Isolation, Development and Validation of Chromatographic Methods for the Estimation of Linoleic Acid from Different Parts of Euphorbia neriifolia Linn.

Objectives: This is the first report on the development and validation of thin-layer chromatography (TLC) and high-performance thin-layer chromatography (HPTLC)-densitometric methods for the identification of linoleic acid (LA) in petroleum ether extract (PEE) of Euphorbia neriifolia (EN) stem (ST), latex (LX), and bark (BA). Methodology: Chromatographic analyses were performed on silica gel-G and silica gel 60 F254 plates and the antioxidant activities of isolated compounds were investigated by 2,2-diphenyl-1- picrylhydrazyl (DPPH) spectrophotometric assay. Results: The chromatographic analyses revealed better spots and well-separated peaks of LA with retention factor (Rf) values at 0.54 (ST), 0.40 (LX), and 0.64 (BA), respectively. The linearity of the calibration curve ranges from 10-50 ng/spot (ST), 10-100 ng/spot (LX), and 50-200 ng/spot (BA). The proposed method was characterized by better accuracy, better robustness, and good precision, ranging from 0.173 to 0.372% (intra-day) and 0.185 to 0.205% (inter-day). The value of the limit of detection and quantification equal to 1.04 and 3.16 ng/spot in ST, 0.87 and 2.64 ng/spot in LX, and 0.177 and 0.53 ng/spot in BA determined the sensitivity of the method. In the obtained chromatogram, no peak was observed other than the LA which determined the specificity of the method. The % RSD of < 2% after periods of 12, 24, 36, 48, and 72 h determined the stability of standard LA. Conclusion: Thus, the fingerprinting method is valuable in determining the adulterants and in routine quality control of formulations and herbal drugs.