Analysis Development Method Of Curcumin, Demethoxycurcumin,Bis-demethoxycurcumin Using Liquid-liquid Microextraction And HPLC

A simple economical rapid analytical method has been developed for the simultaneous determination of curcumin, demethoxycurcumin, Bisdemethoxycurcumin, and tradition medicine samples, such as rhizome turmeric. At present, three Curcumins are widely used in medicine, cosmetic and food due to their antitumor and antioxidant activities. However, owing to the complex sample matrix components and low Curcumins concentration in rhizome turmeric or food samples, it is quite necessary to build a series of sensitive, reliable and rapid methods for the determination of the three Curcumins. In this paper, we have studied several methods based on high performance liquid chromatography to determine curcumin (Curcumin Ⅰ), demethoxycurcumin (Curcumin Ⅱ) and Bisdemethoxycurcumin (Curcumin Ⅲ). The main research contents are as follows:Part 1 CPE-HPLC for the determination of three Curcumins in rhizome turmeric samplesA cloud-point extraction (CPE) method using X 100 (TX-100), it is based on the induction of micellar organized medium by using a non-ionic surfactant. Triton X 100 (TX-100) nonionic surfactant was developed for the extraction and preconcentration of Curcumin I, Curcumin II and Curcumin Ⅲ from rhizome turmeric samples. The proper extraction condition of CPE were 1.5%(v/v) TX-100, were adopted as the optimum amount to achieve best analytical signals and extraction efficiency. It was therefore decided to carry out the extraction of three CURs at 45℃ for 30min. as these conditions provided the maximum extraction efficiency. Linear calibration curves obtained by plotting the peak area against the concentration of the respective compounds were found to be linear over the range of 1-149.4 ng mL-1 for Curcumin I, Curcumin II and Curcumin Ⅲ with recoveries 87.5% to 92.2% with a relative standard deviation (RSD) of 1.62-5.22% and the LOD was 0.02-0.08 μg mL-1. The CPE method was shown to be potentially useful for the preconcentration of the target analytes.Part 22 Vortex-assisted dispersive liquid-liquid microextraction (DLLME) combined with HPLC for the determination of three CurcuminsThe dispersive liquid-liquid microextraction (DLLME) method was adopted to extract the three Curcumins in food samples. The 700 μL of acetonitrile as the dispersant and 100 μL of 1-dedocanol as the extractant were added in the solution which was diluted to pH=7.0. A milky cloudy solution was rapidly formed after vortex mixed and the emulsion was then detached by centrifugation for 10 min at 3000 rpm. Under the optimum conditions, this method was characterized by an acceptable linear range of 1-149.4 ng mL-1 for three CURs. The detection limits(LOD) were 0.043 μg/mL for CUR 1,0.056 μg/mL for CUR II and 0.072 μg/mL for CUR III.The relative standard deviation (RSD) of the method was 1.97-4.56%(n= 5) and recoveries 88.4-93.7%. Intra-day and inter-day relative standard deviations at three different concentrations were determined. The method shortened the extraction time and improved the extraction efficiency and stability. The proposed method greatly improved the sensitivity of high performance liquid chromatography (HPLC) for the determination of three CURs. The method was successfully applied to the determination of curcumin in traditional medicine or foods.The finding show that clouding point extraction and dispersive liquid-liquid microextraction technique combined by high performance liquid chromatography are the effective and reliable methods for analyzed the curcumin, demethoxycurcumin, and bisdemethoxycurcumin.