Graphene as an efficient sorbent for the SPE of organochlorine pesticides in water samples coupled with GC-MS

The determination of organochlorine pesticides in water samples, which are harmful to humans, is very important for environmental risk assessment. Based on the excellent adsorption properties of graphene, an SPE coupled with GC-MS method for the monitoring of organochlorines (four hexachlorcyclohexanes and four dichlorodiphenyltrichloroethanes) was developed. Owing to the hydrophobic interaction and - stacking interaction between the analytes and graphene, the analytes quantitatively adsorbed onto the graphene-based SPE cartridge were eluted by ethyl acetate for analysis. Several parameters influencing the analytical performance, such as the kind of elution, sample volume, reusability of the cartridge, have been investigated in detail. Under the optimal conditions, detection of limits of 1.95-9.38 ng/L, recoveries of 83.9-107.3% at two spiked concentration levels (0.1 and 10 ng/mL) and RSDs in the range of 2.9-7.4% for real water samples were obtained for all the analytes. This work reveals the great potential of graphene in sample preparation procedures.