Benzoic acid – Determination of benzoic acid in workplace air using high-performance liquid chromatography (HPLC-DAD)
Air Monitoring Method – Translation of the German version from 2024
George Dragan1 (Method development)Ralph Hebisch1 (Head of the working group “Air Analyses” of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
Adela Frenzen2 (External verification)
Lutz Nitschke2 (External verification)
Uta Lewin-Kretzschmar3 (Head of the working group “Analytics”)
Andrea Hartwig4 (Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
MAK Commission5
1 Federal Institute for Occupational Safety and Health (BAuA), Friedrich-Henkel-Weg 1–25, 44149 Dortmund, Germany
2 Bavarian State Office for Health and Food Safety (LGL), Pfarrstraße 3, 80538 München, Germany
3 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
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
The working group “Air Analyses” of the German Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) developed and verified the presented analytical method. This analytical method permits the determination of benzoic acid [65-85-0] occurring as inhalable particles and vapour in workplace air. The concentration range covers one tenth up to twice the currently valid occupational exposure limit value (OELV) in Germany of 0.5 mg/m3. Sampling is performed using a flow-regulated pump to draw a defined volume of air through a binder-free quartz fibre filter followed by a sorbent tube filled with silica gel. The volumetric flow rate is 1 l/min and the sampling duration is 2 hours (which corresponds to a sampling volume of 120 l). The collected benzoic acid is extracted with methanol and subsequently analysed by means of high-performance liquid chromatography using diode array detection. Quantitative determination is based on a multiple-point calibration function. For an air sample volume of 120 litres, the relative limit of quantification (LOQ) is 0.0023 mg/m3. The mean recovery is 96.3% and the expanded uncertainty for the validation range of 0.05 to 1 mg/m3 is 18%.
