A Simplified Procedure for the Determination of Urinary -Aminolaevulinic Acid

Abstract
Urinary δ-aminolaevulinic acid (ALA) is commonly estimated by the method of Mauzerall and Granick (1956). In that method porphobilinogen (PBG) and ALA are successively separated from the urine by ion exchange resins. A simplified procedure, omitting the initial separation of PBG, was investigated. Urine samples from 39 lead workers and controls were estimated for ALA by both the original procedure and by this simplified procedure. A correlation coefficient of 0·99 was obtained. It was concluded that the simplified procedure may be used for screening lead workers so long as the possibility of false high readings is borne in mind. Some sources of variation in standardizing the original procedure are also discussed.