Colorimetric Assay of Citral and Citronellal in Volatile Oils

Abstract A specific colorimetric method has been devised for the determination of citral and citronellal in volatile oils in the presence of other constituents , particularly aldehydes and ketones. The method is based on the fact that the reddish color generally produced by Schiff’s reagent with aldehydes fades on t h e addition of methanolic KOH. On acidification with methanolic H2SO4, a permanent, measurable green color develops which is specific for citral and citronellal. Quantitative TLC, based on the color reaction above, was also developed for the determination of citral or citronellal in volatile oils. T h e results were compared with those obtained by the Egyptian Pharmacopoeia 1963 method.