Detection of imidacloprid in biological fluids in a case of fatal insecticide intoxication

Here, we describe a high-performance liquid chromatography/photodiode array detector method for the detection of imidacloprid in biological fluids in a case of suicide by ingestion of liquor mixed with Admire® Flowable insecticide (containing 20% imidacloprid). A plastic bottle containing a cloudy liquid (concentration of ethanol in the liquid was 150 mg/ml and that of imidacloprid was 50 mg/ml) was found near the decedent. The biological fluids collected at autopsy were prepared by deproteinization with acetonitrile. Zolpidem was used as an internal standard. The concentrations of imidacloprid in femoral blood and cerebrospinal fluid were 105 and 58.5 μg/ml, respectively. Ethanol was also detected in the samples, with concentrations of 1.0 mg/ml in femoral blood and 1.4 mg/ml in cerebrospinal fluid.