Open AccessThe influence of pH and solvent polarity on the mechanism and efficiency of folic acid extraction with Amberlite LA-2
Author(s) -
AncaIrina Galaction,
Alexandra Cristina Blaga,
Dan Caşcaval
Publication year - 2005
Publication title -
chemical industry and chemical engineering quarterly
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.189
H-Index - 26
eISSN - 2217-7434
pISSN - 1451-9372
DOI - 10.2298/ciceq0502063g
Subject(s) - chemistry , amberlite , dichloromethane , extraction (chemistry) , chloroform , aqueous solution , solvent , heptane , chromatography , partition coefficient , aqueous two phase system , inorganic chemistry , organic chemistry , adsorption
Studies on the reactive extraction of folic acid with Amberlite LA-2 in three solvents of different polarity (n-heptane, chloroform, dichloromethane), at various extractant concentrations and pH-values of the aqueous solutions, indicated that the pH-value controls the extraction mechanism through the dissociation of carboxylic groups of folic acid. Thus, the solute and the extractant participate at the interfacial reaction at a molar ratio of 1:2 for pH below pK1, and 1:1 for pK1 < pH < pK2. The solvent polarity and pH-value exhibit a significant effect both on the extraction degree of folic acid (for an Amberlite LA-2 concentration of 80 g/l the extraction degree in dichloromethane was about 2-2.7 times greater than that corresponding to extraction in n-heptane, this difference increased with increasing pH of the aqueous solution) and on the extraction constant (by increasing the pH-value from 3 to 5.2, the extraction constants obtained for dichloromethane increased about 2.7 to 27.1 times compared with those obtained for extraction in n-heptane).