Miniaturized dielectric barrier discharge-molecular emission spectrometer for determination of total sulfur dioxide in food

Abstract

SO₂ is a type of additive widely used in the food processing industry as preservative and anti-browning, bleaching, or effective antibacterial agent. However, the SO₂ residue can have adverse effects on human health. In this work, a low-temperature microplasma generated by dielectric barrier discharge was used for the direct, in situ excitation of the molecular emission of SO₂ in food samples. The food samples were acidified and heated to release SO₂ and a miniaturized charge-coupled device spectrometer recorded the characteristic emission line at 301.9 nm. The linear correlation coefficient of the method was greater than 0.99 in the range of 10 to 100 mg L^-1. Moreover, the limit of detection was 0.01 mg L^-1, with recoveries between 72% and 108% and relative standard deviations of 1.5%-7.6%. The method is simple, accurate, low-cost, involves miniaturized and compact equipment and is suitable for the determination of total SO₂ in food samples.

Keywords: Dielectric barrier discharge; Molecular emission spectrometry; SO(2) determination.