Nonlinear Response and Quenching Effect in GC-FPD and GC-PFPD for Quantitative Sulfur Analysis of Low-Sulfur Hydrocarbon Fuels

摘要

Recently,ultra-deep desulfurization of hydrocarbon fuels has become more and more important for environmental protection and for fuel cell applications [1,2].The quantitative analysis methods of sulfur concentration in hydrocarbon fuels,especially in desulfurized liquid fuels,are necessary for these investigations.Gas chromatography coupled with a flame photometric detector (GC-FPD) or pulsed flame photometric detector (GC-FPD) has been used in a number of applications,particularly for the identification of sulfur compounds in the fuels,because it is robust,selective to sulfur containing compounds,and relatively inexpensive.However,we need to keep in mind that the response of FPD and PFPD for sulfur compounds is inherently nonlinear [3,4].The intensity of the blue light emission is theoretically proportional to the square of the sulfur concentration in the flame (n=2) [3].In practice,the n value is dependent upon the operating conditions of the FPD and also sulfur compounds.