抄録
In this study, we developed a method for the detection of the herbicides paraquat (PQ) and diquat (DQ) in human urine and whole blood with an oxidative reaction followed by liquid chromatography/mass spectrometry (LC/MS).
Prior to the oxidative reaction, urine samples were cleaned up by dispersive solid phase extraction with Oasis® WCX, and blood samples were deproteinized with sulfosalicylic acid. These pretreated samples were oxidized with 1 mg/mL potassium ferricyanide and 15 M sodium hydroxide. The oxidative products of PQ and DQ were extracted with high recovery rates by solid phase extraction with Oasis® MAX. These extracted oxidative products were successfully separated and detected by LC/MS using a semi micro C18 column in the gradient solvent system of 10 mM ammonium formate (pH 3) and methanol.
Quantitative analyses for blood samples were carried out using PQ-d6 and ethyl PQ as internal standards. The calibration curves for PQ and DQ showed good linearity in the range of 10-5000 ng/mL. Precision (R.S.D.) was less than 5.8%, and accuracy was ranged from 99% to 112%.
