Extractions of Alkaloids Codeine and Caffeine with [Bmim][BF4

Article Cite This: J. Chem. Eng. Data XXXX, XXX, XXX−XXX

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Extractions of Alkaloids Codeine and Caffeine with [Bmim][BF4]/ Carbohydrate Aqueous Biphasic Systems as a Novel Class of Liquid− Liquid Extraction Systems Bahman Jamehbozorg and Rahmat Sadeghi* Department of Chemistry, University of Kurdistan, Sanandaj 6617715175, Iran

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S Supporting Information *

ABSTRACT: Liquid−liquid equilibrium (LLE) data for several carbohydrate + IL aqueous biphasic systems, including the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) and six carbohydrates: monosaccharides (D-(+)-glucose, D-(−)-fructose, L-(+)-arabinose, and D-(+)-xylose) and disaccharides (sucrose and maltose) were obtained at different temperatures. With fitting the obtained LLE data to a Setschenow-type equation, the positive (soluting-out effect) soluting-out coefficients, ks, were obtained. The obtained ks values increase by decreasing temperature as well as the hydrophobicity of the sugars. Extractions of two alkaloids, including codeine and caffeine, with [Bmim][BF4]/carbohydrate aqueous biphasic systems were examined. The effect of temperature, tie-line length (TLL), hydrophilicity of sugars, and physicochemical properties of alkaloids on the partition coefficient and standard molar Gibbs free energy changes (ΔtrG0m) were studied. Both codeine and caffeine had high tendency for hydrophobic IL-rich phase, and this orientation increased with increasing TLL, hydrophilicity of sugars, and decreasing temperature.

1. INTRODUCTION Bioseparation is an important and fundamental part in biotechnology and therefore there is a potent propensity for the development of the alternative extraction and purification technics for biologically active materials that can be easily scaled-up.1−4 The liquid−liquid extraction (LLE) with organic solvents has a malicious effect on biomaterials, environment, and human health due to their problems such as flammability, toxicity, and high volatility of these solvents. Hence, in recent decades, the aqueous biphasic systems (ABS) have been wellrecognized as a gentle, affordable, helpful, and ideal downstream processing strategy for the recovery of biomolecules and have widely been used for the separation and purification of a wide range of molecules of biotechnological importance from several sources, for example, cell organelles, enzymes, proteins, and nucleic acids.5,6 Because the main component of both phases of ABS is water, these systems offer a biocompatible medium for various biomolecules, maintain their native conformation and biological activity, and hence allow high yields in the purification processes.7−10 The ABS, which have two coexisting equilibrium immiscible aqueous phases, are formed when either two polymers, one polymer and one salt, one polymer and one ionic liquid (IL), one polymer and one carbohydrate, or one polymer and one amino acid are mixed above a critical concentrations of pairs of solutes. The partitioning of biologically active molecules between the ABS phases depends © XXXX American Chemical Society

on several factors, namely pH, temperature, and phase composition.11 ILs are low melting temperature, nonflammable, and nonvolatile organic salts which have a high thermal and chemical sustainability. ILs have similar properties with watersoluble polymers,12 and similarly, they can form ABS with salts, polymers, amino acids, and carbohydrates in aqueous solutions.13 One of the important excellent properties of the IL-containing ABS is the possibility of controlling their phase’s polarities by an appropriate selecting of the ions that combined to form a given IL. Therefore, after introduction of the topic by Rogers and coworkers,14 a large number of scholars have been studying on the IL-based ABS.13,15,16 In recent years, carbohydrates were introduced as the soluting-out agent in the IL-containing ABS.17−20 Because of the nontoxicity and biodegradability of carbohydrates, using the IL-carbohydrate aqueous biphasic systems for bioseparation have various benefits such as facile recycling of IL from phases,21 and eliminate the pH effect on the biomaterials activities.19 For the first time, Rogers and coworkers14 found that ABS can be employed to recycle ILs from aqueous mixture. Later, Zhang and et al.21,22 were recycled [Bmim][BF4] from the [Bmim][BF4]−carbohydrate ABS. Received: July 31, 2018 Accepted: February 4, 2019

A

DOI: 10.1021/acs.jced.8b00678 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

Journal of Chemical & Engineering Data

Article

were mixed in the single-mouth flask connected to a reflux condenser until the IL was dissolved entirely. Eleven grams (0.2 mol) of sodium tetrafluoroborate (NaBF4) was added to the obtained [Bmim][Br] solution, and then the mixture was stirred at 55 °C for 48 h. The reaction mixture was filtered to eliminate the white solid particles and vacuum distilled. To remove the bromide salt, methylene chloride as the extraction solvent was added to the remainder liquid, and the white precipitated sodium bromide salt was obtained and separated by filtration. The obtained solution by filtration was dissolved in excess amount of methylene chloride, and then it was washed with deionized water (3−5 times) to ensure perfect removal of NaBr salt. Aqueous phase was examined with saturated silver nitrate solution. The product was desiccated under vacuum conditions at 120 °C for more than 5 h to eliminate the traces of methylene chloride and water. Finally, a colorless to pale yellow liquid with a yield of 75% was obtained. The synthesized [Bmim][BF4] was identified by FTIR, 1H NMR, and 13C NMR spectroscopy, and its water content measured by Karl Fischer titration was below 1000 ppm. 1H NMR spectrum of the synthesized [Bmim][BF4] was shown in the Supporting Information. 2.4. Liquid−Liquid Equilibrium Measurements. To determine the tie-lines, feed solutions (about 5 mL) were prepared by mixing certain amounts of [Bmim][BF4], carbohydrate, and water in the tube. Samples were stirred for 1 h and then settled for 12 h at the working temperature (298.15, 303.15, 308.15, 313.15, and 318.15 K) to form completely clear phases. After the equilibrium was achieved, samples of each phase were transferred to separate tubes using syringe and then analyzed. Because the optical rotation of the carbohydrates in aqueous mixture was not affected by presence of the IL, the amounts of carbohydrates in both phases were analyzed by polarimetry method with an Anton Paar Gyromat Digital Automatic Polarimeter with an uncertainty of ±0.0002. The concentrations of [Bmim][BF4] in the equilibrium phases were measured using the refractometry analysis using an Anton Paar Abbemat refractometer at 298.15 K. The refractive index of a ternary solution, nD, can be related to the mass fractions of IL, wIL, and sugar, wC by the following equation:

Literature review shows that there is very limited information about the use of IL/carbohydrate ABS in bioseparation (there is only one report for application of these systems in bioseparation).19 These mixtures can also be used for extraction of valuable biomolecules. On the other hand, it has been revealed that these ABSs can be employed to recycle hydrophilic ILs from aqueous mixture.21,22 Alkaloids are a special group of natural opiates that for a long time have been used in pharmacological industries. There is strong commercial interest for separation, enrichment, and purification of these compounds in biotechnology. Aiming at investigating the effects of number of hydroxyl groups and stereochemical features of sugar molecules, physicochemical properties of biomolecules, and temperature on the partitioning behavior, in this work, six sugars, including monosaccharides D-(+)-glucose, D-(−)-fructose, L-(+)-arabinose, D(+)-xylose, and disaccharides sucrose and maltose, were mixed with 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) in aqueous solution to form the different ABSs and then the partitioning of alkaloids codeine and caffeine in them was investigated.

2. EXPERIMENTAL SECTION 2.1. Materials. The characteristics of chemicals utilized in this study were presented in Table 1. The aqueous solutions were prepared by double distilled and deionized water. [Bmim][BF4] was synthesized and purified according to the methods explained in the literature.23 Table 1. Specification of Chemicals Used in this Work chemical D-(+)-xylose L-(+)-arabinose D-(−)-fructose D-(+)-glucose sucrose maltose monohydrate caffeine 1-methylimidazole 1-bromobutane sodium tetrafluoroborate codeine

[Bmim][BF4]

CAS registry number

mass fraction purity

Merck Merck Merck Merck Merck Merck Merck Merck Merck Merck

58-86-6 5328-37-0 57-48-7 50-99-7 57-50-1 6363-53-7 58-08-2 616-47-7 109-65-9 13755-29-8

≥0.99 ≥0.99 ≥0.99 ≥0.99 ≥0.98 ≥0.99 ≥0.98 ≥0.99 ≥0.98 ≥0.97

Shafa Company synthetic

76-57-3

≥0.98

source

nD = n0 + a1wIL + a 2wC

(1)

n0, which is the refractive index of pure water, was set to 1.332424 at 298.15 K. The obtained values of coefficients a1 and a2 for the investigated systems at 298.15 K are given in Table 2. The uncertainty in the measurement of wIL was better than 0.002. On the basis of our experiments, eq 1 is valid only for dilute solutions of IL and sugars. Therefore, all samples were diluted sufficiently prior to refractive index (nD) and optical rotation (ri) measurements to fit within the calibration range.

≥0.98

2.2. Synthesis of [Bmim][Br]. Equimolar amounts of 1bromobutane and 1-methylimidazole (slightly less than that of bromobutane) were mixed with a suitable quantity of ethyl acetate (solvent) in a round-bottomed flask connected to a reflux condenser at 70 °C for 48 h, and the mixture was stirred under an argon atmosphere until two phases formed. The upper phase, which contained unreacted starting substances along with the solvent (ethyl acetate), was decanted, and fresh solvent was again added. This operation was replicated five times. Eventually, the [Bmim][Br] phase (bottom phase) was vacuum desiccated for 3 h at 90 °C to eliminate the traces of the solvent. The IL was identified by FT-IR, 1H NMR, and 13C NMR spectroscopy, and its water content measured using an 831 Coulometric Karl Fischer Titrator was below 3000 ppm. 2.3. Synthesis of [Bmim][BF4]. Twenty-two grams (0.1 mol) [Bmim][Br] and about 100 mL of acetone (as solvent)

Table 2. Refractive Index Calibration Constants of Eq 1 at 298.15 K and 84.5 kPa system [Bmim][BF4] [Bmim][BF4] [Bmim][BF4] [Bmim][BF4] [Bmim][BF4] [Bmim][BF4] B

+ + + + + +

L-(+)-arabinose

+ water D-(+)-xylose + water D-(+)-glucose + water D-(−)-fructose + water maltose + water sucrose + water

a1

a2

0.1419 0.1386 0.1497 0.1489 0.1442 0.1501

0.0711 0.0709 0.0709 0.0704 0.0704 0.0706



Article

Table 3. Experimental Phase Equilibrium Compositions for the Investigated [Bmim][BF4] (IL)−Carbohydrate (C) ABS at Different Temperatures and 84.5 kPaa overall composition carbohydrate maltose

sucrose

glucose

fructose

arabinose

maltose

sucrose

glucose

fructose

arabinose

maltose

sucrose

glucose

fructose

arabinose

sucrose

wIL

wC

0.4046 0.4349 0.2639 0.3997 0.3972 0.3958 0.3699 0.3915 0.2213 0.2583 0.2760 0.3014 0.3542 0.3174 0.4307 0.4205 0.4010 0.4110

0.1121 0.1348 0.2374 0.1125 0.1463 0.1721 0.1148 0.1389 0.2382 0.2727 0.2479 0.2763 0.2789 0.3106 0.0891 0.1084 0.1325 0.1647

0.3952 0.4038 0.3897 0.3912 0.4128 0.3916 0.4289 0.3548 0.3402 0.3842 0.4284 0.3442 0.2545 0.2047 0.4091 0.4332 0.4568

0.1129 0.1382 0.1621 0.0954 0.1257 0.1646 0.1844 0.1284 0.1582 0.1901 0.2224 0.2178 0.3134 0.3950 0.1124 0.1265 0.1442

0.4156 0.4238 0.4418 0.3942 0.4351 0.4538 0.4326 0.4116 0.4676 0.4312 0.3544 0.4361 0.3960 0.3449 0.4403 0.4249 0.4075

0.1026 0.1125 0.1285 0.1300 0.1625 0.1809 0.2215 0.1146 0.1559 0.2250 0.1590 0.1630 0.2343 0.3079 0.1440 0.1745 0.1974

0.3763 0.4229

0.1471 0.1802

top phase wIL 298.15 0.1676 0.7487 0.7835 0.1978 0.1439 0.7604 0.1861 0.1341 0.1023 0.8376 0.7773 0.8106 0.8234 0.8468 0.2382 0.2030 0.1710 0.1324 303.15 0.1934 0.7088 0.7343 0.2647 0.1837 0.7333 0.7794 0.1864 0.1504 0.7727 0.8255 0.7855 0.8311 0.8681 0.2554 0.2166 0.1866 308.15 0.2739 0.1993 0.6910 0.2219 0.7272 0.7617 0.7954 0.2224 0.7658 0.8252 0.1661 0.7571 0.8249 0.8647 0.2234 0.7171 0.7378 313.15 0.6121 0.7352

C

bottom phase wC

wIL

wC

TLL

0.1975 0.0143 0.0126 0.1781 0.2435 0.0148 0.1656 0.2242 0.2783 0.0202 0.0313 0.0255 0.0306 0.0217 0.1393 0.1742 0.2079 0.2736

0.7048 0.1179 0.0913 0.6618 0.7169 0.1141 0.7204 0.7882 0.8079 0.0756 0.0963 0.0784 0.0686 0.0609 0.6701 0.7062 0.7444 0.7853

0.0172 0.2698 0.3211 0.0372 0.0262 0.2896 0.0180 0.0202 0.0174 0.3481 0.3196 0.3814 0.4235 0.4445 0.0359 0.0353 0.0342 0.0286

0.5666 0.6806 0.7578 0.4849 0.6128 0.7023 0.5543 0.6852 0.7523 0.8296 0.7395 0.8141 0.8509 0.8924 0.4441 0.5220 0.5991 0.6974

0.1880 0.0196 0.0162 0.1386 0.2102 0.0201 0.0146 0.1828 0.2262 0.0234 0.0179 0.0239 0.0181 0.0135 0.1627 0.2066 0.2586

0.6701 0.1546 0.1306 0.6001 0.6844 0.1292 0.1028 0.6859 0.7314 0.0968 0.0520 0.1080 0.0771 0.0458 0.6566 0.7047 0.7465

0.0246 0.2463 0.2824 0.0350 0.0263 0.2732 0.3363 0.0340 0.0264 0.3138 0.4146 0.3207 0.3975 0.4797 0.0460 0.0383 0.0353

0.5039 0.5988 0.6598 0.3510 0.5334 0.6550 0.7492 0.5212 0.6144 0.7356 0.8693 0.7397 0.8441 0.9453 0.4178 0.5163 0.6028

0.1534 0.2044 0.0259 0.1964 0.0240 0.0188 0.0161 0.1804 0.0243 0.0182 0.2240 0.0279 0.0199 0.0147 0.2354 0.0526 0.0489

0.6127 0.6610 0.1514 0.6314 0.1277 0.0992 0.0808 0.6747 0.1038 0.0665 0.7205 0.1181 0.0772 0.0406 0.6892 0.1546 0.1452

0.0357 0.0278 0.2638 0.0425 0.3100 0.3613 0.4194 0.0326 0.3187 0.4174 0.0277 0.2975 0.3896 0.4722 0.0537 0.3008 0.3253

0.3587 0.4943 0.5897 0.4375 0.6642 0.7458 0.8206 0.4758 0.7245 0.8573 0.5881 0.6935 0.8341 0.9426 0.5000 0.6148 0.6539

0.0477 0.0216

0.2115 0.1166

0.2154 0.3342

0.3638 0.5338

K

K

K

K



Article

Table 3. continued overall composition carbohydrate

glucose

fructose

arabinose

sucrose

glucose

fructose

arabinose

wIL

wC

0.4531 0.4146 0.4176 0.4404 0.4243 0.3784 0.4768 0.4028 0.3475 0.4260 0.4015 0.4741

0.2066 0.1140 0.1341 0.1633 0.1995 0.1705 0.1601 0.2368 0.3076 0.1473 0.1935 0.2251

0.3955 0.4212 0.4509 0.4304 0.4354 0.4166 0.3931 0.4711 0.4413 0.4324 0.3988 0.4078

0.1655 0.1809 0.2073 0.1465 0.1704 0.1932 0.1785 0.1776 0.2310 0.2615 0.1931 0.2119

top phase wIL 313.15 K 0.7871 0.1937 0.1654 0.7408 0.7784 0.6420 0.7307 0.7848 0.8201 0.2206 0.6790 0.7955 318.15 K 0.6691 0.7119 0.7698 0.6802 0.7293 0.7507 0.6765 0.7441 0.7973 0.8267 0.6639 0.7224

bottom phase wC

wIL

wC

TLL

0.0161 0.1879 0.2287 0.0322 0.0276 0.0639 0.0445 0.0346 0.0306 0.2310 0.0699 0.0431

0.0932 0.6752 0.7047 0.0858 0.0953 0.1855 0.1298 0.0862 0.0674 0.6874 0.1778 0.1122

0.4103 0.0377 0.0327 0.3186 0.3633 0.2520 0.3246 0.4015 0.4636 0.0509 0.3048 0.4429

0.5711 0.5044 0.5738 0.7149 0.7611 0.4937 0.6630 0.7891 0.8684 0.5003 0.5535 0.7917

0.0349 0.0280 0.0199 0.0426 0.0336 0.0305 0.0537 0.0455 0.0332 0.0316 0.0741 0.0580

0.2178 0.1403 0.1181 0.1336 0.0928 0.0860 0.1583 0.1248 0.0830 0.0618 0.1738 0.1490

0.2523 0.3285 0.4049 0.2697 0.3264 0.3488 0.2789 0.3495 0.4244 0.4764 0.3010 0.3471

0.3955 0.4862 0.5258 0.5919 0.7006 0.7370 0.5650 0.6899 0.8144 0.8848 0.5401 0.6422

a

Standard uncertainties u for atmospheric pressure, temperature, mass fraction of the sugars, and mass fraction of the IL are u(p) = 1 kPa, u(T) = 0.2 K, u(wC) = 0.002, and u(wIL) = 0.004, respectively.

2.5. Partitioning of Biomolecules. For each system, three or four tie-lines were selected to evaluate the partitioning of the alkaloids at 298.15 and 308.15 K. Mixtures were prepared with exactly the same overall composition of the selected tie-lines. Solutions by using the very dilute aqueous solutions of alkaloids (for caffeine 100 ppm and for codeine 500 ppm) were prepared. Achieving equilibrium and sampling process were conducted similar to the tie-line determination explained above. The values of codeine and caffeine in the equilibrium phases were determined by UV−vis spectroscopy. Absorption of caffeine and codeine were obtained, respectively, at 272 and 284 nm using a spectrophotometer SPEKOL 2000 (Analytik Jena). Calibration curves were previously obtained for each analyte. It was found that the interference of IL and sugars with the analytical method was not considerable at the magnitude of the dilutions performed.

solute2 (unfavorable for phase formation) interactions. Since the investigated sugars are more hydrophilic than the IL [Bmim][BF4] and also there is an unfavorable [Bmim][BF4]sugar interaction, by addition of the carbohydrates to the aqueous IL solutions, the ions of [Bmim][BF4] as well as the sugars molecules exclude themselves from the vicinity of each other by strengthen their interactions with water molecules. Entropies of water molecules in the hydration layer of the hydrophilic compounds are smaller than those in the bulk and become smaller by strengthen the solutes−water interactions. Hence, entropy of the system decreases when the carbohydrates are added to the aqueous IL solutions, and therefore the ternary [Bmim][BF4]−sugars−water systems are instable and at concentrations higher than a critical point tend to phase separation to two sugar-rich and IL-rich aqueous phases. Effect of Temperature. As shown in Figure 1 and Table 4, at the same overall composition, the slope of the all tie-lines decreases by increasing temperature. The IL−water interactions strengthen with increasing temperature. For this reason, with an increase in temperature, the water molecules spontaneously migrate from the carbohydrate-rich phase to the IL-rich phase to reach equilibrium. Therefore, by increasing temperature, the IL- and sugar-rich phases become more dilute and concentrated, respectively. Due to the change of the water content of the coexisting phases, the volumes of IL-rich and sugar-rich phases increased and decreased, respectively, by increasing temperature. Similar to some the polymeric ABS,27,28 our experimental observations show that the phase inversion may occur in the [Bmim][BF4]−carbohydrate ABS. In this case, as can be seen

3. RESULTS AND DISCUSSION 3.1. Liquid−Liquid Equilibria. Liquid−liquid equilibria data were measured for the investigated [Bmim][BF4]− carbohydrate ABS at various temperatures, and the obtained data are given in Table 3. In the case of aqueous [Bmim][BF4] + xylose system, due to precipitation of this sugar, the tie-lines have not been determined. Meanwhile, the experimental binodal data of this work, which has already been published,24 are compared with the literature in Figure S2 of the Supporting Information.20,22,25,26 This figure shows that our experimental data are in good agreement with the literature. Generally, phase formation in ABS is the result of rivalry between the solutes−water (favorable for phase formation) and solute1− D



Article

Figure 1. Effect of temperature on the equilibrium phase compositions for the [Bmim][BF4] (IL)−sucrose (C) ABS at different temperatures: ×, feed compositions; ●, 298.15 K; ◆, 308.15 K; ▲, 313.15 K; ○, 298.15 K, ◇, 308.15 K; △, 318.15 K.

Figure 2. Phase diagram for the [Bmim][BF4] (IL)−arabinose (C) ABS at (a) 298.15 K, (b) 308.15 K, and (c) 313.15 K; (○), experimental binodal; (●),24 feed compositions; (- × -), experimental tie-lines. Solid tie-lines are for normal (the IL-rich phase is top phase) and dashed lines for inversion phases.

from Table 3, at high temperatures and for the tie-lines far from the binodal curve, the IL-rich phase is the top phase. By decreasing the temperature, for the tie-lines near the binodal curve, phase inversion occurs so that the IL-rich phase which is upper phase at higher temperatures becomes the bottom phase at lower temperatures. As mentioned above, by decreasing the temperature, the IL-rich phase becomes more concentrated, and therefore, its density increases so that it becomes larger than the sugar-rich phase and the phase inversion occurs. For the tie-lines near the binodal curve, the compositions of the coexisting phases are close to each other, and therefore, phase inversion by decreasing temperature occurs more easily than the tie-lines far from the binodal curve. Figure 2 and the data collected in Table 3 show that the concentration range in which the IL-rich phase is the bottom phase increases by decreasing the temperature. Effect of Sugar Type. With the aim of studying the effect of sugar type on the soluting-out effect in aqueous IL solutions, different sugars, including several monosaccharides and disaccharides, were selected, and the effects of structural isomers, epimers, and −OH groups and etheric oxygen numbers were investigated. The Setschenow-type equation

proposed by Hey et al.29 was successfully used to correlate the tie-line compositions of the investigated ABS:

i ji m zyz c i c i lnjjj IL zz = k i(mIL − mIL ) + ks(mC − mC) c z j mIL (2) k { where mIL, mc, ki, and ks are [Bmim][BF4] molality, sugar molality, a parameter relating the [Bmim][BF4] activity coefficient to its molality, and the soluting-out coefficient, respectively.30 Superscripts i and c denote the [Bmim][BF4]rich and sugar-rich phases, respectively. By assuming that the term ki(mcIL − miIL) is smaller than the term ks(mcC − miC), a Setschenow-type relation can be derived from this equation. This condition would imply that ki ≪ ks because the absolute values of (mcIL − miIL) exceed the (mcC − miC) values. According to Table 5, the ks values obtained from eq 2 are positive and in most cases increase with increasing in the oxygen atom number on the sugar molecules and decreasing temperature. This trend is in agreement with the extent of the two-phase area.

Table 4. Slope of Tie-Lines for Some [Bmim][BF4]−Carbohydrate ABS at Different Temperatures and 84.5 kPa overall composition wIL

wC

0.5121 0.2455 0.6571 0.4727 0.5697

0.0900 0.2679 0.0730 0.1297 0.0649

0.6304 0.5620 0.5639 0.3138

0.0796 0.0901 0.0839 0.2239

298.15 K

303.15 K sucrose −2.7227 −2.1032 −2.1032 −2.3868

−3.2931 −2.7045 −3.2064

308.15 K

313.15 K

318.15 K

−2.3888 −1.9789 −1.9343 −2.0759 −2.6608

glucose −2.3275 −2.4069 −3.9046

−2.7515 −2.2486

E

−2.1738 DOI: 10.1021/acs.jced.8b00678 J. Chem. Eng. Data XXXX, XXX, XXX−XXX


Article

Table 5. Values of Parameters from Least-Squares Linear Fits to the Setschenow-type Equation (Eq 2) for Aqueous [Bmim][BF4] + Carbohydrate ABS at Different Temperatures and 84.5 kPa 298.15 K

303.15 K

−1

ks/kg mol maltose sucrose glucose fructose arabinose

1.3759 1.2425 0.9271 0.3910 0.8136

R

308.15 K

−1

2

ks/kg mol

0.9999 0.9957 0.9240 0.9964 0.9331

1.4928 1.2062 0.6738 0.6378 0.5878

−1

2

R

ks/kg mol

0.9584 0.9729 0.9967 0.9839 0.9953

1.4872 1.0407 0.6764 0.6346 0.6433

313.15 K R

2

0.9540 0.9771 0.9744 0.9988 0.9643

ks/kg mol 1.0048 0.6148 0.5705 0.3358

318.15 K

−1

R

2

ks/kg mol−1

R2

0.8219 0.7413 0.5529

0.9167 0.9882 0.9991

0.9647 0.8777 0.9759 1

Table 6. Experimental Equilibrium Compositions, Partition Coefficients of Caffeine, Pcaff, Transfer Standard Molar Gibbs Free Energy Changes, ΔtrG0m, and Tie-Line Lengths in [Bmim][BF4]−Carbohydrate ABS at Different Temperatures and 84.5 kPaa overall composition

top phase

wIL

wC

104wcaff

wIL

0.3997 0.3972 0.3958

0.1125 0.1463 0.1721

0.4657 0.3529 0.3657

0.1978 0.1439 0.7604

0.3699 0.2213 0.2583

0.1148 0.2382 0.2727

0.5224 0.4217 0.4860

0.1861 0.1023 0.8376

0.4307 0.4205 0.4110

0.0891 0.1084 0.1647

0.5708 0.5705 0.5182

0.2382 0.2030 0.1324

0.3942 0.4351 0.4538

0.1300 0.1625 0.1809

0.4912 0.4974 0.5230

0.2219 0.7272 0.7617

0.4326 0.4676 0.4312

0.1225 0.1559 0.2250

0.6387 0.5443 0.4947

0.1338 0.7658 0.8252

0.4508 0.4403 0.4249

0.1191 0.1440 0.1745

0.3791 0.3546 0.3118

0.2624 0.2234 0.7171

wC

bottom phase 104wcaff

wIL

wC

104wcaff

[Bmim][BF4] (IL) + sucrose (C) + water at 298.15 K 0.1781 0.9018 0.6618 0.0372 3.7552 0.2435 0.5894 0.7169 0.0262 3.2933 0.0148 3.4609 0.1141 0.2896 0.5422 [Bmim][BF4] (IL) + glucose (C) + water at 298.15 K 0.1656 0.8004 0.7204 0.0180 3.5776 0.2783 0.5382 0.8079 0.0174 3.8612 0.0202 4.5168 0.0756 0.3481 0.6789 [Bmim][BF4] (IL) + arabinose (C) + water at 298.15 K 0.1393 1.6922 0.6701 0.0359 3.0516 0.1742 1.1606 0.7062 0.0353 3.4805 0.2736 0.8372 0.7853 0.0286 4.3087 [Bmim][BF4] (IL) + sucrose (C) + water at 308.15 K 0.1964 1.0129 0.6314 0.0425 3.6316 0.0240 3.2943 0.1277 0.3100 0.8278 0.0188 3.8317 0.0992 0.3613 0.9466 [Bmim][BF4] (IL) + glucose (C) + water at 308.15 K 0.2281 0.9721 0.7117 0.0309 2.9708 0.0243 3.0653 0.1038 0.3187 0.8979 0.0182 3.1446 0.0665 0.4174 0.6811 [Bmim][BF4] (IL) + arabinose (C) + water at 308.15 K 0.1908 1.5689 0.6364 0.0599 3.9020 0.2354 1.2173 0.6892 0.0537 3.7530 0.0526 3.2790 0.1546 0.3008 1.1786

TLL

Pcaff

ΔtrG0m/kJ mol−1

0.4849 0.6128 0.7023

4.1639 5.5879 6.3827

−3.5359 −4.2651 −4.5947

0.5543 0.7523 0.8296

4.4696 7.1736 6.6531

−3.7115 −4.8843 −4.6976

0.4441 0.5220 0.6974

1.8033 2.9988 5.1467

−1.4616 −2.7223 −4.0612

0.4375 0.6642 0.7458

3.5854 3.9796 4.0479

−3.2713 −3.5385 −3.5821

0.6106 0.7245 0.8573

3.0561 3.4140 4.6168

−2.8621 −3.1458 −3.9190

0.3962 0.5000 0.6148

2.4871 3.0830 2.7821

−2.3342 −2.8845 −2.6214

a

Standard uncertainties u for atmospheric pressure, temperature, mass fraction of the sugars, mass fraction of the IL, and partition coefficients of caffeine are u(p) = 1 kPa, u(T) = 0.2 K, u(wC) = 0.002, u(wIL) = 0.004, and u(PCaff) = 0.10, respectively.

3.2. Partitioning of Biomolecules. Extraction of two model biomolecules from the alkaloids group, including codeine and caffeine, which have many biological and pharmaceutical applications, was examined. For this purpose, aqueous biphasic [Bmim][BF4] + carbohydrate systems, including sucrose, glucose, and arabinose at 298.15 and 308.15 K, were selected. Tie-line length (TLL), which shows the equilibrium compositions of two phases and can be used to investigate the effect of ABS composition on the partitioning of the alkaloids, is calculated by the following equation: top TLL = [(wIL − wILbottom)2 + (wCtop − wCbottom)2 ]0.5

where Ci,IL and Ci,C are the concentration of the biomolecule in the ionic liquid and sugar-rich phases, respectively. The obtained values of Pi are represented in Tables 6 and 7. Hydrolysis of the fluoride containing ILs has been extensively studied.31−34 Freire et al.32 showed that the IL [Bmim][BF4] in aqueous mixtures with water content about 50 wt % decomposes to ∼2% byproducts after being heated to 373 K for 30 min. The hydrolysis of the ILs [Bmim][SbF6], [Bmim][PF6], and [Bmim][BF4] at ordinary temperatures for a period of several days was studied by Yun et al.31 According to the results of this study, fluoride ion was quickly produced from [Bmim][SbF6] during the first 48 h. But, the reaction rate (and therefore the amount of produced fluoride) for the hydrolysis of the IL [Bmim][BF4] was much less than those of the IL [Bmim][SbF6]. Ji et al.34 investigated the effect of hydrolysis of [BF4]− on the vapor−liquid equilibria behavior of aqueous [Bmim][BF4] + alcohol solutions, and it was found that there is no significant change in the results during the experiments lasting at least 8 h. Because the complete phase separation process and alkaloid analysis does not take much

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where wIL and wC are the weight fractions of the IL and carbohydrate, respectively. Partition coefficients, Pi, of the studied biomolecules (Pcode for codeine and Pcaff for caffeine) are defined by the following equation: Pi =

Ci,IL Ci,C

(4) F



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Table 7. Experimental Equilibrium Compositions, Partition Coefficients of Codeine, Pcode, Transfer Standard Molar Gibbs Free Energy Changes, ΔtrG0m, and Tie-Line Lengths in [Bmim][BF4]−Carbohydrate ABS at Different Temperatures and 84.5 kPaa overall composition

top phase 4

wIL

wC

10 wcode

wIL

0.3997 0.3972 0.4205

0.1125 0.1463 0.1916

2.3123 1.9855 2.5290

0.1978 0.1439 0.7919

0.3699 0.3915 0.2213

0.1148 0.1389 0.2382

2.5826 2.6019 2.6970

0.1861 0.1341 0.1023

0.4307 0.4205 0.4010

0.0891 0.1084 0.1325

1.2965 1.4216 1.2386

0.2382 0.2030 0.1710

0.3942 0.4351 0.4326

0.1300 0.1625 0.2215

2.5308 2.5981 2.6708

0.2219 0.7272 0.7954

0.4119 0.4326 0.4312

0.1103 0.1225 0.2250

2.5749 2.5557 2.6643

0.1714 0.1338 0.8252

0.4508 0.4403 0.4249 0.4075

0.1191 0.1440 0.1745 0.1974

2.5986 1.4743 1.2757 2.6060

0.2624 0.2234 0.7171 0.7378

wC

bottom phase 4

10 wcode

wIL

wC

104wcode

[Bmim][BF4] (IL) + sucrose (C) + water at 298.15 K 0.1781 3.3114 0.6618 0.0372 13.3873 0.2435 2.2171 0.7169 0.0262 15.6431 0.0105 16.2254 0.0856 0.3487 1.6324 [Bmim][BF4] (IL) + glucose (C) + water at 298.15 K 0.1656 3.3495 0.7204 0.0180 16.1222 0.2242 1.9743 0.7882 0.0202 16.3125 0.2783 1.6072 0.8079 0.0174 20.9682 [Bmim][BF4] (IL) + arabinose (C) + water at 298.15 K 0.1393 5.1063 0.6701 0.0359 13.8331 0.1742 3.7358 0.7062 0.0353 15.8132 0.2079 3.4609 0.7444 0.0342 14.8223 [Bmim][BF4] (IL) + sucrose (C) + water at 308.15 K 0.1964 4.6249 0.6314 0.0425 15.0827 0.0240 14.7140 0.1277 0.3100 2.1565 0.0161 16.1431 0.0808 0.4194 1.5474 [Bmim][BF4] (IL) + glucose (C) + water at 308.15 K 0.1872 5.1405 0.6642 0.0401 16.3762 0.2281 2.5306 0.7117 0.0309 14.7321 0.0182 17.4531 0.0665 0.4174 1.7250 [Bmim][BF4] (IL) + arabinose (C) + water at 308.15 K 0.1908 7.0830 0.6364 0.0599 17.1872 0.2354 3.5844 0.6892 0.0537 11.8826 0.0526 12.8272 0.1546 0.3008 2.9880 0.0489 21.0965 0.1452 0.3253 3.5887

TLL

PCode

ΔtrG0m/kJ mol−1

0.4849 0.6128 0.7831

4.0428 7.0556 9.9397

−3.4628 −4.8432 −5.6927

0.5543 0.6852 0.7523

4.8133 8.2624 13.0462

−3.8952 −5.2346 −6.3668

0.4441 0.5220 0.5991

2.7090 4.2329 4.2828

−2.4703 −3.5767 −3.6057

0.4375 0.6642 0.8206

3.2612 6.8231 10.4303

−3.0285 −4.9198 −6.0071

0.5143 0.6106 0.8573

3.1857 5.8216 10.1177

−2.9685 −4.5131 −5.9291

0.3962 0.5000 0.6148 0.6539

2.4265 3.3151 4.2929 5.8786

−2.2710 −3.0705 −3.7327 −4.5380

a

Standard uncertainties u for atmospheric pressure, temperature, mass fraction of the sugars, mass fraction of the IL, and partition coefficients of codeine are u(p) = 1 kPa, u(T) = 0.2 K, u(wC) = 0.002, u(wIL) = 0.004, and u(PCode) = 0.10, respectively.

time (about 12 h), the slight hydrolysis of [Bmim][BF4] did not affect the partition coefficient data. In this type of extraction, the effective efficiency of each product depends not only on the system parameters (tie-line length, temperature, the composition of coexisting phases) but also on the physicochemical properties of the product such as its molecular weight, structural properties, and hydrophobicity. Figure 3 represents the experimental values of Pi versus TLL for codeine and caffeine at 298.15 and 308.15 K. As can be seen from this Figure, both alkaloids were concentrated in the IL-rich phase (Pi > 1). This partitioning behavior is driven by different interactions, including hydrophobic interactions between the aliphatic parts of the imidazolium cation and the alkaloids, π···π interactions between the aromatic part of the imidazolium cation and the alkaloids, which has already been demonstrated,35 and hydrogen-bonding, weak interaction between alkaloid and sugar. Effect of TLL on Partitioning Behavior. Figure 4 presents the plots of ln Pi against TLL. For all systems, the plots are linear and may be generally described as ln Pi = αi TLL

Figure 3. Plots of partition coefficients of alkaloids vs tie-line length in the [Bmim][BF4]−sucrose ABS at 298.15 K (filled symbol) and 308.15 K (empty symbol): (●,○), codeine; (◆,◇), caffeine.

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alkaloids and imidazolium cation increase. From Table 8, it can also be seen that for all systems, αcode > αcaffe, and their values decrease by increasing temperature. Effect of Temperature. The obtained results show that for both alkaloids investigated in this work, the values of Pi increase with a decrease in temperature. [Bmim][BF4] and then the IL-rich phase become more hydrophobic by decreasing temperature. Therefore, the tendency of the

where αi is a constant representing the effect of TLL on the partition coefficient of the alkaloid i in the system. The obtained values of αi are presented in Table 8. This table shows that, for all systems αi > 0, which indicates that the values of Pi increase by increasing the TLL. With increasing TLL, the IL-rich phase becomes more hydrophobic, and thus, both of the hydrophobic and π···π interactions between the G



Article

Figure 5. Plots of the partition coefficients of the alkaloids, Pi, vs tieline length, TLL, for (a) codeine in the ●, [Bmim][BF4] + sucrose + H2O; ◆, [Bmim][BF4] + glucose + H2O; ○, [Bmim][BF4] + arabinose + H2O at 308.15 K and (b) caffeine in the ●, [Bmim][BF4] + sucrose + H2O; ◆, [Bmim][BF4] + glucose + H2O; ○, [Bmim][BF4] + arabinose + H2O at 298.15 K.

Figure 4. Logarithms of partition coefficients for codeine (filled circle) and caffeine (empty circle) in [Bmim][BF4]−glucose ABS as a function of the TLL at 308.15 K.

The standard molar Gibbs free energy changes (ΔtrG0m) for transfer of the alkaloids from the sugar-enriched phase to the IL-enriched phase for all systems are calculated by the following equation:37

alkaloids for the IL-rich phase increases by decreasing temperature. Effect of Carbohydrate Type. At a constant temperature and TLL, the Pi values of codeine and caffeine in the investigated ABS obey the following order: sucrose > glucose > arabinose (Figure 5). This order is in agreement with the trend of soluting-out ability of the sugars. The association and solubility behavior of caffeine in water and in aqueous sucrose solutions have been investigated by various measurements.36 The results showed that the association of caffeine in aqueous solution of sucrose significantly increased compared to pure water. Increasing the association and decreasing the solubility of this alkaloid in water with sucrose molality confirms the strength soluting-out effect of sucrose on caffeine. Therefore, the alkaloids are soluted-out from the more hydrophilic sugarrich phase and driven to more hydrophobic IL-rich phase. Effect of Alkaloid Type. Our experimental observations showed that in all the investigated ABS, Pcode > Pcaff, and this difference increased as TLL increased. Compared to caffeine, codeine has fewer heteroatoms and higher hydrocarbon content and therefore is more hydrophobic. Solubility of caffeine and codeine in water at 298.15 K are 2 × 104 and 9 × 103 mg/L, respectively. The more favorable hydrophobic and π···π interactions between codeine and [Bmim][BF4] and on the other hand, sever soluting-out effect of sugars, leading to the higher tendency of codeine to the IL-rich phase. Due to the higher ability of sugars to form hydrogen bonds with water molecules, the water content of IL-rich phase is lower than that of sugar-rich phase, which forces more alkaloid to be moved into the [Bmim][BF4]-rich phase. By decreasing temperature, increasing TLL, and increasing hydrophilicity of sugars, the water contents of IL-rich phase decrease, and then the values of Pi increase (Tables 6 and 7).

Δtr Gm0 = −RT ln Pi

(6)

ΔtrG0m

As can be seen from Tables 6 and 7, values for both the alkaloids in all systems are negative, and magnitude of this quantity for codeine is larger than that for caffeine. The negative values of ΔtrG0m indicate that migration of these alkaloids to IL-enriched phase is a spontaneous process. These Tables show that the values of ΔtrG0m become more negative with decreasing temperature, increasing TLL, increasing hydrophilicity of sugars, and increasing hydrophobicity of alkaloids. [Bmim][CF3SO3]−carbohydrate ABS has also been used for the extraction of caffeine at 298.15 K, and the values of Pcaffe were obtained as 2.19 and 2.57, respectively, for sucrose and glucose.19 Tables 6 and 7 show that the values of Pcaffe in the systems investigated in the present work are between 4.16 to 6.38 for sucrose and 4.46 to 6.65 for glucose. In addition, the selected feed samples in this work are more dilute than those in ref 19, which indicate that the abilities of [Bmim][BF4]− carbohydrate ABS in the extraction of alkaloids are higher than those of [Bmim][CF3SO3]−carbohydrate ABS. This is because the hydrophobicity of [Bmim][BF4] is higher than that of [Bmim][CF3SO3].

4. CONCLUSIONS The extractive potential of [Bmim][BF4] + carbohydrate ABS for extraction of codeine and caffeine was examined at different temperatures. Due to the dominance of π···π and hydrophobic interactions between the imidazolium cation and alkaloids as well as the soluting-out effect of carbohydrates, both alkaloids enriched in the IL-rich phase. Codeine with more complex

Table 8. Values of αi (from Eq 5) for the Partitioning of the Alkaloids in [Bmim][BF4] + Carbohydrate ABS at Different Temperatures and 84.5 kPa codeine

caffeine

298.15 K carbohydrate sucrose glucose arabinose

αcode 2.9973 3.2411 2.5141

308.15 K R2 0.9937 0.9816 0.9760

αcode 2.8758 2.7219 2.3731

298.15 K R2 0.9986 0.9790 0.9979

H

αcaffe 2.7139 2.4262 2.2494

308.15 K R2 0.9932 0.9802 0.9083

αcaffe 1.9236 1.7618 1.8536

R2 0.8997 0.9967 0.9159



Article

(12) Sadeghi, R.; Shekaari, H.; Hosseini, R. Effect of Alkyl Chain Length and Temperature on the Thermodynamic Properties of Ionic Liquids 1-Alkyl-3-Methylimidazolium Bromide in Aqueous and NonAqueous Solutions at Different Temperatures. J. Chem. Thermodyn. 2009, 41, 273−289. (13) Freire, M. G.; Claudio, A. F. M.; Araujo, J. M. M.; Coutinho, J. A. P.; Marrucho, I. M.; Lopes, J. N. C.; Rebelo, L. P. N. Aqueous Biphasic Systems: A Boost Brought about by Using Ionic Liquids. Chem. Soc. Rev. 2012, 41, 4966−4995. (14) Gutowski, K. E.; Broker, G. A.; Willauer, H. D.; Huddleston, J. G.; Swatloski, R. P.; Holbrey, J. D.; Rogers, R. D. Controlling the Aqueous Miscibility of Ionic Liquids: Aqueous Biphasic Systems of Water-Miscible Ionic Liquids and Water-Structuring Salts for Recycle, Metathesis, and Separations. J. Am. Chem. Soc. 2003, 125, 6632−6633. (15) Shukla, S. K.; Pandey, S.; Pandey, S. Applications of Ionic Liquids in Biphasic Separation: Aqueous Biphasic Systems and Liquid-Liquid Equilibria. J. Chromatogr. A 2018, 1559, 44−61. (16) Freire, M. G. Ionic-Liquid-Based Aqueous Biphasic Systems: Fundamentals and Applications; Springer-Verlag: Berlin Heidelberg, 2016. (17) Chen, Y.; Wang, Y.; Cheng, Q.; Liu, X.; Zhang, S. Carbohydrates-Tailored Phase Tunable Systems Composed of Ionic Liquids and Water. J. Chem. Thermodyn. 2009, 41, 1056−1059. (18) Wu, B.; Zhang, Y.; Wang, H.; Yang, L. Temperature Dependence of Phase Behavior for Ternary Systems Composed of Ionic Liquid+ Sucrose+ Water. J. Phys. Chem. B 2008, 112, 13163− 13165. (19) Freire, M. G.; Louros, C. L. S.; Rebelo, L. P. N.; Coutinho, J. A. P. Aqueous Biphasic Systems Composed of a Water-Stable Ionic Liquid+ Carbohydrates and Their Applications. Green Chem. 2011, 13, 1536−1545. (20) Zhang, Y.; Zhang, S.; Chen, Y.; Zhang, J. Aqueous Biphasic Systems Composed of Ionic Liquid and Fructose. Fluid Phase Equilib. 2007, 257, 173−176. (21) Wu, B.; Zhang, Y.; Wang, H. Phase Behavior for Ternary Systems Composed of Ionic Liquid+ Saccharides+ Water. J. Phys. Chem. B 2008, 112, 6426−6429. (22) Wu, B.; Zhang, Y. M.; Wang, H. P. Aqueous Biphasic Systems of Hydrophilic Ionic Liquids+ Sucrose for Separation. J. Chem. Eng. Data 2008, 53, 983−985. (23) Min, G.-H.; Yim, T.; Lee, H.-Y.; Huh, D.-H.; Lee, E.; Mun, J.; Oh, S. M.; Kim, Y.-G. Synthesis and Properties of Ionic Liquids: Imidazolium Tetrafluoroborates with Unsaturated Side Chains. Bull. Korean Chem. Soc. 2006, 37, 847−852. (24) Jamehbozorg, B.; Sadeghi, R. Evaluation of the Effect of Carbohydrates as Renewable, None-Charged and Non-Toxic Soluting-out Agents on the Ionic-Liquid-Based ABS Implementation. J. Mol. Liq. 2018, 255, 476−491. (25) Chen, Y.; Meng, Y.; Zhang, S.; Zhang, Y.; Liu, X.; Yang, J. Liquid− Liquid Equilibria of Aqueous Biphasic Systems Composed of 1-Butyl-3-Methyl Imidazolium Tetrafluoroborate+ Sucrose/maltose+ Water. J. Chem. Eng. Data 2010, 55, 3612−3616. (26) Chen, Y.; Zhang, S. Phase Behavior of (1-Alkyl-3-Methyl Imidazolium Tetrafluoroborate+ 6-(hydroxymethyl) Oxane-2, 3, 4, 5Tetrol+ Water). J. Chem. Eng. Data 2010, 55, 278−282. (27) Zafarani-Moattar, M. T.; Sadeghi, R. Effect of Temperature on the Phase Equilibrium of Aqueous Two-Phase Systems Containing Polyvinylpyrrolidone and Disodium Hydrogen Phosphate or Trisodium Phosphate. Fluid Phase Equilib. 2005, 238, 129−135. (28) Sadeghi, R.; Rafiei, H. R.; Motamedi, M. Phase Equilibrium in Aqueous Two-Phase Systems Containing Poly (vinylpyrrolidone) and Sodium Citrate at Different temperaturesExperimental and Modeling. Thermochim. Acta 2006, 451, 163−167. (29) Hey, M. J.; Jackson, D. P.; Yan, H. The Salting-out Effect and Phase Separation in Aqueous Solutions of Electrolytes and Poly (ethylene Glycol). Polymer 2005, 46, 2567−2572. (30) Li, Y.; Yang, L.; Zhao, X.; Guan, W. Liquid−liquid Equilibria of Ionic Liquid N-Ethylpyridinium Tetrafluoroborate+ Trisodium Citrate/ammonium Citrate Tribasic/sodium Succinate/sodium Tar-

structure and higher hydrophobicity had a partition coefficient larger than that of caffeine. By using the IL/carbohydrate ABS, we can extract these biomolecules from their production environment. The lower temperatures, longer TLL, and sugars with stronger soluting-out effect are more favorable for this bioseparation process.

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ASSOCIATED CONTENT

* Supporting Information S

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.jced.8b00678. Tabulated refractive index data of the aqueous [Bmim][BF4]/carbohydrate solutions and optical rotation data of the aqueous carbohydrate solutions, 1H NMR spectrum of [Bmim][BF4], and binodal curves of the [Bmim][BF4]/carbohydrate aqueous two-phase systems (PDF)

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AUTHOR INFORMATION

Corresponding Author

*Tel.: +98 8733624133; Fax: +98 8733660075; E-mail: [email protected] or [email protected]. ORCID

Rahmat Sadeghi: 0000-0002-5560-5993 Notes

The authors declare no competing financial interest.

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REFERENCES

(1) Domínguez-Pérez, M.; Tomé, L. I. N.; Freire, M. G.; Marrucho, I. M.; Cabeza, O.; Coutinho, J. A. P. (Extraction of Biomolecules Using) Aqueous Biphasic Systems Formed by Ionic Liquids and Aminoacids. Sep. Purif. Technol. 2010, 72, 85−91. (2) Raja, S.; Murty, V. R.; Thivaharan, V.; Rajasekar, V.; Ramesh, V. Aqueous Two Phase Systems for the Recovery of Biomolecules−a Review. Sci. Technol. 2011, 1, 7−16. (3) Martínez-Aragón, M.; Burghoff, S.; Goetheer, E. L. V; de Haan, A. B. Guidelines for Solvent Selection for Carrier Mediated Extraction of Proteins. Sep. Purif. Technol. 2009, 65, 65−72. (4) Souza, R. L.; Ventura, S. P. M.; Soares, C. M. F.; Coutinho, J. A. P.; Lima, Á . S. Lipase Purification Using Ionic Liquids as Adjuvants in Aqueous Two-Phase Systems. Green Chem. 2015, 17, 3026−3034. (5) Albertsson, P. A. Partitioning of Cell Particles and Macromolecules, 3rd Ed.; Wiley-Interscience: New York, 1986. (6) Zaslavsky, B. Y. Aqueous Two-Phase Partitioning: Physical Chemistry and Bioanalytical Applications; Marcel Dekker: New York, 1995. (7) Johansson, H.-O.; Ishii, M.; Minaguti, M.; Feitosa, E.; Penna, T. C. V.; Pessoa, A. Separation and Partitioning of Green Fluorescent Protein from Escherichia Coli Homogenate in Poly (ethylene Glycol)/sodium-Poly (acrylate) Aqueous Two-Phase Systems. Sep. Purif. Technol. 2008, 62, 166−174. (8) Ho, S. L.; Lan, J. C.-W.; Tan, J. S.; Yim, H. S.; Ng, H. S. Aqueous Biphasic System for the Partial Purification of Bacillus Subtilis Carboxymethyl Cellulase. Process Biochem. 2017, 58, 276−281. (9) Santos, J. H. P. M.; e Silva, F. A.; Coutinho, J. A. P.; Ventura, S. P. M.; Pessoa, A. Ionic Liquids as a Novel Class of Electrolytes in Polymeric Aqueous Biphasic Systems. Process Biochem. 2015, 50, 661−668. (10) Capela, E. V.; Quental, M. V.; Domingues, P.; Coutinho, J. A. P.; Freire, M. G. Effective Separation of Aromatic and Aliphatic Amino Acid Mixtures Using Ionic-Liquid-Based Aqueous Biphasic Systems. Green Chem. 2017, 19, 1850−1854. (11) Asenjo, J. A.; Andrews, B. A. Aqueous Two-Phase Systems for Protein Separation: A Perspective. J. Chromatogr. A 2011, 1218, 8826−8835. I



Article

trate Aqueous Two-Phase Systems at 298.15 K. Thermochim. Acta 2012, 550, 5−12. (31) Cho, C.-W.; Pham, T. P. T.; Jeon, Y.-C.; Yun, Y.-S. Influence of Anions on the Toxic Effects of Ionic Liquids to a Phytoplankton Selenastrum Capricornutum. Green Chem. 2008, 10, 67−72. (32) Freire, M. G.; Neves, C. M. S. S.; Marrucho, I. M.; Coutinho, J. A. P.; Fernandes, A. M. Hydrolysis of Tetrafluoroborate and Hexafluorophosphate Counter Ions in Imidazolium-Based Ionic Liquids. J. Phys. Chem. A 2010, 114, 3744−3749. (33) Wagner, M.; Stanga, O.; Schröer, W. Corresponding States Analysis of the Critical Points in Binary Solutions of Room Temperature Ionic Liquids. Phys. Chem. Chem. Phys. 2003, 5, 3943−3950. (34) Zhang, L.; Han, J.; Wang, R.; Qiu, X.; Ji, J. Isobaric Vapor− Liquid Equilibria for Three Ternary Systems: Water+ 2-Propanol+ 1Ethyl-3-Methylimidazolium Tetrafluoroborate, Water+ 1-Propanol+ 1-Ethyl-3-Methylimidazolium Tetrafluoroborate, and Water+ 1Propanol+ 1-Butyl-3-Methylimidazolium Tetrafluoro. J. Chem. Eng. Data 2007, 52, 1401−1407. (35) Holbrey, J. D.; Reichert, W. M.; Nieuwenhuyzen, M.; Sheppard, O.; Hardacre, C.; Rogers, R. D. Liquid Clathrate Formation in Ionic Liquid−aromatic Mixtures. Chem. Commun. 2003, 4, 476−477. (36) Lilley, T. H.; Linsdell, H.; Maestre, A. Association of Caffeine in Water and in Aqueous Solutions of Sucrose. J. Chem. Soc., Faraday Trans. 1992, 88, 2865−2870. (37) Ottiger, C.; Wunderli-Allenspach, H. Immobilized Artificial Membrane (lAM)-HPLC for Partition Studies of Neutral and Ionized Acids and Bases in Comparison with the Liposomal Partition System. Pharm. Res. 1999, 16, 643−650.

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Extractions of Alkaloids Codeine and Caffeine with [Bmim][BF4

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