Direct sample introduction GC-MS/MS for quantification of organic chemicals in mammalian tissues and blood extracted with polymers without clean-up

Andreas Baumer,Julia Landmann,Nadin Ulrich,Beate I Escher

doi:10.1007/s00216-020-02864-6

Abstract

Solvent extracts of mammalian tissues and blood contain a large amount of co-extracted matrix components, in particular lipids, which can adversely affect instrumental analysis. Clean-up typically degrades non-persistent chemicals. Alternatively, passive sampling with the polymer polydimethylsiloxane (PDMS) has been used for a comprehensive extraction from tissue without altering the mixture composition. Despite a smaller fraction of matrix being co-extracted by PDMS than by solvent extraction, direct analysis of PDMS extracts was only possible with direct sample introduction (DSI) GC-MS/MS, which prevented co-extracted matrix components entering the system. Limits of quantitation (LOQ) ranged from 4 to 20 pg μL−1 ethyl acetate (PDMS extract) for pesticides and persistent organic pollutants (POPs). The group of organophosphorus flame retardants showed higher LOQs up to 107 pg μL−1 due to sorption to active sites at the injection system. Intraday precision ranged between 1 and 10%, while the range of interday precision was between 1 and 18% depending on the analyte. The method was developed using pork liver, brain, and fat as well as blood and was then applied to analyze human post-mortem tissues where polychlorinated biphenyls (PCBs) as well as dichlorodiphenyltrichloroethane (DDT) and DDT metabolites were detected.Graphical abstract

Highlights

Organisms are exposed to a variety of chemicals that are present in environmental matrices like air, water, and soil
Most analyses of biological tissues have been carried out using solvent extraction methods followed by various cleanup procedures in order to reduce the amount of co-extracted matrix components prior to GC-MS measurements [10,11,12]
The results showed a similar pattern of the detected analytes with DDE as highly abundant pesticide metabolite, DDD only detected in liver as metabolic active organ, and polychlorinated biphenyls (PCBs) congeners 138, 153 and 180 present in all tissues as most abundant PCB congeners

Summary

Introduction

Organisms are exposed to a variety of chemicals that are present in environmental matrices like air, water, and soil. Equilibrium passive sampling with polydimethylsiloxane (PDMS) can be applied to complex biota matrices [13] without altering the mixture composition, including all HOCs [14, 15]. This extraction method was applied to the analysis of environmental contaminants in various complex biota matrices, e.g., fish [13, 16, 17], eel [18], blubber [19, 20], blood plasma [21], urine [22], and whole blood [22, 23]. Another study investigated the partitioning of POPs between PDMS and pure oils and reported an average co-extracted amount of lipids of 0.9% [25]

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