Determination of sulphur in trace levels in petroleum products by wavelength-dispersive X-ray fluorescence spectroscopy

Determination of sulphur in trace levels in various petroleum products is i mportant due to the deleterious effect of sulphur during the usage and furt her processing of these products. The environmental regulations of state an d local agencies also restrict the sulphur content in distillate fuels to m inimum acceptable levels. Sulphur content in low ppm levels in petroleum pr oducts can be determined by various standard methods, which are based on we t chemical and spectroscopic methods, proposed by agencies like ASTM, IP an d UOP. The wet chemical methods are time consuming, tedious and require fin e chemicals while the spectroscopic methods are applicable for relatively h igher levels of sulphur. In the present work, a method has been developed f or the determination of sulphur content in petroleum products up to 1 ppm, level using wavelength-dispersive X-ray fluorescence (WDXRF) spectroscopy. The effect of various experimental parameters, viz. sample holder, sample m ask, mylar film and sample matrix, which considerably influence the analysi s, has been discussed. The developed method has been validated against the standard Raney nickel reduction method (UOP-375-80). (C) 2001 Elsevier Scie nce Ltd. All rights reserved.