Monitoring of organophosphate and pyrethroid metabolites in human urine samples by an automated method (TurboFlow™) coupled to ultra-high performance liquid chromatography-Orbitrap mass spectrometry

Abstract

There is a growing concern to pesticide exposure in humans, being the organophosphate (OP), carbamate and pyrethroid the most commonly used insecticides. Therefore, a fast, simple and automated screening method based on ultra-high performance liquid chromatography coupled to Orbitrap high resolution mass spectrometry (UHPLC-Orbitrap-MS) has been developed to determine six OPs metabolites (3,5,6-trichloro-2-pyridinol “TCPy”, 2-isopropyl-6-methyl-4-pyrimidinol “IMPY”, 4-nitrophenol “PNP”, 4-nitrophenol-d4 “PNP-d4″, 3-chloro-7-hydroxy-4-methylcoumarin “CMHC” and 2-diethylamino-6-methylpyrimidin-4ol “DEAMPY”) and three pyrethroid metabolites (3-phenoxybenzoic acid “3-PBA”, 4-fluoro-3-phenoxybenzoic acid “4-F-3-PBA” and 3-(2,2-dichlorovinyl)-2,2-dimethyl-1-cyclopropanecarboxylic acid “cis/trans-DCCA”) in human urine samples. Off-line solid phase extraction (SPE), on-line SPE and turbulent flow chromatography (TurboFlow™) extraction methodologies were compared, obtaining better results when TurboFlow™ was applied, achieving a total analysis time of 13.83 min. Several validation parameters were tested, obtaining suitable results for all studied compounds. Recoveries ranged from 70 to 116%, meanwhile repeatability and reproducibility were lower than or equal to 7% and 13%, respectively. The limits of quantification (LOQs) were set in the range from 1 μg/L to 5 μg/L (except for DCCA at 10 μg/L). Finally, thirty seven urine samples from women and men living near the agricultural areas of Almeria (Spain) were analyzed to know and control the contamination on the human health. PNP, DEAMPY and IMPY were detected in six urine samples at trace levels except IMPY, which was detected at 3.44 μg/L in one of the samples. Additionally, a post-targeted and untargeted analysis were carried out in the samples, identifying eleven insecticides such as bensulide or cinerin II, one insecticide metabolite, fipronil sulfone, one drug metabolite, carboxyibuprofen and two nicotine metabolites, cotinine and 2-(1-pyrrolidinyl)isonicotinic acid, in several samples.