PCB 47, PCB 51 and PCB 68 – Determination of PCB 47, PCB 51 and PCB 68 in workplace air using gas chromatography (GC-ECD)

Air Monitoring Method – Translation of the German version from 2023

Silke Werner¹ (Method development)
Michael Tschickardt² (External verification)
  Ralph Hebisch³ (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)
  Thomas Helmut Brock⁴ (Head of the working group “Analytics”)
  Andrea Hartwig⁵ (Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
  MAK Commission<sup>6

1</sup> Institute for Occupational Safety and Health (IFA) of the German Social Accident Insurance (DGUV), Alte Heerstraße 111, 53757 Sankt Augustin, Germany
² Scientific Consulting for Environmental Protection and Occupational Safety (WBUA), Westring 24, 55120 Mainz, Germany
³ Federal Institute for Occupational Safety and Health (BAuA), Friedrich-Henkel-Weg 1–25, 44149 Dortmund, Germany
⁴ 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
⁵ Federal Institute for Occupational Safety and Health (BAuA), Adenauerring 20a, Building 50.41, 76131 Karlsruhe, Germany
⁶ 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 the three tetrachlorinated biphenyls PCB 47 [2437-79-8], PCB 51 [68194-04-7] and PCB 68 [73575-52-7] in workplace air in a concentration range of 0.16 to 0.62 µg/m³. It was developed to detect PCBs that only may be generated during the manufacture of silicone products with peroxidic crosslinking with bis(2,4-dichlorobenzoyl) peroxide. By measurement in manufacturing plants it could be proven that the PCBs to be investigated are present exclusively in vapour form. For this reason, the method was only validated for vaporous samples. There are currently no valid evaluation criteria for these PCBs. Therefore, the German Occupational Exposure Limit Value for the sum of all PCBs (5 × sum of the 6 indicator PCBs [28, 52, 101, 138, 152, 180]) of 3 µg/m³ was used as the assessment standard for each congener. For sampling, a defined volume of air is drawn through a sorbent tube filled with Florisil. The flow rate is set to 1 l/min and sampling duration is 4 hours (which correspond to a sampling volume of 240 l). The PCBs are extracted with n-hexane at 40 °C in an ultrasonic bath and subsequently analysed using gas chromatography with electron capture detection. The quantitative determination is based on a calibration function. The limit of quantification is 0.11 µg/m³ based on an air sample volume of 240 l. The mean recovery is 96% and the expanded uncertainty for the validation range of 0.16 to 0.62 µg/m³ is 22 to 24%.

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