Rhodamine B in spices determined by a sensitive UPLC-MS/MS method

Rhodamine B (RhB) is a banned food additive and has been classified as illegal colourant. Therefore, the risk of RhB contamination should be strictly monitored. In this study, a sensitive UPLC-MS/MS method was applied to monitor RhB in 292 various spices such as chilli, pepper and tomato products. The results showed 22.7% of chilli powder samples, 18.5% of pepper powder samples, 11.1% of chilli oil samples and 9.1% of pepper oil samples were contaminated with RhB. Chilli powder contained RhB up to 44,935 μg/kg with an average of 743 μg/kg, pepper powder up to 65.9 μg/kg with an average of 4.1 μg/kg, chilli oil up to 14.6 μg/kg with an average of 1.0 μg/kg and pepper oil up to 1.1 μg/kg with an average of 0.2 μg/kg, respectively. Considering the common consumption of chilli products and pepper products by so many consumers, RhB exposure is significant and should be decreased.