GAS-CHROMATOGRAPHIC DETERMINATION OF VOLATILE HYDROCARBONS IN AIR BY USING ADSORBENT COLLECTION

A simple method for the collection and determination of volatile hydrocarbons in air was examined. The investigated thirteen volatile hydrocarbons were benzene, toluene, ethylbenzene, three kinds of xylene, cumene, three kinds of ethyltoluene, mesitylene, octane and nonane. Air dehumidified by magnesium perchlorate was sampled at 0.5 l/min for 24 h through a glass tube (2.6 mm i.d.) packed with 400 mg of Carbosieve S-III (60/80 mesh) which was divided into a 200 mg front bed and a 200 mg rear bed. Each sampled Carbosieve S-III was extracted ultrasonically with 1 ml of carbon disulfide for 10 min. An aliquot of the extract was analyzed by GC equipped with a FID on a glass column (3 mm i.d. by 2 m long) packed with 5% SP-1200 and 1.75% Bentone 34 on Chromosorb W (AW, DMCS, 60/80 mesh). The efficiencies and recoveries of the collection of the volatile hydrocarbons were quantitative; the minimum range of detectable concentrations were from 0.03 ppb for benzene to 0.16 ppb for cumene, m-ethyltoluene and mesitylene. This method could be applied to analyze the volatile hydrocarbons in indoor air from laboratories and houses, and in the atmosphere.