IMPROVED METHOD FOR THE DETERMINATION OF SULFUR COMPONENTS IN NATURAL-GAS

Determination of trace concentrations of sulfur components in natural gas is a true analytical challenge. Only analytical procedures based on gas chromatography can meet the sensitivity and accuracy requirements dictated by environmental regulation institutions and modern chemical industry, In the present contribution the sample pretreatment and chromatographic separation steps have been evaluated and optimized based on the use of a flame-based sulfur chemiluminescence detector (SCD) for target compound detection. The proposed instrument consists of a programmed temperature vaporizing (PTV) injector employing a liner packed with Chromosorb 104, a 4 mu m thick film apolar column and a flame-based SCD, Using a 13 mt sample loop the detection limit achievable the new method is 3 mu g S/m(3). The precision of replicate measurements is generally in the range of 5-15 % relative standard deviation, Lower detection limits can be achieved by preconcentrating larger sample volumes, e,g. 100 mt.