ISO 4096:1978

Essential oils (containing tertiary alcohols) — Evaluation of free alcohols content by determination of ester value after cold formylation

The essential oil is subjected to cold formylation by a mixture of formic acid and acetic anhydride. After formylation the ester value is determined. The free alcohols content is calculated taking into account the ester values of the same oil before formylation. Total alcohols and combined alcohols content can also be determined with this method.