Determination of Residues of Hexachlorocyclohexanes and Dichlorodiphenyltrichloroethanes in Rice by QuEChERS Combined with GC-MS/MS

Abstract:

[Objective] To establish a method for the quantitative detection of residues of hexachlorocyclohexanes (BHCs) and dichlorodiphenyltrichloroethanes (DDTs) in rice by combining QuEChERS with gas chromatography-tandem mass spectrometry (GC-MS/MS). [Method] Rice samples were mixed with water and extracted with acetonitrile-acetic acid solution. The extracts were purified by PSA/C18 solid phase extraction. After high-speed centrifugation and concentration by nitrogen flushing, the samples were detected by GC-MS/MS, and the internal standard method was used for quantitation. [Result] Four BHCs and four DDTs showed excellent linearity within the mass concentration range of 6.25~100.00 ng/mL, with R² greater than 0.999. The limits of detection and quantitation were within the ranges of 0.000 2~0.000 5 mg/kg and 0.000 5~0.002 0 mg/kg, respectively. The average recovery rates of matrix addition were between 92.27% and 98.76%, and the relative standard deviations (RSD) were between 0.44% and 1.88%. Quality control samples for validation were detected by the established method, and the results were within the true value range. The comparison results of the samples participating in the assessment were all satisfactory. [Conclusion] The established method demonstrates high sensitivity, good repeatability, and high accuracy, being suitable for rapid determination of residues of BHCs and DDTs in rice.