Abstract
The separation of homologous compounds of aliphatic monoalcohols and glycols was investigated by high performance liquid chromatography as their 3, 5-dinitrobenzoates. The aliphatic alcohols were quantitatively converted to corresponding 3, 5-dinitrobenzoates in a pyridine solution. The molar absorbance of the derivatives at 254 nm, 1.0×104 for monoalcohols and 2.08×104 for glycols, facilitated the use of UV detection. The mixtures of alcohols of carbon numbers of C1 to C6 were chromatographed by an ODS-column. (RP-18, 25 cm) with methanol-water (55/45) as a mobile phase. The mixtures of alcohols of C1 to C12 were completely separated by a gradient elution technique. Glycols such as poly-methylene, poly-ethylene glycol were separated according to the corresponding methylene unit by a polymer column with methanol-2, 2, 4-trimethylpentane(95/5) as a mobile phase. This method was applied to clarify the molecular distribution in the commercially available PEG-200, PEG-400 and PEG-600, and could be applicable for the determination of trace amount of alcohols.
