DETERMINATION OF SULFUR COMPONENTS IN NATURAL-GAS - A REVIEW

More stringent environmental regulations as well as higher demands pre sently being imposed on the sulfur content of natural gas feed-stocks for chemical processes necessitate the development of new analytical p rocedures for sulfur determination in natural gas. Only analytical pro cedures based on gas chromatography can meet the sensitivity and accur acy requirements dictated by environmental regulation institutions and modern chemical industry. The complexity of the natural gas matrix as well as the extremely low concentration levels at which the sulfur sp ecies occur make the development of these analytical methods a true ch allenge. In this review the three steps common for analytical methods for trace analysis in complex matrices, i.e. pretreatment, chromatogra phic separation, and detection, are discussed in detail. Possible meth ods for calibration of the system are discussed in the final section. Various techniques to determine sulfur in natural gas are described. D epending on the application, the most suitable system has to be select ed. For example, for on-line application in a hazardous area a simple and rugged system is required, i.e. a simple gas chromatograph with a flame photometric detector, while for laboratory application a more co mplex instrument including preconcentration, column switching, and mor e exotic detection systems could be more suitable. Therefore it is cru cial to define the requirements of the instrument at an early stage an d use the information in this review article to develop/select a dedic ated instrument/procedure for the problem at hand.