An analytical method is described for the rapid quantitative determination of naphthene aromatics (aromatics) and polar aromatics (polars) in asphalt cement using high-performance liquid chromatography (hplc). The hexane-insoluble asphaltenes are removed beforehand and the petrolene solution passed through an nh2 energy analysis column. After elution of the naphthene aromatics, the solvent flow direction is reversed and the polar aromatics peak follows. Ultraviolet absorption at 254 nm is used for detection. A complete sample run consumes less than 3 hr. Results of analysis agree favorably with those o2btained following the short procedure of astm d4124. Considering the astm d4124 results "correct, " the average absolute error for 49 determinations on 22 samples from four different refineries amounted to plus or minus 0.66 And plus or minus 0.82 Percentage point for thenaphthene aromatics and polar aromatics fractions, respectively. The standard deviation for seven determinations on one sample is 0.89 And 0.45 Percentage point for the naphthene aromatics and polar aromatics fractions, respectively. This paper appears in transportation research record no. 1228, Asphalt mixtures and asphalt chemistry.
Abstract