Diazinon is a synthetic molecule known as an organophosphorus insecticide. It is used for gardens and for agriculture. This molecule represents a toxicological concern for humans. For this reason, the detection and the quantification of the diazinon in human samples are important in order to monitor an exposure and to diagnose intoxications. The aim of this work is to develop a selective method for the quantification of diazinon in human plasma by means of a gas chromatography (GC) with a mass spectroscopy (MS) detector. The method presented in this article includes a liquid-liquid extraction (LLE) using dichloromethane/propanol-2/heptane. The correlation coefficient for the calibration curve is 0.992. The limit of detection (LOD) and the limit of quantification (LOQ) are respectively 5 μg/L and 2 μg/L. The average recovery of the three different concentrations (15, 250 and 375 μg/L) varies from 22.8% to 31%. A test of stability at ambient temperature for 24 hours and at 4 °C for 48 hours was conducted. The relative error factor was found to be inferior to 15%. The results obtained show that the method developed gives satisfying validation parameters in human plasma. Therefore, the compound could be detected at very low concentration with a good linearity. This method can be used with other matrices, such as blood or urine, for a partial validation.
Keywords: GC-MS; LLE; diazinon; limit of detection; limit of quantification; plasma.