Quantitative Determination of Formic, Acetic, Propionic and Butyric Acids in Frozen Whole Eggs by Gas‐Liquid Chromatography

SUMMARY — Whole eggs containing known amounts of formic, acetic, propionic and butyric (C 1 ‐C 4 ) acids were evaluated using gas‐liquid chromatography (GLC) and AOAC (1960) procedures. Acetic, propionic and butyric acids were recovered from whole egg samples and chromatographed as the acids per se, along with an internal standard. Formic and acetic acids were recovered from whole egg samples and chromatographed as their butyl ester derivatives without an internal standard. Quantitation of butyl formate and butyl acetate was accomplished by comparing the chromatogram peak heights of the butyl esters recovered from the egg samples with the chromatogram peak heights of a known concentration of butyl ester standards. The recovery of acids from whole egg samples by GLC procedures was as accurate, and generally less variable, than by AOAC (1960) procedures. The percentage recovery of acids from whole egg samples using GLC procedures depended on the concentrations of the acids present and was as follows: acetic acid varied from 114 to 100% (low to high concentration); propionic acid varied from 101 to 100% (low to high concentrations); and butyric acid varied from 103 to 99% (low to high concentration). The recovery of formic acid as its butyl ester derivative varied from 104 to 96% (low to high concentration), while the recovery of acetic acid as its butyl ester derivative varied from 102 to 98% (low to high concentration).