Determination of ascorbyl palmitate in infant formula milk powder by liquid chromatography-tandem mass spectrometry

Objective To establish a method for rapid detection of ascorbyl palmitate in infant milk powder by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Methods The sample was extracted with 0.1% oxalic acid ethanol solution, and the extract was purified with ethylenediamine-N-propyl silane (primary secondary amine, PSA) and separated by a C18 column, and detected by a triple quadrupole tandem mass spectrometry. Results Ascorbyl palmitate had a good linear relationship with the peak area in the concentration range of 0.02‒0.5 μg/mL, and the correlation coefficient (r2) was 0.9996. The limit of detection (LOD) (S/N=3) was 0.03 mg/kg, and the limit of quantitation (LOQ) (S/N=10) was 0.10 mg/kg. The mean recoveries at spiked levels of 0.5, 1.0 and 10.0 mg/kg were 90.0%‒104.1%, with the relative standard deviations (RSDs) of 1.5%‒2.7%(n=6). Conclusion This method is simple, rapid and sensitive, and can meet the requirements of detecting ascorbic palmitate in infant milk powder.