PCB 47, 51, 68 – Bestimmung von PCB 47, 51, 68 in der Luft am Arbeitsplatz mittels Gaschromatographie (GC-ECD)

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 PCB 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 PCB 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 PCB. Therefore, the German Occupational Exposure Limit Value for the sum of all PCB (5 × sum of the 6 indicator PCB [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 PCB 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%

1,2-Dichloroethane – Method for the determination of 1,2-dichloroethane in workplace air using gas chromatography (GC-MS)

This analytical method is a validated measurement procedure for the determination of 1,2-dichloroethane [107-06-2] after personal or stationary sampling. Sampling is performed by drawing a defined volume of air through an adsorption tube made of stainless steel packed with Chromosorb 106 using a suitable flow-regulated pump. After thermal desorption, the 1,2-dichloroethane retained on the adsorbens is analysed using gas chromatography with flame ionisation detection and mass spectrometry. The relative limit of quantification (LOQ) is 0.009 mg 1,2-dichloroethane/m3 for an air sample volume of 1.2 l. The mean recovery for 1,2-dichloroethane was 101%. The concentration-dependent expanded uncertainty was 20% to 21%. This analytical method has been accredited by the accident insurance companies for the detection in workplace air of substances that are carcinogenic, mutagenic or toxic to reproduction. This method has been tested and recommended for the determination of 1,2-dichloroethane in work areas by the German Social Accident Insurance (DGUV). Both personal and stationary sampling can be performed for measurements in order to evaluate work areas