LANGMUIRIAN BEHAVIOR OF SMELLY VOLATILE ORGANIC-COMPOUNDS ON AIR SAMPLING WITH SOLID ADSORBENTS

A study of the sampling conditions of methylamine, trimethylamine, met hanethiol, acetaldehyde, ethanethiol, dimethyl sulphide and dimethyl d isulphide adsorbed on Carboxen-569 and HayeSep Q showed that the chrom atographic behaviour of these volatile organic compounds (VOC) in thes e packings can be modelled with a Langmuir isotherm. The equations der ived from this model allow the relationship between breakthrough volum es and atmospheric phase concentration of the adsorbates to be describ ed. They also predict, for each adsorbent-adsorbate system, the breakt hrough volumes at infinite dilution and the VOC concentration threshol ds requiring the application of Langmuir isotherms to avoid important quantitative errors.