Accurate Quantification of Saccharin Using Isotope Dilution Liquid Chromatography Mass Spectrometry (ID-LC/MS)

Abstract

Saccharin is a commonly used artificial sweetener in foodstuffs. However, for its carcinogenic dispute, it has beenregulated by government bodies. In this study, isotope dilution mass spectrometry (ID-MS) was introduced for the accuratequantification of saccharin. To employ ID-LC/MS, we obtained its isotope analogue, 13C1−sodium saccharin, by customized synthesis. Samples were spiked with 13C1-sodium saccharin and analyzed with LC/MS in negative mode. Chromatographic conditionswere optimized for the adequate chromatographic retention and separation of saccharin with a C18 column. MS was operatedwith electrospray ionization by the selected ion monitoring (SIM) mode of [M − H]− for saccharin (m/z 182) and [M − Na]− forits isotope analogue (m/z 183). To validate the ID-LC/MS method for accurate measurement, we prepared a batch of a candidatematerial by sortifying quasi−tea−drinks with saccharin and analyzed samples gravimetrically fortified in various levels of concentration. The repeatability and reproducibility of this method was tested by analyzing the reference material. Result show thatID-LC/MS is a reliable method for the quantitative analysis of saccharin.