OBJECTIVES: Agricultural use of neonicotinoid (NEO) insecticides has been increasing in recent years, but their biological monitoring methods have been scarcely reported. In this study, we developed and validated a rapid and sensitive method for quantifying urinary NEO concentrations using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS: After phosphate-induced acidification of a urine sample, urinary NEOs were trapped by a solid-phase extraction column and eluted with methanol for acetamiprid, imidacloprid, thiacloprid, thiamethoxam, clothianidin and dinotefuran and with an acetonitrile and methanol solution (1:1, v/v) containing 5% NH3 for nitenpyram. A separation analysis was performed by LC-MS/MS within 10 minutes for the sample. This method was applied to first morning urine obtained from 52 Japanese (40.9 ± 10.5 years old, mean ± standard deviation) without occupational NEO exposure. RESULTS: The linear dynamic ranges and their limit of quantification (LOQ, signal to noise ratio=10) levels were 0.3-20 or 50 µg/l (r=0.998-0.999) and 0.05-0.36 µg/l, respectively. The absolute recovery was 64-95%, and the intra- and inter-day precisions were less than 16.4% (relative standard deviation, %RSD). This method was successfully applied for analysis of NEOs in human urine samples obtained from 52 adults. The frequencies of individuals who showed more than LOD levels was above 90% for imidacloprid, thiamethoxam, clothianidin and dinotefuran, more than 50% for acetamiprid and thiacloprid and 29% for nitenpyram. CONCLUSIONS: These results indicated that our new method could be applied to biological monitoring of NEO exposure even at environmental exposure levels in Japanese adults without occupational spraying histories.
OBJECTIVES: Agricultural use of neonicotinoid (NEO) insecticides has been increasing in recent years, but their biological monitoring methods have been scarcely reported. In this study, we developed and validated a rapid and sensitive method for quantifying urinary NEO concentrations using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS: After phosphate-induced acidification of a urine sample, urinary NEOs were trapped by a solid-phase extraction column and eluted with methanol for acetamiprid, imidacloprid, thiacloprid, thiamethoxam, clothianidin and dinotefuran and with an acetonitrile and methanol solution (1:1, v/v) containing 5% NH3 for nitenpyram. A separation analysis was performed by LC-MS/MS within 10 minutes for the sample. This method was applied to first morning urine obtained from 52 Japanese (40.9 ± 10.5 years old, mean ± standard deviation) without occupational NEO exposure. RESULTS: The linear dynamic ranges and their limit of quantification (LOQ, signal to noise ratio=10) levels were 0.3-20 or 50 µg/l (r=0.998-0.999) and 0.05-0.36 µg/l, respectively. The absolute recovery was 64-95%, and the intra- and inter-day precisions were less than 16.4% (relative standard deviation, %RSD). This method was successfully applied for analysis of NEOs in human urine samples obtained from 52 adults. The frequencies of individuals who showed more than LOD levels was above 90% for imidacloprid, thiamethoxam, clothianidin and dinotefuran, more than 50% for acetamiprid and thiacloprid and 29% for nitenpyram. CONCLUSIONS: These results indicated that our new method could be applied to biological monitoring of NEO exposure even at environmental exposure levels in Japanese adults without occupational spraying histories.
Authors: Nicolás López-Gálvez; Rietta Wagoner; Robert A Canales; Jill de Zapien; Antonia M Calafat; Maria Ospina; Cecilia Rosales; Paloma Beamer Journal: Int J Hyg Environ Health Date: 2020-09-17 Impact factor: 5.840
Authors: Neeranuch Suwannarin; Tippawan Prapamontol; Tomohiko Isobe; Yukiko Nishihama; Shoji F Nakayama Journal: Int J Environ Res Public Health Date: 2020-10-27 Impact factor: 3.390