INVESTIGATION OF TECHNIQUES FOR THE ANALYSIS OF HEXAVALENT CHROMIUM, TOTAL CHROMIUM AND TOTAL NICKEL IN WELDING FUME: A CO-OPERATIVE STUDY
Abstract
Abstract Although standardized sampling and analysis procedures for welding fumes have been detailed in the draft British Standard DD54: Part 1, analytical problems remain, particularly in the determination of total chromium and nickel compounds and of hexavalent chromium in fume. A project at The Welding Institute, sponsored by a number of U.K. and European organizations, has established a working group of collaborating analysts to examine the specific problems of chromium and nickel and consider preferred analytical methods. Their findings are presented here. A miniaturized procedure for 1 mg fume samples based on the method of BLAKELEY and ZATKA (1978) is preferred for the analysis of hexavalent chromium (soluble and insoluble fractions), using differential alkaline leaches followed by a colorimetric determination with s-diphenyl carbazide. For total chromium, a procedure using perchloric acid fuming with a s-diphenyl carbazide determination is given, although atomic absorption spectrophotometry or X-ray fluorescence has also been used successfully for total chromium and also for total nickel. Details of sensitivity and limits of detection are given and are shown to meet the requirements of existing Threshold Limit Values, using 1 mg samples. © 1983 British Occupational Hygiene Society