Determination of nitenpyram dissipation and residue in kiwifruit by LC-MS/MS.

To investigate the presence of nitenpyram in kiwifruit, a field experiment was conducted in six kiwifruit producing regions in China. A modified quick, easy, cheap, effective, rugged and safe method (QuEChERS) method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the determination of nitenpyram in kiwifruit. Quantitative detection was performed by LC-MS/MS in multiple reaction monitoring (MRM) mode under positive-ion electrospray ionisation. The proposed method is linear and accurate in the range of 0.005 to 4.5 mug/mL. The recovery of nitenpyram was satisfactory (71.96-96.67%) with reasonable RSDs (9.83 %) for 0.01-4.5 mg/kg spiked levels. The limit of quantification (LOQ) was 0.01 mg/kg for nitenpyram. Nitenpyram degraded rapidly in kiwifruit with a half-life <4 days. Residues of nitenpyram were <0.01 - 0.54 mg/kg in kiwifruit 7, 14 and 21 days after spraying at six sites.