Determination of phytonadione in elemental diets by TLC-spectrophotodensitometry

The quantitative analysis of phytonadione in several elemental diet formulations at levels ranging from 90 to 150 ppb is described. After extraction with petroleum either, the sample is cleaned up by silica gel column chromatography and separated on a TLC plate; phytonadione is determined by reflectance densitometry. Recovery data show that the method is accurate (X = 97%) and has a precision (RSD) of +/- 6%.