AbstractThe transesterification by means of methyl alcohol of a low vapor pressure antioxidant additive,n‐octadecyl‐β‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)propionate‐Iraganox 1076®(produced by Ciba‐Geigy) was studied. The classical method to prepare methyl esters from triglycerides in lipids was applied with use of sulfuric acid as a catalyst. The optimum reaction conditions were sulfuric acid concentration of 1 w/v in methyl alcohol, temperature of 75°C, and time of 2 hours. The contents of the additive were determined by gas‐liquid chromatography (GLC) of a portion of transesterificate using 10 SE‐30 on Gaschrom Q (60–80 mesh) or 5 Silicone OV‐17 on Shimalite W (80–100 mesh) as a packing reagent. Irganox 1076 in polypropylene was extracted withn‐hexane. Many interfering substances in the GLC could be completely removed by the Florisil column treatment ofn‐hexane extract. The relative standard deviation was 2.7 for Irganox 1076 at levels corresponding to 0.0142 wt in polypropylene. The limit of
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