Reactive Extraction of Gallic Acid Using Tributyl Phosphate in Different Classes of Diluents

Abstract

Gallic acid is an important carboxylic acid used in pharmaceutical industries owing to its medicinal properties. The separation of gallic acid from fermentation broth and dilute aqueous streams is a challenging task. Therefore, in the present study the reactive extraction of gallic acid from an aqueous solution by using tributyl phosphate in octanol, ethyl acetate, n-hexane, and toluene as diluents, respectively, has been carried out at constant temperature (303 ± 1 K). The results were compared with those of the extraction using pure diluents in order to compute the intensification of extraction obtained. Experiments were performed to investigate the effect of initial acid concentration, extractant concentration, and diluent type. TBP + hexane was found to be most suitable solvent system resulting in the highest distribution coefficient (K D = 24) when TBP was employed at a concentration of 1.516 mol•kg −1 . The equilibrium complexation constant (K E ) was observed to be in the ranges of 3.18−8.8 for n-hexane, 0.91−4.54 for toluene, 2.295−4.546 for ethyl acetate, and 3.57−6.17 for octanol.

The recovery of Gallic acid with Triphenylphosphine Oxide and modelling with Artificial Intelligence

“…The initial pH of HGA was measured to be less than pK a of HGA (pK a = 4.48), showing that the maximum number of acid molecules was present in the undissociated form and could be distributed to the organic phase [27][28][29]. The physical extraction success is dependent on two main parameters; namely the distribution of undissociated acid molecule into the aqueous and organic phases and the dimerization of undissociated acid molecule in the organic phase [30,31].…”

“…Higher K E,MAL value means higher complexation. In this circumstance, solvent would have strong ability to solve the complex and the extractant would display high complexation potential with the acid [27]. K E,MAL values were found to be dissimilar to K E values.…”

“…Although according to the Mass Action Law model, activities of species are proportional to the concentrations of species, a non-ideal behavior can be observed for the equilibrium constant. The following equation gives the relationship of distribution coefficient with Mass Action Law model's equilibrium constant [27,37]: (6) where K E,MAL is the equilibrium constant of the Mass Action Law model, s is the solvation number.…”

“…HGA was adsorbed onto Na-montmorillonite [14], and a coal-based activated carbon [15]. HGA was extracted by molecular imprinted polymers [16], ethanol [17], tributyl phosphate [18,19], trioctyl amine and aliquat 336 [20,21]. All of these separation methods have their advantages and disadvantages in terms of selectivity, simplicity, performance, and cost [22,23].…”

Novel tributyl phosphate-based hydrophobic deep eutectic solvent: application in simultaneous liquid–liquid microextraction of parabens and their metabolite in surface water samples

“…28,29 Since it contains strongly polar functional -PvO groups and thus showing high nucleophilicity, TBP can be used as HBA, and the application to the extraction of phenols and carboxylic acids by TBP has been reported through complexation reaction between TBP and polar compounds. [30][31][32][33] However, this preferred extractant suffers from high viscosity and poor chromatographic behavior, as well as poor extraction capacity for weakly polar and non-polar compounds, which limit its application in analytical chemistry. [34][35][36] D,L-Menthol (M) is a kind of natural perfume which can be extracted from Mentha species.…”