Monitoring of bacterial contamination in food samples using capillary zone electrophoresis

A capillary electrophoresis method with UV detection is proposed for the identification and quantitation of bacterial contamination in food samples. The electrophoretic separation relies on the differential mobility of bacteria in the capillary. Electrophoretic resolution is improved by using calcium and myoinositol hexakisphosphate as specific ions that interact with the bacterial surface changing its electrical properties and electrophoretic mobility. The proposed method allows the effective separation of eight different types of bacteria in only 25 min. It was successfully used to detect the presence of bacteria in contaminated food. The precision of the analysis of real spiked samples ranges from 3.3 to 7.0%, and the overall analysis time is 7 h, which is much shorter than the 24-48 h typically required for plate counts. The validity of the method was established by comparison with the standard plate counting method.