SL number Carboxylic acid Extractant Diluent Parameters studied Findings References 1 Different carboxylic acids Organophosphorous and aliphatic amines Alcohols, ketones, ethers, and hydrocarbons Various aqueous and organic phase parameters Reviewed the extraction chemistry of carboxylic acids [3 ] 2 Lactic acid TOA Hexane Type of acid and initial acid concentration Hydrophobicity of the acid controls equilibrium constants [20 ] 3 Acetic, lactic, succinic, malonic, fumaric, and maleic Tri-alkyl amine (Alamine 336) Methyl isobutyl ketone (MIBK), n-heptane, dichloromethane (DCM), and nitrobenzene Effects of diluent-complex interactions Equilibrium constants, partition coefficient and dimerization constant determined [13 ] 4 Citric Alamine 336 Effect of diluents [12 ] 6 Lactic TOA Xylene Temperature, acid and TOA concentration (1 : 1), (1 : 2), and (3 : 1) acid-TOA complexes formed [21 ] 7 (L+) lactic Tri-propyl amine (TPA) and TOA 1-octanol and heptane Acid and amine concentration Mixed tertiary amine of short and long chain can facilitate easy phase separation [22 ] 8 Citric, lactic, and malic Tri-iso-octyl amine (TIOA) 1-octanol and heptane Effect of modifier and type of acid Extraction mechanism is proposed considering physical and chemical extraction [23 ] 9 Glyoxylic, glycolic, acrylic, and benzoic Tri-alkyl phosphine oxide (TRPO) Kerosene Aqueous and organic phase compositions Equilibrium model for [24 ] 10 Propionic Aliquat 336 Cyclohexane, hexane, toluene, MIBK, ethyl acetate, hexane + MIBK, hexane + toluene, and MIBK + toluene Effect of diluent and diluent mixture, acid and amine concentration Order of extraction: ethyl acetate > MIBK > MIBK + toluene > toluene > hexane + MIBK > toluene + hexane > cyclohexane > hexane [25 ] 11 Propionic Tri- 1-Octanol Acid and extractant concentration Order of extractibility is found to be TOA > Aliquat 336 > TBP, 1 : 1 complex formed [26 ] 12 Itaconic, maleic, malic, oxalic, tartaric, and succinic TBP Do-decane pH and initial acid concentration Mechanism of di-carboxylic acids is proposed [27 ] 13 Nicotinic TOPO and TBP Benzene, heptane, kerosene, 1-octanol, MIBK, diethyl ether, decane, kerosene + 1-octanol, and heptane + 1-octanol Effect of diluent, extractant type, initial acid, and extractant concentration Solvation number and equilibrium extraction constants are determined [28 ] 14 Levulinic Dimethyl phthalate, dimethyl adipate, dimethyl succinate, dimethyl glutarate, diethyl carbonate, isoamyl alcohol, 1-hexanol, 1-octanol, 1-nonanol, 1-decanol, diisobutyl ketone (DIBK), and MIBK Diluent effect, and amine concentration LSER model proposed and [29 ] 15 Formic Amberlite LA-2 Dimethyl phthalate, dimethyl adipate, dimethyl succinate, dimethyl glutarate, diethyl carbonate, isoamyl alcohol, 1-hexanol, 1-octanol, 1-nonanol, 1-decanol, DIBK, and MIBK Effect of diluent and amine concentration Extraction constants ( [30 ] 16 Nicotinic Organophosphorous and aliphatic amines Alcohols, ketones, ethers, and hydrocarbons Various aqueous and organic phase parameters Reviewed the extraction chemistry of nicotinic acid [31 ] 17 Glycolic Amberlite LA-2 1-Octanol, cyclohexane, iso-octane, toluene, 2-octanone, and MIBK Solvent type, amine and acid concentration Order of extraction: MIBK > 2-octanone > 1-octanol > toluene > iso-octane > cyclohexane [32 ] 18 Citric Tri-dodecylamine (TDDA) and Amberlite LA-2 MIBK, 1-octanol, toluene, cyclohexane, 1-octanol + toluene, 1-octanol + MIBK, MIBK + toluene, 1-octanol + toluene, 1-octanol + MIBK, MIBK + toluene, and iso-octane Diluent effect, amine and acid concentration 1-Octanol proposed to be most effective solvent [33 ] 19 Glutaric TOA Isoamyl alcohol, 1-octanol, 1-nonanol, 1-decanol, methyl ethyl ketone (MEK), diisobutyl Diluent effect, amine and acid concentration Kerosene is found to be the most effective diluent. Equilibrium constants for 1 : 1 and 2 : 1 complex are estimated. [34 ] 20 Lactic TBP Dodecane Acid and solvent composition, change in the phase volumes and pH Apparent equilibrium constants and the number of reacting extractant molecules [35 ] 21 Acrylic Amberlite LA-2 Cyclohexane, 2-octanone, toluene, MIBK, iso-octane, hexane, and 1-octanol Type of diluent, and amine concentration 1 : 1 & 1 : 2 acid-amine complexes for proton-donating diluents and 1 : 1 & 2 : 3 for non-proton-donating diluents, overall extraction constants ( [36 ] 22 Formic TDDA and TBP Ethyl valerate, diethyl adipate, diethyl sebacate, 1-octanol, and heptane Effect of diluent, acid and amine concentration Comparative study of physical and chemical extraction, TDDA suggested to be the best extractant [37 ] 23 Penicillin G Di- n-Butyl acetate, MIBK, 2-ethyl hexanol, kerosene, and heptane Initial acid concentration, pH and temperature Effect of extractant on the stability of penicillin G mainly depends on temperature, degradation of penicillin G in alkali solution is governed by pH, mechanism of degradation discussed [38 ] 24 Succinic Amberlite LA-2 Hexane, cyclohexane, toluene, iso-octane, MIBK, 2-octanone, and 1-octanol Initial extractant concentration Extraction constants (1 : 1, 1 : 2 & 2 : 3) found out, order of extraction of diluents: 1-octanol > 2-octanone > MIBK > toluene > iso-octane > hexane > cyclohexane [39 ] 25 Itaconic TBP and Aliquat 336 Sunflower oil Initial acid and extractant concentration Non toxic system proposed [40 ] 26 Propionic TBP Kerosene and 1-decanol Aqueous and organic phase compositions, and temperature Modifier has a strong effect on degree of extraction [41 ] 27 L (+) Tartaric Amberlite LA-2 1-octanol, cyclohexane, isooctane, hexane, and MIBK Organic phase compositions Extractability of acid is high especially with polar solvents (MIBK and 1-octanol) [42 ] 28 Caproic TBP MIBK and xylene Phase compositions MIBK is a better solvent than xylene [43 ] 29 Acetic TOA DCM, butyl acetate, heptanes, and 1-octanol Organic phase compositions and pH The solvent polarity controls the formed structure of the interfacial acid and TOA compounds [44 ] 30 Picolinic TBP Sunflower and castor oil Aqueous and organic phase compositions Different models are used to represent the equilibrium data [45 ] 31 Picolinic Trialkylamine (N235), TBP Tetrachloromethane, kerosene, and 1-octanol Aqueous and organic phase compositions, and pH Distribution coefficient highly dependent on pH and the apparent alkalinity of N235/1-octanol [46 ] 32 Acetic, propionic, butyric and valeric TBP Cyclohexane, sulfonated kerosene, and 1-octanol Equilibrium time, temperature and phase ratio Conditions of extraction and stripping are found [47 ] 33 Citric TOA Rice bran oil, sunflower oil, soybean oil, and sesame oil Aqueous and organic and phase compositions Overall extraction constants and association numbers [48 ]
