Application of Response Surface Methodology and Dispersive Liquid-Liquid Microextraction by Microvolume Spectrophotometry Method for Rapid Determination of Curcumin in Water, Wastewater, and Food Samples

A simple and efficient determination of curcumin in water and food samples based on the combination of dispersive liquid-liquid microextraction (DLLME) and spectrophotometric estimation has been described. The effects of DLLME effective parameters [extraction solvent (CHCl3), disperser solvent (ethanol), pH, centrifugation time, and KCl concentration] were optimized via central composite design (CCD) and response surface methodology (RSM) and desirability function (DF) using STATISTICA. At optimum condition specified as 150 mu L of chloroform, 900 mu L of ethanol, pH = 4.0, and 4 min of centrifugation time in the absence of any salt, a linear calibration graph in the range of 10-2000 ng mL(-1) of curcumin with R (2) = 0.99942 (n = 6) confirms good applicability of the method for quantification of analytes over a wide range of analytes. The reasonable limit of detection (LOD) and quantification (LOQ) (0. 23 and 0.78 ng mL(-1), respectively) makes it suitable for trace analysis. Good relative standard deviation [1.16-2.3 % (n = 12)] and high enrichment factor (EF) 2182.04 are a good remark of the present method. Curcumin with relative standard deviation (RSD) less than 3 % (n = 4) and recoveries in the range 91.76-100 % can be successfully quantified in different real samples.