Abstract

Sensitivity and selectivity determination of erythrosine in food sample by ionic liquid-liquid phasemicroextraction

Author(s): Yunrong Li, HaoWu, Lizhen Zhang, Nannan Gao, Hong Tian, Liming Du

In this paper, a new method was developed to determinate the erythrosine in candy and tomato sauce using in-situ ionic liquid formation liquid-liquid microextraction (ISILF–LLME) followed by fluorescence detection. In this experiment, a little amount of the KPF6 (as an ion-pairing agent) was join to the sample solution containing small number of the [C8MIM][Br] (as hydrophilic ionic liquid). The fine droplets of 1-octyl- 3-methylimidazoliumhexafluorophosphate [C8MIM][PF6] was formed and a cloudy solution was obtained. The main factors influencing the extraction efficiency of ISILF–LLME including the selection of IL, amount of KPF6, solution pH, the extraction time, and centrifugation time, were optimized. The effect of other synthetic food colorants for determination of erythrosine was evacuated. Under optimal conditions, erythrosine had good linearity, with a correlation coefficients of 0.9996, linear range from 0.2 to 80 ng mL-1, and detection limits of 0.055 ng mL-1. The spiked recovery of samples was from 91.2 to 102.3%. The results indicate that the developed method was successfully applied to analytical erythrosine in candy and tomato sauce.