J.Z. Huo, H.J. Nelis, P. Lavens, P. Sorgeloos, A.P. De Leenheer-1997

Journal of Chromatography, 782 (1) : 63-68 (from Current Contents)

Abstract:

No validated high performance liquid chromatography (HPLC) methods for the determination of vitamin E in algae have been reported. We developed and evaluated a new procedure for the quantitation of microalgal alpha and gamma tocopherol (alpha T and gamma T) using reversed phase HPLC with fluorescence detection. The compounds of interest were extracted with a mixture of petroleum ether-diisopropyl ether (3:1, v/v) after saponification in the presence of pyrogallol. Delta Tocopherol (delta T) or tocol was used as an internal standard. Linearity was achieved (r>0.999) over the range of 0.11 similar to 2.32 mu g/ml for alpha T and 0.02 similar to 0.23 mu g/ml for gamma T. The within run coefficients of variation for repetitive analysis were 1.9%, 1.7% and 1.0% (n=10) for alpha T at concentrations of 0.09, 1.24 and 1.55 mu g/ml, and 1.9%, 0.8% and 0.3% (n=10) for gamma T at concentrations of 0.02, 0.08 and 0.23 mu g/ml, respectively. The recoveries at low concentration levels (0.11 and 0.02 mu g/ml) were 82.4% and 96.2% (n=5) for alpha T and gamma T, respectively. For medium concentrations (0.78 and 0.12 mu g/ml) and high concentrations (2.32 and 0.20 mu g/ml), the recoveries were 94.3 similar to 98.7% for the two tocopherols. The limits of quantitation of alpha T and gamma T were 20 and 5 mu g/g dry mass, respectively. This method has been routinely used as part of nutritional studies on fish and shrimp larvae fed on microalgae.

(Univ. Gent, Lab. Med. Biochem. Klin. Anal., Harelbekestr. 72, B-9000, Gent, Belgium)