Analysis of benzoic acid and sorbic acid in Thai rice wines and distillates by solid-phase sorbent extraction and high-performance liquid chromatography

An application of solid-phase extraction (SPE) for high-performance liquid chromatography (HPLC) analysis was developed for the rapid determination of benzoic acid and sorbic acid in Thai rice wine and distillate products. The SPE extraction gave promising results with 95.7+1.7% recovery for benzoic acid standard, and 95.2+2.3% for sorbic acid standard. Mean relative standard deviation (RSD) for both acids was 1.99%. Percentage recoveries when spiked in real samples were 92.6+1.2% and 93.7+1.7% for benzoic acid and sorbic acid in rice wine, and 92.7+1.2% and 92.5+1.8% in distillate, respectively. Detection limits were 0.2 mg/L for benzoic acid and 0.1 mg/L for sorbic acid. The overall experimental time for each sample was 15 min with 1.56% RSD. Results show that all detected data were below the maximum permitted concentration by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Results showed a broad range between products from different areas, explained by principal component analysis (PCA) models. This SPE-HPLC technique was proved to be rapid, accurate, and precise for the analysis of benzoic and sorbic acid in alcoholic beverages.