Tri-(2-ethylhexyl)trimellitat – Bestimmung von 1-MEHTM, 2-MEHTM, 5OH-1-MEHTM, 5OH-2-MEHTM, 5cx-1-MEPTM und 5cx-2-MEPTM in Urin mittels LC-MS/MS
Biomonitoring-Methode
Laura Kuhlmann1 (Methodenentwicklung)Elisabeth Eckert1 (Methodenentwicklung)
Christine Höllerer-Mittelmaier1 (Methodenentwicklung)
Thomas Göen1 (Methodenentwicklung; Leitung der Arbeitsgruppe „Analysen in biologischem Material“ der Ständigen Senatskommission zur Prüfung gesundheitsschädlicher Arbeitsstoffe, Deutsche Forschungsgemeinschaft)
Veronika Spindler2 (Methodenprüfung)
Gerhard Scherer2 (Methodenprüfung)
Craig Sams3 (Methodenprüfung)
Kate Jones3 (Methodenprüfung)
Andrea Hartwig4 (Vorsitz der Ständigen Senatskommission zur Prüfung gesundheitsschädlicher Arbeitsstoffe, Deutsche Forschungsgemeinschaft)
MAK Commission5
1 Friedrich-Alexander-Universität Erlangen-Nürnberg, Institut und Poliklinik für Arbeits-, Sozial- und Umweltmedizin, Henkestraße 9–11, 91054 Erlangen, Deutschland
2 ABF Analytisch-biologisches Forschungslabor GmbH, Semmelweisstraße 5, 82152 Planegg, Deutschland
3 Health and Safety Executive (HSE) Science and Research Centre, Harpur Hill, SK17 9JN Buxton (Derbyshire), Vereinigtes Königreich
4 Institut für Angewandte Biowissenschaften, Abteilung Lebensmittelchemie und Toxikologie, Karlsruher Institut für Technologie (KIT), Adenauerring 20a, Geb. 50.41, 76131 Karlsruhe, Deutschland
5 Ständige Senatskommission zur Prüfung gesundheitsschädlicher Arbeitsstoffe, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Deutschland
Abstract
The working group “Analyses in Biological Materials” of the German Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) developed and verified this biomonitoring method for the measurement of six specific metabolites of the plasticiser tri‑(2‑ethylhexyl) trimellitate (TEHTM) in urine. Specifically, this method determines two monoester isomers as primary hydrolysis products of TEHTM, 1‑mono-(2‑ethylhexyl) trimellitate (1‑MEHTM) and 2‑mono-(2‑ethylhexyl) trimellitate (2‑MEHTM), as well as the oxidatively formed secondary derivatives, namely 1‑mono-(2‑ethyl-5‑hydroxyhexyl) trimellitate (5OH‑1‑MEHTM), 2‑mono-(2‑ethyl-5‑hydroxyhexyl) trimellitate (5OH‑2‑MEHTM), 1‑mono-(2‑ethyl-5‑carboxypentyl) trimellitate (5cx‑1‑MEPTM), and 2‑mono-(2‑ethyl-5‑carboxypentyl) trimellitate (5cx‑2‑MEPTM). Determination is carried out after enzymatic hydrolysis of the urine sample as well as enrichment of the analytes by online SPE. Via integrated, automatic column-switching, the analytes are transferred onto the analytical column in backflush mode, separated by liquid chromatography, and quantified by tandem mass spectrometry. Calibration is performed using calibration standards prepared in pooled urine and processed analogously to the samples to be analysed. The following isotope-labelled substances are added to the urine samples as internal standards: D5‑1‑MEHTM, D5‑2‑MEHTM, D5‑5OH‑1‑MEHTM, D5‑5cx‑1‑MEPTM, and D5‑5cx‑2‑MEPTM. The method provides reliable and accurate analytical results, as shown by the good precision data with standard deviations no greater than 8%. Good accuracy data were obtained with mean relative recoveries in the range of 97–109%. The method is both selective and sensitive, and provides quantitation limits in the range of 0.04–0.12 μg/l.
