Quantitative hydrocarbon group type analysis of petroleum hydroconversion products using an improved TLC-FID System

Abstract

This work deals with the study of an improved thin-layer chromatographic-flame-ionization detection (TLC-FID) system (using the newer configuration of the detector, an automatic sample spotter, and a careful selection of the operating parameters) in the quantitative hydrocarbon group type analysis of a deasphalted heavy oil from petroleum and its derived hydrocracking products. The separation method proposed allows for the detection and quantitation of saturates, alkylaromatics, aromatics, polars, and an uneluted fraction. The repeatability of the experiments has always been better than that of the ASTM D2007 standard for each fraction. It is not affected by application volumes or concentration in the studied ranges. Results from the absolute calibration method and from a variety of the internal normalization procedures are comparable, although the latter is faster and allows a rapid determination of the linear range of the detector. Factors such as eluent development length or application spot size do not influence the FID response of our samples under the studied conditions. Likewise, the behavior of the detector is linear with mass in the range studied for each separated fraction.