Molecules (May 2024)

Determination of Sulfites in Dried Fruits by Paper Spray Ionization Tandem Mass Spectrometry

  • Donghoon Lee,
  • Heejin Ro,
  • Seoyoung Hwang,
  • Minkyu Lee,
  • Hyebeen Kim,
  • Jaeyoung Heo,
  • Sangwon Cha

DOI
https://doi.org/10.3390/molecules29102192
Journal volume & issue
Vol. 29, no. 10
p. 2192

Abstract

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Sulfite, a widely used food additive, is subject to regulated labeling. The extraction of sulfite as the stable hydroxymethylsulfonate (HMS) form and its quantitative analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been recognized for their good sensitivity, selectivity, and versatility across various food materials. This study aimed to develop a cost-effective and simpler method for sulfite quantitation, while maintaining the superior sensitivity and selectivity of mass spectrometry (MS). To achieve this, we introduced paper spray ionization (PSI), an ambient desorption ionization technique that could achieve the direct measurement of analytes without employing separation. We also employed a novel internal standard (IS) structurally similar to the analyte, replacing the more expensive isotopically labeled IS. Although the PSI-MS/MS method developed in this study exhibited slightly lower analytical performance compared to the conventional LC-MS/MS, it remained effective for sulfite analysis in dried fruits.

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