Simultaneous determination of multiple flavorings in infant formula by direct analysis in real time-mass spectrometry

The excessive flavorings in food are a growing public health concern, particularly in foods for infants and children. A rapid and simple method for simultaneous detection of multiple flavorings in food is urgently needed. In this work, a method with direct analysis in real time-mass spectrometry has been developed and applied to the simultaneous determination of four flavorings, including maltol, ethyl maltol, vanillin, and ethyl vanillin. The ionization efficiency of flavor compounds in the quantitatively-dip-it probe mode was compared with that in the quick strip mode, which revealed that a solvent-assisted ionization mechanism might be involved in the ionization process. The developed method showed good linearity ( R 2  > 0.99) in the range from 5 to 1000 μg L −1 , sensitivity (LODs <3.3 μg L −1 ), recoveries (84.8%–96.9%), satisfactory repeatability (RSD <14.3%, n = 5), and high-throughout (12 infant formula samples completed in 15 min). The LOQs (0.55–1.1 mg kg −1 ) for the infant formula sample were much lower than the regulatory limits. The developed method provided an alternative way to monitor the excessive addition of flavorings.