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1000
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Abstract/Summary
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This analytical method is a validated measurement procedure for the determination of hexavalent chromium in workplace air averaged over the sampling period after personal or stationary sampling. Sampling is performed by drawing a defined volume of air through a quartz fibre filter located in a GSP sampling head using a suitable flow‐regulated pump. The flow rate is set to 3.5 or 10 L/min with a recommended air sample volume of 420 or 1200 L. The collected hexavalent chromium oxidised 1,5‐diphenylcarbazide to 1,5‐diphenylcarbazone, which forms a red‐violet coloured complex with the generated trivalent chromium. The filtered extract is measured photometrically at 540 nm after a waiting time of 30 minutes within a period of 15 minutes. The quantitative determination is based on a calibration function obtained by means of multi‐point calibrations. The absolute limit of quantification (LOQ) is 0.1 µg for hexavalent chromium deposited on the filter. The mean recovery was 104% and the expanded uncertainty for hexavalent chromium was approx. 20%. Joint Publication of the Analytical Subcommittee of the Chemistry Board of Experts of the Expert Committee Raw Materials and Chemical Industry of the German Social Accident Insurance and the working group “Air Analyses” of the Permanent Senate Commission of the Deutsche Forschungsgemeinschaft for the Investigation of Health Hazards of Chemical Compounds in the Work Area.
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