Comparison of steradiene analysis between GC and HPLC

Steradienes are sterol dehydration products formed in the vegetable oil refining process during the bleaching and deodorization process. The 3,5-stigmastadiene content of vegetable oils was quantified by GC as well as by HPLC. A good repeatability, as indicated by the low relative standard deviation of 1.11 and 2.46%, and accuracy levels of 113.9 and 107.7% were obtained for the GC and HPLC analytical method respectively. Although a good comparison between both analytical methods was observed, GC data consistently gave on average a higher 3,5-stigmastadiene content of 19.6% compared to HPLC data. Probably there is an overestimation of the steradiene content analyzed by GC due to peak overlap with other hydrocarbons as the FID detector is not as selective compared to the UV detector applied in the HPLC analysis.