Fast Determination And On-Line Stacking Based On Moving Reaction Boundary For Clenbuterol Andsalbutamol In Swine Feed And Urine By Capillary Electrophoresis

In recent years, capillary electrophoresis (CE) has become one of the most outstanding separation techniques because it is superior in terms of rapid, high resolving, and low samples and reagents reqiured. Now it is widely used for the analysis of drugs and metabolites and become a powerful technique for the analysis of physiological samples. However, the detection sensitivity of CE is low due to the short length of optical path and small volume of sample injected.To overcome the weakness of CE, many on-line stacking techniques have been developed to improve the Limit of Detection (LOD). In general, these techniques are designed to compress the low concentration analyte bands, therefore increase the sample injection. Our work is based on the moving reaction boundary (MRB), one of the on-line stacking theories, to make research of its application to the food additives. In this paper, we firstly introduce the theory of CE technology and make a review of several on-line stacking methods. Then the MRB mode is introduced and applied into the stacking and detection ofβ2-Agonists.The researches include two experimental parts. Part one is the study of fast determination of Clenbuterol and Salbutamol with capillary zone electrophoresis (CZE) method. We innovatively use alkaline phosphate electrolyte as running buffer, and optimized the experiment conditions such as pH value and concentration of the buffer and the applied voltage. All our analytes are detected within 4.5 minutes under the optimized condition. Then this method is applied to the fast detection of Clenbuterol and Salbutamol in swine feed, and we found no interference from the complex background extractants.Part two of our experiment is to apply the MRB theory to the on-line stacking of Clenbuterol and Salbutamol in swine urine. We optimized the pH value and concentration of the sample buffer and running buffer, the sample injection method and work voltage. Under the optimized condition, we get over 705-fold and 274-fold improve of LOD for Clenbuterol and Salbutamol.