Capillary fluid chromatography

L. Karlsson, L. Mathiasson, J. Akesson, and J.A. Jonsson, Quantitative aspects of the determination of compounds with wide varying polarity using capillary fluid chromatography, J. Chromatogr., 557 99(1991). 

Dionex Corporation, in an application note on its series 600-D SFC, describe a method for the determination of polymer additives. The possibilities of SFC for determining polymer additives have been recently demonstrated [90-101]. The low elution temperature and high resolution of capillary fluid chromatography makes this technique very attractive. Other advantages are that a FID can be used and that interfacing with spectroscopic detectors is somewhat easier than with HPLC. Quantitation in capillary SFC has been found to be more difficult than in HPLC and capillary gas chromatography, however, because of lack of precision in injection [97]. 

Cyclopentadiene oligomers up to octamers can be effectively analy2ed and quantified by supercritical fluid chromatography using a chemically bonded methyl siUcone capillary column. 

H. Daimon and Y. Hirata, Direct coupling of capillary supercritical fluid chromatography with superaitical fluid extraction using modified carbon dioxide , J. High Resolut. Chromatogr. 17 809-813 (1994). 

An on-line supercritical fluid chromatography-capillary gas chromatography (SFC-GC) technique has been demonstrated for the direct transfer of SFC fractions from a packed column SFC system to a GC system. This technique has been applied in the analysis of industrial samples such as aviation fuel (24). This type of coupled technique is sometimes more advantageous than the traditional LC-GC coupled technique since SFC is compatible with GC, because most supercritical fluids decompress into gases at GC conditions and are not detected by flame-ionization detection. The use of solvent evaporation techniques are not necessary. SFC, in the same way as LC, can be used to preseparate a sample into classes of compounds where the individual components can then be analyzed and quantified by GC. The supercritical fluid sample effluent is decompressed through a restrictor directly into a capillary GC injection port. In addition, this technique allows selective or multi-step heart-cutting of various sample peaks as they elute from the supercritical fluid... 

Figure 12.19 Schematic diagram of the interface system used for supercritical fluid cliromatography-gas chromatography. Reprinted from Journal of High Resolution Chromatography, 10, J. M. Levy et al., On-line multidimensional supercritical fluid clrromatogi a-phy/capillary gas chromatography , pp. 337-341, 1987, with permission from Wiley-VCH.

Figure 12.23 SFC-SFC analysis, involving a rotaiy valve interface, of a standard coal tar sample (SRM 1597). Two fractions were collected from the first SFC separation (a) and then analyzed simultaneously in the second SFC system (h) cuts a and h are taken between 20.2 and 21.2 min, and 38.7 and 40.2 min, respectively. Peak identification is as follows 1, tii-phenylene 2, chrysene 3, henzo[g/ i]perylene 4, antliracene. Reprinted from Analytical Chemistry, 62, Z. Juvancz et al, Multidimensional packed capillary coupled to open tubular column supercritical fluid chromatography using a valve-switcliing interface , pp. 1384-1388, copyright 1990, with permission from the American Chemical Society.

Figure 12.24 Schematic diagram of the multidimensional packed capillary to open tubular column SFC-SFC system. Reprinted from Analytical Chemistry, 62, Z. Juvancz et al., Multidimensional packed capillary coupled to open tubular column supercritical fluid chromatography using a valve-switching interface , pp. 1384-1388, copyright 1990, with permission from the American Chemical Society.

J. M. Eevy, J. P. Guzowski and W. E. Huhak, On-line multidimensional superaitical fluid chromatography/capillary gas chromatography. J. High Resolut. Chromatogr. 10 337-341 (1987). 

Z. Juvancz, K. M. Payne, K. E. Markides and M. E. Eee, Multidimensional packed capillary coupled to open tubular column superaitical fluid chromatography using a valveswitching interface , Awa/. Chem. 62 1384-1388(1990). 

Cortes, H. J., Campbell, R. M., Himes, R. P., and Pfeiffer, C. D., On-line coupled liquid chromatography and capillary supercritical fluid chromatography large-volume injection system for capillary SFC, ]. Microcol. Sep., 4, 239, 1992. 

Kuitunen ML, Hartonen K, Riekkoa ML. 1991. Analysis of chemical warfare agents in soil samples by off-line supercritical fluid extraction and capillary gas chromatography. Journal of Microcolumn Separation 3(6) 505-512. 

In analytical chemistry there is an ever-increasing demand for rapid, sensitive, low-cost, and selective detection methods. When POCL has been employed as a detection method in combination with separation techniques, it has been shown to meet many of these requirements. Since 1977, when the first application dealing with detection of fluorophores was published [60], numerous articles have appeared in the literature [6-8], However, significant problems are still encountered with derivatization reactions, as outlined earlier. Consequently, improvements in the efficiency of labeling reactions will ultimately lead to significant improvements in the detection of these analytes by the POCL reaction. A promising trend is to apply this sensitive chemistry in other techniques, e.g., in supercritical fluid chromatography [186] and capillary electrophoresis [56-59], An alter-... 

SFC is now one of the fastest growing analytical techniques. The first paper on the technique was by Klesper et al. [21], but supercritical fluid chromatography did not catch the analyst s attention until Novotny et al. [22] published the first paper on capillary SFC. 

A paper has been published showing the use of the photoionization detector [26], Polyaromatic hydrocarbons are very sensitive using the photoionization detector and the levels detected did not break any new ground in terms of sensitivity. It did inspire HNS Systems (Newtown MA, USA), who market a photoionization detector, to try the detector with a capillary system, interfaced to a Lee Scientific 602 supercritical fluid chromatography (Lee Scientific, Salt Lake City, Utah, USA). 

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