Abstract
Gas-liquid chromatographic (GLC) and high-performance liquid chromatographic (HPLC) methods for the determination of vitamin D_2 and ergosterol in dried yeasts were investigated and the correlation between the corresponding two methods was discussed. The GLC method for the determination of vitamin D_2 includes alkali-saponification, isolation of unsaponifiable matters, thin-layer chromatography (TLC), trimethylsilylation and GLC, whereas ergosterol is determined by applying the trimethylsilyl ethers of the unsaponifiable matters directly to GLC. In the HPLC methods, the sample solutions obtained by similar treatment according to the GLC procedure without trimethylsilylation are applied to HPLC. All of them were confirmed to be useful for the determination of vitamin D_2 or ergosterol in commercial dried yeasts. When the content of vitamin D_2 in a sample of irradiated dried yeast and that of ergosterol in non-irradiated one were repeatedly estimated by both the GLC and HPLC methods, the correlation coefficients were 0.967 for vitamin D_2 and 0.927 for ergosterol.
