This International Standard specifies a charcoal tube/gas chromatographic method for the determination of the vinyl chloride monomer concentration in workplace air.
The method is valid for vinyl chloride concentrations in the range from 250 Mg/m3 (≈100ul/m3) to 25 mg/m3 ( ≈ 10 ml/m3) when sampling 30 litres of air11'.
NOTE — The upper limit of the useful range is set by the adsorptive capacity of the charcoal tube used. This capacity is measured as a break-through volume of air, which volume should not be exceeded during sampling. The lower limit is set by a number of parameters, in-cluding the noise level of the detector, blank concentrations due to contamination of the charcoal and carbon disulfide by vinyl chloride, poor desorption efficiency at very low sample loadings, and in-terference of the solvent peak in the gas chromatographic analysis.
This procedure is compatible with low flow-rate personal sampling equipment and can be used for personal and fixed location sampling. It cannot be used to measure instantaneous or short-term fluctuations in vinyl chloride concentrations. Alternative on-site procedures, such as gas chromatography or infra-red spectrometry, should be used to measure rapidly changing concentrations. Organic components which have the same or nearly the same retention time as vinyl chloride during the gas chromatographic analysis will interfere. Interferences can be minimized by proper selection of gas chromatographic columns and programme conditions.
For certain applications, alternative detectors such as the photo-ionization detector may offer greater selectivity and sen-sitivity to vinyl chloride.
Water mists, high relative humidity, and other vapours at high concentrations reduce the adsorptive capacity of the charcoal for vinyl chloride.
The sampling method gives a time-weighted average result.
SIS SS-ISO 8762:1990 history
1990SIS SS-ISO 8762:1990 Workplace air — Determination of vinyl chloride — Charcoal tube/gas chromato- graphic method