Sample Preparation in Capillary Electrophoresis for Food Analysis

Abstract

This chapter introduces sample preparation techniques in Capillary Electrophoresis (CE) for food analysis. Food sample preparation prior to CE analysis aims to transfer target analytes from random statuses in the original food matrix to highly ordered pre-detection statuses, which is an entropy reduction procedure and cannot happen spontaneously. Generally, this is a time-consuming, labor-intensive, and error-prone step in complex sample analysis, especially in food analysis. Nevertheless, to match the fast analysis nature of CE, food samples have to be prepared efficiently in a relatively short time. Therefore, many highly efficient and fast sample preparation techniques were applied in CE for food analysis, including phase separation, field assisted extraction, membrane separation, chemical conversion, and online coupling of sample preparation/analysis techniques. The principles and operation of each of the above-listed sample preparation techniques and some application examples are shown in different sections.