Determination of banned dyes in spices by liquid chromatography-mass spectrometry

Abstract

A simple and rapid multiresidue method for the determination of nine banned synthetic dyes in various spices has been developed. Reversed phase HPLC coupled with mass spectrometry (tandem in time-ion trap mass analyser) was employed for the examination of crude acetonitrile extract acidified with acetic acid. The detection limits of Para Red, Sudan Orange G, Sudan I, Sudan II, Sudan III, Sudan IV, Sudan Red 7B and Rhodamine B were in the range of 0.02-0.1 mg/kg, the recoveries ranged from 75.7-92.3% with repeatability of 0.9-11.3%. Rather worse performance characteristics were obtained with Tropaeolin 000, obviously due to its more polar nature as compared to other dyes involved in this study. In spite of that, the developed method can be used for a reliable control of a wide range of dyes used for illegal colouring of various spices.

Keywords

• sudan dyes
• para red
• rhodamine b
• chilli
• curry
• liquid chromatography-mass spectrometry