Summary
Optimizing the extracted analyte collection step in analytical supercritical fluid extraction (SFE) is of key importance in achieving high analyte recoveries and extraction efficiencies. Whereas the extraction step in SFE has been well characterized both theoretically and experimentally; the analyte collection step after SFE has few theoretical guidelines, aside from a few empirical studies which have appeared in the literature. In this study, we have applied several theoretical approaches using experimental data to optimize analyte trapping efficiency in SFE. A vapour-liquid equilibrium model has been formulated to predict the trapping efficiency for extracted solute collection in a open collection vessel. Secondly, a simple solution thermodynamic model for predicting solute (analyte) activity coefficients in various trapping solvents has been shown to have utility in predicting collection efficiencies. Finally, effective trapping efficiency after SFE using sorbent media is related to the extent of analyte breakthrough on the sorbent-filled trap after depressurization of supercritical fluid. Using experimental data determined via physico-chemical gas chromatographic measurements (i. e., specific retention volumes), we have shown the relationship between analyte breakthrough volume off of the trapping sorbent and volume of depressurized fluid through the collection trap. The above theoretical guidlines should prove of value to analysts in designing and optimizing the best conditions for trapping analytes after extraction via analytical SFE.
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J. W. King, J. Chromatographic Sci.,27, 355 (1989).
L. T. Taylor, Supercritical Fluid Extraction, Wiley-Interscience, New York, 1996.
J. W. King, J. E. France, in B. Wenelawiak, Ed., Analysis with Supercritical Fluids: Extraction and Chromatography, Springer-Verlag, Berlin, 1992.
K. D. Bartle, A. A. Clifford, in F.B. Padley, Ed., Advances in Applied Lipid Research, JAI Press Ltd., London, 1992, pp. 229–239.
S. M. Hitchen, J. R. Dean, in J.R. Dean, Ed., Application of Supercritical Fluids in Industrial Analysis, Blackie Academic, Glascow, 1993, pp. 1–12.
T. Clifford, Fundamentals of Supercritical Fluids, Oxford University Press, Oxford, 1999, Chapter 5.
A. A. Clifford, in E.D. Ramsey, Ed., Analytical Supercritical Fluid Extraction Techniques, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1998, Chapter 1.
L. J. Mulcahey, L. T. Taylor, Anal. Chem.64, 2352 (1992).
D. J. Miller, S. B. Hawthorne, M. E. P McNally, Anal. Chem.65, 1038 (1993).
J. W. King, J. H. Johnson, J. P. Friedrich, J. Agric. Food Chem.37, 951 (1989).
G. L. McDaniel, L. T. Long, L. T. Taylor, J. High Resolut. Chromatogr.21, 245 (1998).
P. G. Thompson, L. D. Taylor, B. E. Richter, N. L. Porter, J. L. Ezzell, J. High Resolut Chromatogr.16, 713 (1993).
P. G. Thompson, L. T. Taylor, J. High Resolut. Chromatogr.17, 759 (1994).
J. J. Lagenfeld, M. D. Burford, S. B. Hawthorne, D. J. Miller, J. Chromatogr.594, 297 (1992).
J. Vejrosta, P. Karasek, J. Planeta, Anal. Chem.71, 905 (1999).
P. R. Eckard, L. T. Taylor, J. High Resolut. Chromatogr.19, 117 (1996).
L. J. Mulcahey, J. L. Hedrick, L. T. Taylor, Anal. Chem.63, 2225 (1991).
W. N. Moore, L. T. Taylor, Anal. Chem.67, 2030 (1995).
X. Chaudot, A. Tambute, M. Caude, J. High Resolut. Chromatogr.21, 175 (1998).
S. L. Taylor, J. W. King, S. E. Abel, Abstracts of the 5th International Symposium on Supercritical Fluid Chromatography and Extraction, Supercritical Conferences, Cincinnati, OH, 1994, D 16–17.
D. Van der Straeten, H. Van Langenhove, N. Schamp, J. Chromatogr.331, 207 (1985).
P. Sandra, F. David, E. Baltusan, T. De Smaele, in A. J. Handley, Ed., Extraction Methods in Organic Analysis, Sheffield Academic Press, Sheffield, England 1999, pp. 244–247.
R. F. Gallant, J. W. King, P. L. Levins, J. F. Piecewicz, Characterization of Sorbent Resins for Use in Environmental Sampling, EPA Report No. 600/7-78-054 March, 1978.
J. J. Manura, The Mass Spec Source 7/94, Scientific Instrument Services, Ringoes, NJ, 1994, pp. 3–11.
R. F. Fedors, Poly. Eng. Sci.14, 147 (1974).
J. W. King, S. L. Taylor, S. E. Abel, Submitted to Anal. Chem.
R. J. Laub, R. L. Pecsok, Physicochemical Applications of Gas Chromatography, Wiley-Interscience, New York, 1978, pp. 102–103.
J. W. King, in B. A. Charpentier and M. R. Sevenants, Eds., Supercritical Fluids—Chemical and Engineering Principles and Applications, American Chemical Society, Washington, DC, 1987, pp. 150–171.
J. Gmehling, J. Menke, M. Schiller, Activity Coefficients at Infinite Dilution, Dechema, Frankfurt, 1994.
C. Molllmann, J. Gmehling, J. Chem. Eng. Data5, 35 (1997).
A. V. Kiselev, Y. I. Yashin, Gas Adsorption Chromatography, Plenum Press, New York, 1989.
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King, J.W., Zhang, Z. Theoretical optimization of analyte collection in analytical supercritical fluid extraction. Chromatographia 51, 467–472 (2000). https://doi.org/10.1007/BF02490486
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DOI: https://doi.org/10.1007/BF02490486