Measurement and Correlation of the Solubility for Camptothecine in

Measurement and Correlation of the Solubility for Camptothecine in Different Organic Solvents. Juanjuan Zhi† ... Publication Date (Web): May 4, 2016...
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Measurement and Correlation of the Solubility for Camptothecine in Different Organic Solvents Juanjuan Zhi,† Qiong Liu,†,‡ Tao Li,*,† and Baozeng Ren*,† †

School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou 450001, P. R. China Department of Environmental Engineering and Chemistry, Luoyang Institute of Science and Technology, Luoyang 471023, P. R. China

‡

ABSTRACT: Dissolution thermodynamics of camptothecine in chloroform, methanol, ethanol, and {chloroform + (methanol or ethanol)} mixed organic solvents were studied and correlated. The solubility of camptothecine in the above solvents was measured over the temperature range of 275.76−328.42 K at around 3 K intervals at atmospheric pressure. Experimental results showed that the solubility of camptothecine in the mixtures solvents increased with the increasing temperature. The mole fraction solubility of camptothecine reached a maximum at the mole fraction of chloroform 0.8016 in chloroform + methanol mixed solvent and 0.8031 in chloroform + ethanol mixed solvent. The experimental solubility data were well-correlated by using the modified Apelblat equation, the λh equation, and the ideal equation, respectively. The λh equation was proved to be the best-fit model for correlating the solubility of camptothecine from the analysis of the Akaike’s Information Criterion (AIC). Apelblat equation, the λh equation, and the ideal solution equation.

1. INTRODUCTION Camptothecine (CAS No.: 7689-03-4) is a monoterpenederived indole alkaloid; its molecular formula is C20H16N2O4, and the molecular structure is presented in Figure 1, which is

2. EXPERIMENTAL SECTION 2.1. Materials. In the experiments, camptothecine (molecular weight 348.35) was purchased from Aladdin Industrial Corporation (Shanghai, China). Its mass faction purity was 98% determined by HPLC (type Agilent 1100, Agilent Technologies). Methanol, ethanol, and chloroform of analytical grade were purchased from Tianjin Kemiou Chemical Reagent Co. Ltd. The sources and purity of the materials are shown in Table 1. 2.2. Verification of Procedure. To identify the reliability of measuring method, the measured mole fraction solubilities of

Figure 1. Chemical structure of camptothecin.

produced by the Chinese Camptotheca acuminatatree.1,2 In the pharmaceutical industry, camptothecine is necessary in the manufacture of irinotecan and topotecan. Because we know that so much of the quality of camptothecine depends on the crystallization processes, the appropriate method should be found to obtain the purify camptothecine. It is essential to choose a proper solvent in the process of crystallization for it has important influence on the purity, form, crystal morphology, and so on. Moreover, the solubility data is an important factor to obtain the optimization of crystallization processes.3 However, in our knowledge, no experimental study concerning the solubility of camptothecine in the system of chloroform, methanol, ethanol, and {chloroform + (methanol or ethanol)} mixed solvents. In this work, solubility data were experimentally determined at atmospheric pressure over the temperature range of 276.13−326.59 K by using a gravimetric method. The experimental results were correlated with the © XXXX American Chemical Society

Table 1. Sources and Purity of the Materials chemical name

sources

purity

camptothecine methanol

Aladdin Industrial Corporation Tianjin Kemiou Chemical Reagent Co. Ltd. Tianjin Kemiou Chemical Reagent Co. Ltd. Tianjin Kemiou Chemical Reagent Co. Ltd. Tianjin Kemiou Chemical Reagent Co. Ltd. Our Laboratory (Double distilled)

mass purity ≥0.98 mass purity ≥0.998

p-toluic acid ethanol chloroform water

mass purity ≥0.998 mass purity ≥0.998 mass purity ≥0.999 conductivity ≤0.1 μs/cm

Received: November 23, 2015 Accepted: April 20, 2016

A

DOI: 10.1021/acs.jced.5b00994 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

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p-toluic acid in water and the results from the literature4,5 are given in Table 2 and graphically shown in Figure 2. From Table

x1 =

m1/M1 m1/M1 + m2 /M 2 + m3 /M3

(1)

Table 2. Mole Fraction Solubility xexp of p-Toluic Acid in Water and the Results from the Literature xlit at Temperature T and Pressure p = 0.1 MPaa

x2 =

m2 /M 2 m2 /M 2 + m3 /M3

(2)

T (K)

293.15

303.15

313.15

323.15

333.15

343.15

104xexp 104xlit

0.3463 0.3479

0.5294 0.5695

0.7878 0.8050

1.198 1.1588

1.711 1.6938

2.494 2.5079

where M1, M2, and M3 are the molar mass of camptothecine, chloroform, and methanol (or ethanol), respectively, and m1, m2, and m3 are the mass of camptothecine, chloroform and methanol (or ethanol), in the sample taken upper solution, respectively. x2 is the mole fraction of chloroform in mixed solvents. The samples in the process have been identified by consistency before and after measurement by XRD. Figure 3

a Standard uncertainties u are u(T) = 0.05 K, u(p) = 5 kPa and the combined expanded uncertainties Uc are Uc,r(xexp) = 0.02 with a 0.95 level of confidence (k = 2).

Figure 2. Solubility (x) of p-toluic acid in water over the temperature range from 293.15 to 343.15 K: ◆, this work; △, literature data. Figure 3. XRD pattern of before and after recrystallization of CPT.

2, the relative error of in the mole fraction solubility was less than 3%. The deviations may be attributed to different measurement methods. Therefore, it was regarded as a reliable method of measuring the solubility data of CPT from 275.76 to 328.42 K. 2.3. Apparatus and Procedures. The solubility of camptothecine in chloroform, methanol, ethanol, and mixture solvents of {chloroform + (methanol or ethanol)} was measured by a gravimetric method, which was similar to the literature reported before.6,7 First, the excess amount of camptothecine was added in a known mass of solvent in a cylindrical double-jacketed glass vessel (60 cm3) controlled by circulating water with a thermoelectric controller. The temperature of water to circulate through the jacket was controlled to within ±0.01 K. A thermometer (uncertainty of ±0.01 K) was put into the vessel to measure the solution temperature. In order to prevent the solvents from evaporating, a condenser was connected to the glass vessel. The supersaturated solution was stirred at a desired temperature for at least 12 h to reach equilibrium. The stirring was stopped, and the undissolved solid was settled down for at least 8 h. Supernatant liquid was taken approximately 8 mL and filtered with membrane (0.45 μm); the sample was reweighed and then was quickly transferred to a vacuum oven to dry at 313.15 K for 12 h. The supernatant solvent was completely evaporated, and the mass of the residue was reweighed. The solvent and solute were measured by an analytic balance (uncertainty of 0.0001 g). The mole fraction solubility data were calculated by the average value of the experiment data which repeated three times. The following equation was used to calculate the mole fraction solubility x1 of camptothecine in solvent mixtures.

presents the XRD pattern of the crystal. Compared with the powder diffraction file of before and after recrystallization of CPT, the morphologies of CPT was not changed after recrystallization.

3. RESULTS AND DISCUSSION 3.1. Solubility Data. The measured experimental solubility data x1 of camptothecine in methane, ethanol, chloroform, and mixed solvent mixtures {chloroform + (methanol or ethanol)} are shown in Table 3 and graphically shown in Figures 4−7. x2 is the mole fraction of chloroform in solute-free solvent system in Figures 6 and 7. As it can be observed from Table 3 and Figures 4−7, during the increasing of the mole fraction of chloroform in mixture solvent, the mole fraction solubility of camptothecine increased with increasing temperature, but the solubility value had a peak and then declined. The curve of solubility showed a maximum point (x2 = 0.8016 in chloroform + methanol mixture), and the maximum point did not change with temperature. The solubility of camptothecine in {chloroform (x2) + methanol (1 − x2) solvents} is in this order: x2 = 0.0000 < x2 = 0.1008 < x2 = 0.1991 < x2 = 0.3012 < x2 = 0.4003 < x2 = 0.5017 < x2 = 0.6028 < x2 = 0.6989 < x2 = 0.8016 > x2 = 0.9004 > x2 = 1.0000. In {chloroform (x2) + ethanol (1 − x2) solvents} is in this order: x2 = 0.0000 < x2 = 0.0998 < x2 = 0.2035 < x2 = 0.3027 < x2 = 0.3994 < x2 = 0.5011 < x2 = 0.5970 < x2 = 0.6978 < x2 = 0.8031 > x2 = 0.9003 > x2 = 1.0000. Intermolecular forces between the molecules of a mixture play an important role for thermodynamics properties. The situation of a mixture is complicated since intermolecular forces consists of same molecules and dissimilar molecules. It is essential to B

DOI: 10.1021/acs.jced.5b00994 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

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Table 3. Mole Fraction Solubility x1 of Camptothecine in Chloroform + Methanol (or Ethanol) Solvent Mixtures at Temperature T and Pressure p = 0.1 MPaa 100RD T/K

104x1

eq 7

eq 3

100RD T/K

eq 8

104x1

eq 7

eq 3

eq 8

−3.66 −2.55 −2.57 0.47 −1.04 0.55 0.00 0.85 1.10 1.40 0.58 0.47 0.46 −0.02 −0.24 0.07 −0.65

−4.60 −3.33 −3.23 −0.07 −1.49 0.21 −0.27 0.66 0.95 1.28 0.46 0.33 0.29 −0.22 −0.50 −0.26 −1.07

−3.32 −3.82 −3.25 −1.79 −1.10 −0.06 0.34 1.14 1.44 2.49 1.27 1.85 1.23 0.26 −0.53 −0.92 −1.60

−4.27 −4.57 −3.84 −2.23 −1.42 −0.27 0.21 1.08 1.43 2.49 1.27 1.83 1.17 0.14 −0.75 −1.25 −2.07

7.55 5.47 3.74 0.35 −0.36 −1.99 −1.38 −1.89 −2.47 −2.33 −2.72 −1.43 −1.02 −0.35 0.31 1.01

6.74 4.90 3.40 0.27 −0.27 −1.74 −1.01 −1.44 −1.97 −1.81 −2.20 −0.96 −0.63 −0.09 0.44 0.95

3.27 1.34 0.30

2.03 0.45 −0.34

Chloroform + Ethanol 277.98 281.62 284.67 287.95 291.00 294.63 297.81 301.09 304.26 307.54 310.47 313.63 316.57 319.26 321.70 324.43 326.30

0.0903 0.1076 0.1250 0.1392 0.1597 0.1784 0.2007 0.2243 0.2464 0.2763 0.3063 0.3331 0.3678 0.4009 0.4314 0.4640 0.4908

277.65 280.70 283.66 286.97 290.41 293.50 296.92 300.15 303.29 306.61 309.65 312.61 315.40 318.36 320.86 323.55 325.97

0.3208 0.3542 0.3844 0.4239 0.4691 0.5209 0.5723 0.6328 0.6995 0.7724 0.8452 0.9212 0.9909 1.0726 1.1577 1.2578 1.3455

276.77 279.42 282.59 285.39 288.56 291.91 294.54 298.59 302.00 304.76 307.74 311.09 313.89 317.42 320.24 322.52

1.5502 1.6298 1.7562 1.8838 2.0266 2.2011 2.3439 2.5347 2.7729 2.9479 3.1376 3.3600 3.5824 3.8048 4.0424 4.2169

276.53 279.07 282.26

3.7973 3.9085 4.1081

x2 = 0.0000 −9.40 −4.72 −0.61 −1.49 1.63 0.19 1.15 1.27 0.15 0.83 1.64 −0.11 0.48 0.64 0.40 −0.72 −0.84 x2 = 0.2035 0.15 0.55 −0.41 −0.80 −1.17 −0.09 −0.99 −0.59 0.10 0.20 0.31 0.28 −0.50 −1.11 −0.65 −0.01 −0.14 x2 = 0.3994 −0.31 −2.02 −2.42 −2.23 −2.51 −2.09 −1.87 −3.22 −1.72 −1.58 −1.71 −1.88 −1.23 −2.37 −1.90 −2.15 x2 = 0.5970 2.77 1.64 1.44

−5.47 −2.07 1.16 −0.43 2.10 0.14 0.76 0.63 −0.63 0.01 0.86 −0.77 0.02 0.42 0.45 −0.32 −0.16

−6.55 −2.97 0.40 −1.09 1.54 −0.33 0.35 0.28 −0.95 −0.28 0.58 −1.06 −0.28 0.09 0.08 −0.75 −0.64

279.76 283.03 285.69 288.36 291.32 294.81 297.86 301.72 304.89 308.41 311.46 314.51 317.32 320.03 322.84 325.42 328.23

0.2015 0.2293 0.2520 0.2849 0.3105 0.3545 0.3894 0.4444 0.4918 0.5493 0.5967 0.6517 0.7065 0.7590 0.8189 0.8813 0.9438

5.19 4.32 2.33 0.91 −0.35 0.09 −1.35 −1.30 −0.80 −0.75 −0.57 −0.41 −0.92 −1.15 −0.27 0.87 1.26

4.12 3.40 1.53 0.24 −0.90 −0.36 −1.71 −1.59 −1.04 −0.97 −0.77 −0.62 −1.16 −1.42 −0.60 0.48 0.79

276.64 279.67 282.45 285.47 288.25 290.92 293.71 296.84 299.97 303.11 306.01 308.68 311.57 314.37 317.15 320.16 322.83

0.8812 0.9587 1.0447 1.1542 1.2553 1.3639 1.4750 1.6142 1.7544 1.9183 2.0345 2.1828 2.3235 2.4558 2.5965 2.7675 2.9158

2.11 0.31 −0.22 −0.15 −0.51 −0.19 −0.01 −1.38 0.07 0.21 0.10 −0.03 0.65 −0.40 0.13 −0.06

1.43 −0.17 −0.48 −0.23 −0.43 0.04 0.31 −0.96 0.53 0.68 0.55 0.36 0.97 −0.20 0.20 −0.12

276.42 279.40 282.38 286.24 288.98 292.08 295.28 298.03 300.90 304.09 307.40 310.16 313.36 316.66 319.42 322.73

2.7706 2.9065 3.0562 3.2199 3.3959 3.5720 3.8437 4.0475 4.2652 4.5509 4.8350 5.1608 5.5005 5.8819 6.2216 6.6416

5.52 3.29 1.86

4.73 2.73 1.57

276.65 279.73 282.26

5.2487 5.4217 5.5946

C

x2 = 0.0998 −2.22 −1.96 −2.57 −0.03 −2.05 −0.90 −1.77 −1.18 −1.06 −0.80 −1.61 −1.62 −1.48 −1.77 −1.73 −1.13 −1.50 x2 = 0.3027 −4.19 −3.84 −2.61 −0.56 0.57 1.95 2.62 3.63 4.05 5.10 3.87 4.33 3.56 2.37 1.29 0.52 −0.56 x2 = 0.5011 2.62 2.54 2.57 1.13 1.56 0.99 2.36 2.32 2.04 2.25 1.71 2.63 2.45 2.29 2.10 1.59 x2 = 0.6918 3.10 1.98 1.53

DOI: 10.1021/acs.jced.5b00994 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

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Table 3. continued 100RD T/K

104x1

285.35 287.99 290.98 294.28 297.59 300.67 303.77 306.30 309.16 311.92 315.05 317.99 321.07 324.60

4.3304 4.4416 4.7069 5.0404 5.2855 5.5736 5.8843 6.1749 6.5514 6.8647 7.2634 7.6404 8.0194 8.5298

276.21 279.29 282.38 285.46 287.78 290.54 293.62 296.92 300.12 303.10 306.08 309.27 312.36 315.55 318.43 321.51 324.48

5.9361 6.1442 6.3540 6.5949 6.7701 6.9964 7.2847 7.5894 7.8777 8.1825 8.4891 8.8412 9.1953 9.5803 9.9489 10.3000 10.7000

277.52 280.45 283.37 286.20 289.49 293.24 296.60 299.68 302.78 305.61 308.45 311.02 313.77 316.53 319.02 321.42 323.48

0.1270 0.1425 0.1567 0.1722 0.1952 0.2204 0.2486 0.2742 0.3025 0.3351 0.3662 0.4002 0.4368 0.4780 0.5204 0.5585 0.5953

276.75 279.92 283.47 286.75 290.31 293.73

0.5241 0.5817 0.6449 0.7043 0.7814 0.8603

eq 7 x2 = 0.5970 1.65 −0.19 0.61 1.86 0.96 0.94 0.98 1.35 2.21 2.00 2.05 1.85 1.14 0.92 x2 = 0.8031 −1.28 −1.43 −1.71 −1.65 −1.81 −1.85 −1.55 −1.48 −1.70 −1.60 −1.62 −1.56 −1.51 −1.45 −1.32 −1.78 −1.76 x2 = 0.0000 0.12 1.42 0.69 0.34 1.51 0.86 1.54 0.97 0.44 1.24 0.77 1.20 1.00 1.06 1.53 0.90 0.70 x2 = 0.1991 −5.14 −2.47 −0.94 −0.28 1.25 2.32

100RD

eq 3

eq 8

T/K

104x1

1.05 −1.54 −1.40 −0.67 −1.95 −2.13 −2.09 −1.59 −0.46 −0.34 0.24 0.64 0.67 1.46

1.00 −1.42 −1.12 −0.25 −1.43 −1.56 −1.52 −1.04 0.03 0.07 0.52 0.75 0.59 1.10

284.58 287.55 290.75 293.95 297.03 300.34 303.22 306.41 309.50 312.91 315.55 318.31 321.62 324.38

5.8363 6.0446 6.3040 6.6499 6.9604 7.2886 7.6345 7.9804 8.3439 8.7743 9.1044 9.4837 9.9161 10.2000

1.82 277.40 1.17 279.90 0.47 283.32 0.18 286.18 −0.19 289.68 −0.44 292.82 −0.31 295.59 −0.35 298.11 −0.61 300.89 −0.49 303.94 −0.46 306.90 −0.28 309.86 −0.08 313.00 0.19 315.96 0.54 319.27 0.35 322.23 0.65 325.18 Chloroform + Methanol

4.8998 5.0577 5.3335 5.5713 5.8471 6.1362 6.3455 6.5947 6.8458 7.1083 7.3974 7.6866 7.9890 8.2915 8.6586 8.9877 9.3415

2.87 1.84 0.81 0.23 −0.32 −0.75 −0.77 −0.93 −1.24 −1.13 −1.06 −0.79 −0.45 0.01 0.57 0.65 1.25

4.19 4.16 2.32 1.02 1.26 −0.22 −0.07 −0.99 −1.72 −0.95 −1.36 −0.76 −0.68 −0.26 0.63 0.47 0.73

3.62 3.69 1.94 0.71 1.03 −0.37 −0.17 −1.04 −1.75 −0.96 −1.37 −0.77 −0.72 −0.33 0.53 0.32 0.53

276.58 279.24 282.42 285.68 288.96 292.01 294.88 298.02 300.98 304.25 307.42 310.75 313.18 316.49 319.18 321.78 324.02

0.2421 0.2725 0.3079 0.3507 0.3870 0.4358 0.4870 0.5314 0.5869 0.6437 0.7044 0.7660 0.8207 0.8848 0.9383 0.9918 1.0568

0.37 1.17 1.00 0.34 0.70 0.91

−1.29 −0.23 −0.17 −0.64 −0.09 0.26

277.12 279.70 283.05 286.76 289.90 293.50

1.3260 1.4257 1.5483 1.6887 1.8404 1.9806

D

eq 7 x2 = 0.6918 2.43 1.71 1.35 2.10 2.24 2.10 2.61 2.45 2.48 2.62 2.52 2.65 2.37 1.27 x2 = 0.9003 0.29 −0.26 0.04 0.25 0.10 0.51 0.02 0.42 0.40 0.08 0.16 0.14 −0.05 −0.09 0.08 0.15 0.38 x2 = 0.1008 −8.24 −5.64 −4.28 −2.15 −3.03 −0.83 1.34 0.54 1.69 1.46 1.51 0.72 1.07 −0.14 −1.21 −2.28 −1.48 x2 = 0.3012 −2.35 −1.03 −0.51 −0.38 1.02 0.12

eq 3

eq 8

0.75 −0.49 −1.29 −0.84 −0.89 −1.14 −0.62 −0.68 −0.48 −0.05 0.14 0.63 0.86 0.23

0.32 −0.68 −1.28 −0.67 −0.62 −0.80 −0.27 −0.36 −0.23 0.06 0.11 0.43 0.40 −0.49

0.88 0.10 0.15 0.18 −0.14 0.16 −0.41 −0.05 −0.11 −0.42 −0.32 −0.29 −0.39 −0.34 −0.02 0.20 0.60

−0.27 −0.74 −0.32 −0.02 −0.08 0.40 −0.05 0.38 0.38 0.07 0.15 0.10 −0.12 −0.23 −0.14 −0.17 −0.05

−8.82 −5.93 −4.27 −1.89 −2.57 −0.22 2.04 1.32 2.51 2.30 2.34 1.51 1.81 0.50 −0.67 −1.86 −1.17

−9.54 −6.49 −4.69 −2.17 −2.74 −0.31 2.02 1.36 2.57 2.38 2.42 1.56 1.83 0.46 −0.78 −2.06 −1.45

1.50 1.73 1.07 0.10 0.75 −0.82

0.59 1.02 0.59 −0.15 0.66 −0.76

DOI: 10.1021/acs.jced.5b00994 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

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Table 3. continued 100RD T/K

104x1

297.27 300.57 304.36 307.65 310.83 313.88 316.94 319.75 322.80 325.64 328.42

0.9339 1.0339 1.1232 1.2229 1.3122 1.4279 1.5330 1.6380 1.7484 1.8713 2.0006

277.92 280.83 283.84 286.66 289.67 292.68 296.08 299.29 302.20 304.63 307.15 310.55 313.38 316.58 319.49 322.99 277.92

3.2023 3.4518 3.6877 3.8918 4.1730 4.5019 4.7831 5.1143 5.3955 5.6768 5.9285 6.3050 6.6339 6.9628 7.4005 7.8564 3.2023

277.20 280.17 282.93 285.45 288.67 291.24 294.27 298.03 301.67 304.21 307.18 310.26 313.57 317.21 320.52 323.94 326.59

7.3508 7.5402 7.7989 8.0292 8.3668 8.6405 9.0566 9.5564 10.0258 10.4499 10.9646 11.5514 12.1381 12.9356 13.5917 14.2718 14.8585

277.20 279.35 282.33 284.83 287.70 290.09 293.20 296.42 299.06 301.80

8.9872 9.1624 9.5000 9.7737 10.0785 10.3358 10.7044 11.0566 11.4106 11.7318

eq 7 x2 = 0.1991 1.69 3.58 2.44 2.71 1.85 2.66 2.15 1.79 0.71 0.45 0.23 x2 = 0.4003 −0.62 0.69 0.98 0.51 1.32 2.80 2.09 2.48 2.19 2.59 2.16 1.94 1.78 0.76 1.58 1.30 −0.62 x2 = 0.6028 0.97 −0.09 −0.16 −0.50 −0.63 −0.89 −0.39 −0.34 −0.87 −0.49 −0.17 0.30 0.08 0.65 0.26 −0.47 −0.83 x2 = 0.8016 0.65 0.44 1.01 1.25 1.29 1.23 1.32 0.96 1.11 0.73

100RD

eq 3

eq 8

T/K

104x1

−0.41 1.09 −0.33 −0.09 −0.83 0.27 0.16 0.29 −0.14 0.32 0.90

−0.94 0.66 −0.71 −0.44 −1.18 −0.10 −0.26 −0.20 −0.73 −0.39 0.06

296.39 299.18 302.54 306.73 310.20 313.34 316.01 319.38 321.70 324.13 326.34

2.1449 2.2738 2.4722 2.6946 2.9044 3.1394 3.3265 3.5476 3.7700 3.9457 4.1453

−0.67 0.23 0.16 −0.60 −0.04 1.25 0.37 0.66 0.32 0.72 0.30 0.14 0.09 −0.80 0.21 0.18 −0.67

−1.69 −0.51 −0.34 −0.91 −0.16 1.28 0.52 0.88 0.58 0.99 0.56 0.35 0.22 −0.78 0.08 −0.16 −1.69

276.65 279.63 282.60 285.46 288.45 290.98 294.28 297.03 299.91 302.66 305.31 308.51 311.48 314.45 317.55 321.30 276.65

4.9875 5.2550 5.5981 5.8403 6.1729 6.4319 6.8215 7.0994 7.4321 7.8026 8.1185 8.5985 8.9691 9.3944 9.9503 10.5062 4.9875

6.26 3.69 2.33 0.97 −0.26 −1.25 −1.40 −1.91 −2.70 −2.33 −1.88 −1.10 −0.81 0.54 1.02 1.37 1.96

4.97 2.71 1.63 0.50 −0.48 −1.30 −1.28 −1.64 −2.35 −1.97 −1.53 −0.81 −0.63 0.54 0.81 0.89 1.24

276.76 279.96 282.26 285.13 288.22 291.42 294.18 297.05 300.46 302.66 305.75 308.61 311.48 314.90 317.55 321.18 324.71

8.6717 8.9875 9.1918 9.3960 9.6908 10.0424 10.3203 10.6810 11.1183 11.4131 11.8405 12.3396 12.7480 13.3039 13.8408 14.5630 15.3210

2.83 1.90 1.59 1.20 0.63 0.18 −0.12 −0.74 −0.68 −1.08

1.49 0.80 0.80 0.64 0.30 −0.01 −0.16 −0.68 −0.58 −0.96

277.31 280.71 284.12 287.43 290.75 293.80 296.85 299.72 302.95 305.21

6.1159 6.3727 6.6910 7.0246 7.3275 7.6611 8.0101 8.3152 8.6335 8.9205

E

eq 7 x2 = 0.3012 1.46 0.95 1.66 0.78 0.43 1.14 0.92 −0.20 0.70 −0.17 −0.14 x2 = 0.5017 −0.24 −0.21 0.97 0.30 0.75 0.57 0.90 0.29 0.10 0.42 0.06 0.60 0.03 −0.10 0.71 0.23 −0.24 x2 = 0.6989 −0.85 −0.79 −1.12 −2.18 −2.62 −2.76 −3.27 −3.23 −3.28 −3.32 −3.38 −2.72 −3.01 −2.98 −2.30 −1.76 −1.13 x2 = 0.9004 2.43 1.66 1.69 1.91 1.54 1.82 2.15 2.05 1.55 1.86

eq 3

eq 8

0.13 −0.66 −0.12 −1.02 −1.23 −0.24 −0.14 −0.75 0.57 0.21 0.74

0.28 −0.43 0.16 −0.72 −0.94 −0.01 0.02 −0.70 0.52 0.03 0.44

1.63 1.07 1.73 0.66 0.75 0.33 0.43 −0.32 −0.59 −0.28 −0.62 0.03 −0.40 −0.32 0.77 0.68 1.63

0.19 −0.06 0.89 0.03 0.33 0.05 0.29 −0.37 −0.57 −0.25 −0.59 0.00 −0.51 −0.55 0.37 0.03 0.19

4.05 3.16 2.24 0.57 −0.43 −1.02 −1.82 −1.97 −2.13 −2.16 −2.12 −1.28 −1.28 −0.82 0.26 1.44 2.80

3.12 2.62 1.95 0.55 −0.21 −0.59 −1.25 −1.30 −1.40 −1.43 −1.42 −0.66 −0.78 −0.50 0.38 1.27 2.28

1.70 0.56 0.28 0.26 −0.31 −0.16 0.08 −0.07 −0.60 −0.27

0.34 −0.39 −0.32 −0.05 −0.38 −0.06 0.30 0.22 −0.28 0.04

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Table 3. continued 100RD T/K 304.79 307.89 310.64 313.62 317.08 319.95 322.34 x2 = 1.0000 275.76 279.07 282.38 285.02 287.55 291.19 294.18 297.25 300.57 303.10 305.96 308.51 311.59 315.12 318.31 322.39 326.25

104x1 12.1971 12.5985 13.0310 13.5456 14.0420 14.6369 15.1661 2.2153 2.4563 2.7188 2.8763 3.0756 3.3166 3.5373 3.7484 4.0409 4.2091 4.4083 4.6506 4.8916 5.1326 5.4368 5.7518 6.1301

eq 7 x2 = 0.8016 1.12 0.70 0.76 1.02 0.37 0.96 1.51 −4.19 −2.34 −0.36 −1.04 −0.19 −0.72 −0.64 −1.16 −0.19 −0.93 −1.56 −0.72 −0.96 −1.95 −1.20 −1.69 −0.81

100RD

eq 3

eq 8

T/K

104x1

−0.56 −0.76 −0.38 0.32 0.29 1.49 2.61

−0.48 −0.77 −0.51 0.02 −0.25 0.71 1.60

307.79 310.48 313.71 316.85 319.81 322.50 325.00

9.2392 9.5729 9.9811 10.3000 10.8000 11.1000 11.4000

−5.23 −2.19 0.77 0.75 2.11 2.19 2.63 2.39 3.48 2.80 2.15 2.84 2.39 1.05 1.33 0.14 0.20

−8.12 −4.64 −1.32 −1.13 0.44 0.73 1.31 1.17 2.34 1.68 1.02 1.70 1.19 −0.28 −0.15 −1.59 −1.83

eq 7 x2 = 0.9004 2.02 2.12 2.19 1.40 2.45 1.89 1.51

eq 3

eq 8

−0.08 0.08 0.26 −0.41 0.81 0.41 0.20

0.20 0.28 0.32 −0.52 0.49 −0.14 −0.60

a

x1, x2, and RD represent the mole fraction solubility of camptothecine in the solution, the mole fraction of chloroform in the chloroform + methanol (or ethanol) binary mixed solvents, and the relative deviation, respectively. Standard uncertainties u are u(T) = 0.05 K, u(p) = 5 kPa, and the combined expanded uncertainties Uc are Uc,r(x1) = 0.05, Uc,r(x2) = 0.02 with a 0.95 level of confidence (k = 2).

Figure 5. Solubilities of camptothecine in chloroform, ethanol, and chloroform + ethanol mixed solutions: black ■, x2 = 0.0000; red ○, x2 = 0.0998; blue ▲, x2 = 0.2035; dark cyan ▽, x2 = 0.3027; magenta ☆, x2 = 0.3994; dark yellow ×, x2 = 0.5011; navy ◆, x2 = 0.5970; wine +, x2 = 0.6918; pink ◇, x2 = 0.8031; olive *, x2 = 0.9003.

Figure 4. Solubilities of camptothecine in chloroform, methanol, and chloroform + methanol mixed solutions: black ■, x2 = 0.0000; red ○, x2 = 0.1008; blue ▲, x2 = 0.1991; dark cyan ▽, x2 = 0.3012; magenta ☆, x2 = 0.4003; dark yellow ×, x2 = 0.5017; navy ◆, x2 = 0.6028; wine +, x2 = 0.6989; pink ◇, x2 = 0.8016; olive *, x2 = 0.9004; royal ★, x2 = 1.0000.

considered. Chemical effects in solution are conveniently classified in terms of association or solvation. Camptothecine contains the hydroxyl (−OH), ester group, tertiary amine, and carbon ring groups from Figure 1. When camptothecine dissolved in chloroform and methanol (or ethanol) solvent mixtures, there were both self-association and cross-association

gain some understanding of intermolecular forces to interpret and correlate the mixture thermodynamic properties. There are many different types of intermolecular forces, which are electrostatic forces, induction forces, dispersion forces, specific (chemical) forces, and so on, but here, only chemical forces are F

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between the primary hydrogen of the chloroform and the hydroxyl of the camptothecine, the solubility reached a maximum. When the solubility parameter of solvent and solute is same, the solubility of the solute is a maximum in that solvent from Scatchard−Hildebrand theory. Scatchard−Hildebrand theory suggests that the solubility of the solute in two solvents should pass a maximum if solvents were selected carefully.8 3.2. Data Correlation. 3.2.1. Ideal Model. The solubility temperature dependence of camptothecine can be described by the ideal eq 39,10 a ln x1 = +b (3) T /K where a and b are the ideal solution model parameters; x1 is the mole fraction of the solubility at the absolute temperature T. The relative deviation (RD), the corresponding average absolute deviation (AAD), and the root-mean-square deviations (RMSD) were calculated by the following:

Figure 6. Experimental solubility (x1) of camptothecine at different temperatures in {(x2) chloroform + (1 − x2) methanol} mixed solutions: ■, T = 283.15 K; ○, T = 293.15 K; ▲, T = 303.15 K; ☆, T = 313.15 K; ×, T = 323.15 K.

RD =

x1exp − x1cal x1exp N

AAD =

∑i = 1

(4)

|x1exp − x1cal| x1exp

(5)

N

⎡ N (x − x )2 ⎤1/2 i ,cal i ,exp ⎥ RMSD = ⎢∑ ⎢⎣ i = 1 ⎥⎦ N

(6) 2

The correlation value of a and b, coupled with R , AAD, and RMSD, are listed in Table 4. Table 4. Parameters of the Ideal Model for Camptothecine in a Mixed Systema

Figure 7. Experiment solubility (x1) of camptothecine at different temperatures in {(x2) chloroform + (1 − x2) ethanol} mixed solutions: ■, T = 283.15 K; ○, T = 293.15 K; ▲, T = 303.15 K; ☆,T = 313.15 K; ×, T = 323.15 K.

between molecules of methanol (or ethanol) and chloroform. When the mole fraction of chloroform in mixed solvents was lower (x2 < 0.80), the concentration of methanol (or ethanol) was high, and methanol (or ethanol) consists primarily of dimer, trimer, and tetramer due to hydrogen bonding, so the solubility in mixture increased with the mole fraction of chloroform increasing. With the mole fraction of chloroform in mixed solvents increasing (x2 > 0.80), the concentration of methanol (or ethanol) was lower, methanol (or ethanol) existed primarily as a monomer, there was a tendency for chloroform to solvate with methanol (or ethanol) due to hydrogen bonding between the primary hydrogen of the chloroform and the hydroxyl of the methanol (or ethanol), so the solubility in mixture decreased with the mole fraction of chloroform increased. When the mole fraction of chloroform was around 0.8 in the mixed solvents, methanol (or ethanol) existed primarily as a monomer, there was a tendency to form hydrogen bonds between the hydroxyl of the methanol (or ethanol) and the carbonyl oxygen of the camptothecine and

x2

10−3 a

0.0000 0.1008 0.1991 0.3012 0.4003 0.5017 0.6028 0.6989 0.8016 0.9004 1.0000

−3.09 −2.65 −2.35 −2.11 −1.77 −1.50 −1.37 −1.09 −1.04 −1.21 −1.72

0.0000 0.0998 0.2035 0.3027 0.3994 0.5011 0.5970 0.6918 0.8031 0.9003

−3.08 −2.87 −2.76 −2.28 −2.00 −1.82 −1.59 −1.31 −1.12 −1.22

b

R2

Chloroform + Methanol −0.19 0.999 −0.98 0.997 −1.38 1.00 −1.34 1.00 −1.67 1.00 −2.19 0.999 −2.33 0.992 −3.15 0.987 −3.29 0.994 −3.07 1.00 −2.13 0.997 Chloroform + Ethanol −0.48 1.00 −0.52 0.999 −0.46 0.999 −1.06 0.998 −1.58 1.00 −1.70 0.993 −2.18 0.996 −2.86 0.998 −3.39 0.997 −3.22 1.00

100 AAD

106 RMSD

1.28 2.45 0.55 0.69 0.43 0.71 1.87 1.74 1.02 0.39 2.04

0.35 1.28 0.72 1.92 2.82 6.30 20.83 21.88 15.12 4.18 8.59

0.97 0.98 1.34 1.55 0.39 2.18 1.58 0.82 0.92 0.28

0.21 0.44 0.94 2.81 1.40 10.50 9.41 6.71 8.19 2.44

a

a and b are parameters of the ideal equation. R2 is the coefficient of determination, ADD is the average absolute deviation, and RMSD represents the root-mean-square deviations. G

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uncertainty u is u(Tm) = 5 K. The values of λ and h were determined from a correlation of the experimental data in Table 6 using eq 8.

3.2.2. Modified Apelblat Model. The relationship between the solubility of camptothecine in the selected solvents and the absolute temperature T can be fitted via the modified Apelblat equation,11 which is described as ln x1 = A +

B + C ln(T /K) (T /K)

Table 6. Parameters of the λh Equation for Camptothecine in Mixed Systemsa

(7)

where A, B, and C are the parameters of the modified Apelblat equation; x1 represents the experimental mole fraction solubility of camptothecine; T is the absolute temperature. The values of empirical parameters A, B, and C are listed in Table 5. Table 5. Parameters of the Modified Apelblat Equation for Camptothecine in Mixed Systemsa x2

A

0.0000 0.1008 0.1991 0.3012 0.4003 0.5017 0.6028 0.6989 0.8016 0.9004 1.0000

−91.22 18.65 −103.5 −82.06 −31.18 −45.15 −119.4 −72.97 −84.71 −26.59 67.53

0.0000 0.0998 0.2035 0.3027 0.3994 0.5011 0.5970 0.6918 0.8031 0.9003

−58.28 48.51 −83.51 −57.61 −12.04 −147.3 −99.93 −61.74 −67.58 −22.22

10−2 B

C

R2

Chloroform + Methanol 10.46 13.54 1.00 −35.35 −2.92 0.998 23.07 15.18 0.999 15.53 12.01 0.999 −4.35 4.39 0.999 4.33 6.40 1.00 39.16 17.43 0.999 20.46 10.41 0.997 26.07 12.14 1.00 −1.45 3.50 1.00 −48.61 −10.37 0.999 Chloroform + Ethanol −4.41 8.59 0.999 −51.16 −7.28 1.00 10.21 12.35 1.00 2.69 8.42 0.995 −15.23 1.56 1.00 47.61 21.67 1.00 28.11 14.56 0.999 13.40 8.77 0.999 17.59 9.57 1.00 −3.67 2.83 1.00

100 AAD

106 RMSD

0.96 2.21 1.92 0.82 1.60 0.41 0.48 2.39 0.97 1.90 1.22

0.4 1.2 2.3 2.2 10.0 3.8 5.8 29.6 12.1 17.0 5.5

1.54 1.49 0.47 2.68 1.96 2.08 1.44 2.20 1.59 0.20

0.34 0.86 0.4 5.5 6.0 10.1 9.3 17.3 13.1 1.7

103 λ

0.0000 0.1008 0.1991 0.3012 0.4003 0.5017 0.6028 0.6989 0.8016 0.9004 1.0000

2.63 2.58 2.80 4.29 5.06 4.23 4.10 2.10 1.85 2.20 3.46

0.0000 0.0998 0.2035 0.3027 0.3994 0.5011 0.5970 0.6918 0.8031 0.9003

1.99 2.75 3.54 4.37 4.00 4.60 3.84 2.58 1.66 1.88

10−5 h

R2

100 AAD

Chloroform + Methanol 11.58 1.00 10.01 0.997 8.02 1.00 4.63 1.00 3.15 1.00 3.00 1.00 2.66 0.995 3.36 0.993 3.44 0.998 3.93 1.00 4.42 0.995 Chloroform + Ethanol 15.25 1.00 10.22 0.999 7.62 0.999 5.00 0.997 4.65 1.00 3.58 0.995 3.59 0.997 3.92 0.999 4.55 0.999 4.74 1.00

106 RMSD

1.17 2.64 0.49 0.47 0.59 0.33 1.49 1.28 0.63 0.29 1.80

0.32 1.38 0.67 1.40 3.42 3.25 16.32 16.48 9.22 3.11 7.65

1.07 1.13 1.28 1.78 0.46 1.84 1.26 0.56 0.50 0.22

0.24 0.52 0.88 3.20 1.49 9.08 7.58 4.57 4.57 1.69

λ and h are parameters of the λh equation. R2 is the coefficient of determination, AAD is the average absolute deviation, and RMSD represents the root-mean-square deviations.

a

The correlated values of the two parameters λ and h together with the average absolute deviation (AAD) and the root-meansquare deviations (RMSD) are listed in Table 5. To sum up, three models were used to fit the solid−liquid equilibrium data. OriginPro 8.0 was used to obtain the parameters in the different model equations. However, it is not sufficient to tell which is the best-fit model just from AAD and RMSD values. The Akaike’s Information Criterion (AIC) is a model-selection criterion which is widely used to select the best-fit model.15 The model with the lowest value of AIC can be supposed to be the best-fit model. The value of AIC is given as follows:16

a A, B, and C are parameters of the Apelblat equation. R2 is the coefficient of determination, AAD is the average absolute deviation, and RMSD represents the root-mean square deviations.

3.2.3. λh Model. The λh equation with only two adjustable parameters was first proposed by Buchowski et al.12 and especially could fit the solid−liquid equilibrium systems.13 The solubility data were also correlated with the λh equation, which is given as ⎡ ⎛ 1 λ(1 − x1) ⎤ 1 ⎞ ln⎢1 + − ⎥ = λh⎜ ⎟ (Tm/K) ⎠ x1 ⎦ ⎣ ⎝ (T /K)

x2

AIC = 2κ − 2 ln(L)

(9)

where κ is the number of parameters in the statistical model and L is the maximized value of the likelihood function for the estimated model. Variance of the model errors is assumed equal. AIC simplifies to17

(8)

where λ and h are the model parameters, x1 is the mole fraction of the solubility at the system temperature T, and Tm is the normal melting temperature which had been measured by DSC(STA409PC-luxx). Camptothecine was weighed into standard DSC aluminum pans and scanned between 20 and 600 °C at a heating rate of 20 °C/min in an atmosphere of dry nitrogen [30 mL/min flow rate]. The melting parameter value (Tm) for camptothecine lies within the range 528−550 K.14 The value of Tm was found to be 543.95 K. The standard

AIC = 2κ + N ln(RSS/N )

(10)

N

RSS =

∑ (xi ,cal − xi ,exp)2 i=1

(11)

where N is the number of experimental points and RSS is the residual sum of squares. H

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Funding

AIC produces an effect on statistical model evaluation problems and penalizes overparameterization more stringently to select the best-fit model which has the lowest value. As we can see from the Table 7, the value of AIC of the λh equation is lower than the modified Apelblat equation and the

This research was financially supported by Technology Breakthrough Major Project in Henan Province (Grant No.: 112101210200) and the Natural Science Foundation of China (21506197). Notes

The authors declare no competing financial interest.

Table 7. Value of Akaike’s Information Criterion of the Modified Apelblat Equation, λh Equation, and Ideal Model in Mixed Systems model modified Apelblat equation λh equation ideal equation modified Apelblat equation λh equation ideal equation

RSS

a

N

b

parameter

c

AIC

Akaike weight

Chloroform + Methanol 17 3 −339.4 2.55 × 10−8

7.05 × 10−4

1.22 × 10−8 4.24 × 10−7

1 7.97 × 10−14

17 17

2 2

−353.9 −293.6

Chloroform + Ethanol 1.29 × 10−8 17 3 −351.0

3.62 × 10−5

4.36 × 10−9 6.23 × 10−9

1 4.84 × 10−2

17 17

2 2

−371.4 −365.4

■

a

RSS is the residual sum of squares between experimental and correlated solubility values. bN is the number of experimental points. c AIC is the value of Akaike’s Information Criterion for each model.

ideal equation, which indicates that the λh equation can regress the solubility data much better than the modified Apelblat equation and the ideal equation. In (chloroform + methanol) mixed system the probability of the λh equation is 1419 and 1.26 × 1013 times higher than the modified Apelblat equation and the ideal equation getting minimum correlation error, and in (chloroform + ethanol) mixed systems the probability of the λh equation is 2.77 × 104 and 21 times higher than the other two equations getting the minimum correlation error, respectively.

■

REFERENCES

(1) Wall, M.; Wani, C.; Cook, C.; Palmer, K. Antitumor agent I: the isolation and struction of camptothecin, a novel alkaloidal leukemia and tumor inhibitor from camptotheca acuminate[J]. J. Am. Chem. Soc. 1966, 88, 3888−3890. (2) Hertzberg, R.; Caranfa, M.; Holden, K.; Jakas, D.; Liu, L. DNA Toposiomerases. Topoisomerase-Targeting Drugs; Academy Press: New York, 1994. (3) Zhang, Y.; Liu, J.; Zhang, L.; Wang, X. Solubility of 2,5-Di-tertbutylhydroquinone and process design for its purification using crystallization. J. Chem. Eng. Data 2015, 60, 1968−1974. (4) Sugunan, S.; Thomas, B. Salting Coefficients of 2-, 3-, and 4Methylbenzoic Acids. J. Chem. Eng. Data 1993, 38, 520−521. (5) Apelblat, A.; Manzurola, E. Solubilities of o-acetylsalicylic, 4aminosalicylic, 3,5-dinitrosalicylic, and p-toluic acid, and magnesiumDL-aspartate in water from T = (278 to 348) K. J. Chem. Thermodyn. 1999, 31, 85−91. (6) Shen, Y.; Liu, Z.; Li, T.; Ren, B. Determination and correlation of solubility of tylosin tartrate in alcohol mixtures. J. Chem. Thermodyn. 2015, 80, 128−134. (7) Li, C.; Wang, Q.; Shen, B.; Xiong, Z.; Chen, C. Solubilities of 5,10,15,20-Tetraphenylporphyrin and 5,10,15,20-Tetra(pchlorophenyl)porphyrin in Binary N,N-Dimethylformamide + Water Solvent Mixtures. J. Chem. Eng. Data 2015, 60, 2834−2842. (8) Prausnitz, J.; Lichtenthaler, R.; Azevedo, E. Molecular Thermodynamics of Fluid-Phase Equilibria, 3rd ed.; Prentice-Hall, PTR: Upper Saddle River, NJ, 1999. (9) Gao, X.; Xue, W.; Zeng, Z.; Fan, X. Determination and Correlation of Solubility of N-tert-Butylacrylamide in Seven Different Solvents at Temperatures between (279.15 and 353.15) K. J. Chem. Eng. Data 2015, 60, 2273−2279.

4. CONCLUSIONS The solubility data of camptothecine in chloroform, methanol, ethanol, and {chloroform + (methanol or ethanol)} mixed solvents were experimentally determined by using the gravimetric method from 275.76 to 328.42 K. The mole fraction solubility of camptothecine increased with increasing temperature, but the solubility reached a maximum first and then decreased with the increasing of the mole fraction of chloroform in mixture solvent. The experimental solubility data of camptothecine in chloroform, methanol, ethanol, and {chloroform + (methanol or ethanol)} mixed solvents were well correlated by using the modified Apelblat equation, the λh equation, and the ideal model, respectively. The modified Apelblat equation was proved to be the best-fit model for correlating the solubility of camptothecine from the analysis of AIC.

■

LIST OF SYMBOLS x1 the mole fraction solubility of camptothecine in the solvent x2 the mole fraction of chloroform in chloroform + methanol (or ethanol) mixed solvents xi,cal calculated solubility of camptothecine xi,exp experimental solubility of camptothecine m1, m2, m3 mass of camptothecine, chloroform, and methanol (g) M1, M2, M3 molecular weight of camptothecine, chloroform, and methanol (g·mol−1) A, B, C the three-parameter values of the Apelblat equation λ, h the two-parameter values of the λh equation a, b the two-parameter values of the ideal equation N the number of experimental points T the absolute temperature (K) Tm the normal melting temperature Thm the mean harmonic temperature AAD the average absolute deviation RMSD the root-mean-square deviation R gas constant (J·mol−1·K−1) R2 coefficient of determination x1 the mole fraction of camptothecine in the mixed solvents x2 the mole fraction of chloroform in the chloroform + methanol mixed solvents

AUTHOR INFORMATION

Corresponding Authors

*E-mail: [email protected] (Baozeng Ren). Tel.: +86-37167781223. Fax: +86-371-67781267. *E-mail: [email protected] (Tao Li). Tel.: +86-37167781267. Fax: +86-371-67781267. I

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(10) Wu, G.; Hu, Y.; Gu, P.; Yang, W.; Ding, Z.; Wang, C.; Qian, Y. Solubility and Solution Thermodynamics of Gibberellin A4 in Different Organic Solvents from 278.15 to 333.15 K. J. Chem. Eng. Data 2015, 60, 2104−2109. (11) Deng, Y.; Xu, L.; Sun, X.; Cheng, L.; Liu, G. Measurement and Correlation of the Solubility for 4,4′-Diaminodiphenylmethane in Different Solvents. J. Chem. Eng. Data 2015, 60, 2028−2034. (12) Buchowski, H.; Pietrzyk, S. Solvent activity along a saturation line and solubility of hydrogen-bonding solids. J. Phys. Chem. 1980, 84, 975−979. (13) Ksiazczak, A.; Moorthi, K.; Nagata, I. Solid-solid transition and solubility of even n-alkanes. Fluid Phase Equilib. 1994, 95, 15−29. (14) Puri, S.; Handa, G.; Suri, O.; Qazi, G. Urea-Mediated Regioselective Nitration of (20S)-Camptothecin. Synth. Commun. 2004, 34, 3443−3448. (15) Burnham, K.; Anderson, D.; Huyvaert, K. AIC model selection and multimodel inference in behavioral ecology: some background, observations, and comparisons. Behav. Ecol. Sociobiol. 2011, 65, 23−35. (16) Kai, Y.; Hu, Y.; Liu, Y.; Liang, M.; Yang, W.; Xi, Y. The solubility of mercaptosuccinic acid in water + (methanol, ethanol, acetone) mixtures from (278.15 to 333.15 K). Fluid Phase Equilib. 2014, 361, 282−288. (17) Krug, R.; Hunter, W.; Grieger, R. Enthalpy-entropy compensation. 1. Some fundamental statistical problems associated with the analysis of van’t Hoff and Arrhenius data. J. Phys. Chem. 1976, 80, 2335−2341.

J

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