[Objective] The contents of benzoic acid and sorbic acid in liquid milk were determined by optimizing the liquid chromatography method in the first step of “GB 5009.28-2016 National Food Safety Standard - Determination of Benzoic Acid, Sorbic Acid and Sodium Saccharin in Foods”,and the extraction effect of the optimized method was verified. [Method] The applicability of this optimized method was verified by monitoring the recovery rate detection,precision detection and repeatability detection,and the data was accumulated. [Result] The optimized method had a higher extraction effect,the precision meets the requirements,and the recovery rate was closer to the true value. [Conclusion] The optimized method was more adequate for the extraction of benzoic acid and sorbic acid.It could be used as anauxiliary in the daily detection of complex matrix samples.

optimized method  /  extraction effect  /  recovery rate  /  standard curve  /  resolution