Micro‐estimation of major mustard oils and oxazolidinethione in small amounts of plant material

A method for the separate measurement of volatile and non‐volatile mustard oils in small amounts of plant material is described. Thioglucosides are first preserved by boiling the plant material in alcohol. After evaporation of the alcohol and enzymic splitting of thioglucosides the aglucones are extracted with ether. From this extract volatile mustard oils may be easily evaporated together with ether, and the non‐volatile mustard oils remain in the residue. By this method mustard oils were fractionated into ether‐volatile and ether‐non‐volatile fractions. Both of them are quantitatively measured with the aid of ultra‐violet spectrophotometry in the range 230–260 nm. Separation of the individual compounds from these fractions by paper chromatography is described, and qualitative and quantitative aspects of this method are discussed.