Simultaneous determination of nine neonicotinoids in human urine using isotope-dilution ultra-performance liquid chromatography-tandem mass spectrometry.

Neonicotinoids (neonics), a class of systemic insecticides, have been frequently detected in pollen, vegetables, and fruits. Recently, an increasing concern has been aroused for human exposure to neonics. However, biological monitoring for quantifying body burden of neonics has rarely been reported. In this study, we developed an isotope-dilution ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) method to simultaneously quantify nine neonics, including acetamiprid (ACE), thiamethoxam (THIAM), imidacloprid (IMIP), clothianidin (CLO), flonicamid (FLO), thiacloprid (THIAC), dinotefuran (DIN), nitenpyram (NIT), and imidaclothiz (IMIT) in urine. The limits of quantification were 0.1 μg/L for ACE, FLO, DIN, NIT and IMIT, and 0.2 μg/L for THIAM, IMIP, CLO, and THIAC. The overall recoveries were 80.8-103%, 81.5-91.7% and 83.0-92.3% for QA/QC samples fortifying at 1, 25, and 100 μg/L levels, respectively. UPLC/MS/MS method was used to analyze urine samples obtained from 10 children in Hangzhou, China. The detection frequencies were 80% for ACE and IMIP, 70% for THIAM and CLO, 20% for DIN and IMIT and 10% for THIAC. FLO and NIT were not detected in those urine samples. The data provided here will be helpful for conducting biological monitoring of neonics exposure in the future.