SinS - Abstract

Abstract Title: Analysis of persistent and mobile organic compounds (PMOCs) in human urine by mixed-mode liquid chromatography
Presenter Name: Mr Mikel Musatadi
Co-authors:Mr Jon Zumalabe
Dr Leire Mijangos
Dr Ailette Prieto
Dr Maitane Olivares
Dr Olatz Zuloaga
Company/Organisation: University of the Basque Country (UPV/EHU)
Country: Spain

Abstract Information :

In recent years, the concept of “exposome” has emerged as a novel research paradigm aiming to understand and correlate both, external exposures and internal factors with disease etiology. In the analytical chemistry field, efforts have been made in developing methods to analyze semi-polar or non-polar chemicals in human matrices, while very polar compounds are still overlooked. The issue arises when very polar compounds are also persistent since they are highly mobile in water but are not degraded or eliminated in wastewater treatment plants, meaning that they can eventually reach drinking water. Those chemicals have been named “persistent and mobile organic contaminants” (PMOCs) or even “(very) persistent, (very) mobile and toxic substances” (PMT/vPvMT) if they are known to be toxic. At present, an analytical gap exists for those chemicals, which makes the study of their occurrence, fate, or potential adverse effects, and therefore, their subsequent integration into regulatory lists, challenging. In that scenario, the aim of the present work has been to develop an analytical method to determine 40 diverse PMOCs in human urine through mixed-mode liquid chromatography coupled with tandem mass spectrometry (MMLC-MS/MS). Several sample preparation procedures were evaluated using synthetic urine spiked with all the analytes, such as salt-assisted liquid-liquid extraction (SALLE), reverse phase solid phase extraction (RP-SPE), mixed-mode solid phase extraction (MM-SPE), lyophilization and dilute-and-shoot (DS)). Regarding the analysis, reverse phase (RP), hydrophilic interaction chromatography (HILIC), and MMLC were studied. From the several sample preparation procedures evaluated, DS and a combination of SPE with SALLE turned out to be the best ones for the simultaneous analysis of PMOCs in urine, while the analysis by MMLC was proven to be compulsory in order to retain the very polar and often ionic analytes. Therefore, both procedures were fully validated at 5 and 50 ng/mL levels. Among the figures of merit, instrumental limits of quantification, linearity ranges, instrumental repeatability, procedural limits of quantification (pLOQ), accuracy (absolute and apparent recoveries), and methods´ precision were calculated, obtaining satisfactory results considering the difficult nature of the PMOCs and MMLC. Lastly, both protocols were applied to pooled real urine samples to assess the general exposure to PMOCs. Precisely, biocides (6-chloropyridine-3-carboxylic acid and diethyl phosphate) and industrial chemicals (N,N-dimethylbenzylamine and melamine) were detected.