Simultaneous Determination of Sudan Dyes along with Dimethyl Yellow in Indian Curry Samples by Reverse Phase Liquid Chromatography

Sumita Dixit

doi:10.4172/2157-7064.1000150

Abstract

The synthetic organic azo dyes have been studied for their toxicity risk due to formation of suspected carcinogenic aromatic amines on reduction. Based on toxicity data, various unauthorized azo dyes are sometimes illegally used in food preparations either to enhance or to maintain the appearance of food products. Therefore suitable analytical screening and confirmatory methods are required for compliance verification of foodstuffs. Although several methods are available, no method for the simultaneous determination of all the four Sudan dyes along with dimethyl yellow in oil rich Indian curry samples has been reported so far. The present method utilizes a simple extraction step and simultaneous HPLC resolution of Sudan I, II, III, IV and dimethyl yellow in oil rich Indian curry samples. Analysis was performed on a reversed-phase LiChroCART(R) RP-18 column using the gradient mixture of acidified water, acetonitrile and methanol. The flow rate was 1.0 ml min-1 with λ max of 420 up to 4 min and then 500 nm, respectively to monitor dimethyl yellow and Sudan dyes. All the five colors showed good linearity at the concentrations of 0.25- 25.0 mgL-1 with the regression coefficient from 0.997 to 0.999. The LOD ranged from 0.23-0.33 mgL-1 while LOQ varied between 1.19-1.70 mgL-1. The intraday and interday precision gave good RSDs between 0.78 to 4.32%, and percentage recoveries ranged from 62.3 to 77.3%. The applicability of the method has been verified by analyzing fifteen curry samples procured from local markets.

Highlights

The most widely used synthetic organic azo dyes have been studied for their toxicity risk [1]
In the present paper we have developed and validated a simple reversed phase HPLC method for the simultaneous identification and determination of Sudan I, Sudan II, Sudan III, Sudan IV and dimethyl yellow in curry samples
The peaks became sharp in the presence of acid but increase in concentration of methanol tend to merge the peak of dimethyl yellow with curcumin, one of the basic constituent of Indian curry sample

Summary

Introduction

The most widely used synthetic organic azo dyes have been studied for their toxicity risk [1]. The chromophoric azo group on reduction forms suspected carcinogenic aromatic amines under certain conditions [2]. Some of these dyes are used in food industry with the regulation of maximum permissible levels in a particular foodstuff [3]. The UK Food Standard Agency issued alert for various meat preparations in UK market for contamination with Sudan I [8]. The Agence Federale pour la Securite de la Chaine Alimentaire recalled curry samples contaminated with dimethyl yellow [9]. The Rapid Alert System for Food and Feed (RASFF) determined more than 0.50 mg dimethyl yellow per kg in curry powder in India [10]

Methods

Results

Conclusion