Multiresidue determination of nicotinoid insecticide residues in drinking water by liquid chromatography with electrospray ionization mass spectrometry

A multianalyte method has been developed for the confirmation and quantification of four neonicotinoids, acetamiprid, imidacloprid, thiacloprid and thiamethoxam in drinking water. These insecticides were extracted from water by solid-phase extraction (SPE) LiChrolut EN. Analytes’ determination and quantification were performed by liquid chromatography–mass spectrometry (LC–MS). Extraction efficiency experiments demonstrated the ability of this method to extract nicotinoids from water samples. Confirmatory analysis was carried out by LC-electrospray ionization–mass spectrometry (LC-ESI–MS) instrumentation equipped with a single-quadrupole mass filter. MS data acquisition was performed by two-ion selected ion monitoring (SIM) program. Average recoveries of the four analytes from drinking water samples were in the range of 95 and 104% with relative standard deviations (R.S.D.) < 20%. The limit of quantification (LOQ) for each of the four insecticides was 0.03 microgL−1.