Method for determining concentration of dichlorvos in serum by gas chromatography

Objective To 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.Methods The 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.Results A 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％.Conclusion This determination method is easy to operate,efficient,and accurate,and can be used for quickly diagnosing dichlorvos poisoning and quantitatively evaluating treatment outcome. Key words: Dichlorvos; Poisoning; Serum concentration; Gas chromatography; Hemoperfusion