Development and Validation of Dispersive Liquid-liquid Microextraction Coupled to Spectrophotometry for Extraction and Determination of Carmoisine in Foodstuff

Synthetic colorants are very important class of food additives. They are widely used all over the world in food and feed industries due to their low price, high effectiveness and excellent stability. In this research, a simple, rapid and sensitive method termed as “dispersive liquid-liquid microextraction” combined with spectrophotometry determination is proposed for determining the trace amounts of carmoisine in food samples.
Several factors influencing the extraction efficiency of carmoisine including the type and amount of extraction solvent and disperser solvent, pH, ionic strength, and amount of ion-pairing reagent were studied and optimized. The proposed method was validated by high performance liquid chromatography technique.
Under the optimal conditions, a good linear behavior over the investigated concentration ranges (10-2000 μg/L) with good correlation of determination, R2> 0.9993, was obtained. The relative standard deviation (RSD) based on six replicate determinations at 250 μg/L level of carmoisine was 6%. The extraction percent was 90%, and the limit of detection (LOD) of the proposed approach was 2.0 μg/L.
Dispersive liquid-liquid microextraction method coupled with spectrophotometric has good accuracy (spike recoveries greater than 95%) for determining the trace amounts of carmoisine (μg/L).