Analysis of ochratoxin A in malt beverage samples using dispersive liquid–liquid microextraction coupled with liquid chromatography-fluorescence detection

摘要

A simple and economic pro cedure based on dispersive liquid–liquid microextraction has been applied to extract and pre-concentrate trace levels of ochratoxin A (OTA) in malt beverage prior to analysis using high performance liquid chromatography with fluorescence detection. The method was based on the formation of fine droplets of a water-immiscible extraction solvent in the sample solution using a water-miscible disperser solvent. The influences of vari -ous parameters such as the type and volume of extraction and disperser solvents, centrifuging time, sonication time, and salt concentration on the extraction efficiency of ochratoxin A were investigated. Under optimum conditions, the relative standard deviations for five replicates of 2 ng/ml of OTA were 3.4% as within-day and 6.2% as between-day precisions. The detection limit (S/N = 3) was 0.1 ng/ml and the mean recoveries of OTA from malt beverage samples at spiking levels of 0.5, 2, and 4 ng/ml were in the range of 104–108.2%