Rapid determination of blood serum retinol by reverse phase open column chromatography

An aqueous, reverse phase, open column procedure (RP C18) was developed for the rapid determination of retinol in serum. The samples were extracted with hexane and separated on the column with methanol and water as the mobile phase. Two methods were developed depending on the size of the sample. For 2 ml of serum a spectrophotometer was used to quantify the sample and for 0.1 ml of serum a fluorometer was used. Phytofluene was retained on the top of the column and the column was reusable. The agreement between HPLC and the RP C18 open column was good. The lower limit of detection for micromethod was about 1.25 micrograms of retinol per dl of serum and the recovery of added retinol was quantitative.