Method for the determination of hexavalent chromium in workplace air using photometry
Air Monitoring Method
Wolfgang Schneider1Thomas Helmut Brock2
Ralph Hebisch3
Andrea Hartwig4
MAK Commission5
1 Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA), Alte Heerstraße 111, 53757 Sankt Augustin, Germany
2 German Social Accident Insurance, Institution for the raw materials and chemical industry, Prevention - Department of Hazardous Substances, Biological Agents and Analytical Chemistry, Kurfürsten-Anlage 62, 69115 Heidelberg, Germany
3 Federal Institute for Occupational Safety and Health (BAuA), Friedrich-Henkel-Weg 1–25, 44149 Dortmund, Germany
4 Institute of Applied Biosciences, Department of Food Chemistry and Toxicology, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Building 50.41, 76131 Karlsruhe, Germany
5 Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Germany
Abstract
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.
