Aliphatic hydroxy acids were esterified in aqueous solution in the presence of different amounts of sulfuric acid. Esterification of lactic, tartronic, malic and citric acids in water/n-propanol mixtures with mole ratios between 0.03 and 2.15 can be utilized for the determination of these acids by gas chromatography. Water does not interfere at water/n-propanol mole ratios below 0.03. For mole ratios above 0.03 anhydrous sodium sulfate is used for the binding of water. The mole ratio range was 0.24-2.13 for anhydrous sodium sulfate/water, and 0.16-1.28 for sulfuric acid/anhydrous sodium sulfate.
- Esterification in aqueous solution
- Gas chromatography
- n-Propyl esters of aliphatic hydroxy acids
ASJC Scopus subject areas
- Analytical Chemistry
- Clinical Biochemistry
- Organic Chemistry