Abstract: An ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to determine 90 nafils in health foods. The samples were extracted with methanol, and the extracts were then separated on a Waters Acquity UPLC BEH C18 (2.1 mm × 100 mm, 2.5 μm) using a gradient mobile phase composed of acetonitrile and 0.1% formic acid in water. Multiple reaction monitoring was used to acquire mass spectrometric data. An external standard method was adopted for quantification. The results showed that good linearity was obtained in the concentration range of 0.2–50 ng/mL for the 90 nafils with correlation coefficients higher than 0.995. The limits of detection (LODs) were in the range of 2.5–25.0 μg/kg, and the limits of quantitation (LOQs) were in the range of 5.0–50.0 μg/kg. The recoveries were in the range of 78.0%–109.9% at spiked concentration levels between 5.0 and 500 μg/kg with relative standard deviations (RSDs) lower than 10%. The developed method was successfully used for accurate and quantitative measurement of the 90 nafils in health foods.

Key words: nafils; ultra-high performance liquid chromatography-tandem mass spectrometry; health foods