Simultaneous determination of polar pesticides in human blood serum by liquid chromatography coupled to triple quadrupole mass spectrometer.

In this study a simple and rapid method was used for the determination of 5 polar pesticides and 3 metabolites, ethephon, 2-hydroxyethyl phosphonic acid (HEPA), fosetyl-aluminum, phosphonic acid, glyphosate, chlorate, glufosinate and 3-methylphosphinicopropionic acid (MPPA) in human blood serum. Acidified water (1% formic acid) and acetonitrile (1% formic acid) were used as extraction solvents and n-hexane was utilized as a clean-up step for lipid removal. The analytical method was based on liquid chromatography coupled to triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS). The proposed method was validated, obtaining recoveries ranging from 70 to 110% and precision values lower than 17% for all analytes. Limit of quantification was 0.01 mg/L for ethephon, fosetyl-aluminum, MPPA and HEPA, 0.025 mg/L for glyphosate, phosphonic acid and chlorate and 0.05 mg/L for glufosinate. This is the first time that an analytical method was developed for the determination of a high number of polar pesticides in human blood serum, allowing the simultaneous monitoring of these compounds in a complex matrix as human blood serum.