Hollow fibre supported liquid membrane extraction for BTEX metabolites analysis in human teeth as biomarkers
| Autor: | Albert Pell, Manuel Valiente, Johannes Luis González, Montserrat López-Mesas |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Environmental Engineering
Liquid Phase Microextraction Dodecane BTEX Xylenes 010501 environmental sciences 01 natural sciences chemistry.chemical_compound Benzene Derivatives Environmental Chemistry Waste Management and Disposal 0105 earth and related environmental sciences Detection limit Chromatography Facilitated diffusion 010401 analytical chemistry Extraction (chemistry) Benzene Environmental Exposure Environmental exposure Mandelic acid Pollution 0104 chemical sciences Membrane chemistry Environmental Pollutants Tooth Biomarkers Toluene |
| Zdroj: | Science of The Total Environment. 630:323-330 |
| ISSN: | 0048-9697 |
| DOI: | 10.1016/j.scitotenv.2018.02.195 |
| Popis: | The use of human teeth as biomarkers has been previously applied to characterize environmental exposure mainly to metal contamination. Difficulties arise when the contaminants are volatile or its concentration level is very low. This study presents the development of a methodology based on the transport through hollow fibre membrane liquid-phase microextraction (HF-LPME), followed by HPLC-UV measurement, to determine three different metabolites of BTEX contaminants, mandelic acid (MA), hyppuric acid (HA), and methylhippuric acid (4mHA). The driving force for the liquid membrane has been studied by using both non-facilitated (pH gradient 2-12) and facilitated transport (ionic and non-ionic carriers). Enrichment factors of several hundreds were accomplished. Different ionic and non-ionic water insoluble compounds were used as metabolite carriers for the facilitated transport at HF-LPME. Three organic solvents were used to constitute the liquid membrane, dodecane, dihexyl ether and n-decanol. Other parameters affecting the extraction process, such as extraction time, stirring speed, acceptor buffer and salt content were optimised in spiked solutions and selected those that presented the best enrichment factors for all analytes. Final conditions were established for donor solution as 20mL, pH2 of 0.5M NaCl, the OLM (Organic Liquid Membrane) as n-decanol and the acceptor solution as 40μL of 1M NaOH. The selected extraction time was 20h with stirring speed of 500rpm. Validation of the optimised method included the determination of individual linearity range (MA: 0.002-5.7μg; HA: 0.01-7.9μg; 4mHA 0.002-5.3μg), limits of detection (MA: 1.6ng; HA: 0.2ng; 4mHA 0.2ng), repeatability (RSD 7-10%) and reproducibility (5-8%). The developed method was applied to the analysis of MA, HA and 4mHA in teeth samples of 8 workers exposed to BTEX. |
| Databáze: | OpenAIRE |
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