Simple Method for Determination of Urinary δ-Aminolevulinic Acid as an Index of Lead Exposure

Abstract A simple method is described for the quantitative analysis of urinary δ-aminolevulinic acid. 2-Methyl3-carbethoxy-4-(3-propionic acid) pyrrole, produced by the condensation of δ-aminolevulinic acid with ethyl acetoacetate, is almost completely extracted from an aqueous solution with ethyl acetate without resorting to ion-exchange column chromatography. The pyrrole is determined colorimetrically by treating an aliquot of the extract with a modified Ehrlich’s reagent.