Lead and its compounds – Determination of δ‐aminolevulinic acid in urine by HPLC with fluorescence detection

Biomonitoring Method – Translation of the German version from 2018

  Thomas Göen¹ (Method development; Head of the working group “Analyses in Biological Materials” of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
Louisa Weißflog¹ (Method development)
Meinolf Blaszkewicz² (External verification)
Gabriele Baumhoer² (External verification)
Thomas Schettgen³ (External verification)
Petra Dewes³ (External verification)
  Andrea Hartwig⁴ (Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
  MAK Commission<sup>5

1</sup> Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute and Outpatient Clinic of Occupational, Social, and Environmental Medicine, Henkestraße 9–11, 91054 Erlangen, Germany
² Leibniz Research Center for Working Environment and Human Factors, TU Dortmund, Ardeystraße 67, 44139 Dortmund, Germany
³ Institute for Occupational and Social Medicine, RWTH Aachen University, Faculty of Medicine, Pauwelsstraße 30, 52074 Aachen, Germany
⁴ Institute of Applied Biosciences, Department of Food Chemistry and Toxicology, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Building 50.41, 76131 Karlsruhe, Germany
⁵ Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Germany

Abstract

The working group “Analyses in Biological Materials” of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area verified the presented biomonitoring method.

The method described hereinafter permits the determination of δ‐aminolevulinic acid (ALA) in urine as a biological marker of effect to assess exposure to lead. An indicator of such exposure is the increased urinary excretion of ALA caused by lead‐induced inhibition of the enzyme δ‐aminolevulinic acid dehydratase. The determination of ALA in urine is based on a condensation reaction of ALA with formaldehyde and acetylacetone yielding a pyrrolizine derivate, which can be sensitively detected using fluorescence detection. 6‐Amino‐5‐oxohexanoic acid is used as an internal standard. Calibration standards are prepared in pooled urine and processed in the same way as the samples to be analysed.

The method was extensively validated and the reliability data were confirmed by two independent laboratories, which have established and cross‐checked the whole procedure.

---