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 o n gas chromatography can meet the sensitivity and accuracy requirement s dictated by environmental regulation institutions and modern chemica l industry, In the present contribution the sample pretreatment and ch romatographic separation steps have been evaluated and optimized based on the use of a flame-based sulfur chemiluminescence detector (SCD) f or target compound detection. The proposed instrument consists of a pr ogrammed temperature vaporizing (PTV) injector employing a liner packe d with Chromosorb 104, a 4 mu m thick film apolar column and a flame-b ased 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 vo lumes, e,g. 100 mt.