OBJECTIVETo develop a method for determining the concentration of dichlorvos in serum by gas chromatography and to provide a basis for clinical diagnosis and monitoring of dichlorvos poisoning.

METHODSThe serum (0.5 ml)collected from patients with dichlorvos poisoning was mixed with ethyl acetate (2.0 ml) and underwent shaking/extraction; the obtained liquid was subjected to standing (5 min) and centrifuging (4000 rpm); the obtained supernatant was collected and blow-dried with nitrogen and was then dissolved in ethanol (50 µl); 1.0 µl of the obtained liquid was collected and loaded into a glass-packed column; gas chromatography was performed using a nitrogen-phosphorus detector.

RESULTSA linear relationship was found when the concentration of dichlorvos in serum was 5.0 ∼ 50.0 µg/ml, with a regression equation of y = 804.13x-691.8 (r = 0.9992). The minimum detectable concentration was 2.0 µg/ml, the recovery rate was 86.8% ∼ 94.5%, the relative standard deviation (RSD) was 4.6% ∼ 5.5%, with an intra-day RSD of 4.52% ∼ 5.21% and an inter-day RSD of 3.56% ∼ 5.52%.

CONCLUSIONThis determination method is easy to operate, efficient, and accurate, and can be used for quickly diagnosing dichlorvos poisoning and quantitatively evaluating treatment outcome.