Some organic halogen compounds (halocarbons) are recognized or suspected to be mutagen and/or carcinogen. A sampling method which determines the average concentration levels of halocarbons for 1~2 weeks and their total exposure levels for a long period has been proposed. Halocarbons in air were adsorbed by a selected activated carbon and desorbed by hexane. Air was supplied to the carbon column at a constant low flow rate (50~100 ml/min) for a long time by a miniscale vacuum pump fitted with a capillary tube (Fig. 1). The activated carbon which was made from coal and with particle size of 0.25~0. 42 mm showed good performance of adsorption and desorption. The amount of the carbon enough to adsorb the halocarbons almost completely was 5 g. The adsorbed halocarbons were eluted with hexane at a flow rate of 30~50ml/h by a simple equipment (Fig. 3). The desorption efficiencies were sufficiently high for all compounds (Table 4). The eluate was analyzed by a gas chromatograph equipped with electron capture detector. The average concentrations of the halocarbons for 1~2 weeks could be determined at many sites by the proposed sampling method, and this method was expected to be useful to monitor, and evaluate air pollution with halocarbons.
ASJC Scopus subject areas
- Chemical Engineering(all)