Fast Simultaneous Determination of Eight Sudan Dyes in Chili Oil by Ultra-High-Performance Supercritical Fluid Chromatography.

Yunjia Yang,Yi Yang,Jie Yin,Jing Zhang

doi:10.1155/2019/3731028

Abstract

A rapid and simple ultra-high-performance supercritical fluid chromatography (UHPSFC) with photodiode array (PDA) method was developed and validated for simultaneous determination of eight Sudan dyes in chili oil. In particular, a pair of isomer, Sudan red B and Sudan IV, was included in the analysis. After being diluted with dichloromethane, the analytes were separated on an Acquity UPC2 HSS C18 SB column with gradient elution using CO2 as the mobile phase and acetonitrile/methanol (v/v, 45/55, containing 0.1% formic acid) as the organic modifier. Analytes were quantified by external calibration curves over ranges of 0.5–50 mg/L, with correlation coefficients above 0.999. The method gave recoveries of the target compounds (spiked at levels of 1, 5, and 25 mg/kg) ranging from 82.6 to 108.3%, with intraday and interday relative standard deviations of less than 8.0% and 8.6%, respectively. The limits of detection (LODs) and the limits of quantification (LOQs) for eight dyes were from 0.10 to 0.30 mg/kg and 0.30–1.00 mg/kg, respectively. This method was applied for the analysis of chili oil samples collected from the supermarket in Beijing. This validated that the UHPSFC-PDA method provides a useful strategy for the simultaneous determination of Sudan dyes in chili oil for routine analysis.

Highlights

Sudan dyes are lipophilic azo dyes that are commonly used as industrial dyes and biochemical reagents. ey have been banned for use as food additives because of their carcinogenicity. e remarkable characteristic of Sudan dyes is the fact that they are chromophoric azo groups, which can be reduced by mammalian and microbial enzyme systems
On the contrary, performing photodiode array detector (PDA) on an HPLC system for the determination of Sudan dyes is really a challenging task since they include a group of lipophilic chemicals having more similarities in molecular structure and some of them are even isomers
It integrates supercritical fluid chromatography (SFC) and LC technologies and shows many advantages including high efficiency, low cost, reduced solvent consumption, and sensitivity with the aid of a special column compacted with sub-2 μm particles, which makes its application in routine analysis more attractive [22, 23]

Summary

Introduction

Sudan dyes are lipophilic azo dyes that are commonly used as industrial dyes and biochemical reagents. ey have been banned for use as food additives because of their carcinogenicity. e remarkable characteristic of Sudan dyes is the fact that they are chromophoric azo groups, which can be reduced by mammalian and microbial enzyme systems. A new analytical method was utilized for the separation of Sudan dyes in food: ultra performance convergence chromatography (UPC2). It integrates supercritical fluid chromatography (SFC) and LC technologies and shows many advantages including high efficiency, low cost, reduced solvent consumption, and sensitivity with the aid of a special column compacted with sub-2 μm particles, which makes its application in routine analysis more attractive [22, 23]. The aim of the present work was to develop and optimize UHPSFC separation coupled with the PDA detection method for the simultaneous determination of eight Sudan dyes in chili oil

Materials and Methods

Result and Discussion

G Methanol

Method Validation

Findings

Conclusions