It is important to understand the mechanism and implications of different modifiers on analytical and preparative processes under chromatography with supercritical fluids (SFs) and under extraction with SFs. Supercritical fluid chromatography (SFC) and supercritical fluid extraction are generally carried out with neat supercritical carbon dioxide (SCCO2) or with SCCO2 containing modifiers (or cosolvents), especially for strongly polar compounds. For example, methanol is added as a cosolvent/modifier to SCCO2 for the extraction/separation of polar compounds. This paper discusses the influence of the modifier on the colligative properties of the principal mobile phase, which may define the situation in the total mobile phase in a chromatography column or in parts of a column under SFC. No colligative behavior of solutions reflects individual properties of the solutes. Their cross-interactions with solvents are discussed.
Poole, C.F. (2000) Progress in Packed Column Supercritical Fluid Chromatography: Materials and Methods. Journal of Biochemical and Biophysical Methods, 43, 3-23.
SjÖberg, P.J.R. and Markides, K.E. (1999) Capillary Column Supercritical Fluid Chromatography–Atmospheric Pressure Ionization Mass Spectrometry: Interface Performance of Atmospheric Pressure Chemical Ionization and Electrospray Ionization. Journal of Chromatography A, 855, 317-327.
Baker, T.R. and Pinkston, J.D. (1998) Development and Application of Packed Column Supercritical Fluid Chromatography/Pneumatically Assisted Electrospray Mass Spectrometry. Journal of the American Society for Mass Spectrometry, 9, 498-509. https://doi.org/10.1016/S1044-0305(98)00006-3
Schweighardt, F.K. and Mathias, P.M. (1993) Impact of Phase Equilibria on the Behavior of CylinderStored CO2—Modifier Mixtures Used as Supercritical Fluid. Journal of Chromatographic Science, 31, 207-211.
Brondz, I. and HØiland, K. (2008) Chemotaxonomic Differentiation between Cortinarius infractus and Cortinarius subtortus by Supercritical Fluid Chromatography Connected to a Multi-Detection System. Trends in Chromatography, 4, 79-87.
Brondz, I. (2012) Editorial: Yesterday, Today and Tomorrow of Supercritical Fluid Extraction and Chromatography. American Journal of Analytical Chemistry, 3, 867 -869. https://doi.org/10.4236/ajac.2012.312A114
Brondz, I. and Brondz, A. (2014) Review: Isomer Separation, Chiral Resolution, and Structure Elucidation Analyses Are the Future of Analytical Supercritical Fluid Chromatography—Mass Spectrometry. International Journal of Analytical Mass Spectrometry and Chromatography, 2, 15-24.
Brondz, I. and Brondz, A. (2012) The Technology for Preparation of Generic (Monoenantiomeric) Antimalarial Drug Primaquine by Using Supercritical Fluid Chromatography. Separation of Primaquine from Quinocide: Simultaneous Resolution of the Enantiomers of Primaquine and Their Separation from Quinocide in One Run. American Journal of Analytical Chemistry, 3, 884-890.
Brondz, I., HØiland, K. and Lefler, J. (2007) Supercritical Fluid Chromatography of Secondary Metabolites and Multi-Analysis by Mass Spectrometry-Ultraviolet and Corona Charged Aerosol Detection. 12 Norwegian MS-Winter Meeting, Hafjell, 21-24 January 2007, 63.
Pitchaiah, K.C., Brahmananda Rao, C.V.S., Sivaraman, N., Joseph, M. Madras, G. and Brondz, I. (2017) Solubility of Dialkylalkyl Phosphonates in Supercritical Carbon Dioxide: Experimental and Modeling Approach. Fluid Phase Equilibria, 435, 88 -97. https://doi.org/10.1016/j.fluid.2016.12.011
Sedunov, B. (2013) The Equilibrium Thermal Physics of Supercritical Fluids. International Journal of Analytical Mass Spectrometry and Chromatography, 1, 103-108.
Sedunov, B. Brondz, I. (2016) Analytical Approach to Clusters in near Critical CO2. International Journal of Analytical Mass Spectrometry and Chromatography, 4, 39-50. https://doi.org/10.4236/ijamsc.2016.43005
Brondz, I. and Brondz, A. (2012) Supercritical Fluid Chromatography—Mass Spectrometry (SFC-MS) of Heterocyclic Compounds with Trivalent and Pentavalent Nitrogen in Cough Relief Medical Forms Tuxi and Cosylan. American Journal of Analytical Chemistry, 3, 870-876. https://doi.org/10.4236/ajac.2012.312A115
Mehl, A., Nascimento, F.P., Falcao, P.W., Pessoa, F.L.P. and Cardozo-Filho, L. (2011) Vapor-Liquid Equilibrium of Carbon Dioxide + Ethanol: Experimental Measurements with Acoustic Method and Thermodynamic Modeling. Journal of Thermodynamics, 2011, 11 p.
Gernert, J. Jager, A. and Span, R. (2014) Calculation of Phase Equilibria for Multy-Component Mixtures Using Highly Accurate Helholtz Energy Equations of State. Fluid Phase Equilibria, 375, 209-218. https://doi.org/10.1016/j.fluid.2014.05.012
Chueh, P.L. and Prausnitz, J.M. (1967) Vapor-Liquid Equilibria at High Pressures: Calculation of Critical Temperatures, Volumes, and Pressures of Nonpolar Mixtures. American Institute of Chemical Engineers, 13, 107-1113.
Chueh, P. L. Prausnitz, J. M. (1967), Vapor-Liquid Equilibria at High-Pressures: Calculation of Partial Molar Volumes in Nonpolar Liquid Mixtures. American Institute of Chemical Engineers, 13, 1099-1107.
Brunner, E. Hultenschmidt, W. and Schlichtharle, G. (1987) Fluid Mixtures at High Pressures IV. Isothermal Phase Equilibria in Binary Mixtures Consisting of Methanol + Hydrogen or Nitrogen or Methane or Carbon Monoxide or Carbon Dioxide. The Journal of Chemical Thermodynamics, 19, 273-291.
Lin, Y. Wai, C.M. Jean, F.M. and Brauer, R.D. (1994) Supercritical Fluid Extraction of Thorium and Uranium Ions from Solid and Liquid Materials with Fluorinated β-Diketones and Tri-Butyl Phosphate. Environmental Science & Technology, 28, 1190-1193. https://doi.org/10.1021/es00055a034
Lin, Y., Brauer, R.D., Laintz, K.E. and Wai, C.M. (1993) Supercritical Fluid Extraction of Lanthanides and Actinides from Solid Materials with a Fluorinated ß-Diketone. Analytical Chemistry, 65, 2549-2551.
Lin, Y. and Wai, C.M. (1994) Supercritical Fluid Extraction of Lanthanides with Fluorinated β-Diketones and Tri-Butyl Phosphate. Analytical Chemistry, 66, 1971-1975. https://doi.org/10.1021/ac00085a008
Shimad, T., Ogumo, S., Sawada, K., Enokida, Y. and Yamamato, Y. (2006) Selective Extraction of Uranium from a Mixture of Metal or Metal Oxides by a Tri-n-Butylphosphate Complex with HNO3 and H2O in Supercritical CO2. Analytical Sciences, 22, 1387-1391. https://doi.org/10.2116/analsci.22.1387
Kumar, R. Sivaraman, N. Sujatha, K. Srinivasan, T.G. and Vasudeva Rao, P.R. (2007) Removal of Plutonium and Americium from Waste Matrices by Supercritical Carbon Dioxide Extraction. Radiochimica Acta, 95, 577-584.
Coan, C.R. and King, A.D. (1971) Solubility of Water in Compressed Carbon Dioxide, Nitrous Oxide, and Ethane. Evidence for Hydration of Carbon Dioxide and Nitrous Oxide in the Gas Phase. Journal of the American Chemical Society, 93, 1857. https://doi.org/10.1021/ja00737a004
Sedunov, B. and Brondz, I. (2017) The Zigzag Progression of Melting and Triple Point Properties of n-Alkanes, n-Alcohols, n-Alkanoic Amines and n-Alkanoic Acids. Voice of the Publisher, 3, 1-14. https://doi.org/10.4236/vp.2017.31001
Mathias, P.M., Klotz, H.C. and Prausnitz, J.M. (1991) Equation-of-State Mixing Rules for Multicomponent Mixtures: the Problem of Invariance, Fluid Phase Equilibria, 67, 31-44. https://doi.org/10.1016/0378-3812(91)90045-9
McHugh, M.A. and Krukonis, V.J. (1994) Supercritical Fluid Extraction: Principles and Practice. Butterworth-Heinemann, Boston.
Brondz, I., Ekeberg, D., Bell, D.S., Hustad, J.A., Svendsen, R., Vlachos, V., Oakley, P., Langley, G.J., Mohini, T. and Amaury, C-G. Mikhalitsyn, F. (2007) Nature of the Main Contaminant in the Drug Primaquine Diphosphate: SFC and SFC-MS Methods of Analysis. Journal of Pharmaceutical and Biomedical Analysis, 43, 937-944.
Yiling, T. Michelberger, Th. and Franck, E.U. (1991) High-Pressure Phase Equilibria and Critical Curves of (Water + n-Butane) and (Water + n-Hexane) at Temperatures to 700 K and Pressures to 300 MPa. The Journal of Chemical Thermodynamics, 23, 105-112. https://doi.org/10.1016/S0021-9614(05)80063-1