Development of an Efficient Sample Preparation Method Based on Homogeneous Liquid-Liquid Extraction Combined with Dispersive Liquid-Liquid Microextraction Solidification of Floating Organic Drop for Trace Analysis of Pesticide Residues in Fruit and Fruit Juice Samples

摘要

In this study, a simple and reliable sample preparation method based on an efficient version of homogeneous liquid-liquid extraction combined with dispersive liquid-liquid microextraction solidification of floating organic drop has been introduced to analyze some pesticide residues in fruit and fruit juice samples with gas chromatography-flame ionization detection. Under the optimum experimental conditions, limits of detection and quantification were in the ranges of 0.20-0.60 and 0.66-2.0 mu g L-1, respectively. The repeatability of the method was good and the relative standard deviations were less than 7 % for intra- (n=6) and inter-day (n=4) precisions at a concentration of 50 mu g L-1 of each analyte. High enrichment factors (3265-3728) and extraction recoveries (82-93 %) were obtained. Finally, the method was applied for determination of pesticides in the selected samples and chlorpyrifos was found in strawberry at ng g(-1) concentration. Furthermore, no filtration was used in the cases of the fruit samples.