Automated in situ analysis of volatile sulphur gases using a Sulphur Gas analyser (SUGAR) based on cryogenic trapping and gas-chromatographic separation

Based on the technique of cryogenic trapping, gas-chromatographic separation, and flame-photometric detection, we designed an instrument for the analysis of reduced sulfur compounds. The fully automated Sulfur Gas Analyser (SUGAR) consists of a dual sampling system, an electrically cooled cryotrap, and a newly devised small gas chromatograph, which is integrated mechanically and in terms of system control. The system incorporates microprocessor control and provides significant ease of operation. All operational parameters necessary for a complete sampling audit trail are logged on non-volatile memory. SUGAR achieves adequate sensitivity for measuring reduced sulfur gases at typical atmospheric concentrations. Applications under laboratory conditions and in the field demonstrate the versatility of the automated system. Field deployment proved the capability of continuous operation over a period of several weeks. The potential for further improvements of sensitivity and portability by use of different sulfur specific GC detectors is discussed