Capillary supercritical fluid

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). 

Z. Liu, I. Osti ovsky, P. B. Farnsworth and M. L. Lee, Insti umentation for comprehensive two-dimensional capillary supercritical fluid-gas chromatography , Chromato-gmphia 35 567-573 (1993). 

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. 

Donnecke, J. et ah. Evaluation of a vancomycin chiral stationary phase in packed capillary supercritical fluid chromatography, J. Microcol. Sep., 11, 521, 1999. 

P. O. Chye, P. C. Kiat, K. L. Hian and F. Y. L. Sam, Analysis of nitroaromatics in aqueous samples by capillary supercritical fluid chromatography. International Journal of Environmental Studies, 1992, 41, 17-25. 

Zegers BN, Hogenboom AC, Dekkers SEG, et al. 1994a. Packed capillary supercritical fluid chromatography of organophosphorus pesticides Selective detection and application. J Microcol Sep... 

The separation of all eight cis/trans isomers of methyl 18 3 was similar to, but with better resolution than, the separation obtained with a 50-m CP Sil 88 capillary GC column (46) or by packed capillary supercritical fluid chromatography (47], The FAMEs eluted in four peaks or sets of peaks corresponding to the total number of cis and trans double bonds. These are marked as A (three trans), B (two trans, one cis), C (one trans, two cis), and D (three cis). 

Many reports (78-84) investigated the differences in packed and capillary supercritical fluid chromatography. Unfortunately, the rift between packed and capillary column users of SFC impeded the development of the science. This rift is a likely cause of the current low interest in SFC. Ideally, the unique features of the mobile phase is the area of scientific exploration that should be exploited. Choice of column size or type should be dependent upon the analytical problem to be solved. 

Mobile fluid interaction with the stationary phase in SFC was investigated with mass spectrometric tracer pulse chromatography (96). Using capillary supercritical fluid chromatography, the effect of methanol as an additive was studied on the partition behavior of n-pentane into 5 % phenylmethylsilicone stationary phase. The results showed that the mobile fluid uptake by the stationary phase decreased with increasing temperature and pressure. Thus suggests that stationary phase swelling, may occur in SFC. 

M. C. H. Tavares, J. H. Vilegas and F. M. Langas, Capillary supercritical fluid chromatography (c-SFC) analysis of underivatized triterpenic acids , Phytochem. Anal. 12 134-137 (2001). 

M. C. H. Tavares, Project, construction and applications of a new capillary supercritical fluid chromatography , Ph. D. Thesis, University of Sao Paulo, Brazil. (1999)... 

Figure 7.16 Capillary supercritical fluid chromatogram of tetrahydrocannabinol and six metabolites. Conditions supercritical C02 at 120°C 15-m x 50-/itn ID SE-33 column density programmed from 0.40 g/ml after a 7-min hold to 0.56 g/ml at 0.01 g/ml/min FID at 280°C. (Reprinted from Ref. 27, J. Chromatogr. Sci. by permission of Preston Publications, a division of Preston Industries.)...

D. R. Luffer and M. V. Novotny, Capillary supercritical fluid chromatography and microwave-induced plasma detection of cyclic boron-ate esters of hydroxy compounds, J. Microcolumn Sep., 3 39-46 (1991). 

M. Jung and V. Schurig, Extending the scope of enantiomer separation by capillary supercritical fluid chromatography on immobilized polysiloxane anchored permethyl-B-cyclodextrin (Chirasil-Dex), J. High Resolut. Chromstogr., 76 215 (1993). 

Capillary supercritical fluid chromatography (SFC) columns are 0.1-0.025 mm ID and 3-20 m in length. Good reviews of the technique of SFC have been recently published [52-55]. It was reported that the optimum inner diameter for capillary SFC based on plate height, linear velocity, analysis time, and column length was around 0.050 mm. 

D. Later, B. Richter, et al., Capillary supercritical fluid chromatography instrumentation and applications, Am. Lab., (August 1986). 

J. Fjeldsted and M. Lee, Capillary supercritical fluid chromatography, Anal. Chem., 56(4) 619A-628A (1984). 

S. Fields, R. Kong, et al., Effect of column diameter on efficiency in capillary supercritical fluid chromatography, HRC CC J. High Res. Chromotogr. Chromatogr. Commun., 7 312-318 (1984). 

Edder et al. reported the capillary supercritical fluid chromatography of basic drugs of abuse, namely nicotine, caffeine, methadone, cocaine, imipramine, codeine, diazepam, morphine, benzoylecgonine, papverine, narcotine, and strychnine [25]. They compared the separation of these drugs on DBS and DB wax columns. The chromatographic conditions included a carbon dioxide mobile phase and a flame-ionization detector. It was noted that on the DBS column, all peaks other than methadone and cocaine were separated. With the exception of benzoylecgonine and papaverine, all other peaks were separated on a DB wax column. A reproducibility of less than 5% was obtained with an internal standard method. The detection limits obtained were within 10-50 ppm on both the columns. A linearity of >0.99 was obtained for methadone, codeine, and morphine in the concentration range 10-1000 ppm. 

Figure 7.17 Capillary supercritical fluid chromatograms of ginseng extract. (1) Methyltestosterone (internal standard), (2) panaxadiol, (3) panaxatriol. [Reprinted from Ref. 28, Biomedical Chrom. (1992) with kind permission of John Wiley and Sons, Ltd., UK.]...

G.A. MacKay and G. D. Reed, Application of capillary supercritical fluid chromatography, packed column supercritical fluid chromatography, and capillary supercritical fluid chromatography-mass spectrometry in the analysis of controlled drugs, J. High Resolut. Chromatogr., 14 531 (1991). 

P. Edder, W. Haerdi, I. Veuthey, and C. Staub, Quantitative capillary supercritical fluid chromatography and supercritical fluid extraction of basic drugs of abuse, Chimia, 46 141 (1992). 

Supercritical fluid chromatography is now one of the fastest-growing analytical techniques. The first paper on the technique was by Klesper et al. [15], but supercritical fluid chromatography did not catch the analyst s attention until Novotny et al. [16] published the first paper on capillary supercritical fluid chromatography. 

Good reproducibility has been reported for capillary supercritical fluid chromatography using a direct injection method without a split restrictor. This method (Fig. 1.2(b)) utilises a rapidly rotating internal-loop injector (Valeo Inst. Switzerland) which remains in-line with the column for only a short period of time. This then gives a reproducible method of injecting a small fraction of the loop into the column. For this method to be reproducible the valve must be able to switch very rapidly to put a small slug of sample into the column. To attain this a method called timed-split injection was developed (Lee Scientific). For timed split to operate it is essential that helium is used to... 

Chester, T. L. (1984). Capillary supercritical-fluid chromatography with flame-ionization detection reduction of detection artifacts and extension of detectable molecular weight range. J. Chromatogr. 299 424-431. 

Chester, T. L., and Innis, D. P. (1986). Separation of oligo- and polysaccharides by capillary supercritical fluid chromatography. J. High Res. Chromatogr. Chromatogr. Commun. 9 209-212. 

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