Liquid Chromatographic Method for Determination of Vanillin and Related Flavor Compounds in Vanilla Extract: Collaborative Study

Abstract

A liquid chromatographic method for determination of vanillin, vanillic acid, p-hydroxybenzaldehyde, and p-hydroxybenzoic acid was collaboratively studied. The compounds are separated on a reversephase C-8 column using an acidic 10% methanol solvent and are detected at 254 nm. Recoveries for the 4 compounds present in vanilla extract ranged from 94 to 99%. Method performance as measured by repeatability and reproducibility standard deviations (sr and sR) and relative standard deviations (RSDr and RSDR), respectively, for determination of the 4 flavor compounds in authentic and adulterated vanilla extracts were as follows: p-hydroxybenzoic acid—sr 0.29, SR 0.39, RSDr 8.98%, RSDR 11.68%; p-hydroxybenzaldehyde—sr 0.92, sR 1.20, RSDr 6.16%, RSDR 6.95%; vanillic acid—sr 0.85, sR 1.12, RSDr 7.47%, RSDR 9.97%; vanillin—sr 7.45, sR 7.50, RSDr 3.43%, RSDR 3.48%. The method has been approved interim official first action.