Curcumin is small molecular weight polyphenolic compound and lipophillic in nature. This active constituent of turmeric is isolated from curcuma longa and it provides colour to turmeric. Curcumin has various medicinal properties and shows Antiinflammatory, anti-oxidant, anti-bacterial and anticancer activities. It has been observed that the chemical composition of most of the herbs changes with geographical region which may be due to climatic conditions and biochemical variations. The present work deals with phytochemical investigation of the turmeric rhizomes obtained from Bhandara District and determination of its curcumin content. Curcumin was isolated from turmeric rhizomes using reported method. The isolated curcumin was characterised by UV, FTIR and TLC methods. Calibration curve can be plotted using different concentration values of curcumin versus their respective absorbances. The regression equation obtained for the straight line was y=0.1595x-0.0229, where x is concentration and y is the absorbance. The correlation coefficient was 0.9964, indicating good linearity

https://www.omicsonline.org/open-access/phytochemical-evaluation-and-curcumin-content-determination-of-turmeric-rhizomes-2161-0444.1000588.pdf

Hi Suresh, thank you so much for taking time in helping me out.

Dear Sir. Concerning your issue about how to do calibration curve for Curcuma longa. A mixed stock solution containing reference standards was prepared by dissolving weighed accurately samples of each compound in methanol, which obtained curcumin 138.51 μg·mL−1, demethoxycurcumin 28.20 μg·mL−1, and bisdemethoxycurcumin 19.58 μg·mL−1. The calibration curves were established by further dilution with methanol gives at least six different concentrations, and the six different concentrations of mixed standard solutions were injected (10 μL) and calculated. The series of working solutions are within the ranges of 3.3242 to 13.851 μg·mL−1 for curcumin, 0.6768 to 2.82 μg·mL−1 for demethoxycurcumin, and 0.4699 to 1.958 μg·mL−1 for bisdemethoxycurcumin. I think the following below links and the attached file may help you in your analysis:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5742517/pdf/ECAM2017-2830754.pdf https://academic.oup.com/chromsci/article/53/8/1346/312947

http://nopr.niscair.res.in/bitstream/123456789/11499/1/IJTK%2010%282%29%20247-250.pdf

Thanks

Dear Sir, thank you for your respon. May I ask how to conduct preparation of standard solution for turmeric essential oil? The link above meant for turmeric powder.

Thank you..