Quantitative analysis of fourteen synthetic dyes in jelly and gummy candy by ultra performance liquid chromatography

Abstract

An analytical method was developed for the simultaneous determination of 14 dyes (tartrazine, sunset yellow, ponceau 4R, allura red, brilliant blue, carmoisine, amaranth, indigo carmine, erythrosine, new red, acid green, patent blue, acid rose red B and rose bengal) in jelly and gummy candy using ultra performance liquid chromatography (UPLC) with a photodiode array detector. Analytes were extracted with hot water (55 ± 5 °C), and ammonium sulfate was added for selectively precipitating protein and polysaccharide. Then, the supernatant was purified using an Oasis WAX solid-phase extraction cartridge. Chromatographic separation was performed on an ACQUITY UPLC® BEH shield RP18 column with gradient elution using acetonitrile and water containing 10 mmol L⁻¹ ammonium acetate as the mobile phase. Analytes were quantified by external calibration curves over ranges of 0.25–50 mg L⁻¹ with correlation coefficients >0.9999. Recoveries of the target compounds (spiked at levels of 1, 5, and 25 mg kg⁻¹) ranged from 81.4 ± 6.34% to 97.5 ± 3.05%, while intraday and interday relative standard deviations ranged from 0.90% to 8.74% and from 3.36% to 9.62%, respectively. The limit of quantification for the 14 dyes was 0.25 mg kg⁻¹.