[Determination of naphthoquinone in zicao]

A TLC-spectrophotometric method for the separation and determination of the naphthoquinones in Zicao is described. The sample solution was applied at a point 1 cm from the bottom edge of a silica gel G plate. A mixture of n-hexane-acetone-chloroform-glacial acetic acid was used as the developing solvent. The plate was saturated for 30 min and developed. The spots were scraped and extracted with chloroform for spectrophotometric determination at 523nm. The method has been applied to the analysis of different samples.