Intensification of Pyridine-3-carboxylic Acid Extraction Using N-Methyl

Article pubs.acs.org/jced

Intensification of Pyridine-3-carboxylic Acid Extraction Using N‑Methyl-N,N-dioctyloctan-1-ammonium Chloride in Different Type of Diluents Seyhan Günyeli,† Hasan Uslu,*,‡ and Ş. Iṡ mail Kırbaşlar† Engineering Faculty, Chemical Engineering Department, Iṡ tanbul University, 34320, Avcılar, Iṡ tanbul, Turkey Engineering & Architecture Faculty, Chemical Engineering Department, Beykent University, Ayazağa, Iṡ tanbul, Turkey

† ‡

ABSTRACT: The extraction of pyridine-3-carboxylic acid was investigated using N-methyl-N,N-dioctyloctan-1-ammonium chloride (TOMAC) with different diluents having distinct functional groups. Nine diluents were used in the study, i.e., octan-1-ol, nonan-1-ol, decan-1-ol, ethyl ethanoate, propyl ethanoate, heptan-2-one, octan-2one, octane, and decane. The measurements were performed at room temperature (T = 298 K). The experimental results of batch extractions were used to calculate distribution coefficients (KD), loading factors (Z), and extraction efficiency (E). The maximum distribution coefficient (KD = 2.335) was obtained with octan-1-ol, and its extraction efficiency was 70.16 %. Besides, the highest loading factor was reached to a value of (0.179 at 0.440) mol·kg−1 equilibrium amine concentration. The results of the liquid−liquid equilibrium measurements were correlated by a linear solvation energy relationship (LSER) model which takes into account physical interactions. Experimental and model results of pyridine-3-carboxylic acid extraction from aqueous solution was compared. LSER model has been applied to experimental results with 0.98 R square.

1. INTRODUCTION Pyridine carboxylic acids and their derivatives are used in many natural products.1 Especially, it is extensively used in the pharmaceutical industry. It is also as well-known that nicotinic acid or niacin or vitamin B 3 (C6H 5NO2) is a white semitransparent crystalline solid with a carboxyl side chain at the 3-position.1 Therefore, it is important to purification of nicotinic acid. Although, there are many separation methods for carboxylic acids the reactive extraction is the most promising method. Reactive extraction describes the reactions between extractants and extract. Hydrocarbon, phosphorus, and aliphatic amines are used as extractants. The bigger reactor yield, use of a betterconcentration substrate as the process feed to decrease process wastes and fabrication costs, and ease in pH control without requiring base addition are many of the advantages of reactive extraction.1,2 There are limited studies in the literature about reactive extraction of pyridine-3-carboxylic acid. Waghmare et al.1 studied reactive extraction of pyridine carboxylic acids by TBP in soybean oil as natural nontoxic diluent. Relative basicity, Langmuir, and mass action law models were tested to represent extraction equilibria for pyridine-tri-n-butyl phosphate−diluents ternary systems. Kumar and Datta3 investigated extraction of 3pyridine carboxylic acid by trioctyl amine in 4-methylpentan-2one diluent from aqueous solutions in respect to both equilibrium and kinetic for design of an extraction process. In equilibrium study, the chemical equilibrium of acid and amine © XXXX American Chemical Society

was interpreted as a result of the formation of both 1:1 and 2:1 complexes. In kinetic study, the reaction was found to be a very slow chemical reaction occurring in the bulk of the organic phase according to Hatta number. Li et al.4 reported data about pyridine-3-carboxylic acid extraction by trialkyamine in octan-1ol. It was found that N235/n-octanol was an efficient extractant for extracting 3-pyridine carboxylic acid. They also studied effect of pH to this extraction. The constructive operation situation was found for equilibrium aqueous pH values as 4.2 to 5.5. Li et al.5 examined effect of solvents on the extraction of iso nicotinic acid by Alamine 336. Alamine 336 was dissolved in 1octanol, tetrachloromethane, and kerosene. The polar diluent (octan-1-ol) is favorable for extracting iso nicotinic acid when Alamine 336 is used as extractant. They reported that distribution coefficient increases with the increasing Alamine 336 concentration. Kumar et al.6 focused to increase the recovery of 3-pyridine carboxylic acid by method of reactive extraction using phosphorus based extractants tri-n-octyl phosphine oxide (TOPO) and tri-n-butyl phosphate (TBP). The partition of pyridine-3-carboxylic acid between aqueous phase and organic phase and the comparison of extraction degree with pure diluents was investigated. The highest efficeincy of pyridine-3-carboxylic acid extraction was obtained by dissolving TOPO in 4-methylpentan-2-one. Received: March 25, 2014 Accepted: June 27, 2014

A

dx.doi.org/10.1021/je500280j | J. Chem. Eng. Data XXXX, XXX, XXX−XXX

Journal of Chemical & Engineering Data

Article

Table 1. Results for Extraction of Pyridine-3-carboxylic Acid with TOA + Alcohol System at T = 298 Ka solvents (alcohols)

pHaq

C̅ ER4NCl/mol·kg−1

CHA/mol·kg−1

KD

100 E

Z

ZM

KE

octan-1-ol

3.12 3.16 3.22 3.33 3.48 3.07 3.13 3.20 3.30 3.37 3.01 3.11 3.17 3.23 3.29

0.440 0.871 1.310 1.751 2.210 0.440 0.871 1.310 1.751 2.210 0.440 0.871 1.310 1.751 2.210

0.043 0.042 0.040 0.039 0.036 0.043 0.043 0.041 0.040 0.038 0.050 0.049 0.047 0.047 0.042

1.85 1.92 2.02 2.14 2.35 1.82 1.86 1.99 2.07 2.18 1.43 1.48 1.58 1.61 1.88

64.88 65.71 66.92 68.18 70.16 64.52 65.09 66.57 67.45 68.52 58.79 59.61 61.17 61.68 65.32

0.179 0.093 0.062 0.048 0.039 0.179 0.091 0.062 0.047 0.038 0.163 0.085 0.057 0.043 0.036

0.163 0.083 0.069 0.044 0.036 0.169 0.095 0.066 0.049 0.043 0.167 0.083 0.061 0.044 0.041

4.122 2.159 1.545 1.200 1.068 4.122 2.082 1.489 1.156 0.988 4.122 2.159 1.545 1.200 1.068

nonan-1-ol

decan-1-ol

a

pHaq is the pH value of aqueous phase, C̅ ER4NCl is the equilibrium concentration of amine in the organic phase, CHA is the concentration in the aqueous phase after extraction, KD is the distribution coefficient, Z is the loading factor, E is the extraction efficiency, KE is the equilibrium extraction constant. The uncertainty for the ph measurements was 1 %.

Table 2. Results for Extraction of Pyridine-3-carboxylic Acid with TOMAC + Ketone System at T = 298 Ka solvents (ketones)

pHaq

C̅ RE 4NCl/mol·kg−1

CHA/mol·kg−1

KD

100E

Z

KE

heptan-2-one

3.01 3.05 3.09 3.11 3.16 2.98 3.01 3.03 3.08 3.10

0.440 0.871 1.310 1.751 2.210 0.440 0.871 1.310 1.751 2.210

0.053 0.046 0.044 0.042 0.041 0.055 0.045 0.044 0.044 0.044

1.29 1.64 1.77 1.91 2.00 1.23 1.70 1.77 1.78 1.79

56.34 62.14 63.89 65.63 66.63 55.17 62.96 63.91 64.05 64.18

0.159 0.087 0.059 0.046 0.037 0.153 0.088 0.059 0.045 0.036

2.915 1.871 1.335 1.074 0.882 2.727 1.939 1.335 0.999 0.791

octan-2-one

a


2.2. Experimental Procedure. Experimental procedure was done according to Günyeli et al.’s procedure.7 “Initial concentrations of acid of 0.121 mol·kg−1 (approximately 8 % in weight) were prepared with distilled water. Different ratios of TOMAC to diluent were mixed for preparing organic solution between (0.440 and 2.210) mol·kg−1. Equal volumes (20 mL) of both phases were added to 100 mL Erlenmeyer flasks. Erlenmeyer flasks were shaken in thermostat shaker for 2 h. Then, samples were kept for 3 h equilibration to separate phases. The concentration of pyridine-3-carboxylic acid was determined by titration method. Sodium hydroxide (relative uncertainty: ± 1 % in mass) as a standard solution was used to analyze the concentration of pyridine-3-carboxylic acid by using phenolphthalein as an indicator. Each measurement was carried out in duplicate. In most cases, the deviation between the amount of acid analyzed and the amount of acid known did not exceed ± 3 %. The pH value of the aqueous phase was measured by pH meter (Mettler Toledo pH meter Model S40). The uncertainty for the ph measurements was 1 %. Volume changes in both phase were neglected.7

A literature survey shows that there is no available data about pyridine-3-carbocxylic acid reactive extraction by TOMAC. In this study, the reactive extraction of pyridine-3-carboxylic acid from aqueous media was studied by TOMAC in two different acetates (ethyl ethanoate, and propyl ethanoate), three different alcohols (octan-1-ol, nonan-1-ol and decan-1-ol), two different ketones (heptan-2-one and octan-2-one), and two different alkanes (octane, decane). This study is also complementary study for above-mentioned studies.

2. MATERIALS AND EXPERIMENTAL PROCEDURE 2.1. Materials. TOMAC, ((Sigma (CAS: 63393-96-4)) > 99 % in mass), is an anion exchange extractant and liquid with a molecular weight of 374.10. Pyridine-3-carboxylic acid (Sigma (CAS: 59-67-6) > 98 % in mass, molecular weight:123.11 g· mol−1, pKa:4.85). Alcohols (octan-1-ol (CAS: 111-87-5), nonan-1-ol (CAS: 143-08-8), decan-1-ol (CAS: 112-30-1)), alkanes (octane (CAS: 111-65-9), decane (CAS: 124-18-5), acetates (ethyl ethanoate (CAS: 141-78-6) and propyl ethanoate (CAS: 109-60-4)) and ketones (heptan-2-one (CAS: 110-43-0) and octan-2-one(111-13-7), have been supplied from Aldrich and Fluka. Purities of other chemicals used in this study are upper 98% in mass. B



Article

Table 3. Results for Extraction of Pyridine-3-carboxylic Acid with TOMAC + Ester System at T = 298 Ka solvents (esters)

pHaq

C̅ RE 4NCl/mol·kg−1

CHA/mol·kg−1

KD

100E

Z

KE

ethyl ethanoate

3.00 3.03 3.06 3.09 3.14 2.99 3.02 3.03 3.09 3.12

0.440 0.871 1.310 1.751 2.210 0.440 0.871 1.310 1.751 2.210

0.055 0.049 0.047 0.044 0.042 0.056 0.049 0.047 0.045 0.043

1.21 1.50 1.62 1.77 1.88 1.18 1.50 1.60 1.69 1.81

54.75 60.06 61.77 63.87 65.32 54.09 59.99 61.57 62.84 64.36

0.152 0.084 0.057 0.044 0.036 0.150 0.084 0.057 0.044 0.036

2.727 1.687 1.201 0.999 0.851 2.637 1.687 1.201 0.964 0.820

propyl ethanoate

a


Table 4. Results for Extraction of Pyridine-3-carboxylic Acid with TOMAC + Alkane System at T = 298 Ka solvents (alkanes)

pHaq

C̅ ER4NCl/mol·kg−1

CHA/mol·kg−1

KD

100E

Z

KE

octane

2.78 2.84 2.89 2.95 3.03 2.76 2.88 2.91 2.97 3.02

0.440 0.871 1.310 1.751 2.210 0.440 0.871 1.310 1.751 2.210

0.054 0.054 0.052 0.049 0.045 0.055 0.052 0.051 0.047 0.046

1.25 1.27 1.33 1.49 1.69 1.21 1.34 1.40 1.60 1.66

55.53 56.03 57.13 59.82 62.84 54.70 57.18 58.35 61.55 62.36

0.154 0.078 0.053 0.042 0.035 0.151 0.080 0.054 0.043 0.035

2.819 1.424 1.012 0.839 0.764 2.727 1.523 1.047 0.899 0.737

decane

a


3. RESULTS AND DISCUSSION 3.1. Distribution Coefficient. TOMAC was chosen as an extractant for testing extractant efficiency of pyridine-3carboxylic acid from aqueous phase. Both the dissociated and undissociated forms of acids can be extracted by TOMAC.7,8 Distribution coefficient of pyridine-3-carboxylate ions KD(A−) for pyridine-3-carboxylic acid (HA) extraction by TOMAC (R4N+Cl−) can be defined as KD(A)‐ =

Tables 1 to 4. The TOMAC concentrations in various solvents were varied from (0.440 to 2.210) mol·kg−1. Initial concentration of pyridine-3-carboxylic acid in the aqueous phase was 0.121 mol·kg−1. It was observed that the extraction efficiency of (TOMAC + diluents) mixtures changed with increasing TOMAC initial concentration in the organic phase. Following orders for the distribution coefficients of pyridine-3-carboxylic acid extracted with TOMAC were found (Table 1 to 4): in alcohols: octan‐1‐ol > nonan‐1‐ol > decan‐1‐ol

C̅ R 4N+Cl‐:A‐ C HA + C A‐

in ketones: heptan‐2‐one > octan‐2‐one

(1)

in acetates: ethyl ethanoate > propyl ethanoate

In eq 1, C and over bar ( ̅ ) indicate concentration and organic phase, respectively. For extraction of the undissociated molecules, distribution coefficient of undissociated acid KD(HA) can be written as KD(HA) =

in alkane:

Polarity of solvent is also an important parameter for the extraction. Polarity is a function of ET which is called transition energy. Kosower9 expressed polarity parameter (ET) as the molar transition energy, for the CT absorption band of 1-ethyl4-(methoxycarbonyl) pyridinium iodide in the suitable solvent. A high ET value corresponds to the higher solvent polarity. Dimroth and Reichardt10,11 have explained a term ET(30) as a solvent polarity parameter. This parameter was derived from the transition energy for the highest-wavelength solvatochromic absorption band of the pyridinium N-phenolate betaine dye. Due to this unusually large dislocation of the solvatochromic absorption band, the ET(30) values gives an admirable and very sensitive polarity characterization of solvents. If it gives high ET(30) values this relates a high solvent polarity”.7

C̅ R 4N+Cl‐:HA C HA + C A‐

(2)

The overall distribution coefficient (KD) can be represented as KD = KD(A)‐ + KD(HA)

octane > decane

(3)

The pyridine-3-carboxylic acid extraction by TOMAC dissolved in esters (ethyl ethanoate, and propyl ethanoate) alcohols (octan-1-ol, nonan-1-ol, decan-1-ol), alkanes (octane, decane), and ketones (heptan-2-one and octan-2-one) has been studied. The results of the equilibrium data on reactive extraction of pyridine-3-carboxylic acid were tabulated in C



Article

3.3. Extraction Efficiency. The ratio of pyridine-3carboxylic acid concentration in organic phase to the initial acid concentration in aqueous phase is called as extraction efficiency (E %) and defined as K × 100 E% = D 1 + KD (8)

The equilibrium data about the distribution of pyridine-3carboxylic acid for ketones used in this study have been presented in Table 2. If the results are investigated in regards of solvents polarities used in this study, the extraction efficiency of TOMAC is shown to be more effective with heptan-2-one than with octan-2-one. In comparison of their polarities, heptan-2one has 11.9 polarity but octan-2-one has 10.3 polarity. The decane, octane, propyl ethanoate, and ethyl ethanoate has 2, 1.96, 6.3, and 6 polarities, respectively. 3.2. Loading Factor and Complexation Constant. At low pH, undissociated molecules were extracted more than dissociated molecules for acids having one carboxylic group.12 Undissociated molecules of carboxylic acids increase At the high pH values. Therefore, pH is the most efficient factor for undissociated acid concentration. The extraction of the undissociated molecules for pyridine-3-carboxylic acid by chemical interaction can be represented as13 R 4NCl + HA ↔ R 4NCl: HA

The highest extraction efficiency of pyridine-3-carboxylic acid has been found as 70.16% with octan-1-ol at 2.210 mol·dm−3 initial TOMAC concentration. The acid concentration in the aqueous phase has been decreased from 0.056 mol·kg−1 to 0.036 mol·kg−1 when the concentration of TOMAC was increased from 0.440 mol·kg−1 to 2.210 mol·kg−1. It could be clearly seen from Tables 1 to 4 and Figure 1 that the increases

(4)

with combining the extraction constant (KE) KD(HA) (1 − α)

= KEC̅ RE4NCl

(5)

In eqs 4 and 5, overbar ()̅ indicates organic phase, is the equilibrium amine concentration in the organic phase, C̅ HA is concentration of the pyridine-3-carboxylic acid in the organic phase, C̅ ER4NCl:HA is concentration of the acid-amine complex in the organic phase, KE and Ka are the extraction constant and dissociation constant related carboxylic acid, respectively. α = Ka/(Ka + [H+]) represents the part of dissociated form of acid. The distribution coefficient and equilibrium extraction coefficients of the undissociated molecules can be determined in the case of α = 0, and eq 5 can be linearized C̅ RE 4NCl

log K D = log K E + log C̅ RE4NCl

Figure 1. Plot of extraction efficiencies, E, against the concentration of amine. ●, Ethyl ethanoate; ■, heptan-2-one; ▲, octane; and ⧫, octan1-ol.

in amine concentration cause a slow increase in the extraction efficiency. The highest extraction efficiency of the pyridine-3carboxylic acid 70.16 %, 66.63 %, 65.32 %, and 62.84 % has been achieved in the near of 2.210 mol·kg−1 of TOMAC concentration in use of octan-1-ol, heptan-2-one, ethyl ethanoate, and octane, respectively. This depth according to molecular size describes the “cavity” employed by a solvent particle in the liquid solvent. At the same time, this can be expressed as the mean gap among the centers of mass of two neighboring molecules in the fluid. As the molecular diameter of solvent raises, solvation powers of the solvents reduce.17 3.3.1. LSER Model Equation. Kamlet et al.18 originally presented The linear solvation energy relationship (LSER). Several kind of chemical properties (selected as XYZ) for example aqueous solubility, octan-1-ol-water separation coefficient,19 HPLC capability issues utilizing many mobiles and immobile phases,20 and toxicity to a diversity of species,21 depended on solute−solvent relations. The model could be explained by an equation including three simple terms:

(6)

The plot of log KD against logC̅ ER4NCl gives a straight line by the intercept log KE, from which the equilibrium complex constant can be find. C̅ ER4NCl is the amine concentration at equilibrium in the organic media. Equation 7 allows us to find KE by using loading factors (Z) Z = KEC HA (1 − Z)

(7)

The results of loading factors for pyridine-3-carboxylic extraction acid using TOMAC has been presented in Tables 1 to 4. It has been clearly observed that Z values increases with decreasing concentration of TOMAC. Overloading is defined as greater than unity. This explains that acid amine complexes with more than one acid per amine were formed. Overloading has not been determined at the any amine concentrations used in this study. This situation shows that tthe complex which contains only one amine and one acid molecule was formed. The KE values for each concentration of amine were tabulated in Tables 1 to 4. The consequential acid-amine complexes are supposed to become constant due to the hydrogen bonding with solvents.8,14 The first acid relates openly with the amine to form an ion pair, and the hydroxyl group of the another acid molecule carboxyl connect a hydrogen bond by the conjugated CO of the carboxy group of the first acid to form an acid− amine complex.15,16

XYZ(property) = cavity term + dipolar term + hydrogen − bonding terms

(9)

This equation can be transformed for predictive equation: ln Z = ln Z D0 + s(π * + dδ) + bβ + aα

(10)

In eq 10, the dipolar−polarizability term, π*, corresponds to the exoergic property of solute−solvent dipole−dipole and D



■

dipole−induced dipole relations and π* is a determine of the molecule’s skill to stabilize a nearest charge or dipole throughout distracted dielectric relations. The hydrogenbonding terms β and α stand for the exoergic property of hydrogen bonding concerning the solvent as hydrogen bond donor acid and the solute as hydrogen bond acceptor base, and the solute as hydrogen bond donor acid and the solvent as hydrogen bond acceptor base, respectively. s, a, and b are coefficients obtained from regression. The loading factors could be regressed with the solvatochromic parameters of the solvents which was presented in Table 5.18−22 The regressions were

*E-mail:[email protected]. Funding

This work was supported by the Research Fund of Istanbul University Project No. 16710. Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS This work is a part of master thesis entitled “Reactive Extraction of Some Organic Acid” which is pursued by Institute of Science of Istanbul University.

■

Kamlet solvatochromic parameters π*

δ

β

α

octan-1-ol nonan-1-ol decan-1-ol

0.40 0.40 0.40

0 0 0

0.81 0.81 0.81

0.77 0.74 0.72

π* is the dipole−dipole interaction; δ is the dipole−induced dipole interaction; The β term is of solvent HBA (hydrogen-bond acceptor) basicities. The α term is of solvent HBD (hydrogen-bond donor) acidities.

done with eq 10 and obtained results were tabulated in eq 11. SPSS v14.023 regressed the loading factor values and obtained LSER parameters were presented in eq 11: ln Z = (0.012) + (− 0.115)(π * − 0.δ) + 0.105β (11)

LSER model results for loading factors were presented in Table 1 as ZM. The root-mean-square deviation (RMSD) method were used to calculate deviations for experimental and prediction data (eq 12) RMSD =

1 N

n

∑ (Z − Z Ml) i=1

REFERENCES

(1) Waghmare, M. D.; Wasewar, K. L.; Sonawane, S. S.; Shende, D. Z. Reactive extraction of picolinic and nicotinic acid by natural nontoxic solvent. Sep. Purif. Technol. 2013, 120, 296−303. (2) Kumar, S.; Babu, B. V. Process Intensification of Nicotinic Acid Production via Enzymatic Conversion using Reactive Extraction. Chem. Biochem. Eng. 2009, 23, 367−376. (3) Datta, D.; Kumar, S. Extraction of Pyridine-3-carboxylic Acid Using 1-Dioctylphosphoryloctane (TOPO) with Different Diluents: Equilibrium Studies. Ind. Eng. Chem. Res. 2013, 52, 14680−14686. (4) Li, D.; Yu, F.; Chang, Z. Reactive Extraction of Nicotinic Acid with Trialkylamine in n-Octanol. Chin. J. Chem. Eng. 2012, 20, 843− 848. (5) Li, D.; Cui, J.; Chang, Z.; Yu, P.; Zhang, Z. Reactive Extraction of iso-Nicotinic Acid with Trialkylamine in Different Diluents. J. Chem. Eng. Data 2009, 54, 795−800. (6) Kumar, S.; Wasewar, K. L.; Babu, B. V. Intensification of Nicotinic Acid Separation using Organophosphorous Solvating Extractants by Reactive Extraction. Chem. Eng. Technol. 2008, 31, 1584−1590. (7) Günyeli, S.; Uslu, H.; Kırbaşlar, Ş. I.̇ Effect of Solvent on Reactive Extraction of 2-Methylidenebutanedioic Acid by Using N-MethylN,N-dioctyloctan-1-ammonium Chloride. J. Chem. Eng. Data 2014, 59, 461−465. (8) Yang, S. T.; White, S. A.; Hsu, S. T. Extraction of Carboxylic Acids with Tertiary and Quaternary Amines. Effect of pH. Ind. Eng. Chem. Res. 1991, 30, 1335−1342. (9) Kosower, E. M. An Introduction to Physical Organic Chemistry; Wiley: New York, 1968. (10) Reichardt, C. Solvent and solvent effect in organic chemistry. Wiley: New York, 2004. (11) Dimroth, K.; Reichardt, C.; Siepmann, T.; Bohlmann, F.; Dimroth, K.; Reichardt, C. Pyridinium N-phenolbetaines and their use for the characterization of the polarity of solvents. Justus Liebigs Ann. Chem. 1963, 661, 1−37. (12) Kyuchoukov, G.; Marinova, M.; Albet, J.; Molinier, J. New Method for the Extraction of Lactic Acid by Means of a Modified Extractant (Aliquat 336). Ind. Eng. Chem. Res. 2004, 43, 1179−1184. (13) Wasewar, K. L.; Shende, D.; Keshav, A. Reactive Extraction of Itaconic Acid Using Quaternary Amine Aliquat 336 in Ethyl Acetate, Toluene, Hexane, and Kerosene. J. Chem. Eng. Data 2011, 50, 1003− 1011. (14) Wennersten, R. Extraction of Carboxylic Acid from Fermentation Broth in Using Solution of Tertiary Amine. J. Chem. Technol. Biotechnol. 1983, 33, 85−94. (15) Barrow, G. M.; Yerger, E. A. Acid-Base Reactions in Nondissociating Solvents. Acetic Acid and Triethylamine in Carbon Tetrachloride and Chloroform. J. Am. Chem. Soc. 1954, 76, 5211− 5216. (16) Yerger, E. A.; Barrow, G. M. Acid-Base Reactions in Nondissociating Solvents n-Butylamine and Acetic Acid in Carbon Tetrachloride and Chloroform. J. Am. Chem. Soc. 1955, 77, 6206− 6207.

a

+ ( −0.0421)α

AUTHOR INFORMATION

Corresponding Author

Table 5. Solvatochromic Parameters18,22a diluents

Article

(12)

where Z is the experimental loading factor values and ZM is the predicted loading factor values. N is the number of experimental data. The rmsd result was calculated as 0.98. This result shows that all predicted loading factor values fitted with each other, and taking into account well experimental uncertainty.

4. CONCLUSION The extractability of pyridine-3-carboxylic acid by TOMAC diluted in different diluent types as 2 ketones, 3 alcohols, 2 alkanes, and 2 acetates was studied. Experimental results were evaluated in terms of loading factors, distribution coefficients, and extraction efficiency. The extraction equilibria for pyridine3-carboxylic acid was interpereted in consequence of successive formation of acid−amine with stoichiometry of 1 acid/1 amine. Equilibrium extraction constants (KE), were determined for each concentration. The highest synergistic extraction efficiency was raised with TOMAC + octan-1-ol extractant mixture with KD value of 2.35 and equilibrium extraction constant (KE) gave the maximum value of 4.122. E



Article

(17) Yizhak, M. The properties of solvents. Wiley Series in Solution Chemistry; Willey: Chichester, U.K., 1999. (18) Kamlet, M. J.; Abboud, M.; Abraham, M. H.; Taft, R. W. Linear solvation energy relationships. 23. A comprehensive collection of the solvatochromic parameters, .pi.*, .alpha., and.beta., and some methods for simplifying the generalized solvatochromic equation. J. Org. Chem. 1983, 48, 2877−2887. (19) Kamlet, M. J.; Doherty, R. M.; Abraham, M. H.; Taft, R. W. Linear solvation energy relationship. 46. An improved equation for correlation and prediction of octanol/water partition coefficients of organic nonelectrolytes (including strong hydrogen bond donor solutes). J. Phys. Chem. 1988, 92, 5244−5255. (20) Leahy, D. E.; Carr, P. W.; Pearlman, R. S.; Taft, R. W.; Kamlet, M. J. Linear solvation energy relationships. A comparison of molar volume and intrinsic molecular volume as measures of the cavity term in reversed phase liquid chromatography. Chromatographia 1986, 21, 473−478. (21) Kamlet, M. J.; Doherty, R. M.; Veith, G. D.; Taft, R. W.; Abraham, M. Solubility properties in polymers and biological media. 7. An analysis of toxicant properties that influence inhibition of bioluminescence in Photobacterium phosphoreum (the Microtox test). Environ. Sci. Technol. 1986, 20, 690−695. (22) Legget, D. N. Modeling solvent extraction using the solvatochromic parameters.alpha., .beta., and.pi.*. Anal. Chem. 1993, 65, 2907−2909. (23) www.ibm.com/software/analytics/spss/; accessed on June, 2013.

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Intensification of Pyridine-3-carboxylic Acid Extraction Using N-Methyl

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