Alginic acid exchange

When treated with 5% sulfuric acid for 1.5 hours at 150°, pectin and D-galacturonic acid give reductic acid in yields of approximately 10% it is also formed on treatment of alginic acid with acid.96,119 The original preparation from pectin has been improved by using ion-exchange techniques,110 and synthetic preparations have been developed.188... 

The organoleptic characteristics, level of impurities, exchange capacities, pRa/ pH, affinity for inorganic ions, intrinsic viscosities, molecular weights, buffer capacity in artificial gastric fluids and other properties of 3 different types of alginic acids used in antacid preparations are discussed."... 

Since only the sodium and potassium salts of alginic acid are soluble in water, the first aim of the extraction process is to convert the insoluble calcium and magnesium salts into sodium alginate. If the seaweed is treated with alkali, then the process necessary for extraction is an ion exchange ... 

Alginic acid is found in brown algae, where it acts as an ion exchange agent in the cell walls. It is obtained as alginate in England, France, Norway, Japan, Southern California, and Australia by extracting the cell walls with soda solution. 

Takahashi T., Ishiwatari Y., Shirai H., Ion exchange of alginic acid. IV. Selective ion exchange behavior of alginate in mixed solutions of metal ions, Kogyo Kagaku Zasshi, 66(10), 1963, 1458-1461. 

Cellulose/alginic acid ion-exchange membrane have been prepared by coagulating a blend of cellulose cuoxam and alginate solution and used for the adsorption of Cd + and Sr + ions (Zhang etal, 1999). 

Zhang, L., Zhou, J., Zhou, D. Tang, Y. (1999) Adsorption of cadmium and strontium on cellulose/alginic acid ion-exchange membrane. Journal of Membrane Science, 162, 103-109. 

If these beads of alginic acid and the metallic ion are embedded in the body, the metallic ion that forms the complex might exchange with monovalent sodium ions and dissolve. The multivalent ions also have cell toxicity. Hence, microcapsules must be created with a polyion complex of alginic acid [3,4] and not a multivalent one. 

The determination of strychnine in nux vomica and its preparations may be carried out by solvent extraction and ion exchange isolation of the alkaloids followed by a 2-point spectrophotometric method. Oxy-cellulose can be used or, preferably, treated alginic. acid which can replace it in all cases, is more stable and less difficult to prepare. 

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