Vanadium concentration of urine; rapid colorimetric method for its estimation.

VANADIUM COMPOUNDS are used in dye, ink, and glass manufacture, as an alloy component in the steel industry, and as a catalyst in the production of sulfuric acid. Toxic exposures have been reported in the extraction of vanadium from ores and residues (1-5) and in the cleaning of burners fired with vanadium-bearing oil (6-8). The outstanding symptom associated with excessive inhalation of vanadium compounds, particularly the pentavalent forms, is acute irritation of the respiratory tract, sometimes attended by chemical pneumonitis (5). Irritation of the conjunctivae and eczematous lesions of the skin may also occur. Exposure to low levels of vanadium may cause metabolic disturbances as evidenced by a reduction in the fingernail cystine content (9). Talvitie and Wagner (10) have shown that urinary vanadium concentrations constitute a reliable index to the degree of absorption of vanadium. Although vanadium in urine may be determined accurately with the method described by Talvitie (11), the need arose in toxicologic investigations for a faster screening test to provide pilot information on the absorption of vanadium. For this purpose a simple, colorimetric test for vanadium in urine was devised. Necessary requirements for the test were (a) that only a small amount of urine be consumed in order to conserve the bulk of the sample for more accurate analysis, and (b) that the sensitivity be sufficient to detect minimal concentrations of vanadium. These conditions were met by basing the test on the catalytic effect of vanadium on the oxidation of organic chromogens by potassium chlorate. Szebelledy and Ajtai (12)