| Capillary Electrophoresis?CE?is a new type of liquid phase separation technique with high voltage direct current electric field as the driving force.The technology has the advantages of fast,efficient and multiple separation modes.In order to solve the defects with low detection sensitivity of CE,on-column sample enrichment technology has become an effective method.This kind of enrichment technology has been rapidly developed in recent years because it has the advantages of no need to modify the experimental instruments,simple and convenient to use.The paper focused on the on-column enrichment technology of capillary electrophoresis,with sulfonamides and monoamine neurotransmitters as target compounds.The pH-mediated base stacking method and field-enhanced sample injection-micelle solvent stacking-capillary zone electrophoresis has been studied,and the good results and application range of CE have been achieved.The details are as follows:1 IntroductionThis part mainly introduces the overview of on-column sample enrichment technology in capillary electrophoresis.We also highlights the different analysis methods of sulfonamide residues in the ecological environment and biogenic amine neurotransmitters.The significance of the research topic was also elaborated.2 pH-mediated base stacking with CZE for the analysis of sulfamethoxazole and trimethoprimin compound sulfamethoxazole tabletsThis section uses pH-mediated base stacking on-column preconcentration techniques to increase CE-UV sensitivity.The method is environmentally friendly and non-toxic.It overcomes the limitation of low sensitivity due to the short optical path length in the capillary,and obtains satisfactory analysis results.Under the optimized conditions,the detection limit?S/N=3?of SMZ was 3.4×10-6 mol/L,and the detection limit of SMP?S/N=3?was 2.6×10-6mol/L.3 Field-enhanced sample injection-micelle solvent stacking-determination of biogenic amine neurotransmitters by capillary zone electrophoresisThis section aims to establish a simple,fast and accurate method for the separation of biogenic amine neurotransmitters by capillary zone electrophoresis?CZE?.On-line enrichment technique?FASI?and micellar solvent stacking?MSS?were combined for capillary zone electrophoresis?CZE?.The running buffer consists of 150 mmol/L phosphate buffer?Na2HPO4-NaH2PO4?-25%ACN containing 30 mmol/L borax.At pH 4.9,four biogenic amine neurotransmitters?5-hydroxytryptamine,dopamine,norepinephrine,epinephrine?were well separated and enriched.The detection limits?S/N=3?of the four were2.4×10-8 mol/L,4.5×10-8 mol/L,3.2×10-88 mol/L and 2.5×10-8 mol/L,respectively. |
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