Capillary supercritical fluid separation

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). 

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). 

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. 

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. 

A polar stationary phases such as ODS and TMS and polar such as CN, diol, or NO2 have been successfully applied to the separation of monosaccharides Separation of maltodextrin derivatized with trifluoroacetic anhydride using FID and a CN packed column Capillary supercritical fluid chromatography-MS is well suited to confirm the identity of the TMS derivative of inositol triphosphate Chiral analytes Enantioseparation... 

Vela, N.P., Caruso, J.A. Comparison of flame ionization and inductively coupled plasma mass spectrometry for the detection of organometallics separated by capillary supercritical-fluid chromatography. J. Chromatogr. 641, 337-345 (1993)... 

Among the works of supercritical fluid separations of PCBs, UV has been the most popular detector. A Microbore Cig column was used to separate individual PCB congeners in Aroclor mixtures. Density and temperature programming was also utilized for separation of PCBs. Both packed (with phenyl and Cig) and capillary (Sphery-5 cyanopropyl) columns were used in this work. Carbon dioxide, nitrous oxide, and sulfur hexafluoride were tested as mobile phases for the separation of PCBs. 

In the light of the aforesaid limitations of the application of gas chromatography or HPLC for the separation of compounds having limited volatility and thermal stability it is too obvious that there is need to use other alternatives for separating such compounds. Capillary supercritical fluid chromatography is such an alternative and although of comparatively recent origin, meets the said need adequately. 

The three requirements for achieving optimal results using capillary supercritical fluid chromatography for separation of mixtures are ... 

Since the discovery of the carcinogenicity of A-nitrosamines and their occurrence in the environment, many separation and detection methods have been developed for their analysis. Polarographic, spectrophotometric, and thin-layer chromatographic methods have been the earliest techniques employed and have been reviewed by several authors.However, the A-nitrosamines are now routinely analyzed by chromatographic procedures. Two major types of chromatography methods are commonly used, namely, GC and HPLC. Other techniques like capillary electrophoresis and capillary supercritical fluid chromatography have been introduced most recently. 

Recent developments in separation science are covered from the standpoint of their impact on various modes of chromatography. Chromatographic applications of cyclodextrin and phenylboronic acid stationary phases are discussed. The renaissance in electrophoresis has given risen to high-resolution, two-dimensional gel electrophoresis. The basic methodology and recent advances are provided for studies on protein separations. Finally, the combination of capillary supercritical fluid chromatography and mass... 

Demirbiiker, M., Hagglund, I. and Blomberg, L. G. (1992) Separation of unsaturated fatty acid methyl esters by packed capillary supercritical fluid chromatography. Comparison of different column packings. J. Chromatogr., 605, 263-7. 

Francis, E.S. Eatough, D.J. Lee, M.L. Capillary supercritical fluid chromatography with nitro- and nitroso-specific-chemiluminescence detection. J. Microcol. Separ. 1994, 6(4), 395 1. 

Tavares, M.C.H. Vilegas, J.H.Y. Langas, F.M. Separation of underivatised tritepene acids by capillary supercritical fluid chromatography. Phytochem. Anal. 2001, 72 (2), 134-137. 

ON-LINE COUPLING OF SUPERCRITICAL FLUID EXTRACTION WITH CAPILLARY ELECTRODRIVEN SEPARATION TECHNIQUES (SFE-CESTs)... 

Figure 12.20 SFC-GC analysis of a sample of aviation fuel (a) SFC separation into two peaks (b and c) coixesponding GC ttaces of the respective peaks (flame-ionization detection used throughout). Reprinted from Journal of High Resolution Chromatography, 10, J. M. Levy et ah, On-line multidimensional supercritical fluid chromatography/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.

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