Selective separation and determination strategy for monitoring E100, E127, E129 and E133 in foodstuffs: Vortex assisted sequential-simultaneous liquid phase micro-extraction

A green, speedy and handy, vortex assisted sequential-simultaneous liquid phase micro-extraction procedure (VA-SS-LPME) was established first time without using any instrumental chromatographic techniques for sepa-ration, preconcentration and spectrophotometric determination of four important popularly and widely used food colorants, namely curcumin (E100), erythrosine (E127), allura red (E129) and brilliant blue (E133). Here, n-nonanol and n-nonanol based deep eutectic solvent were used as extraction solvents. The procedure has included two simultaneous and sequential separation steps by different extractants and two simultaneous UV-vis spectrophotometric determination steps. First, simultaneous separation of E100 and E127 from aqueous solution containing E129 and E133 was achieved and then simultaneous separation of E129 and E133 from aqueous solutions was applied and simultaneous spectrophotometric determinations were performed finally for binary mixture dyes (E100 and E127) and (E129 and E133). The parameters including pH, types and amounts of extractants, vortex time and rate, centrifugation time and rate were investigated in detail for sequential two steps separation and quantitative simultaneous extraction of the dyes. Interference effect of matrix ions, target and other dyes were examined. Possible envisaged extraction mechanisms were elucidated. Green analytical pro-cedure index (GAPI) and analytical eco-scale (AES) parameters of the procedure were determined. As last, E100, E127, E129 and E133 contents of some foodstuffs and pharmaceuticals such as confectioneries, beverages, drugs and syrups were determined by applying optimized procedure. Colourful food additive concentrations of real samples were determined between 2.9 and 93.8 mu g/g and 5.3-112.4 mu g/mL for solid and liquid samples, respectively.

Automated summary

A green, speedy, and handy method for separation and determination of four commonly used food colorants was established using vortex assisted sequential-simultaneous liquid phase micro-extraction (VA-SS-LPME). The method does not require any instrumental chromatographic techniques. The procedure includes sequential separation steps using different extractants and simultaneous UV-vis spectrophotometric determination steps. The method is environmentally friendly and applicable for determination of colorants in food and pharmaceuticals.