Study of an Analytical Method for Hexavalent Chromium

Abstract

The diphenylcarbazide colorimetric method was evaluated by analyzing spiked PVC filters prepared by an AIHA-accredited consultant laboratory for chromium (VI). All seven participating laboratories received the samples and performed the analyses at the same time. Three laboratories simultaneously tested three alternative analytical procedures. Reduced amounts of chromium (VI) were found by both the consultant and participating laboratories when using the test procedure and one of the alternative methods. Two of the alternative analytical methods, both of which involve an alkaline extraction procedure, provided higher recoveries and more precise values for the test filters. It appears that the alkaline extraction procedure may be more appropriate for occupational health samples taken in steel industry environments which may include several interferents. Suggestions are made for further studies to determine the most appropriate analytical method.

Airborne Particulate Emissions from a Chromic Acid Anodizing Process Tank

“…Chemical analysis methods for hexavalent chromium concentrations include the diphenylcarbazide colorimetric and ion chromatography procedures. Analytical methods for hexavalent and total chromium concentrations in the airborne particle samples were reported by Bhargava et al (1983), 5 Abell and Carlberg (1974), 6 and Thomsen and Stern (1976). 7 All concur that the colorimetric method using diphenylcarbazide is an accurate means of measuring hexavalent chromium concentrations in aqueous solutions down to about 0.5 u,g of Cr +6 .…”