A new procedure for the formation of isotachysterol derivatives of subnanomole quantities of ergocalciferol, cholecalciferol and its metabolites prior to gas liquid chromatography

摘要: Abstract Gas-liquid chromatography of vitamin D is complicated by the thermal rearrangement which occurs at relatively high column temperatures used. Two peaks (pyro- and isopyro-) are thus obtained from every compound. A new procedure for isomerisation Vitamin its metabolites to isotachysterol derivatives, give single during gas chromatography, has been carefully evaluated. This uses hydrochloric acid 0°C in dichloroethane (dichloromethane chloroform equally good). Quantitative recoveries ergocalciferol, cholecalciferol were down levels 100 ng. Below this level, loss destruction occurred could be overcome addition 200 ng carrier D. 1α-Hydroxylated derivatives not isomerized way.