Chromatography technology

Campbell, C. The ion trap detector for gas Chromatography technology and application. Finnigan MAT IDT 15. 

Crude extract was also separated and collected on another Waters system, which consisted of a 600 pump, a 2996 Photodiode Array Detector, and a 2767 fraction collector. The detection wavelength was set in the ultraviolet (UV) between 190 and 400 nm. The column used was a 150 x 21 mm long ACE AQ with 10-mm particles (Advanced Chromatography Technologies, Aberdeen, UK). The system was operated at room temperature. The injection volume was 1500 pL. The mobile phase consisted of 1 3 acetonitrile water with 0.01% trifluoroacetic acid, which was flowing at a rate of 10 mL/min. The system was operated in the isocratic mode. Fractions of 1.25 mL were collected every 7.5 s. 

The development of ultra high-pressure liquid chromatography technology has dramatically reduced the analysis time for a number of small molecules. However, we have found that the analysis of carotenes is poor with the currently available column chemistries. The development of C30 columns with backbones that can withstand ultra high pressure would allow carotenoid chemists to take full advantage of this technology. 

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Guide to HPLC and LC-MS Buffer Selection, Advanced Chromatography Technologies, Aberdeen, free at... 

Actually, chromatographic ion-exchange separations have been used for many years and an extensive literature exists. Although older ion-exchange separations are often slow and cumbersome by modern standards, these procedures illustrate a number of clever and useful approaches. There is no reason why many of these classical separations cannot be adapted to more modem chromatography technology. 

Solid-phase extraction is a sample preparation technique that has been derived from liquid chromatography technology and has been applied extensively to the analysis of biological samples as well as pharmaceutical products. It is a step gradient technique in which the analyte, dissolved in a weak solvent, is retained on a stationary phase and subsequent additions of various moving phases of increasing solvent strength results in selective and controlled elution of the interferences and analytes. 

A fundamental study of surface reactions of many organic structures and various adsorbents (e.g., aluminas, silicas) was done by L. R. Snyder in the 1958-1968 period. This provided an excellent evaluation of the relative elution of both hydrocarbons and nonhydrocarbons in numerous chromatographic systems. These studies were a necessary ingredient in the LEAC technique that he utilized on petroleum products. These studies indicated that carbazoles and benzocarbazoles are major nonhydrocarbon types in petroleum (6). With the advent of many selective isolation techniques for nonhydrocarbons since 1965 and high-pressure liquid chromatography technology, the correlations that he developed should now find numerous applications. 

As in SFC time ranges are shorter than on any other preparative chromatography technologies (some purifications can be handled with cycle times shorter than a minute), flow control is then a key point to obtain reproducible chromatograms. 

Fifteen-meter columns have been used conventionally for simple mixtures (less than 10 components) or for sample screening purposes. However, the advent of fast chromatography technology is opening new possibilities for the use of short columns for more complex mixtures. This issue is discussed in more detail later in this chapter. 

C. Campbell, The Ion Trap Detector for Gas Chromatography Technology and Application, Finnegan MAT IDT Publication 15. 

C. Campbell, Ion Trap Detector Gas Chromatography Technology, Finnegan MAT, IDT Publication No.l5. 

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