(in German)

This analytical method is a validated measurement procedure for the determination of he 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%.

Please download the article "MAK Commission: PCB 47, PCB 51 and PCB 68 - Determination of PCB 47, PCB 51 and PCB 68 in workplace air using gas chromatography (GC-ECD)" (in German only).