GC Determination of 12 Organic Acids in Foods

GC was applied to the determination of 12 organic acids in foods. 12 organic acids in foods were derived with H₂SO₄-CH₃OH solution. The optimized conditions found were as follows:① volume fraction of H₂SO₄-CH₃OH solution (derivative reagent) was 20%; ② derivative temperature was 80℃; ③ adding amount of derivative reagent was 4.0 mL; ④ derivative time was 60 min; ⑤ extraction reagent was CHCl₃. The analytes were separated on Agilent HP-5 capillary column (30 m×0.32 mm, 0.25 μm) and detected by FID. Linear relationships between values of peak area of the derivative product and mass concentration of the 12 organic acids were kept in definite ranges. Detection limits (3S/N) found were ranged from 0.023 to 0.076 mg·kg^-1. The proposed method was applied to the analysis of foods samples, giving values of recovery and RSD's (n=6) in the ranges of 76.0%-107% and 1.5%-6.9% respectively.