Determination of Ascorbyl Palmitate and Ascorbyl Stearate in Foods by LC-MS/MS

Ascorbyl palmitate (AP) and ascorbyl stearate (AS), together called ascorbyl esters, are antioxidants that are used as food additives to prolong the shelf-life of foods by protecting against deterioration caused by oxidation.

This article aimed to develop a simple solvent extraction and LC-MS/MS method for the determination of AP and AS in a broad range of food matrices.

AP and AS in foods were extracted with methanol containing 0.5% (w/v) L-ascorbic acid and analyzed by liquid chromatography-tandem mass spectrometry in negative electrospray ionization and multiple reaction monitoring (MRM) mode.

The method was able to quantitatively detect AP and AS in different food matrices (canned drink, dessert, frozen fish, herbs, oils, infant formula/formulated products, etc.) with recoveries of AP and AS at 73-113% and 75-113%, respectively, and the corresponding relative standard deviations (RSDs) of 0.3-16.1% and 0.2-13.7%. The limits of quantitation were 0.23 mg/kg for AP and 0.14 mg/kg for AS. Method applicability was also demonstrated by the detection of AP in powdered infant formula purchased from local market.

A simple solvent extraction and LC-MS/MS method was developed, validated, and demonstrated for the quantitative determination of AP and AS in various foods.

The validated method based on solvent extraction with LC-MS/MS detection offered a fast and simple method for the analysis of AP and AS in a wide range of foods.