Determination of aromatic hydrocarbons in naphtha and kerosine cuts

For the determination of aromatic hydrocarbons in light petroleum cuts, several standardized methods have been developed, based on adsorption [i], absorption [2], chromatography [3], and gas chromatography [4]. The adsorption method is used in investigating naphtha cuts with end points up to 205~ which are free of aromatic hydrocarbons. The reproducibility of the method is • 0.2%, but the method is at a disadvantage because of the rather long time required for analysis. The absorption method (acid extraction) is used in investigating cuts distilling up to 315~ With this method the total content of aromatic and unsaturated hy, drocarbons can be determined; the reproducibility is • 2.6%. The chromatographic method (FIA) is used in investigating cuts distilling within this same temperature range, i.e., up to 315~ It is the most selective with respect to the various classes of hydrocarbons; and, depending on the group composition, its reproducibility will range from • 0.8% to • 3.5%. The gas chromatographic method is also selective, but it can be used only in analyzing comparatively light fractions such as reformer feedstocks distilling below 180~