[Simultaneous determination of five hypertoxic rodenticides in serum by gas chromatography-mass spectrometry]

A fast analytical method based on gas chromatography-mass spectrometry (GC-MS) was established for the simultaneous determination of tetramine, fluoroacetamide, sodium fluoroacetate, gliftor I and gliftor II in serum. At pH 2.0, sodium fluoroacetate was derivatizated at room temperature for 5 min by using N,N-diethyl-p-phenylenediamine as the derivatization reagent and N, N'-dicyclohexylcarbodiimide as the catalyst. The derivative and other rodenticides were extracted with ethyl acetate and concentrated with nitrogen at 50 °C, then determined by GC-MS in selected ion monitoring (SIM) mode, and quantified with matrix-match standard solutions. The analysis was carried out on an ionic liquid chromatographic capillary column (SLB-IL59, 30 m x 0.25 mm x 0.20 µm, maximum temperature 300 °C) at a flow rate of 1.0 mL/min, and the five rodenticides were successfully separated in 15 min when temperature programming was used. The results showed that the calibration curves were linear in the range of 0.01-1.0 mg/L, except for fluoroacetamide (0.02-2.0 mg/L) and tetramine (0.02-10 mg/L), with correlation coefficients (R2) greater than 0.995, and the limits of detection (LODs) were 0.001-0.002 mg/L (S/N = 3). The recoveries were 84.0%-110.0% at three different spiked levels, and the relative standard deviations (RSDs) were 2.9%-7.5% (n = 6). The method is simple, accurate, highly sensitive and suitable for the detection of the five hypertoxic rodenticides in serum for toxicological purposes.