No abstract

Direct measurement of the gases adsorbed on charcoal disk was examined by the gas-chromatograph with thermal desorption devices to improve the inadequacies of the common passive monitor. Since the most satisfactory values were obtained by a preliminary experiment with toluene vapor, the experiments were done with concentrations of 20, 40 and 80ppm, respectively to get a linear relation ship between the mean adsorption per piece and the concentration of toluene. Adsorption on the charcoal disk, and its extraction by carbon disulfide without degeneration, are the necessary conditions for the measurement of gas concentration. Methanol was selected as typical from among the gases for which the common passive monitor is inapplicable. The experiment on methanol was carried out in a manner similar to that done on toluene. In conclusion, our method was found to be satisfactory for the analysis of toluene, and, if the con ditions are appropriate, for methanol.