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, fieldassisted 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.
Keywords: Chemical conversion, Field- assisted extraction, Food analysis, Membrane separation, Sample preparation, capillary electrophoresis, phase partition
