Simple Resolution of Butylated Hydroxyanisole and n-Propyl Gallate in Fatty Foods and Cosmetics Samples by Flow-Injection Solid-Phase Spectrophotometry

A biparameter sensor using flow injection with solid‐phase spectrophotometry for the simultaneous determination of butylated hydroxyanisole (BHA) and n‐propyl gallate (n‐PG) in fatty foods and cosmetics is proposed. The method is based on different transient retentions of these antioxidants when carried with methanol‐water 30:70%, vol/vol, through a flow cell packed to a 25‐mm height with C₁₈ silica. Each antioxidant was determined by measuring its intrinsic absorbance at its residence time (40 s at 272 nm for n‐PG; 200 s at 288 nm for BHA; calibration: 5.0 to 300.0 μg/mL; RSD: 1.7%) by flow technique and diode‐array detector. Resolution of the BHA‐n‐PG mixture in ratios between 1:10 and 10:1 is possible.