Investigation of different solvents for selective, safe and rapid extraction of curcumin from various food and herbal supplement products: Multivariate strategy and assessment of green profile

Abstract

In the paper, different extraction solvents including magnetic ionic liquids (MILs), deep eutectic solvents, SUPRAS and surfactant were investigated for the fast, reliable and simple extraction of curcumin in the dispersive liquid–liquid microextraction (DLLME) method prior to UV–Vis spectrophotometric analysis. As a result of preliminary studies, the [Co(C8IM)42+]2[Cl−] MIL was selected as the extraction solvent for the extraction of curcumin from various matrix samples. Optimization of essential factors in the DLLME method was carried out with central composite design (CCD). Effective dispersion of the [Co(C8IM)42+]2[Cl−] MIL in the sample solution was achieved by orbital shaking (OS). After the CCD modelling, the OS-MIL-DLLME method provided linearity in the range of 0.5–225 ng mL−1 with a detection limit of 0.15 ng mL−1 for the model solution. The OS-MIL-DLLME method showed a matrix effect of 7.6 % with an enrichment factor of 135. Validation parameters of the OS-MIL-DLLME method such as selectivity, robustness, intraday/interday precision and recovery test were investigated in detail. The green analytical scale of the method was determined using the analytical greenness calculator tool. The OS-MIL-DLLME method was applied to the foods and herbal supplement products together with the reference method, and quantitative recoveries and statistically reliable results were obtained.