component completely retained by the micellar phase. A micelle marker, for example, is sudan 3. Abbreviations .this. KZE KKM CSAV CE MVI MS MC MEKH PZU TFE FITC FCA FTG FTC-derivatives Full name ,4,5-trichlorophenoxyacetic acid anionic surfactant amino acids benzimidazole high performance liquid chromatography humic acids sodium dodecyl sulfate diethanolamine electric double layer isoelectric point capillary zone electrophoresis critical micelle concentration cationic surfactant capillary electrophoresis measurement technique mass spectrometry macrocycle micellar electrokinetic chromatography ROM solid phase extraction phenylisothiocyanate phenoxycarboxylic acids phenylthiohydantoin phenylthiocarbamyl derivatives

6 8 Analytical Instrumentation Company “Lumex” Capillary electrophoresis system “Kapel” 9 FAA phenoxyacetic acid t m migration time CD cyclodextrin Thr threonine CTAB cetyltrimethylammonium bromide Trp tryptophan CTAOH cetyltrimethylammonium hydroxide Tyr tyrosine EDTA ethylenediaminetetraacetic acid (and its salts) U potential difference image intensifier tube electroosmotic flow Val valine Ala alanine W 1/2 peak width at half maximum Arg arginine selectivity factor Asn asparagine interfacial potential difference Asp aspartic acid dielectric constant Cys-Cys cystine zeta potential D diffusion coefficient solution viscosity Gln Glu Gly His ID Ile k" L total Leu Lys Met N Phe pk a Pro q r R s Ser glutamine glutamic acid glycine histidine capillary inner diameter isoleucine capacitance factor total capillary length effective capillary length leucine lysine methionine efficiency phenylalanine dissociation constant proline particle charge particle radius resolution of adjacent peaks serine µ total total particle mobility µ eop electroosmotic flow mobility µ eff electrophoretic particle mobility

7 10 Analytical Instrumentation Company “Lumex” Capillary electrophoresis system “Kapel” 11 Introduction In the last two decades, there has been an active interest in the world in a new, intensively developing method for separating complex mixtures - capillary electrophoresis, which makes it possible to analyze ionic and neutral components of various nature with high rapidity and unique efficiency. Capillary electrophoresis is based on electrokinetic phenomena - electromigration of ions and other charged particles and electroosmosis. These phenomena occur in solutions when they are placed in an electric field, mainly of high voltage. If the solution is in a thin capillary, for example, in a quartz capillary, then the electric field applied along the capillary causes the movement of charged particles and a passive flow of liquid in it, as a result of which the sample is divided into individual components, since the electromigration parameters are specific for each type of charged particles . At the same time, such perturbing factors as diffusion, sorption, convection, gravitational, etc., are significantly weakened in the capillary, due to which record separation efficiencies are achieved. Traditionally, capillary electrophoresis has been compared to high performance liquid chromatography (HPLC) because both methods separate in a limited space (capillary or column) with the participation of a moving liquid phase (buffer solution or mobile phase (eluent)) and use similar detection principles to record signals. and data processing programs. Nevertheless, the methods have differences that, of course, relate to the advantages of capillary electrophoresis: high separation efficiency (hundreds of thousands of theoretical plates), inaccessible HPLC and associated with a flat image tube profile, a small volume of the analyzed sample and buffers (no more than 12 ml in day), while the use of high-purity, expensive organic solvents is practically not required, the absence of a column, sorbent, problems with its aging and, therefore, the replacement of the column, simple and inexpensive equipment, rapidity and low cost of a single analysis. The method of capillary electrophoresis is now successfully used to analyze various substances (inorganic and organic cations and anions, amino acids, vitamins, drugs, dyes, proteins, etc.) and objects (to control the quality of water and drinks, technological control of production, input control raw materials, analysis of pharmaceuticals and food products, in forensics, medicine, biochemistry, etc. d.). In Russia, works related to the study of the possibilities of the CE method and its analytical applications began to appear only in recent years, which was largely initiated by the creation of domestic devices for capillary electrophoresis. Capillary electrophoresis systems "Kapel", developed and manufactured by Lumex, are the first serial family of devices in Russia and the CIS, included in the State Register of Measuring Instruments and intended for the implementation of this method. The family today includes the following modifications certified as measuring instruments: Kapel-103R, Kapel-103RT, Kapel-104T, Kapel-104M, Kapel-105 and Kapel-105M . The company also produces experimental modifications of Kapel-RE electroinjection analyzers. Models with a built-in block for measuring the flow potential "Kapel-PT" are being developed. Capillary electrophoresis systems "Kapel" are designed for quantitative and qualitative determination of the composition of samples of substances in aqueous and aqueous-organic solutions by capillary electrophoresis. On devices of any of the modifications, techniques using the main variants of CE, capillary zone electrophoresis (CZE) or micellar electrokinetic chromatography (MEKH), can be implemented without restrictions. The first option is intended for the analysis of only ionic components of samples, the second for the analysis of both ionic compounds and molecular forms of substances. A variety of technical solutions used by the specialists of the company "Lumex" in the creation of devices of the "Capel" family, Table. 1 allows the consumer to choose the system that best suits the nature of the problem being solved. Of the limitations of CE, it should be noted that, compared to HPLC, the concentration sensitivity is low and the requirement for the analyzed compounds to dissolve in water and dilute aqueous-organic mixtures. At the same time, these limitations are not insurmountable. Thus, the insufficient sensitivity of detection when using UV detection (due to the short optical path length equal to the inner diameter of the capillary) can be compensated by the use of such types of detection as laser-induced fluorimetric or mass spectrometric in combination with various methods of on-line sample concentration (so-called staking and sweeping). And the option of non-aqueous capillary electrophoresis successfully allows you to separate and analyze highly hydrophobic, insoluble in aqueous solutions, sample components.

8 12 Lumex Analytical Instrumentation Company Capillary electrophoresis system Kapel 13 Kapel-103R is the most simple model with manual control and step-by-step operating principle. Only one test tube with the analyzed solution can be installed in the device. "Kapel-103R" is ideal for teaching the method of capillary electrophoresis at universities, technical lyceums and laboratories due to the clarity of all procedures and ease of management. Table 1. Technical characteristics of devices of the Kapel series. Characteristics Capel -103R Capel -103RT Capel -104T photometric detector high-voltage unit sample injection sample change capillary flushing capillary cooling possibility to set and/or change parameters during analysis kv, changeable polarity, µA current hydrodynamic or electrokinetic automatic with two manual autosamplers for 10 input and 10 output tubes at a constant pressure of ~1000 mbar quartz (length cm, inner diameter 50 or 75 µm) coolant temperature control (range from 10 to +30 C from ambient temperature) analysis time pressure temperature voltage analysis time wavelength pressure temperature voltage supply V, 50/60 Hz power consumption, W dimensions, mm 420x330x x350x x500x weight, kg (105M ) Collection, processing and output of data is carried out using personal computer with the operating system "Windows 98/ME/NT/2000/XP", on which the program for collecting and processing chromatographic data "MultiChrome for Windows", version 1.5x is installed. For modifications "KAPEL-105M/104M" control of the device, collection and processing of data is carried out using the software "Elforan". For the modification of "KAPEL-105M" control of the device, collection and processing of data is possible using the software "MultiChrome for Windows", version 2.5x. "Kapel-103RT" differs from the previous model in the presence of a liquid capillary cooling system, which allows you to maintain the temperature of the coolant at a given level regardless of the temperature of the laboratory room, thereby increasing the reproducibility of measurement results. Efficient cooling of the capillary makes it possible to use higher voltages for analysis, which leads to an increase in separation efficiency and a decrease in analysis time. "Kapel-104T" is designed to perform serial analyzes. It is equipped with two autosamplers, capillary liquid cooling system, has user-friendly interface, which allows you to create programs for the operation of the device in automatic mode. A simpler model "Capel-104" (with air, less efficient cooling of the capillary) is currently out of production. Capel-104M, retaining all the capabilities of Capel-104T, has the most modern electronics to date, is fully controlled from a computer, and is equipped with a single program for controlling, collecting and processing electrophoretic data. The advanced capillary cassette design allows fast and reliable capillary replacement. "Kapel-105" is a device with the widest possibilities. It retains the best qualities of previous models - liquid capillary cooling system, autosamplers, the ability to work in a programmable automatic mode. In addition to this, the instrument has a spectrophotometric detector based on a deuterium lamp and a monochromator with a diffraction grating, due to which the operating wavelength range covers the region from 190 to 400 nm. All this makes Kapel-105 an indispensable instrument for research work both in the development of new methods and in analytical practice. The latest of the certified models in the Kapel series today is Kapel-105M. Along with the latest electronic base, it implements full control instrument, collecting and processing data using its own software, as well as the possibility of recording the absorption spectra of the components of the analyzed sample during the analysis. Experimental modifications of "Capel-RE" are electroinjection analyzers devices for the implementation of a new method of capillary electrophoresis. In this method, components that are capable of interacting with each other are introduced into the capillary by an electrokinetic method from both ends. Meeting in the capillary, these components form new compounds that have a different mobility than the original ones, and, therefore, can be registered when passing through the detection zone. The device may be of interest to those who deal with the problems of chemical kinetics, reactivity,

9 14 Analytical Instrumentation Company “Lumex” Chapter 1. Physical and chemical bases of the method of capillary electrophoresis 15 conformation, etc. A feature of the device is a special cassette in which the detector window is located in the middle of the capillary, due to which the effective length of the capillary is the same as for cationic, and for the anionic components of the samples. In addition to the mercury lamp, the device is equipped with a replaceable incandescent lamp and a set of light filters, which allow you to expand the operating wavelength range to the visible and near infrared region of the spectrum. The Kapel-PT modification is equipped with a block for measuring the flow potential. The flow potential (in the English literature, streaming potential), in its physical essence, the phenomenon is the reverse of the electroosmotic flow, occurs at the ends of the capillary, when an electrolyte flow is created in it. It also occurs when the capillary is washed with a leading buffer solution during capillary conditioning. Measuring the flow potential (PT) at this moment makes it possible to assess the degree of readiness of the capillary for the next analysis, and, thereby, to increase the reproducibility of the release time of the components in a series of similar electrophoregrams. In turn, the improvement in the reproducibility of release times is accompanied by an improvement in the reproducibility of the amount of substance in the peak, i.e., the reproducibility of the quantification of the concentration of the substance in the sample. In any model of the Kapel system, you can set or change during the analysis: pressure, voltage, analysis time, temperature (for systems with liquid cooling of the capillary), wavelength (for models 105/105M). Thus, the wide possibilities of the method, combined with the versatility of instrumentation, make it possible to use capillary electrophoresis and Kapel devices to solve a wide variety of analytical problems. Chapter 1. Physical and chemical foundations of the method of capillary electrophoresis The movement of charged colloidal particles under the action of an external electric field is called electrophoresis. Electrophoresis as a separation method was proposed in the 30s of the XX century. Tiselius. He placed a mixture of blood serum proteins in a buffer solution and, upon application of an electric field, found that the components of the sample migrated in a direction and at a rate determined by their size, shape, and electrical charge. In 1948, the work was awarded the Nobel Prize in Chemistry. The main limitation of the wide use of the method was the low separation efficiency due to thermal effects and fluid convection. This problem has been partly solved by using a non-convective medium (polyacrylamide gels) in gel electrophoresis. Despite the fact that separation in a gel is quite widespread, especially in biochemistry, its limitations are also obvious: a long analysis time, insufficient efficiency, and difficulties in detection and automation. In 1967, the Swedish scientist Hirten proposed to carry out electrophoretic separation not on a plane, but in open capillary tubes with an internal diameter of 15 mm, thus laying the foundation for the method of capillary electrophoresis. Later, Virtanen and Mickers used glass and Teflon capillaries with an internal diameter of 200 microns, and finally, in the early 80s. 20th century Jorgenson and Lucas demonstrated the separation capabilities of a quartz capillary with an internal diameter of 75 µm, using the latest advances in the manufacture of quartz capillaries with very small and uniform internal diameters (~ tens of µm), transparent in the ultraviolet region of the spectrum. In addition, considerable experience has already been accumulated in the world on the possibilities of detecting analytical signals in a stream. From this moment, the active development of the method of capillary electrophoresis in its modern format begins, which continues to the present. The CE method is based on the separation of charged components of a complex mixture in a quartz capillary under the action of an applied electric field. A microvolume of the analyzed solution (~2 nl) is introduced into a quartz capillary pre-filled with a suitable electrolyte buffer. After applying a high voltage (up to 30 kV) to the ends of the capillary, the mixture components begin to move at different speeds, depending primarily on the charge and mass (more precisely, the ionic radius) and, accordingly, reach the detection zone at different times. The resulting sequence of peaks is called an electrophoregram; a qualitative characteristic of a substance is the migration time, and a quantitative characteristic is the height or area of the peak, which is proportional to the concentration of the substance. In order to get a more detailed understanding of the method, it is necessary to consider a number of processes occurring in a capillary filled with an electrolyte and placed in a longitudinal electric field. The siloxane groups located on the surface of fused quartz upon contact with water or aqueous solutions are hydrolyzed to form a double amount of silanol groups, which are then hydrated. >Si=O H 2 O >Si OH OH

10 16 System of capillary electrophoresis "Capel" Chapter 1. Physical and chemical bases of the method of capillary electrophoresis 17 The rate and degree of hydrolysis depend on the temperature and pH of aqueous solutions and, to a lesser extent, on the concentration of the salt background of the solution. In aqueous solution, silanol groups are capable of acid dissociation. The first stage constant has the value K a1 = 2.5x10-3. This means that when the pH of the aqueous solution is greater than 2.5, the quartz surface acquires a certain negative charge, which increases with increasing pH of the solution. On the contrary, at pH ~2 and less, the dissociation of silanol groups is almost completely suppressed, and the quartz surface becomes neutral. The dissociation of silanol groups causes the formation of an electric double layer (EDL) at the interface between quartz and an aqueous electrolyte solution, fig. 1a. Its first lining consists of immobile negatively charged silanol groups. The second plate of the double layer consists of positively charged cations that exist in solution. The dielectric separating the plates of this capacitor are water molecules that hydrate both silanol groups and cations. The positive part of the EDL, in turn, is divided into two parts: the first (or immovable), directly adjacent to the quartz surface, and the second (or diffuse), located at some distance from the surface. In the immobile part, the number of positive charges is less than the number of negative charges on the surface of quartz due to the increase in the size of cations due to hydration. As a result, some excess concentration of cations is formed in the diffuse part of the DEL. Between these two layers passes the so-called. the slip boundary, when an electric field is applied along the capillary, the stationary part remains in place, while the diffuse part begins to migrate to the cathode, dragging along with it the entire mass of liquid in the capillary due to intermolecular adhesion. An electroosmotic flow (EOF) occurs, which passively transfers the solution inside the capillary. The EOP rate strongly depends on the pH of the solution: in strongly acidic solutions, the EOP is absent, in weakly acid solutions, its rate is negligible, and upon transition to the neutral and alkaline region of pH, the EOP rate increases to the maximum possible. On the other hand, this value depends on the electrolyte concentration in the leading buffer: the higher it is, the higher the proportion of cations in the stationary part of the DEL becomes, and the thickness of the diffuse part decreases and, accordingly, the electroosmotic flow rate decreases. On fig. 1b shows the distribution of charges in the DEL. The total potential () created by dissociated silanol groups is proportional to the charge. Part of this potential () is neutralized by the positive charges of the ions of the fixed part of the second lining of the double layer. The rest of the positive charges creates an electrokinetic or -potential (zeta potential) in the near-surface layer of the solution. Rice. 1a. The structure of the electrical double layer. The thickness of the diffuse part of the DEL 1b. Distribution of charges in DES.

11 18 Capillary electrophoresis system "Kapel" Chapter 1. Physical and chemical bases of the method of capillary electrophoresis 19 The unique property of the image intensifier tube lies in a flat flow profile (in contrast to the parabolic one in HPLC), which practically does not cause their broadening when the zones of the components inside the capillary move (Fig. .2). Due to this, the CE method is characterized by the highest efficiency (~ hundreds of thousands of theoretical plates). Electroosmotic flow In devices for capillary electrophoresis, a capillary filled with an electrolyte solution is lowered with its ends into two vessels containing the same electrolyte, into which electrodes are inserted. The electrolyte should have buffer properties, on the one hand, to prevent changes in the composition of the solution in the near-electrode spaces, and on the other hand, to stabilize the state of the sample components during the analysis. When a high voltage is applied to the electrodes, a stationary state is quickly established in the capillary: a constant electroosmotic flow flows through the capillary, on which mutually opposite electromigration of cations and anions is superimposed. If a small volume of sample solution is introduced into the capillary from the anode side, then the image intensifier tube will transfer this zone to the cathode (to the detection area), and the zone can be in the capillary for some time under the influence of a high-voltage electric field. During this time, the charged components of the sample will move according to their electrophoretic mobilities. The cationic components of the sample, moving towards the cathode, will overtake the electroosmotic flow (Fig. 3). The speed of their movement is the sum of the speed of the image intensifier tube and the speed of electromigration, therefore, at the exit of the capillary, cations appear first and the earlier, the greater their electrophoretic mobility. The neutral components of the sample are able to move only under the influence of the electroosmotic flow, while the anionic components will move towards the anode at velocities lower than the speed of the image intensifier tube. Slowly migrating anions will appear at the outlet after the EOP, and those whose electromigration rate in absolute value exceeds the rate of the EOP will exit the capillary into the anode space. Laminar flow Fig. 2. Influence of the flow profile on the width of the substance zone.

12 20 System of capillary electrophoresis "Kapel" Chapter 1. Physical and chemical bases of the method of capillary electrophoresis 21 At the exit of the capillary, near the cathode, one can observe the zones of the solution, in which the individual components of the sample are located. The leading electrolyte (also called the working buffer solution) must have a concentration at which the electrical resistance of the solution in the capillary will be sufficiently high. This requirement is due to the fact that when an electric current passes through a conductor, heat is generated. If the current is high enough, the liquid in the capillary may even boil. It is traditionally believed that the electric current in the capillary obeys Ohm's law, although it is known that the linear relationship between current and voltage exists in solution only in a limited range of voltages. Let's take a look at some aspects of this phenomenon. specific example . Let the total length of the capillary be 60 cm, the effective length (i.e., the length from the entrance to the detector window) be 50 cm, the operating voltage applied to the electrodes be 25 kV, and the current in the capillary be 100 μA. The strength of the current in the capillary depends on its length and diameter, as well as on the concentration of the electrolyte in the solution. For a capillary with an inner diameter of 75 μm, a current strength of 100 μA at a voltage of 25 kV is achieved at a salt concentration in the electrolyte of 0.03–0.04 mol/l. Under the chosen conditions, the electrical resistance of the circuit is 250 M (megaohm), the voltage gradient, which practically coincides with the field gradient, is 416 V/cm. The power released in the capillary in this case is 2.5 W. Since all of it is converted into thermal energy, it is more convenient to convert it into calorie thermal units. The recalculation shows that a gigantic amount of 0.6 calories is released every second in the capillary, given that the volume of liquid in a capillary with a diameter of 75 microns is only 2.65 microliters. If we do not take into account the transfer of heat through the wall of the capillary, then such an amount is sufficient for the temperature of the liquid in the capillary to increase by 225 C (!) within 1 second. Rice. 3. Electrophoretic migration of ions in the presence of an electroosmotic flow. This formal calculation shows how serious the problem of capillary cooling in CE is. In fact, the released heat is spent not only on heating the solution, but also on heating the quartz walls and the polyimide shell. It should also be taken into account that the heat capacity of quartz is ~6 times less than that of an aqueous solution, and the thermal conductivity of fused quartz is 16 times greater than that of water. All these circumstances contribute to the efficient removal of heat to the external environment, however, if special measures are not taken, the liquid in the capillary will boil very soon. Therefore, devices for CE always contain either capillary cooling systems by vigorous air blowing or liquid cooling systems. Thermal equilibrium in the capillary is established fairly quickly. It is characterized by a relatively small difference in the temperature of the solution in the radial direction in the inner channel of the capillary and a stable temperature gradient between the inner and outer walls of the capillary. Heating of the liquid does not cause the appearance of convective flows, since heating occurs evenly throughout the entire lumen of the capillary. As a result, there is no mixing of the liquid, which leads to the erosion of the zones of the components being determined. With excessive heating, boiling of the liquid is possible, and vapor bubbles interrupt the current in the capillary, which makes

13 22 System of capillary electrophoresis "Kapel" Chapter 1. Physical and chemical bases of the method of capillary electrophoresis 23 no analysis is possible. Therefore, when choosing the conditions for electrophoretic separation, one should strive to minimize the current by an appropriate choice of the concentration of the leading electrolyte. Depending on the concentration of electrolytes in the buffer and sample solutions, the behavior of the components during separation may differ slightly. If the conductivities of the leading electrolyte and the sample are the same, then the voltage drop over the entire length of the capillary is uniform, and the sample components move uniformly each with its own speed. In this case, at the capillary outlet (more precisely, in the area of the detector window), the peak width will be approximately equal to the width of the sample area (if smearing is neglected). Therefore, efficient separation can be achieved with the introduction of the smallest possible sample volume (but to ensure the necessary sensitivity, the concentration of the components to be determined in the sample should be as high as possible). A different behavior is observed if the electrical conductivity of the sample solution is less than the electrical conductivity of the leading electrolyte. In this case, a section with high resistance appears in the capillary and the current through the capillary decreases, but in accordance with Ohm's law, the voltage drop in the section occupied by the sample increases as many times as the resistance of the sample is greater than the resistance of an equal section of the leading electrolyte. Thus, if the resistance of the sample solution in the capillary is 10 times greater than the resistance of the leading electrolyte, the potential gradient in the sample zone will be 10 times higher than in the rest of the capillary. A high potential gradient in the sample zone causes the sample components to migrate faster to the zone boundary, where they pass into the leading electrolyte in a concentrated and pre-separated form, and there they continue, but more slowly, moving towards the detector. The described phenomenon is called stacking and is widely used in the practice of electrophoretic separations. It makes it possible to obtain very narrow peaks of the determined components and, as a result, their concentration in the peak turns out to be much higher than in the original sample. In practice, stacking is carried out in such a way that, before injection, the sample is diluted with a special buffer solution (the concentration of which is 10 times less than the concentration of the working buffer solution) or even with distilled water. use such compositions of buffer leading electrolytes in which water decomposes on the electrodes (borax solution is one of the most common buffers for CE). Hydrogen ions are reduced at the cathode, molecular hydrogen is released on the cathode surface, and hydroxyl ions are formed in the near-cathode space. At the anode, the oxidation of hydroxide ions, the release of molecular oxygen on the anode surface, and the formation of hydrogen ions in the anode space. At the cathode: 2H 2 O + 2e - Η 2 + 2ΟΗ At the anode: 2ΟΗ 2e - Ο 2 + 2Η + At high potential differences that are used in CE, other parallel electrochemical reactions can occur on the electrodes, but the above are the main ones. The resulting hydroxide and hydrogen ions are neutralized by the buffer components of the leading electrolyte: when using a borate buffer in the cathode layer with boric acid, in the anode layer with borate ion. Thus, in the near-electrode spaces, only a change in the molar ratio of the components of the buffer mixture occurs, leading to only a slight change in the pH of the solution. On fig. 4 shows a typical location of the capillary and electrode in a test tube with an electrolyte solution, adopted in the Kapel systems. In the same case, when the electrical conductivity of the sample solution is greater than the electrical conductivity of the leading electrolyte, the voltage drop in the area occupied by the sample decreases sharply. As a result, the rate of electromigration of the sample components decreases, they reach the zone boundary more slowly, and upon transition to the leading electrolyte, the rate of their movement increases. The peaks are smeared, they overlap each other, and the separation efficiency deteriorates sharply. Capillary electrophoresis uses open systems in the sense that the electrolyte solution in which the separation occurs is not separated from the electrodes to which the voltage is applied, although the near-electrode spaces are connected through a thin quartz capillary, which performs the main separating function, but also serves as an electrolytic bridge that closes the electrical circuit. In electrical circuits containing both conductors of the first and second kind, the flow of current is impossible without electrochemical reactions at the metal-solution boundaries. In capillary electrophoresis, they try to use 4. Typical arrangement of a capillary and an electrode in a test tube with a solution.

14 24 System of capillary electrophoresis "Kapel" Chapter 1. Physical and chemical bases of the method of capillary electrophoresis 25 The mouth of the capillary is located in the lower third of the volume of the test tube; the lower cut of the electrode is approximately at the lower level of the upper third of the solution. With this arrangement, the products of electrochemical reactions, in particular, gas bubbles, cannot penetrate into the lumen of the capillary, as well as the leading electrolyte solution containing neutralization products and differing in composition from the original one. At the same time, the consumption of the leading electrolyte due to the image intensifier tube occurs due to the unchanged solution from the middle third of the volume. The preservation of the described state is facilitated by the absence of mixing of the solution during the analysis. Assume that the analysis is carried out at a current of 100 μA for 15 minutes. During this time, 1x10-4 Ax900 sec = 0.09 coulombs of electricity will pass through the solution, which is equivalent to 9.33x10-7 mol. The same number of moles of hydrogen and hydroxyl ions is formed in test tubes containing 500 µl of buffer solution. Therefore, during one analysis, the concentration of one of the components of the buffer solution will change by 9.33x10-7 /5x10-4 = 1.86x10-3 mol/l. If the initial total concentration of the components of the buffer solution is ~0.02 M, then after 56 analyzes the buffer capacity of the leading electrolyte will be completely exhausted. The given example shows that the concentrations of the components of the leading electrolyte change significantly during the analysis. Therefore, in order to obtain reproducible results, it is necessary to regularly, on average, every 3-4 analyzes, replace the leading electrolyte solutions in working tubes with fresh portions. This is all the more important because the cathode space accumulates cationic components of the samples, which can be reduced on the cathode to the elemental state during subsequent analyses. Similarly, anionic components of samples can accumulate in the anode space. One of the most unpleasant of them is the Cl anion, which, oxidizing on the electrode to free chlorine, causes corrosion of the platinum anode. cal balance in the near-electrode layers cause electromigration of excess ions of the leading electrolyte in mutually opposite directions. Inside the capillary, these fluxes of excess ions are joined by the migration of an excess concentration of cations from the diffuse part of the double layer of the capillary. The mechanism of movement is, apparently, a relay-race character. Each elementary act of electrode reactions causes the entire mass of ions in the solution to move by the value of the interionic distance in the solution. The speed of movement is such that the electrical neutrality of the solution is observed in the entire volume of the capillary at any point and at any time. Thus, the role of these flows is to equalize the stoichiometric disturbances that take place in the near-electrode spaces. The factors that limit and regulate the rate of electromigration are electrochemical reactions at the electrode surface. The entry of cations into the cathode space is stoichiometrically compensated by an electrochemical reaction, as a result of which a certain amount of cations is reduced to a molecular state and an equivalent amount of anions is formed, which in turn compensate for the loss of anions from the cathode space. In the near-anode space, at the same time and in the same quantity, an electrochemical oxidation reaction of anions and the formation of an equivalent amount of cations are carried out. If a sample is introduced into the capillary, then it is transferred to the detector by the liquid flow. Those ions that differ from the ions of the leading electrolyte migrate under the action of an electric field in mutually opposite directions, and the migration rates will be specific for each type of ions. With regard to capillary electrophoresis, the physical picture of the ongoing processes is as follows. The imposition of a potential on the electrodes of the system causes the formation of a double electric layer in the immediate vicinity of the electrode surface. Potential gradients at the boundaries of near-electrode double layers exceed the water decomposition potential, and electrochemical reactions start at the electrodes. Hydrogen ions are reduced at the cathode, and hydroxyl ions are oxidized at the anode. The reduction of one hydrogen ion at the cathode is accompanied by the formation of one hydroxyl ion in the cathode layer, and the oxidation of one hydroxyl ion at the anode is accompanied by the formation of one hydrogen ion in the anode layer. These two elementary acts of electrochemical reactions on the electrodes are equivalent to the passage of one electron through the solution. The ions formed as a result of electrode reactions are redundant; they disrupt the material and electrical balance in the near-electrode layers. These ions are rejected by the oppositely charged surface of the electrodes, and quickly, practically without leaving the near-electrode layers, are neutralized by the buffer components of the leading electrolyte in the near-cathode zone by the acid component, and in the near-anode zone by the main component. With the location of the capillary and electrodes, which is described above, the change in the acid-base balance will occur only in the upper layers of the reservoirs. Violation of the stoichiometry of solutions, i.e., the formation in the near-electrode layers of excess concentrations of cations (in the near-anode) and anions (in the near-cathode), as well as a violation of the electrical

15 26 Capillary electrophoresis system "Kapel" Chapter 2. The main options for capillary electrophoresis 27 Chapter 2. The main options for capillary electrophoresis We have already mentioned above that the most common options for the method of capillary electrophoresis are capillary zone electrophoresis and micellar electrokinetic chromatography. The simplest CE option is capillary zone electrophoresis (CZE). The components of a complex mixture move in an electrolyte medium with different speeds , forming discrete zones. A distinctive feature of CZE is that it is suitable for separating only ionogenic components of the sample, while neutral compounds that do not have their own electrophoretic mobility move at the speed of the image intensifier tube and exit in the zone of neutral components, the zone of the image intensifier tube marker. In capillary electrophoresis instruments that use a quartz capillary, the polarity of the input end is most often positive (anode), and the image intensifier tube transfers the sample area to the cathode. A detector is installed near the cathode outlet. Under these conditions, the cationic components of the sample, also migrating to the cathode, overtake the image intensifier tube and are the first to reach the detector in the form of separate zones, which are recorded by individual peaks on the electrophoregram. After some time, the zone of the initial solution, in which the neutral components of the sample remained, also reaches the detector. Depending on whether they absorb or not, a direct (in some cases reverse) peak is recorded on the electrophoregram, which is often called a systemic one. Sometimes, to identify the systemic peak, special substances (EOP markers) are added to the sample, for example, benzyl alcohol. As for the anionic components of the sample, their behavior depends on the ratio of the rates of the image intensifier tube and the electromigration of anions. If the anion migration rate exceeds the EOF rate, then such an anion will sooner or later leave the capillary into the near-anode space (this is undesirable, since some anions, such as chloride, getting into the working buffer solution, will, by discharging at the anode, cause corrosion of the platinum electrode ). If the anion electromigration rate is less than the EOP rate, then such an anion can be registered on the same electrophoregram after the release of the systemic peak. In this version of CZE with positive polarity, the cationic components of samples and most organic anions can be determined. In order for the CZE method to be able to determine the anionic components of samples (mainly of inorganic origin), it is necessary to change the polarity of the applied voltage. However, in this case, not only the direction of anion migration will change, but also the direction of the image intensifier tube. To overcome this contradiction, it is necessary to modify the surface of the quartz capillary so that the signs of the charges of the electrical double layer are reversed. This is achieved by introducing a cationic surfactant, such as cetyltrimethylammonium bromide (CTAB), into the working buffer solution. The CTA+ cation is actively sorbed on the quartz surface, occupying all vacancies in the layer closest to the surface at its sufficient concentration. The surface, as it were, "bristles" with long cetyl (C 16 H 33) chains. The surface that has become hydrophobic during further washing with a working buffer solution sorbs another layer of a surface-active cation oriented with the ammonium end outwards (brush-to-brush sorption). As a result, the first layer of the electric double layer becomes positive, and the second layer, including its diffuse part, becomes negative, and the image intensifier tube again moves from the input end to the detector, somewhat lagging behind the faster migrating anions. Despite the fact that in recent years the original, more correct name proposed by Hirten, free solution electrophoresis has returned, the vast majority of publications in the field of CE continue to use the traditional name "capillary zone electrophoresis". The main advantage of CZE is its high efficiency (hundreds of thousands of theoretical plates), while the selectivity determined by the separation mechanism within one phase is insufficient in CZE. An increase in selectivity can be achieved by changing the pH of the leading electrolyte, introducing various additives into the buffer composition: surfactants, macrocycles, organic solvents, etc. Micellar electrokinetic chromatography combines electrophoresis and chromatography. Introduced in 1984 by the Japanese scientist Terabe, MEKC has become the most widely used among other variants of capillary electrophoresis, primarily due to the ability to separate both ionic and uncharged sample components. The separation of neutral compounds became possible due to the introduction of micelle formers into the composition of the leading electrolyte. Most often, anionic surfactants are used (for example, sodium dodecyl sulfate SDS, eng. SDS) at concentrations exceeding the critical micelle concentration (CMC), which, for example, for SDS in an aqueous solution is 8 mm. In this case, the electrolyte solution contains mainly micelles and a small fraction of the monomeric form of the surfactant. Monomers consist of a hydrophobic "tail" and a hydrophilic (in the case of an anionic surfactant negatively charged) "head". During the formation of straight micelles, monomeric fragments are aggregated with their nonpolar ends inward, and the outer spherical surface of the micelles becomes negatively charged. Each micelle is surrounded by its own electrical double layer, the outer diffuse part of which is formed by cations present in the leading electrolyte solution. The number of monomers forming a micelle can vary from 60 to 100 molecules; however, the total charge of a micelle is significantly lower due to the presence of hydrated cations in the immobile part of the second DEL layer. Neither the micellar nor the monomeric form of surfactants interact with the wall of the quartz capillary, but when a high voltage is applied to the capillary, both forms migrate to the anode, while the image intensifier tube is directed to the cathode. If a sample containing neutral and charged components is introduced into the capillary on the anode side, then the image intensifier tube will transfer them to the cathode, and the flow of negatively charged surfactant micelles will move towards it. The neutral components of the sample can be distributed between the solution phase and the micellar phase, and the constant of this distribution is specific for each kind of sample molecules. As a result, an electrophoregram of neutral components, as well as slowly migrating sample anions, is recorded at the capillary outlet.

Research and Production Company of Analytical Instrumentation N.V. Komarova, Ya.S. Kamentsev PRACTICAL GUIDE TO THE USE OF CAPILLARY ELECTROPHORESIS SYSTEMS "DROPS" St. Petersburg N.V. Komarova,

MINISTRY OF HEALTH OF THE RUSSIAN FEDERATION GENERAL PHARMACOPEIAL AUTHORIZATION Electrophoresis OFS.1.2.1.0021.15 Instead of Art. SP XI, issue 1 Electrophoresis method of analysis based on the ability of charged particles,

Lecture 15 Conductivity of electrolytes Questions. electrolytes. electrolytic dissociation. Ion mobility. Ohm's law for electrolytes. Electrolysis. Faraday's laws. Determining the charge of an ion. 15.1.

Topic 23. Amines. Amino acids and peptides Content of the topic: Amines, their classification and nomenclature. Methods for obtaining and chemical properties of amines. Aniline, its electronic structure. Main properties dependency

8. Questions 1. Define chromatography. 2. What features of chromatography make it possible to achieve a better separation of substances with similar properties compared to other separation methods. 3. List

Electrochemistry (lectures, #6) Doctor of Chemical Sciences, Professor A.V. Churikov Saratov State University named after N.G. Chernyshevsky Institute of Chemistry In the Arrhenius theory of electrolytic dissociation

Lecture 3 Voltammetric analysis Lecture plan 1. General concepts of voltammetry (polarography). 2. Polarograms (voltammograms) 3. Qualitative analysis in voltammetry. 4.Voltammetric

MINISTRY OF HEALTH OF THE RUSSIAN FEDERATION GENERAL PHARMACOPEIAL AUTHORIZATION Capillary electrophoresis OFS.1.2.1.0022.15 Introduced for the first time Capillary electrophoresis is a physical method of analysis based on

Appendix to certificate 43903 sheet 1 on approval of the type of measuring instruments

LECTURE 12 (ELECTIVE) ELECTROKINETIC PHENOMENA IN DISPERSIVE SYSTEMS AND SOLUTIONS OF IMC For reasons of occurrence, electrokinetic phenomena are divided into two groups: phenomena in which the relative motion

T.P. Vavilova A.E. Medvedev Biological Chemistry Biochemistry of the Oral Cavity Textbook Ministry of Education and Science of the Russian Federation Recommended by the First Moscow State Medical University named after

Ministry of Education and Science of the Russian Federation

ELECTROLYSIS OF AQUEOUS SOLUTIONS AND MELTS OF SALT Vadim E. Matulis, Vitaliy E. Matulis, TA Kolevich, 1. The concept of general Let's carry out the following experiment. We place two metal plates in a solution of copper (II) chloride,

01/2016:20247 2.2.47. CAPILLARY ELECTROPHORESIS GENERAL PRINCIPLES Capillary electrophoresis is a physical method of analysis based on the migration of charged particles within a capillary.

Master's program 150400.32 Modern principles of hardware design of heat and mass transfer processes Head of the program Doctor of Technical Sciences, prof. Konovalov V.I. Brykina E.V., Romanova E.V. STUDY

Electrochemistry (lectures, #5) Doctor of Chemical Sciences, Professor A.V. Churikov Saratov State University named after N.G. Chernyshevsky Institute of Chemistry Application of the Debye Hückel theory to weak electrolytes

5. Capillary electrophoresis The method of capillary electrophoresis (CE) is based on the separation of the components of a complex mixture in a quartz capillary under the action of an applied electric field. The microvolume of the analyzed

MINISTRY OF GENERAL AND VOCATIONAL EDUCATION OF THE RUSSIAN FEDERATION NOVOSIBIRSK STATE UNIVERSITY Faculty of Physics Department of General Physics DESCRIPTION OF LABORATORY WORKS Part 2. Molecular

VOLTAMMETRY POLARIZATION OF THE ELECTRODE If E is the potential of the electrode through which the electric current flows, E i \u003d 0 is the potential of the same electrode at I \u003d 0, then E E i \u003d 0 \u003d P polarization of the electrode is polarized,

Chemistry Lecture 3 α-amino acids, peptides, proteins. The lecture is given by prof. Belavin Ivan Yurievich 2. α-amino acids, peptides, proteins α-amino acids proteins bioregulators source of energy α-amino acids heterofunctional

Ministry of Education and Science of the Russian Federation FGAOU VPO Kazan (Volga Region) Federal University A.M. Butlerova Department of Physical Chemistry Vladimir Alexandrovich Sirotkin PHYSICAL

Electrochemistry (lectures, #13) Doctor of Chemical Sciences, Professor A.V. Churikov Saratov State University named after N.G. Chernyshevsky Institute of Chemistry Faraday and non-Faraday processes Considered

1. Classification of solids by conductivity in accordance with the band theory. In accordance with the principle of quantum mechanics, the electrons of an atom can have certain values of energy or be located

1. Covalent bonds in proteins and enzymes. Give examples. TICKET 1 2. What is the basis for the separation of proteins by fractionation in the presence of different concentrations of salts. From what impurities this method allows

ELECTROCHEMICAL PROCESSES Electrochemical processes are processes of mutual conversion of chemical and electrical energy based on redox reactions (ORD). Conversion process

Bank of tasks "PHYSICS_10_MODULE 8 _PART 2_ electric current in various environments". Task 1 3.2.10. Electric current in semiconductors What is the difference between the structure of semiconductors and metals? 3) 4) in metals

Potential 1.60. In a uniform electric field with a strength of E = 1 kv / m, a charge q = 50 ncl is moved to a distance l = 12 cm at an angle = 60 0 to the lines of force. Determine the work A of the field when moving

13 "Generation and recombination of charge carriers" The formation of free electrons and holes, the generation of charge carriers occurs under the influence of thermal chaotic motion of atoms of the crystal lattice

Moscow Institute of Physics and Technology Department of Molecular and Biological Physics Physical Research Methods Lecture 9 Gas Chromatography Experimental Technique and Methods Dolgoprudny, April 3

Moscow Institute of Physics and Technology (State University)) Department of Molecular Physics Physical Methods of Research Lecture 0 Gas Chromatography Dolgoprudny, November 5, 0g. Plan. Story

4 ELECTROSTATIC FIELD IN THE PRESENCE OF CONDUCTORS Conductors of electricity are substances containing free charged particles. in conducting bodies electric charges can move freely in space.

LECTURE 7 CHROMATOGRAPHY AS A METHOD OF SEPARATION, IDENTIFICATION AND QUANTITATIVE DETERMINATION Basic concepts and definitions Various classifications chromatographic methods Chemisorption chromatography

Lecture 6 Lukyanov I.V. Transport phenomena in gases. Contents: 1. The length of the free path of molecules. 2. Distribution of molecules over their mean free paths. 3. Diffusion. 4. Viscosity of the gas (internal friction).

Ministry of Education of the Russian Federation Tomsk Polytechnic University Department of Theoretical and Experimental Physics "APPROVED" Dean of ENMF I.P. Tyurin 007 DETERMINATION OF THE CHARGE OF THE HYDROGEN ION

3. THE EFFECT OF POLARITY AND THE INFLUENCE OF BARRIERS ON THE ELECTRICAL STRENGTH OF AIR GAPS AT DC VOLTAGE

CHEMISTRY. GENERAL AND INORGANIC CHEMISTRY. ELECTROLYTIC DISSOCIATION OF ELECTROLYTES IN AQUEOUS SOLUTIONS AND ION EXCHANGE REACTIONS. ELECTROLYTES AND NON-ELECTROLYTES. From the lessons of physics it is known that solutions of some substances

Job. MEASURING THE THERMAL CONDUCTIVITY OF AIR Task To measure the thermal conductivity of air. r INTRODUCTION In a state of equilibrium, the temperature of a gas (as well as any other substance) in all

Scientific and practical conference"Engineering-geological problems of our time and methods for their solution" Methods for determining the electric potential of clay soil particles Korolev V.A., Nesterov D.S., Chernov

METHODOLOGICAL MATERIALS FOR PRACTICAL CLASSES (2 HOURS) Elements of hydrogen energy for autonomous systems Technologies for producing hydrogen One of the aspen and most promising in terms of autonomous

FEDERAL AGENCY FOR EDUCATION State Educational Institution of Higher Professional Education “Ural State University. A.M. Gorky" IONTS "Ecology and nature management"

Lecture 10 ELECTROLYTIC DISSOCIATION Purpose: to study the process of electrolyte dissociation Educational questions: 1. Chemical equilibrium in solutions. Aqueous solutions of electrolytes. Theory of electrolytic dissociation.

Lecture 1, 2. Fundamentals of electrochemistry Lecturer: ass. cafe OKHT Ph.D. Abramova Polina Vladimirovna e-mail: [email protected] LECTURE OUTLINE I. Basic concepts II. A series of metal stresses III. Galvanic cells

Lecture 1: The primary structure of proteins - amino acids 1 Diversity of proteins Many of the biological functions of the body are carried out by proteins. These functions include the transport and storage of oxygen (hemoglobin

Uncharged glass cubes 1 and 2 were brought close together and placed in the electric field of a positively charged sphere, as shown in the upper part of the figure. Then the cubes were moved apart and only then the charged

Thermo Scientific Model 60i How it works The Model 60i analyzer performs concentration measurements using non-dispersive infrared spectroscopy (NDIR) technology. The 60i combines

Federal State Budgetary Educational Institution of Higher Professional Education "OMSK STATE TECHNICAL UNIVERSITY" DEPARTMENT OF CHEMISTRY LABORATORY WORK "Electrolysis of water

1.23. Conductors in an electric field 1.23.a Charge distribution in a conductor In conductors, unlike dielectrics, the concentration of free charge carriers is very high ~ 10 23 cm -3. These charges

Electrochemistry (lectures, #7) Doctor of Chemical Sciences, Professor A.V. Churikov Saratov State University named after N.G. Chernyshevsky Institute of Chemistry ELECTROCHEMISTRY OF HETEROGENEOUS SYSTEMS (ELECTRODICS) Subject

Electrochemistry (lectures, #14) Doctor of Chemical Sciences, Professor A.V. Churikov Saratov State University named after N.G. Chernyshevsky Institute of Chemistry Dependence of DEL capacity on potential and concentration

Benefits of Agilent AdvanceBio SEC SEC columns for biopharmaceutical analysis Comparing columns from different vendors to improve data quality Technical Overview

Since 1998, the KAPEL devices manufactured by the LUMEX Group of Companies have been the only mass-produced capillary electrophoresis systems in Russia and the CIS countries. ADVANTAGES OF THE METHOD Capillary

Laboratory work 0 DC. OHM'S LAW. Purpose and content of the work The purpose of the work is to analyze Ohm's law for a circuit section containing a conductor and a current source. The job is to measure

Lecture 7 (9.05.05) TRANSFER PROCESSES IN GAS

GOST R 51435-99 Apple juice, concentrated apple juice and drinks containing apple juice. Method for determination of patulin content using high performance liquid chromatography. OKS 67.160.20

Work 42 Study of the characteristics of the photoresistor The purpose of the work To get acquainted with the principle of operation of the photoresistor and to investigate its current-voltage, light and spectral characteristics, to estimate the band gap

Federal Agency for Education State Educational Institution of Higher Professional Education PETROZAVODSK STATE UNIVERSITY STUDYING THE DIELECTRIC PROPERTIES OF VARIOUS