Characterization of Adjuvant Mineral Oils

Analysis of two lots of mineral oil indicated the overall composition to be quite similar with two major hydrocarbon ranges: a low range from C14 to C20 with a maximum at C16 and a high range from C20 to C30 with a maximum at C25. The low range components represented 40.8 and 49.3 wt. % of Lots Q-9 and Q-10, respectively. Urea fractionation of the paraffin-naphthene fraction from silica gel chromatography yielded 28.2 and 28.8 wt. % for Lots Q-9 and Q-10, respectively. The nonadductable material consisted of highly branched and cyclic structures containing up to four-ring systems. The total butyl phthalate content in Lots Q-9 and Q-10 was 13.2 and 7.0 p.p.m., respectively, with the ratio of mono-butyl phthalate to dibutyl phthalate being 9:1. No evidence was found to indicate the presence of polynuclear aromatic hydrocarbons.