Abstract:

A gas chromatography-mass spectrometry (GC-MS) method for the determination of hexachlorocyclohexane (BHC) and dichlorodiphenyltrichloroethane (DDT) residues in honey was developed using dispersive liquid-liquid microextraction (DLLME) as sample preparation method. The samples were extracted with chloroform, and concentrated into chloroform by vortex and centrifuging. The analytes were analyzed by GC-MS. The factors affecting the extraction efficiency were investigated, such as the type and volume of extraction and dispersive solvent, extraction time, etc. The matrix effects and method performance were evaluated at the same time. The results indicated that all the eight BHC and DDT pesticides displayed the enhancement of signals due to the matrix effects. The calibration curves were linear in the range of 2-500 μg/L and the correlation coefficients were 0.991-0.998 for the eight BHC and DDT pesticides. The enrichment factors (EF) were 74-96 for the eight pesticides. The recoveries of the eight BHC and DDT pesticides at three spiked levels of 20, 50 and 100 μg/kg were 61.0%-100.1%, while the RSDs were 2.2%-19.5%. The limits of quantification for the eight pesticides were 20 μg/kg, and the limits of detection were 1.0 ng. The developed method is easy, quick and with high performance. It is applicable for the determination of BHC and DDT residues in honey.

Key words: dichlorodiphenyltrichloroethane (DDT), dispersive liquid-liquid microextraction (DLLME), gas chromatography-mass spectrometry (GC-MS), hexachlorocyclohexane (BHC), honey