Detection of some aliphatic saturated long-chain hydrocarbon derivatives by thin-layer chromatography

The aliphatic saturated long-chain alcohols, aldehydes, and diols were identified to a sensitivity of 50 μg from the parent hydrocarbons (C₁₀, C₁₂, C₁₄ and C₁₆) by thin-layer chromatography using “Silica Gel G”-coated pyrex chromatoplates for the fixed phase and ethyl acetate-n-hexane mixtures as the mobile phase. Identification of the developed spots was made by a modified charring technique employing ground glass pyrex plates coated with pyrosulfuric acid. Identification of the 1,n-dicarboxylic acid from the n-mono- or the 1,n-hydroxycarboxylic acid derived from the same parent hydrocarbon was effected in a mobile phase of 7:3:3 v/v ethanol- ammonia (conc.)-tetrahydrofuran. The indicator spray employed was an ethanolic solution of bromothymol blue. The spray was followed by exposure to ammonia vapor for intensification of the yellow acid spots.R_F value trends for the n-mono- and 1,n-bifunctional derivatives of the C₁₀ C₁₂, C₁₄ and C₁₆ aliphatic saturated hydrocarbons based on the—OH, —COOH and —CHO groups as the possible substituents are outlined.