GAS-CHROMATOGRAPHIC ANALYSIS OF ATMOSPHERIC SULFUR-COMPOUNDS USING CRYOGENIC SAMPLING AND A MODIFIED THERMAL DESORBER

A refined cryogenic sampling method and a modification of a commercial ized thermal desorber for automatic analysis of atmospheric sulfur com pounds with a gas chromatography coupled to the sulfur chemiluminescen ce detector is reported. Twenty eight reduced sulfur compounds were an alyzed on a 30m x 0.32 mm i.d., 4 mu m film thickness, Quadrex 007 ser ies (dimethyl silicon phase) capillary column. The problems of retenti on time shift and peak splitting caused by the water were significantl y improved by connecting a 70-cm deactivated column before the analyti cal column. For one-liter air sample with 80% relative humidity at 30 degrees C, the retention time shift can be diminished to 1% for the co mpounds with boiling point higher than ethanethiol.