Lectures in Modern Chemical Separation Technology Chapter 5 Capillary Electrophoresis

Lectures on Separation Technology of Fine Petrochemicals Modern Engineering Chapter 4 Capillary Electrophoresis 4 Micellar Electrokinetic Capillary Chromatography iMEKCl 4.1 Separation principle, which is to divide the solute between the micellar phase and the aqueous phase, and the solute in the chromatogram is in the stationary phase and the mobile phase. The similar distribution between phases but the chromatographic stationary phase is solid or liquid, while the ancient phase of 1 Hong is the flowing micellar phase, so it is called the quasi-stationary phase. Both phases are fluid in the river raft, and the flow of the water is related to the synergistic effect of the electroosmotic velocity of the solution and the electrophoretic velocity of the micelles. In shearing, the separation of the components in the sample is based on the difference in the hydrophobicity of the solute, the hydrophobic solute in the micellar phase, the longer, and the hydrophobic part. The retention time of small solute in the micellar phase is relatively short. The most commonly used surfactant is yang 3, which is an anionic surfactant when the concentration of Yang 3 exceeds its critical adhesive concentration. In order to form a spherical micelle, the outside of micelles is negatively charged in an acidic or alkaline aqueous solution, while the burning base is hidden inside. In the DC electric field, the micelles move toward the anode and the micelles have a solubilizing effect. The solute molecules can be dissolved in it, so that the neutral molecules contained in the sample can also be separated by the river tile. 1 is the intention of 303 micellar electrokinetic separation.

The basic equation describing the retention time of neutral solutes and the resolution of neutral solutes is the amount of substances in the bulk aqueous solutes; it is the theoretical plate number, which is the choice of household; it is the retention of essential oils in the aqueous phase. The time is completely dissolved in the solute retention time in the micellar phase, that is, the migration time of the micelles = the retention time of the neutral solute in the river 1 and between the corpse and if in the rainbow, the two peaks are very close, ie Zuo Ji 2, left, then equation 19 is approximately equal. Equations 8 and 9 become general chromatographic retention equations and resolution equation 4.2. The optimization of the separation parameters is shown in equation 1920. In order to obtain the best resolution and the best unit time resolution, consider the following: Influencing Factors Surfactant Organic Additive Types and Concentrations Buffer Solution Types and Concentrations Operating Voltages Temperature Buffer Solution 1 etc. These factors are all related to the capacity factor.

4.2.1 The best capacity factor and optimum surfactant concentration have been mentioned before. The tolerance factor in 1 is defined as the ratio of the amount of substance in the micellar phase of the solute to the amount of substance in the aqueous phase of the solute. The last two terms of Equation 20 are used by the manufacturer.

In the red. The material balance of the electrically neutral component is assumed to be independent of 7 and D, and the formula 21 is differentiated and the volume factor is determined. From Formula 22, if the surfactant concentration or other parameters are adjusted such that it satisfies the relationship of Formula 22, the corresponding optimum surface-concentration agent concentration (1) may be 23. The distribution coefficient between phases and micelles is 4.2.2. Effect of Organic Additives on Separation In River 1, the addition of organic additives to the buffer solution can increase the selectivity of the separation. Commonly used organic additives are methanol isopropoxide B, cyclodextrin urea and quaternary ammonium salts. By adding organic additives, the polarity of the aqueous solution can be changed to adjust the partition coefficient between the water and the micelle phase, so that the selectivity of the separation can be improved. The methanol and isopropanol can inhibit the electroosmotic flow and delay the shear migration time. The effect of acetonitrile on the electroosmotic flow is determined by the effect of the value of the buffer solution on the separation in the bamboo, the electrolyte, the buffer solution 1 value, the electroosmotic flow velocity, the migration velocity of the micelles, and the migration direction of the femoral bundles to varying degrees. For example, in a buffer solution with a 0.1-salt background electrolyte, the 1 value can change from 3.07.0 to high, and the high value increases, whereas the micelle migration velocity 1 also increases with a value of 7 at 3.07.0. Adding and analyzing the separation and analysis of micellar 5-capillary ionophoretic ion and other low-molecular-weight ions of Hedamin. Compared with classical ion chromatography, the injection volume of 01 has dropped from 1,050 to 10, and the analysis time has been shortened from 20 to 510 minutes. The selectivity of ion chromatography is limited by the type of column and stationary phase. When the sample composition is complex, gradient elution is needed. Wash to complete the separation. The selectivity of capillary ion electrophoresis is determined by the ion equivalent conductance, and the equivalent conductance of most anions is sufficiently different to complete the separation. Although the difference in the equivalent conductance between the cations is small, the secondary complex reaction can also be completed. Separated.

The electroosmotic flow modifier is added to the solution to reduce the electroosmotic flow. Usually, the direction of electroosmotic flow moves from the anode to the cathode, and the electromigration direction of the anion moves from the cathode to the anode, which is exactly the same as the migration speed of the anion in the electroosmotic flow. Electroosmotic flow is equivalent, resulting in the separation, a very electroosmotic flow modifier between the positive and negative electricity, the electroosmotic flow can be reversed from the cathode to the anode and therefore can be used and injection. 1; extremely detectable way, in extremely bright. Anion was detected in 1 room. Electroosmotic flow modifiers usually use cationic surfactants such as aliphatic quaternary ammonium salts or amines, such as human 8 hexadecyl group and 18-kilo-16 reagents. The electroosmotic flow reforming agent's rich and co-existent ions and the complexing effect of Qiaoyang, such as +, can change the mobility and resolution of some ions. Currently, it has been used to determine inorganic anions, organic weak acids, aliphatic carboxylic acid salts, and aliphatic acids. Salt Aliphatic sulphate Aliphatic phosphate and other anions. 5 is the analysis of normal anions in drinking water.

Since the equivalent conductivities of free metal cations are close to each other, it is difficult to separate them only by the difference in the mobility of free metal ions. When ligands capable of complexing with metal ions are added to the carrier electrolyte solution, various metal ions are added. The difference in the stability of the complexes formed can change the apparent mobility of metal ions. When the stability constant of the complex is small, the mobility of the metal ion decreases less, and when the complex is stable When the constant is large, the mobility of the metal ion decreases greatly, so that the purpose of separating the metal ion can be achieved to regulate the concentration of the carrier electrolyte solution, the value or the ligand, and the resolution between different metal ions can be changed. The complexing agent is hydroxyisocitric acid tartaric acid and the benzoic acid should also be thrown off the current mechanical Teng, Meng Meng, 汕 1 leg 孺 genus, right 髹 Pan 镧 镧 Department of halogen phosphonium quaternary ammonium cation and other cations. 6 is the electrophoresis of an alkali metal alkaline earth metal lanthanide metal.

Capillary 365 must be 75 恪glow gutta-percha; voltage 30 1+; injection 29 seconds fluid power; detector 241; standard alkali metal.

6 Because the sample zone is under the action of the high voltage electric field and the migration speed is fast, the detectors used must have very fast organic materials such as white matter and others. Most of them contain organic compounds. Ultraviolet chromophoric groups, and quartz capillary column has good UV permeability, so the UV detector is currently the most widely used detector However, due to the capillary diameter is very small detection of optical path and other reasons, the detection sensitivity is limited. UV detectors can be used directly for the determination of underivatized proteins.

For example, the detection limit of lysozyme is approximately 20101221 absorption wavelength, capillary inner diameter 75 If the sample components do not contain UV-chromophoric groups, it can be labeled with UV-derived reagents, and then separated for fluorescence detection. Detectors, + only a few compounds exhibit intrinsic fluorescence and require a derivatization reaction, so are used in use. The limited-concentration photometric detector can be used to directly determine the tryptophan-containing protein, for example using an inner diameter of 75. The detection limit of the capillary and trypsinogen can be made to be ICT15,1. If the laser is used, the strong excitation light can be enhanced and increased. Degrees of argon ion lasers. In addition to tannic acid, electrochemical detectors for electro-active substances, conductance amps, radioactive detectors, and mass spectrometer detectors have also been reported as several detection modes and detection limits. Detection principle Detection limit Detection principle Detection of photometric intensity Absorption Electrochemical Fluorescence Conductivity Pre-column Derivation Potential Not reported on-column derivatization Amperometric post-column derivatization Radioactivity is inexhaustible Nankai University Department of Chemistry Gansu Feeds Subscriptions 2002 Fine and Specialty Chemicals Monthly Seminar Fine and Specialty Chemicals Sponsored by China National Chemical Information Center Professional and information periodicals issued publicly at home and abroad. Postal code 82877.24 Children's Republic of China, hooked up with the editorial department to receive 1 free recent sample column to set up the market information expert forum technical progress new product introduction consumption-oriented development guide statistical data comprehensive information intermediates and special chemicals supply and demand information foreign special chemical literature reports difficult to help Wait. Scope of report Organic raw materials and intermediates Coatings Pesticide dyes Pharmaceutical raw materials Pigments Adhesives Food and feed additives Chemicals for daily use Surfactants1 Biochemical reagents Catalyst synthesis materials Additives1 Electronics chemicals Chemicals for papermaking Chemicals for the oilfield Chemicals for automobiles Products Leather Chemicals Water Treatment Chemicals Foreign Chemicals Production Chemicals Naturally caught, articles 2002 Fine and Specialty Chemicals Gift 2001 China Fine Chemicals Purchase and Sales Guide Advertising Series Contact Address 100029 North Keanwai Xiaoguan Street No. 53 Fine And Specialty Chemicals > Edition