Determination of polychlorinated biphenyls and organochlorine pesticides in Chinese mitten crabs (Eriocheir sinensis) using modified QuEChERS followed by GC-MS

Abstract

Chinese mitten crabs (Eriocheir sinensis) are one of the most popular food items with a high nutritional value. The use of pesticides and environmental pollutants directly influenced improvements in productivity of mitten crabs. However, there is an increasing number of food safety issues raising consumer concerns. It is necessary to determine whether the pollutants that crabs contain are below the maximum residue limits to guarantee food safety. Moreover, there has been very little research on detecting pesticide residues and other pollutants in Chinese mitten crabs due to their complicated matrix effects. In the current study, a Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method has been modified and validated for the simultaneous analysis of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in mitten crabs. By using acetonitrile extraction, low temperature (freezing) precipitation and clean-up by mixed sorbents of C₁₈, PSA and Florisil (magnesium silicate), the method was proved to be valid with linearity, precision, recovery, limit of quantification (LOQ), and limit of detection (LOD) with recoveries ranging from 85.9–119.8% and LOQ within 0.1–3.6 μg kg⁻¹. The method was also applied to detect PCBs and OCPs in 48 crab samples from Jiangxi Province, China. The results showed that most of the crab samples contained PCB 118, beta-HCH and p,p′-DDT, and the content of p,p′-DDD in mitten crabs of Jiangxi Province showed sex-specific differences, which might be connected with sex-differential regulation.