Determination of 7 preservatives in food using high performance liquid chromatography

Objective To establish a method for the simultaneous determination of 7 preservatives(benzoic acid, sorbic acid, dehydroacetic acid, methyl p-hydroxybenzoate, p-hydroxy benzoic acid ethyl ester, p-hydroxy benzoic acid n-propyl, and p-hydroxy benzoic acid butyl ester) in food by high performance liquid chromatography, and determine the wine, drink, soy sauce, and bread in the samples. Methods Samples were extracted with methanol, and assisted by Mg SO4 to remove the water before the centrifugation. After through 0.45 μm filter, 7 kinds of preservatives were detected by HPLC-DAD. Results Under the optimized conditions, the linear range was 0.1~ 10 mg/L with R2≥0.9999. The limits of detection(LOD, S/N=3) were from 50 to 100 μg/L. Besides, recoveries were in the range of 77.28%~106.81%, and the RSDs of the peak areas were between 0.46%~2.38%. Conclusion This method is suitable for simple and sensitive determination of 7 kinds of preservatives in wine, drink, soy sauce and bread.