determination of benzene, toluene and xylene (btx) concentrations in air using hplc developed method compared to gas chromatography

a new method for analysis of benzene, toluene, and xylene (btx) using high performance liquid chromatography-uv detection (hplc-uv) is described and compared to the gas chromatography (gc) method. a charcoal adsorption tube connected to a small pump was used to obtain samples from an atmosphere chamber standard. samples were extracted with methanol and analyzed by hplc-uv. chromatography was isocratic in a mobile phase consisting of water-methanol (30-70). the flow rate was set at 1 ml/min. the analyses were completely separated and were quantified using both methods. the results demonstrated no statistically significant differences between btx concentrations between the two analytical methods with a correlation coefficient of 0.98-0.99. the gc method provided higher sensitivity than hplc, but the hplc determination of btx were applicable to real samples because its sensivity was lower than the thershold limit recommended by the american conference of governmental industrial hygienist (acgih) for an 8-hour workday.