Determination of nitenpyram and its metabolites in agricultural products by using hydrophilic interaction liquid chromatography-tandem mass spectrometry

Abstract

A simple and rapid method for the measurement of a neonicotinoid pesticide, nitenpyram, and its metabolites, CPMA and CPMF, was investigated. The three compounds were determined individually and simultaneously by simple ultrasonic extraction followed by hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). Good chromatograms were obtained using a non-modified silica gel column. The calibration curves were straight (R²>0.999) for each compound; they were 0.002–2 mg/kg for 5 g of agricultural product sample with limits of detection (S/N=3) of 0.24–0.36 µg/kg (nitenpyram), 0.12–0.19 µg/kg (CPMA), and 0.13–0.18 µg/kg (CPMF). Good recoveries were obtained for sweet pepper, mandarin orange, onion, and brown rice (93.0–106.6% in recovery). For contaminated samples, data by the presented method agreed well with nitenpyram data by HPLC-UV and the total of CPMA and CPMF by derivatization followed by gas chromatography-flame thermionic detection.