Synthesis and Evaluation of a New Chelating Agent Using Tannic Acid and Palmitic Acid of Grape Seed Oil

Document Type : Original Article


1 Fats and Oils Department, Food Industries and Nutrition Research Institute, National Research Centre, 12622 Dokki, Cairo, Egypt

2 Faculty of Physical Therapy Galala University..


The objective of this research is to create an affordable chelating agent for eliminating heavy metals from polluted water. Water-soluble tannic acid was combined with a fatty residue to produce a new chelating agent that is soluble in hot water but insoluble in cold water due to the presence of a fatty residues that solidify at low temperatures. When this new chelating agent binds to heavy metals (HMs) in warm water, a soluble coordinating complex is formed. Lowering the water temperature causes the complex to become semi-solid and consequently insoluble, allowing for easy removal by scraping. Grape seeds (GS) were utilized as an affordable source of fatty residue. The grape seed was ground and dehydrated. The Grape seeds oil (GSO) was extracted, and hydrolyzed into a mixture of fatty acids and glycerol, followed by individual separation of palmitic acid (PA) using a supercritical carbon dioxide extractor. The produced PA was confirmed based on its chemical analysis, spectral data, and GC mass of its methyl ester. PA was then converted into the corresponding acid chloride, which was esterified with tannic acid to produce various derivatives of tannyl palmitate (TP). Tannyl tripalmitate (TTP) is the desired product, and it was separated according to its molecular weight using column and thin-layer chromatography, with a viscometer. The separated compound was established based on its chemical analyses and spectral data. Finally, TTP was evaluated as a new adsorbent for the removal of heavy metals from synthetic polluted water at different pH, doses, and time intervals. Results showed that TTP is a highly effective adsorbent for the removal of HMs from synthetic polluted water. Furthermore, a total organic carbon test (TOC) was conducted to verify the complete removal of the chelating agent and coordinating complex. The results showed complete removal of organic material from the synthetic polluted water after the scraping of the floating fatty layer.



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