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Fibrin stabilizing factor (FXIII) plays a crucial role in blood clotting, tissue repair, and immune defense. FXIII deficiency after trauma can lead to prolonged wound healing due to persistent infections or coagulation disorders. The aim of this study was to describe the prevalence of acquired FXIII deficiency after trauma and to provide a description of the time-course changes of important coagulation parameters in relation to FXIII activity. In this context, patient characteristics, laboratory data, and treatment modalities were examined with respect to their influence on FXIII activity. Furthermore, the effects of in vitro administration of FXIII on clot firmness and outcomes in patients with severe traumatic brain injury were investigated.Two trauma cohorts (A and B) were examined prospectively in a two-center study, and another (cohort C) was examined retrospectively. In cohort A (trauma patients, n=880) routine laboratory tests were conducted, and FXIII activity was measured. In cohort B (polytrauma patients, n=26), additional clinical parameters were collected, and in-vitro FXIII administration and rotational thromboelastometry (ROTEM) analyses were performed. In cohort C (polytrauma patients with severe traumatic brain injury [sTBI], n=84), the impact of initially measured FXIII activity on clinical outcomes after sTBI was investigated using the modified Rankin Scale (mRS) at least 6 months after trauma.The prevalence of FXIII activity70% in cohort A was 12.4%, with significant differences in age, Hb, fibrinogen, and Hct levels, platelet count, aPTT, and INR (vs. prevalence of FXIII activity70%). Cohort B showed a decrease in FXIII activity from 85% to 58% after 7 days. FXIII deficiency correlated with time after trauma, aPTT, and fibrinogen level, lactate, and Hb levels. In-vitro administration of FXIII showed a positive influence on clot firmness due to improved maximum clot firmness (MCF in FIBTEM) and reduced maximum lysis (ML in EXTEM). Finally, a significant difference in FXIII activity between patients after sTBI with good and poor clinical outcomes was observed 6 months after trauma.We demonstrated that trauma-associated FXIII deficiency is a common coagulation disorder, with FXIII deficiency increasing further in the first 7 days after trauma, the period of early surgical care. In vitro administration of FXIII was able to demonstrate significant clot stabilizing effects. For trauma patients with sTBI, FXIII activity could serve as a prognostic parameter, as it differed significantly between patients with good and poor clinical outcomes.

Zusammenfassung Hintergrund Die komplexe und dynamische Situation im aktuellen Pandemiegeschehen erfordert eine regional abgestimmte und vernetzte Zusammenarbeit in der Gesundheitsversorgung zwischen den verschiedenen Akteuren des Gesundheitswesens, dem stationaren Sektor sowie dem offentlichen Gesundheitsdienst. Ziel der Untersuchung war, das Versorgungsmanagement hinsichtlich der regionalen Vernetzungs- und Kommunikationsstrukturen wahrend der COVID-19-Pandemie im Jahr 2020 zu beleuchten. Methode Im Rahmen des vom Bundesministerium fur Bildung und Forschung (BMBF) geforderten Projekts „egePan Unimed“ wurde im November 2020 allen Vorstanden der 35 deutschen Universitatskliniken ein Online-Fragebogen zum Pandemiemanagement zugesandt. Im Zentrum des Fragebogens standen die Kernthemen Regionale Vernetzung, Krisenmanagement, Datenaustausch und Kommunikation mit politischen Akteuren. Der Fragebogen bestand aus 37 geschlossenen und drei offenen Fragen. Nach der Pilotierung erfolgte die Einladung zur Befragung dreimal per E-Mail und einmal telefonisch. Ergebnisse Von den befragten Universitatskliniken (n = 25, Response 71,4%) bestand bei 68% eine abgestimmte Zusammenarbeit mit anderen regionalen Krankenhausern und bei 86% mit Vertretern des Offentlichen Gesundheitsdienstes (OGD). Eine koordinierte Zusammenarbeit mit dem ambulanten Sektor wurde seltener (26%) angegeben. 84% der Universitatskliniken gaben an, eine Leitungsfunktion im Rahmen eines regionalen COVID-19-Pandemiemanagements innezuhaben. Ein Datenaustausch im Zuge des Pandemiemanagements fand bei 75% mit regionalen Kliniken und bei 67% mit uberregionalen Kliniken statt. Schlussfolgerung Zur Bewaltigung der regionalen medizinischen Versorgung wahrend der COVID-19-Pandemie im Jahr 2020 nahmen Universitatskliniken sehr haufig eine koordinierende Rolle im komplexen pandemischen Versorgungsgeschehen ein. Es bestanden dabei haufig strukturierte Kooperationen mit regionalen Kliniken und Gesundheitsamtern und vergleichsweise selten mit dem ambulanten Versorgungsbereich. Gerade diese Zusammenarbeit hatte jedoch das Potenzial, Uberbelegungen von Kliniken zu verhindern.

To improve the kinetics of enzyme-catalyzed reactions, cosolvents are commonly added to reaction mixtures. The search for a good cosolvent is still empirical and experimentally based. We discuss a thermodynamic activity-based approach that improves biocatalytic processes by predicting cosolvent influences on Michaelis constants, ultimately reducing time and cost.

Primitive thermodynamic models for electrolyte solutions require the dielectric constant e. This property strongly depends on the concentration of the electrolytes in the mixture. Neglecting this dependency might be reasonable for modeling solutions at low electrolyte concentrations. However, in solutions containing ionic liquids (ILs) and especially for the calculation of liquid-liquid equilibria (LLE) of systems with ILs, liquid phases often contain high IL concentrations. At such conditions, neglecting the influence of concentration on e is an oversimplification. In this work, an approach to account for the concentration-dependent dielectric constant within the Debye-Huckel theory was implemented into electrolyte Perturbed-Chain Statistical Associating Fluid Theory (original ePC-SAFT). This new approach was then applied to model LLE of binary mixtures containing water and commonly used hydrophobic ILs. These common ILs are comprised of the IL-cations [Cnmim]+, [Cnpy]+, [Cnmpy]+, [Cnmpyr]+, [C4m4py]+ and the IL-anions [BF4]-, [NTf2]-, [PF6]-, [TFO]-. The LLE of binary mixtures water + IL were modeled at ambient pressure and different temperatures with the new ePC-SAFT and with the original ePC-SAFT [Ji et al. DOI: 10.1016/j.fluid.2012.05.029] without the concentration-dependent e. Overall, the new approach within ePC-SAFT shows superior modeling as well as correlation capability compared to original ePC-SAFT, which was concluded by comparing both models with LLE data from literature.

The use of co-solvents for the enhancement of the reaction parameters reaction rate, yield and enantioselectivity is an established optimization strategy in biotechnology. To determine the influence of co-solvents on even one of these reaction parameters requires a great amount of experimental data. Thus, predictive and physically sound models are desired to decrease the amount of experimental effort. This work aims at providing such a framework, which was applied to the ADH (alcohol dehydrogenase)-catalyzed reduction of acetophenone at 303.15 K and 1 bar in water (neat) and under the influence of up to 20 wt-% of polyethylene glycol (PEG) and 15 wt-% trisodium citrate (Na3Cit). In a first step, the equilibrium composition was measured at constant pH. It was then shown that high concentration of PEG or Na3Cit changed the equilibrium position significantly (up to a factor of 13) compared to neat reaction mixtures. To be able to predict this strong co-solvent influence on the reaction equilibrium, the experimentally determined equilibrium compositions of the neat reaction were converted into a thermodynamic equilibrium constant Kth using the activity coefficients γ i of the reacting agents. The latter were predicted by electrolyte Perturbed-Chain Statistical Associating Fluid Theory (ePC–SAFT). These finally allowed quantitatively predicting the high concentration co-solvent influence on the equilibrium position.

The ocean quahog Arctica islandica is equally attractive to physiologists and environmental scientists due to its long life span of up to 400 years . For physiology, A. islandica is an exciting age model whereas environmental sciences infer past environmental conditions from morphometric and biogeochemical properties of the calcareous shell. In order to evaluate whether and animals from different localities differ, the present study compared genetics and morphometry of six A. islandica populations, from the Norwegian Coast, Kattegat, Kiel bay, White Sea, German Bight and Off Ne Iceland. For genetics, present research found 30 haplotypes of the mitochondrial cytochrome B (cyt B) gene, of which some are widely distributed, whereas others are quite rare. There is no consistent geographical pattern in haplotype distribution, even when a further previously published 11 haplotypes are taken into account. For morphometry, discriminant analysis indicated significant morphometric differences, e.g. in shell shape, between populations which are independent of geographical distance. Moreover, genetic and morphometric patterns appear to be unrelated. Thus, present study reveals morphological differences between populations of A. islandica appear to be driven by the environment rather than underlying genetic differences between populations.

A novel approach towards modeling proteins in aqueous solutions by applying perturbed-chain statistical associating fluid theory (PC-SAFT) is proposed in this work. Lysozyme and bovine serum albumin (BSA) were chosen as model proteins due to a vast database available in literature. However, the huge majority of these literature data had been measured at certain ionic strengths, which is disadvantageous in order to derive pure-component parameters for proteins. Thus, in a first step within this work osmotic coefficients of dialyzed lysozyme and of dialyzed BSA in pure water were measured at 298.15 K. The data were very different for dialyzed and non-dialyzed solutions and further showed a strong dependence on pH and ionic strength. In a second step, the pure-component parameters of lysozyme and BSA were adjusted to the measured osmotic coefficients and to solution densities of dialyzed lysozyme or dialyzed BSA. PC-SAFT explicitly takes into account the complex association behavior between protein and water as well as among the proteins. Therefore, the number of protein association sites of one protein was determined from the sum of association sites of the single amino-acid constituents of a protein available from previous work (Ind. Eng. Chem. Res 50 (2011) 141–151). Similarly, the two PC-SAFT parameters “segment number” and “segment diameter” of a protein were summed or averaged from the single amino-acid constituents. This approach allowed modeling densities and osmotic coefficients of protein solutions with reasonable accuracy compared to experimental data.

The reduction of the sulfur content in crude oil is of utmost importance in order to meet the stringent environmental regulations. Thiophene and its derivatives are considered key substances to be separated from the crude oil. In previous works, six deep eutectic solvents (DESs) based on tetraethylammonium chloride, tetrahexylammonium bromide and methyltriphenylphosphonium bromide as hydrogen bond acceptors (HBAs) and polyols (ethylene glycol and glycerol) as hydrogen bond donors (HBDs) were successfully applied for the extraction of thiophene from {n-alkane + thiophene} mixtures via liquid-liquid extraction. One of the objectives of this work was to study the effect of the aliphatic hydrocarbon type/length (e.g. n-hexane vs n-octane) on the extraction performance of the same DESs. Extraction performance was evaluated by the selectivity and the thiophene distribution coefficient. Based on new experimental data, higher selectivities and lower thiophene distribution coefficients were obtained when thiophene was extracted from n-octane instead of n-hexane. Another objective was to predict the phase behavior of the ternary systems {n-alkane + thiophene + DES} using Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT). The PC-SAFT “pseudo-pure component” approach was applied, in which a DES was considered as a pseudo-pure compound (not a mixture). The pure-component parameters of the DESs were obtained by fitting to liquid density data, which were measured at temperatures between 298.2 K and 323.2 K. Binary interaction parameters were fitted to experimental binary LLE data for the systems {n-alkane + DES} and {thiophene + DES} at 298.2 K and atmospheric pressure, while the LLE data of the ternary systems {n-alkane + thiophene + DES} were fully predicted. It was found that the distribution coefficients and selectivity of the ternary systems containing DESs could be qualitatively well predicted using this model.

The development of separation processes for polymers or proteins from aqueous solutions requires a high amount of experimental effort, including phase-equilibrium data such as solid-liquid, liquid-liquid or vapor-liquid equilibria. This effort can be reduced by means of thermodynamic models. This work presents a new method for parameter estimation and validation of thermodynamic models by means of static-light-scattering (SLS) measurements. In this work the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) was used to predict directly the SLS data (Rayleigh ratio) of macromolecular solutions. In a first step, SLS data were measured for binary water/polyethylene glycol (PEG molecular weight ranging from 2000 to 12000 g/mol) mixtures and for binary water/lysozyme mixtures. Applying pure-component PC-SAFT parameters from literature, the SLS data of these binary mixtures were successfully predicted with PC-SAFT. In a second step, one binary interaction parameter between lysozyme and PEG was adjusted to new experimental SLS data of buffered PEG/lysozyme/water solutions with PEG6000 concentration of 20 g/L. Finally, SLS data for buffered ternary PEG/lysozyme/water solutions with PEG of different molecular weights (2000–12000 g/mol) and different concentrations (1–50 g/L) were accurately predicted with PC-SAFT. Thus, (1) the proposed approach allows predicting SLS data, and (2) the method provides an access to the estimation of model parameters by means of experimental SLS data, which are accessible with much less effort than experimental phase-equilibrium data.

The major goal of this work was the prediction of the solubility of CO 2 and H 2 S in aqueous methyldiethanolamine ( MDEA ) reacting systems using the electrolyte equation of state ePC-SAFT with focus on MDEA weight fractions wMDEA> 0.3 (related to the binary water / MDEA system). Predictions in this work mean that no parameters were adjusted to the experimental gas solubility data in aqueous MDEA solutions. In order to obtain improved prediction results compared to state-of-the-art literature models, binary interaction parameters kij between water - MDEAH + , water- HCO 3 − , and water - HS − were introduced; these kij values were fitted to osmotic-coefficient data measured in this work and from literature. This new possibility to access these kij parameters allowed improved predictions of CO 2 solubility, and the predictions were validated by new experimental data at wMDEA = 0.6. Even more, the influence of the inert gas CH 4 on CO 2 solubility was predicted reasonably correct. Further, the solubility of H 2 S in aqueous MDEA solutions was accurately predicted in the temperature range 298 K

The phase diagrams of six different polyethylene glycol (PEG)–salt aqueous two-phase systems (ATPS) were measured at T = 298.15 K and p = 1 bar. PEG of different molecular weight (4000, 6000 and 8000) and organic salts (potassium citrate, potassium sodium tartrate) were used to form the biphasic systems. The results were compared with data for PEG–sodium citrate ATPS, reported in the literature (PEG 4000, PEG 6000) and measured in this work (PEG 8000). The partition of four dinitrophenyl-amino acids was measured in these ATPS for different tie-line lengths. Based on these data, cation and anion effects were evaluated in terms of the relative hydrophobicity of the phases using ΔG*(CH2) calculations. The distribution coefficients have been obtained spectrophotometrically. Studies on the partitioning indicate the advantage of citrate salts over tartrate salts as well as sodium-based salts over potassium-based salts. This consistently results from the (liquid-liquid) phase behaviour of these systems.

Knowledge about solubility in water is required for crystallization processes, for the development of structure-property relationships, for the establishment of solubility scales, assessing environmental contamination, and for validating thermodynamic models. Approaches are desired that allow predicting solubility without the use of any experimental solubility data. Most methods that have been proposed to predict aqueous solubility of organic compounds face low prediction reliability and the lack of model interpretability. This work proposes the use of a thermodynamic approach for the prediction of solubility of acetanilide and its derivatives in water. This approach requires fusion enthalpy and fusion temperature as well as the activity coefficient of the respective acetanilide derivative. The latter was obtained by the equation of state PC-SAFT, which uses thermochemistry data as input for model parametrization. The thermochemical data on acetanilide and its derivatives (vapor and sublimation pressures, sublimation and fusion enthalpies) were collected from the literature and evaluated for internal consistency. In order to validate the final solubility prediction model, aqueous solubility of acetanilide and 17 derivatives were predicted and compared to experimental solubility data from literature at 298.15 K as well as to an ideal solubility model, which assumes ideal mixture behavior. The results showed that mixtures of acetanilides + water are highly non-ideal, and the average deviations between solubility data and ideal solubility model could be reduced by two orders of magnitude by using PC-SAFT for the solubility predictions. More promising, PC-SAFT was found to allow predicting the temperature dependence of the aqueous solubility accurately, while ideal solubility model failed to quantitatively describe temperature-dependent solubility.

Phlorotannins are highly bioactive phenolic compounds mainly found in brown algae. Phloroglucinol is the basic unit from which phlorotannins polymerize. Deep eutectic solvents (DES) are potentially beneficial for increasing phenolics solubility, therefore good solvent candidates for phlorotannins extraction processes. Solubility measurements were performed for phloroglucinol in pure water and aqueous mixtures of DES or their constituents, i.e., different hydrogen bond donors (HBD) and choline chloride (ChCl). The stable crystal form of the phenolic in equilibrium was phloroglucinol dihydrate within the studied temperature range (293.15–313.15 K) and water weight fractions (≥0.25). The water + ChCl + HBD mixtures yielded higher solubility for phloroglucinol dihydrate than the corresponding water + HBD or water + ChCl mixtures. Solubility predicted with PC-SAFT was in quantitative agreement with the experimental data. The solubility behavior of phloroglucinol dihydrate in the different mixtures was related to the hydrogen bonds formed using molecular dynamics and PC-SAFT.

Amino acids and peptides are essential components for many industrial branches. Knowledge on the solubility behavior is required in purification processes, which often involve crystallization as main unit operation. Since the determination of experimental solubility data is expensive, thermodynamic modeling is meaningful towards reducing the experimental effort. Modeling is usually based on a solid-liquid equilibrium condition that requires the melting properties of the solids. For amino acids and peptides such data is now available, and three gE models (Wilson, NRTL, UNIQUAC) were applied in this work to model solubility in water as well as in water + 2-propanol. The new melting properties were used as input data and binary parameters for each model were fitted to experimental solubility data of the amino acids and peptides in water. Modeling solubility in water + 2-propanol required additional parameters. Binary parameters between water and 2-propanol were fitted to vapor-liquid-equilibrium data, and binary parameters between amino acid and 2-propanol as well as between peptide and 2-propanol were fitted to solubility data in water + 2-propanol mixtures. In general, the gE models allowed describing the solubility in water, while some inaccuracies were observed for the temperature dependence of the modeled solubility. Further, the decrease of solubility upon 2-propanol addition was modeled qualitatively correct using the gE models. The Wilson model was less accurate than NRTL and UNIQUAC, where the latter yielded similar results. The results were finally compared to PC-SAFT, which shows a dramatically improved modeling accuracy while using less binary parameters.

The applications of electrolyte thermodynamic models to non-aqueous systems is of great value to reduce experimental effort and gain inside into molecular interactions. A large-scale application is for example the design of advanced battery electrolytes. For non-aqueous electrolyte systems, the Born term was found to be important, as it accounts for the transfer of ions from water into non-aqueous medium. In part one of this study [Bulow et al., Fluid Phase Equilibria 2021, 112967] the Born term was combined with a concentration-dependent dielectric constant within the ePC-SAFT framework (electrolyte Perturbed-Chain Statistical Associating Fluid Theory). In the present work, the Bjerrum treatment for ion pairing was included in the Debye-Huckel framework within ePC-SAFT. The approach was validated by experimental data for the dissociation of salts in organic solvents derived from conductivity measurements. Further, solubility was modeled of alkali halides in organic solvents and in ionic liquids. Modeling solubility required access to the solubility product K S P , which does not depend on the solvent. The approach within this work was to first determine K S P using experimental solubility data in water and the respective ePC-SAFT predicted activity coefficients prior to predict activity coefficients in non-aqueous medium, finally yielding solubility. The so-determined solubility values were found to be in reasonable agreement with the experimental data without fitting model parameters to any data of the non-aqueous solutions. The solubility product requires the solid form of the precipitating salt to be equal for all solvents; as alkali salts precipitate from aqueous solutions as hydrates, the method cannot be applied. Therefore, a methodology is presented to extrapolate the high-temperature K S P of anhydrates to lower temperature. Using the so-extrapolated K S P allowed predicting solubility of non-solvates in other solvents.

The transition from aqueous electrolyte systems to non-aqueous electrolyte systems is highly demanded in industrial applications and especially challenging for physics-based thermodynamic models. Electrolyte thermodynamics is a complex matter, and still not all physico-chemical effects are accounted for in state-of-the-art equations of state. The dielectric constant of non-aqueous electrolyte systems changes drastically compared to aqueous systems. One main consequence is that ions are very differently solvated in non-aqueous medium compared to aqueous medium. The Born term represents a methodology to account for the influence of solvation energies of ions, which is based on influences of solvent and salt on the dielectric constant. Utilizing the Born term in electrolyte models is extensively debated, and it is often reasonably neglected in predominantly aqueous systems. Yet, it has a significant influence on transferability from aqueous to non-aqueous media i.e., systems with a large difference in polarity or permittivity compared to aqueous systems. In this work, a modified Born term was combined with electrolyte Perturbed-Chain Statistical Associating Fluid Theory (ePC-SAFT) by introducing additionally a salt concentration-dependent dielectric constant, henceforth called altered Born contribution. The new methodology was validated against infinite dilution properties for ion-solvent interactions: Gibbs energy of hydration and Gibbs energy of transfer of alkali halides from water to alcoholic solvents. Further, mean ionic activity coefficients (MIACs) of alkali halides in alcoholic solvents were quantitatively correct predicted with the advanced ePC-SAFT approach. Original ePC-SAFT parameters were applied for all predictions, and no further binary parameters were adjusted. Based on the success of the model predictions, the transferability of pure-ion ePC-SAFT parameters to organic solvents was verified and the incorporation of concentration-dependent dielectric constant into the altered Born contribution and Debye-Huckel theory was proven to be meaningful methods for the transfer of electrolyte thermodynamic models from aqueous to non-aqueous systems.

In this work, ePC-SAFT-DGT (i.e., the coupling of ePC-SAFT with the density gradient theory (DGT)) was further developed by modifying the expression for estimating the chemical potential of IL ion-pair and extended to study the interfacial properties of 82 ionic liquids (ILs) containing one of the IL-cations ([Cnmim]+, [Cnpy]+, [Cnmpy]+, [Cnmpyr]+, and [THTDP]+) and one of the IL-anions ([Tf2N]−, [PF6]−, [BF4]−, [tfo]−, [DCA]−, [SCN]−, [C1SO4]−, [C2SO4]−, [eFAP]−, Cl−, [Ac]−, and Br−). The available experimental surface tensions for these 82 ILs from the literature have been surveyed and evaluated for adjusting the model parameters before the investigation. It shows that the modification results in more reasonable magnitude of influence parameters and ePC-SAFT-DGT can be used to represent the surface tension of ILs reliably compared with the experimental data. Furthermore, using the anion-specific influence parameters that are linearized with the molecular weight of the IL-cations for a homologous series of ILs allows semi-predicting (i.e., parameters obtained by interpolation and extrapolation) the surface tension for the ILs in the same homologous series. ePC-SAFT-DGT can be further used to predict other interfacial properties, for example, the density profile and interfacial thickness in the vapor-liquid interface.

The influence of electrolytes on liquid-liquid equilibria (LLE) of water/1-butanol and on the partitioning of 5-hydroxymethylfurfural (HMF) between water-rich and 1-butanol-rich phases was investigated in this study. For that purpose, the LLE of the ternary systems water/1-butanol/HMF, water/1-butanol/salt, and the LLE of the quaternary system water/1-butanol/HMF/salt were measured at 298.15 K under atmospheric pressure. The investigated salts were composed of one of the anions Cl−, CH3COO−, NO3− and SO42− and either Li+ or Na+. By investigating the LLE of the system water/1-butanol/salt it was found that 1-butanol was salted-out from the aqueous phase by all salts, and the strength of the salting-out increased in the following order NO3− Based on the LLE data, the partition coefficient K HMF w of HMF between 1-butanol and aqueous phase was determined. Li2SO4 caused a pronounced salting-out of HMF from the aqueous phase, whereas only a moderate influence was observed for NaCl and CH3COONa. LiCl even caused a salting-in at LiCl molalities above 6 mol/kgH2O. electrolyte Perturbed-Chain Statistical Associating Fluid Theory (ePC-SAFT) was successfully used to model the influence of salts on the LLE water/1-butanol. Without fitting parameters to LLE data of the quaternary system water/1-butanol/HMF/salt, ePC-SAFT allowed predicting the salt influence on the partitioning of HMF in these systems in good agreement with the experimental data.

Predicting the behavior of dinitrophenylated amino acids (DNP-AA) in aqueous solutions requires an understanding and accurate description of interactions that can occur in such systems. In this work, some properties of DNP-AA (DNP-glycine, DNP-alanine, DNP-valine, DNP-leucine) have been determined experimentally. These were liquid densities obtained at T=298.15 – 318.15 K, p=1 bar, and pH-dependent solubility data measured at T=298.15 K, p=1 bar. It was observed that the solubility order for DNP-AA does not follow the same sequence as for aliphatic amino acids. The thermodynamic model ePC-SAFT has been applied to predict the properties density and solubility, and additionally to estimate partition coefficients of DNP-AA in PEG (PEG 4000, PEG 6000, PEG 8000) - organic salt (sodium citrate, potassium citrate, potassium sodium tartrate) aqueous two-phase systems (ATPS). ePC-SAFT pure-component and binary interaction parameters for neutral DNP-AA were acquired using the joinzt joint-parameter method, namely by combining the parameters for dinitrobenzene with parameters for amino acids (glycine, L-alanine, L-valine, L-leucine) from literature. The pure-component parameters for charged DNP-AA- were inherited from their parent neutral DNP-AA. This work shows that ePC-SAFT allows predicting liquid densities and solubilities of neutral DNP-AA with good agreement to experimental results. Moreover, adjusting in sum six binary parameters between charged DNP-AA- and phase-forming species allowed modeling partition coefficients of four DNP-AA in nine different PEG – organic salt ATPS, each at four different ATPS compositions. This can be considered an excellent modeling result and proofs the suitability of ePC-SAFT for such systems.

In this work we applied experimental and theoretical thermodynamics to methyl ferulate hydrolysis, a model biological reaction, in order to calculate the equilibrium constant and reaction enthalpy. In the first step, reaction data was collected. Temperature-dependent equilibrium concentrations of methyl ferulate hydrolysis have been measured. These were combined with activity coefficients predicted with electrolyte PC-SAFT in order to derive thermodynamic equilibriums constants Ka as a function of temperature. In a second step, thermochemical properties of the highly pure reaction participants methyl ferulate and ferulic acid were measured by complementary thermochemical methods including combustion and differential scanning calorimetry. Vapor pressures and sublimation enthalpies of these compounds were measured by transpiration and TGA methods over a broad temperature range. Thermodynamic data on methyl ferulate and ferulic acid available in the literature were evaluated and combined with our own experimental results. Further, the standard molar enthalpy of methyl ferulate hydrolysis reaction calculated according to the Hess's Law applied to the reaction participants was found to be in agreement with the experimental reaction enthalpy from the equilibrium study. In a final step, the gas-phase equilibrium constant of methyl ferulate hydrolysis at 298.15 K was calculated with the G3MP2 method. This value was adjusted to the liquid phase using the experimental vapor pressures of the reaction participants. As a result, the liquid phase Ka value calculated by quantum chemistry with additional data on the pure reaction participants was in good agreement with the experimental Ka reported in the literature for the aqueous phase. The thermodynamic procedure based on the quantum-chemical calculations is found to be a valuable option for assessment of thermodynamic properties of biologically relevant chemical reactions.

The thermodynamic equilibrium of the aminotransferase reaction from l -alanine and 2-oxoglutarate to l -glutamate and pyruvate in aqueous solution was investigated in a temperature range between 25 and 37 °C and pH between at 5 and 9. Prior to considering the reaction equilibria, measurements were carried out to ensure the enzyme activity in the aqueous reaction media. After that, equilibrium concentrations of reacting agents were measured by HPLC-analysis. At constant temperature and pH, reaction equilibrium was shown to depend on the absolute molalities (0.005–0.130 mol kg−1) as well as on the ratio of initial molalities of the reactants. It could be concluded that reaction equilibrium was shifted towards the product site upon increasing reactant molalities, increasing temperature, and increasing pH. Further, yields of pyruvate were increased upon excess initial molality of l -alanine compared to 2-oxoglutarate. The thermodynamic equilibrium constant K a ∗ was determined by extrapolating the ratio of product equilibrium molalites and reactant equilibrium molalites to infinite dilution of all reacting agents. The activity-coefficient ratio of products and reactants in the reaction media was predicted with ePC-SAFT. Combining K a ∗ and the activity-coefficient ratio allowed quantitatively predicting the influence of temperature, pH, and reacting-agent molalities on the reaction equilibrium.

In biotechnological processes, salts might be present during reaction steps and in downstream processes. Salts are known to have a strong impact on phase equilibria of aqueous systems. In this work, the liquid–liquid equilibria (LLE) of ternary salt/MIBK/water mixtures were measured at 298.15 K and 1 bar up to the salt solubility limit. The salts studied in this work were NaCl, LiCl, KCl, NaNO3, LiNO3, Na2SO4, CH3COONa, and CH3COOLi. From these LLE measurements it was found that a high amount of salt is dissolved in the aqueous phase whereas only a very small amount of salt was detected in the MIBK phase. Further, the salting-out behavior of MIBK from the aqueous phase upon addition of different salts was investigated to study ion-specific effects. Two ion-specific models, ePC-SAFT and an extended version of COSMO-RS for electrolytes were used for modeling the binary system MIBK/water and ternary salt/MIBK/water systems. In case of the COSMO-RS based approach, the modeling results were fully predictive. In contrast, ion-specific binary interaction parameters between MIBK and ions were fitted to experimental LLE data of the ternary systems salt/MIBK/water when using ePC-SAFT. The results show that the COSMO-RS based approach allows for predicting the salt influence on LLE with acceptable accuracy, whereas ePC-SAFT allows for almost quantitative correlations of experimental data.

ePC-SAFT was used to model the densities of ionic liquids (ILs) up to high pressures and temperatures. The ILs under consideration contained one of the IL-cations [Cnmim]+, [Cnpy]+, [Cnmpy]+, [Cnmp ...

Absolute vapor pressures and molar sublimation enthalpies of 2-, 3-, and 4-monohalogenobenzoic acids (halogen = fluorine and iodine) were derived from transpiration measurements. Molar enthalpies of fusion were measured by DSC. Thermochemical data available in the literature were collected, evaluated, and combined with own experimental results in order to recommend sets of sublimation and fusion enthalpies. Further, the recommended data were used to estimate PC-SAFT pure-component parameters. These parameters were applied to predict the solubility of the monohalogenobenzoic acids in water at 298.15 K, yielding satisfying prediction results. This approach proved the capability of PC-SAFT to predict solid–liquid phase equilibria if precise data on sublimation pressures and fusion properties is available.

Organisms developed very different strategies to protect themselves against osmotic stress. To sustain high salt concentrations of their surrounding some organisms accumulate so-called compatible solutes (CSs), which increase the internal osmotic pressure without disturbing the organism’s metabolism. At constant temperature, osmotic pressure is mainly determined by the concentration of the compatible solute and the osmotic coefficient of the aqueous solution, and to a minor extent also by solution densities. Thus, osmotic coefficients and densities were measured for aqueous CS solutions in a broad range of concentration and at three temperatures (273 K, 310 K, 323 K) at atmospheric pressure. Further, the solubility of CSs in water was measured as function of temperature to determine the maximum CS concentration that can be applied in aqueous solutions. CSs under investigation were trimethylamine N-oxide (TMAO), trehalose, citrulline, N,N-dimethylglycine, DMSO, glycerol, methylglycine, and ectoine. The data was used to calculate real osmotic pressures induced by these CSs. PC-SAFT was applied to model thermodynamic properties and phase equilibria of aqueous CS solutions in quantitative agreement to experimental data. Among the CSs investigated in this work, TMAO induced the highest osmotic pressure and thus can be considered the best protector against osmotic stress. The data was finally analyzed concerning the influence of CSs molecular size, charge, and hydrophobicity on osmotic pressure. This included also the comparison to incompatible solutes (urea, glycine).

In this work, ePC-SAFT was extended to predict the second order thermodynamic derivative properties of pure ionic liquids (ILs), such as isothermal and isentropic compressibility coefficients, thermal pressure coefficient, heat capacities, speed of sound, thermal expansion coefficient and internal pressure. ePC-SAFT predictions were compared with available experimental data of imidazolium-based ILs. The pure-component ePC-SAFT parameters for the IL-cations [C2mim]+, [C4mim]+, [C6mim]+ and [C8mim]+, and IL-anions [BF4]−, [PF6]− and [Tf2N]− were taken from literature in order to predict the thermodynamic derivative properties. The pure-component ePC-SAFT parameters for the IL-cations [C3mim]+, [C5mim]+, [C7mim]+ and [C10mim]+ were predicted based on linear molecular-weight-dependent relations. These estimated ePC-SAFT parameters were verified by comparing so-predicted pure-IL density as well as predicted CO2 solubility in ILs with respective experimental data. Further, these parameters were used to predict the second order thermodynamic derivative properties. The comparison of model prediction with experimental data showed that ePC-SAFT predictions were reliable in a wide temperature and pressure range.

Background Thermodynamic methods are finding more and more applications in systems biology, which attempts to understand cell functions mechanistically. Unfortunately, the state variables used (reaction enthalpy and Gibbs energy) do not take sufficient account of the conditions inside of cells, especially the crowding with macromolecules. Methods For this reason, the influence of crowding agents and various other parameters such as salt concentrations, pH and temperature on equilibrium position and reaction enthalpy of the glycolytic example reaction 9 (2-Phospoglycerate - > Phosphoenolpyruvate + H2O) was investigated. The conditions were chosen to be as close as possible to the cytosolic conditions. Poly(ethylene glycol) MW = 20,000 g mol−1 (PEG 20,000) was used to analyze the influence of crowding with macromolecules. The equation of state electrolyte Perturbed-Chain Statistical Associating Fluid Theory (ePC-SAFT) was applied to consider the influence of crowding agents on the reaction equilibria. Results and conclusions For the reaction enthalpies and for the equilibria, it was found that the influence of salts and temperature is not pronounced while that of pH and PEG 20,000 concentration is considerable. Furthermore, it could be shown that under identical measurement conditions there are no differences between the van ‘t Hoff and the calorimetrically determined reaction enthalpy. General significance The results show how important it is to consider the special cytosolic conditions when applying thermodynamic data in systems biology.

In this work, the effects of co-solvent and pressure on Michaelis constants at ambient temperature were analyzed for the enzymatic peptide hydrolyses of L-phenylalanine-p-nitroanilide (HPNA) and of N-succinyl-L-phenylalanine-p-nitroanilide (SPNA). These two substrates resemble each other in their molecular structure. That is, at the position of SPNA’s succinyl-group (S), HPNA possesses a hydrogen atom (H). Two co-solvents were considered: trimethylamine N-oxide and dimethyl sulfoxide. The thermodynamic model Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) was used to predict the activity of HPNA and SPNA under different reaction conditions regarding solvent composition and pressure. The PC-SAFT parameters (pure-component parameters and one binary parameter between substrate and solvent) were fitted to solubility data of HPNA in different solvents (water, ethanol, ethyl acetate, dimethyl sulfoxide), which were measured in this work at 30 °C and 1 bar. The resulting PC-SAFT predicted Michaelis constants were validated by experimental literature data. Results show that pressure decreased the Michaelis constants of both reactions, HPNA hydrolysis and SPNA hydrolysis. In spite of that, co-solvent effects on the Michaelis constants were predicted to be contrary for the two hydrolysis reactions. For the hydrolysis of HPNA, the co-solvents under investigation decreased the Michaelis constant while the co-solvents increased the Michaelis constant for the hydrolysis of SPNA. These PC-SAFT predictions were in qualitative agreement with the experimental literature data. This shows that molecular interactions are the key to understand the effects of co-solvents on Michaelis constants for the considered reactions. Applying the thermodynamic model PC-SAFT allowed predicting the observed combined effects of co-solvent and pressure on enzymatic reaction kinetics, which opens the door for solvent design of enzymatic reactions in the future.

Glycolysis is a very central metabolic pathway for many organisms because it represents a key component in their energy production. For this reason, it has always been an extensively studied pathway. The glyceraldehyde 3-phosphate dehydrogenase (GDH) reaction is an important reaction of glycolysis yielding nicotinamide adenine dinucleotide (NADH). The aim of this work is to investigate the thermodynamics of the GDH reaction and determine the standard Gibbs energy of reaction Δ R g ' 0 and standard enthalpy of reaction Δ R h ' 0 . Currently, so-called ‘standard’ data exist in the literature that depend on the conditions they were measured at. In this work, Δ R g ' 0 and Δ R h ' 0 values were determined that are independent from reaction conditions by accounting for the activity coefficients of the reacting substances. Therefore, the equation of state electrolyte Perturbed-Chain Statistical Associating Fluid Theory (ePC-SAFT) was used. The required ePC-SAFT parameters were taken from literature or fitted to new experimental osmotic coefficients. A value of Δ R g ' 0 = 51.5 ± 0.4 kJ mol−1 was determined at 298.15 K. This value deviates by up to 10 kJ mol−1 from existing literature values, caused by activity coefficients in the reaction medium. It can be used to determine the Gibbs energy of reaction Δ R g ' , which will allow statements concerning the feasibility of the GDH reaction. Further, a method is presented to predict influences of pH, initial substrate concentration and Mg2+ concentration on the reaction equilibrium. Finally, we measured the standard reaction enthalpy for the GDH reaction Δ R h ' 0 by titration calorimetric measurements ( Δ R h ' 0 = 4.6 ± 0.1 kJ mol−1). This value was within van ’t Hoff evaluated Δ R h ' 0 (9 ± 16 kJ mol−1) using temperature-dependent equilibrium constants from equilibrium measurements corrected by ePC-SAFT predicted activity coefficients.

Large-amplitude internal waves (LAIW) cause intense drops in sea water temperature (6–9 °C) and acidity (0.6 pH units) within minutes, posing a major disturbance factor for shallow water corals in the Andaman Sea. During periods of elevated temperatures, however, they may provide a vital source of relief to heat-stressed corals. To assess the effect of LAIW on the thermal tolerance of the massive coral Porites lutea, we carried out a one-month reciprocal LAIW simulation experiment with coral nubbins collected from the LAIW-exposed and LAIW-sheltered sides of the Similan Islands, an offshore archipelago near the Thai Andaman shelf break (distance of sampling locations

In this work, electrolyte PC-SAFT equation of state developed in 2005 with the parameters from Held et al. [Chem. Eng. Res. Des. 92 (2014) 2884–2897] has been applied to predict the solubility of CO 2 in aqueous N -methyldiethanolamine (MDEA) solutions. The considered temperature range was 313–413 K, MDEA weight fractions up to 0.32 (related to the binary water/MDEA system) and loadings of up to 1.32 (mole CO 2 /mole MDEA). In order to predict CO 2 solubilities, the reaction equilibria and phase equilibria were solved simultaneously by explicitly accounting for the electrolyte species being present in the system: H + , OH − , HCO 3 − , CO 3 2− and MDEAH + . The pure-component parameters for the molecular components (H 2 O, CO 2 , MDEA) and for all ions except MDEAH + were already available in the literature. MDEAH + pure-component parameters were inherited from MDEA, and the charge was explicitly accounted for in ePC-SAFT. Binary parameters were applied only for the pairs H 2 O/CO 2 , H 2 O/ions, and H 2 O/MDEA. The deviations between experimental and ePC-SAFT modeled CO 2 solubility in aqueous MDEA solutions was 19.82% for a temperature range of 313–413 K, a MDEA weight fractions of 0.19, and CO 2 loadings of up to 1.3 (mole CO 2 /mole MDEA). As binary parameters have not been adjusted to experimental CO 2 solubility data in aqueous MDEA solutions, these results can be considered as predictive.

So far, the electrolyte PC-SAFT equation of state developed in Cameretti et al. (2005) has been applied to model solution densities, vapor–liquid equilibria (VLE), liquid–liquid equilibria (LLE), and solid–liquid equilibria (SLE) of solutions containing electrolytes. For that purpose, two ion-specific parameters were used to characterize any ion: the diameter of the solvated ion and the dispersion-energy parameter between ion and solvent. Dispersion was only considered between ions and solvents. Considering the small number of adjustable parameters, this approach yielded acceptable results especially for low and moderate electrolyte concentrations. However, for high salt concentrations, a distinct deviation between modeled and experimental data was observed. In this work a new modeling approach is suggested that accounts explicitly also for dispersion interactions between anions and cations. This yields a much more precise description of electrolyte solutions at higher concentrations compared to original ePC-SAFT. With this new approach it is also possible to directly model weak electrolyte solutions without using an additional approach that accounts for ion-pair formation. The new approach for applying ePC-SAFT is now able to model phase equilibria (VLE, LLE, SLE) of ternary electrolyte solutions containing water, organic solvents, salts, and amino acids even at high salt concentrations in good agreement with experimental data.

In this work, Δ R g + values for the enzymatic G6P isomerization were determined as a function of the G6P equilibrium molality between 25 °C and 37 °C. The reaction mixtures were buffered at pH = 8.5. In contrast to standard literature work, Δ R g + values were determined from activity-based equilibrium constants instead of molality-based apparent values. This yielded a Δ R g + value of 2.55 ± 0.05 kJ mol − 1 at 37 °C, independent of the solution pH between 7.5 and 8.5. Furthermore, Δ R h + was measured at pH = 8.5 and 25 °C yielding 12.05 ± 0.2 kJ mol − 1 . Accounting for activity coefficients turned out to influence Δ R g + up to 30% upon increasing the G6P molality. This result was confirmed by predictions using the thermodynamic model ePC-SAFT. Finally, the influence of the buffer and of potassium glutamate as an additive on the reaction equilibrium was measured and predicted with ePC-SAFT in good agreement.

ePC-SAFT was used to model the gas solubility in ionic liquids (ILs). The gases under consideration were CO, H2, H2S and O2, and the imidazolium-based ILs studied were [Cnmim][Tf2N], [Cnmim][PF6] and [Cnmim][BF4] (n = 2, 4, 6 and 8). For the ePC-SAFT modeling, each IL was considered to be completely dissociated into a cation and an anion. Each ion was modeled as a non-spherical species exerting repulsive, dispersive and Coulomb forces. CO, H2 and O2 were modeled as non-spherical molecules exerting repulsive and dispersive forces, and H2S was modeled as a non-spherical, associating molecule. ePC-SAFT reasonably predicts the gas solubility in the considered gas/IL mixtures. In order to describe the experimental gas solubilities quantitatively in a broad temperature and pressure range, one ion-specific binary interaction parameter between the IL-anion and the gas was applied, which was allowed to depend linearly on temperature. Validerad; 2014; 20131120 (andbra)

In this work thermodn. properties of electrolyte/amino acid/water solns. were measured and modeled. Osmotic coeffs. at 298.15 K were measured by means of vapor-pressure osmometry. Amino-acid soly. at 298.15 K was detd. gravimetrically. Considered aq. systems contained one of the four amino acids: glycine, L-/DL-alanine, L-/DL-valine, and L-proline up to the resp. amino-acid soly. limit and one of 13 salts composed of the ions Li+, Na+, K+, NH4+, Cl-, Br-, I-, NO3-, and SO42- at salt molalities of 0.5, 1.0, and 3.0 mol · kg-1, resp. The data show that the salt influence is more pronounced on osmotic coeffs. than on amino-acid soly. The electrolyte Perturbed-Chain Statistical Assocn. Theory (ePC-SAFT) was applied to model thermodn. properties in aq. electrolyte/amino-acid solns. In previous works, this model had been applied to binary salt/water and binary amino acid/water systems. Without fitting any addnl. parameters, osmotic coeffs. and amino-acid soly. in the ternary electrolyte/amino acid/water systems could be predicted with overall deviations of 3.7I‚ and 9.3I‚, resp., compared to the exptl. data. [on SciFinder(R)]

We present measurements, molecular dynamics (MD) simulations, and predictions using Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) of the density of aqueous solutions in a pressure range from 1 bar to 5000 bar, a pressure regime that is highly relevant for both biochemical applications and the fundamental understanding of solvation. The accurate determination of density data of pressurized solutions remains challenging. We determined relative density changes from the variations in X-ray absorption through the sample and developed a new water parameter set for PC-SAFT modeling that is appropriate for high pressure conditions in the kilobar regime. As a showcase, we studied trimethylamine N-oxide (TMAO) solutions and demonstrated that their compressibility decreases with the TMAO content. This result is linked to the stabilizing effect of TMAO on the local H-bond network of water. Experiments and calculations, which represent two independent methods, are in very good agreement and are in accordance with results of force field molecular dynamics simulations of the same systems.

Thermodynamics and kinetics of biochemical reactions depend not only on temperature, but also on pressure and on the presence of cosolvents in the reaction medium. Understanding their effects on biochemical processes is a crucial step towards the design and optimization of industrially relevant enzymatic reactions. Such reactions typically do not take place in pure water. Cosolvents might be present as they are either required as stabilizer, as solubilizer, or in their function to overcome thermodynamic or kinetic limitations. Further, a vast number of enzymes has been found to be piezophilic or at least pressure-tolerant, meaning that nature has adapted them to high-pressure conditions. In this manuscript, we review existing data and we additionally present some new data on the combined cosolvent and pressure influence on the kinetics of biochemical reactions. In particular, we focus on cosolvent and pressure effects on Michaelis constants and catalytic constants of α-CT-catalysed peptide hydrolysis reactions. Two different substrates were considered in this work, N -succinyl-L-phenylalanine- p -nitroanilide and H -phenylalanine- p -nitroanilide. Urea, trimethyl- N -amine oxide, and dimethyl sulfoxide have been under investigation as these cosolvents are often applied in technical as well as in demonstrator systems. Pressure effects have been studied from ambient pressure up to 2 kbar. The existing literature data and the new data show that pressure and cosolvents must not be treated as independent effects. Non-additive interactions on a molecular level lead to a partially compensatory effect of cosolvents and pressure on the kinetic parameters of the hydrolysis reactions considered.

The Gibbs energy of reaction (Δ(R)g) is the key quantity in the thermodynamic characterization of biological reactions. Its calculation requires precise standard Gibbs energy of reaction (Δ(R)g(+)) values. The value of Δ(R)g(+) is usually determined by measuring the apparent (concentration-dependent) equilibrium constants K, e.g., the molality-based Km. However, the thermodynamically consistent determination of Δ(R)g(+) requires the thermodynamic (activity-based) equilibrium constant Ka. These values (Km and Ka) are equal only if the ratio of the activity coefficients of the reactants to the activity coefficients of the products (Kγ) is equal to unity. In this work, the impact of Kγ on the estimation of Ka for biological reactions was investigated using methyl ferulate (MF) hydrolysis as a model reaction. The value of Kγ was experimentally determined from Km values that were measured at different reactant concentrations. Moreover, Kγ was independently predicted using the thermodynamic model ePC-SAFT. Both the experimentally determined and the predicted Kγ values indicate that this value cannot be assumed to be unity in the considered reaction. In fact, in the reaction conditions considered in this work, Kγ was shown to be in the range of 3Kγ6 for different reactant molalities (2mmol MF kg(-1)10). The inclusion of Kγ and thus the use of the thermodynamically correct Ka value instead of Km lead to remarkable differences (almost 40%) in the determination of Δ(R)g(+). Moreover, the new value for Δ(R)g(+) increases the concentration window at which the reaction can thermodynamically occur. The influence of additives was also investigated both experimentally and theoretically. Both procedures consistently indicated that the addition of NaCl (0 to 1molkg(-1) water) moderately decreased the value of Kγ, which means that the values of Km increase and that a higher amount of products is obtained as a result of the addition of salt. Additionally, Km was found to strongly depend on pH. A ten-fold increase in the Km values was observed in the pH range of 6 to 7; this increase corresponds to a change of more than 100% in the value of Δ(R)g(+).

Urea and inorganic ions are present in some of the physiological systems, e.g. urine. Understanding the interactions in urea/salt/water is a preliminary step to shed light on more complicated behavior of multi-component physiological systems. State-of-the-art models as well as thermophysical properties can be applied to understand the interactions in these systems. In order to determine such interactions densities, mean ionic activity coefficients (MIACs), osmotic coefficients, and solubility were measured in aqueous solutions of urea and different salts. Densities were determined at temperatures 293.15, 303.15, and 313.15 K for urea concentrations up to 3 molal and up to 1 molal for NaCl. Osmotic coefficients and MIACs were obtained at 310.15 K by using the vapor-pressure osmometry and potentiometry methods, respectively. Ternary aqueous urea solutions containing NaCl, KCl, NaBr, KBr, LiBr, NaNO3, and LiNO3 at two different concentrations of urea (0.3 and 1 molal) as well as at three salt concentrations (0.25, 0.5, and 0.75 molal) were considered. Moreover, urea solubility was also measured at 310.15 K in 3 and 5 molal NaCl solutions in the present work. Experimental data obtained in this work showed that the salt primarily dictates the volumetric properties and the MIAC while the solute with higher concentration determines the behavior of osmotic coefficients in these solutions. The ePC-SAFT model (without any adjustable mixture parameter) was used to accurately predict the experimental densities, activity and osmotic coefficients, and solubilities of the studied mixtures.

Liquid densities, osmotic coefficients, and mean ionic activity coefficients (MIAC) at 25 °C of single-salt alcohol (methanol and ethanol) solutions containing univalent ions were measured and modeled with the ePC-SAFT equation of state. In accordance with our previous work [Held, C., Cameretti, L.F., Sadowski, G., Fluid Phase Equlilib. 270 (2008) 87–96], only two solvent-specific ion parameters were adjusted to experimental solution densities and osmotic coefficients: the solvated ion diameter and the dispersion-energy parameter. ePC-SAFT was able to reproduce experimental data of the respective alcohol/salt systems with reasonable accuracy. Based on the solvent-specific ion-parameter sets, it is possible to predict densities and MIACs in ternary and quaternary water/alcohol(s)/salt solutions by introducing appropriate mixing rules that do not contain any additional fitting parameters.