Analytical characterization and quantification of curcumin using HPTLC and FT-IR techniques in Curcuma longa Linn.

Curcuma longa L. (turmeric) is a widely used medicinal plant known for its bioactive compound, curcumin, which exhibits various pharmacological properties, including anti-inflammatory, antioxidant, and anticancer effects. The present study aimed to develop a rapid and sensitive High-Performance Thin-Layer Chromatography (HPTLC) method for the quantification of curcumin in C. longa rhizomes cultivated in the Thanjavur region, Tamil Nadu, India. The rhizomes were collected, authenticated, shade-dried, and extracted using Soxhlet extraction with ethanol. The developed HPTLC method was validated following ICH guidelines, assessing parameters such as linearity, precision, accuracy, robustness, specificity, and sensitivity. The calibration curve exhibited a strong correlation (r² = 0.996) over the 200-800 ng/spot concentration, with curcumin detected at an Rf value of 0.56±0.01. The method demonstrated high precision, with intra-day and inter-day %RSD values below 2%. The Limit of Detection (LOD) and Limit of Quantification (LOQ) were determined to be 43.16 ng/spot and 130.80 ng/spot, respectively, indicating high sensitivity. Quantification results revealed that the curcumin content in dried C. longa rhizomes extract was 9.844% by dry weight. Fourier-transform infrared spectroscopy (FT-IR) analysis further confirmed the presence of functional groups corresponding to curcuminoids and other bioactive compounds. The validated HPTLC method provides a reliable and efficient approach for curcumin quantification in C. longa, supporting quality control and standardization of turmeric-based herbal formulations.