Determination of Salicylic Acid in Raw Milk by Ultra Performance Liquid Chromatography

A method for the detection of salicylic acid in raw milk was set up. The sample was extracted with acetonitrile and determined by ultra performance liquid chromatography, and separated on a ZORBAX Eclipse Plus C18 reversed-phase column, using gradient elution, with a mobile phase of phosphoric acid water and methanolic acid, and a DAD detection. The linear range of salicylic acid was 0.5~20 μg/mL, the correlation coefficient squared (R²) was more than 0.995, the detection limit was 0.5 mg/kg, the quantification limit was 1.25 mg/kg, the average recovery rate of the three different levels were between 88.0% to 118.9%, and the relative standard deviation was not more than 10%. The method had the characteristics of simple operation, good reproducibility, high sensitivity, small impurity interference and can be used for the detection of salicylic acid in raw milk.