In the past decade, supercritical fluid chromatography (SFC) has experienced a steady growth in acceptance, particularly in pharmaceutical and chemical laboratories. In SFC, a “supercritical” fluid, most commonly CO2, in combination with one or more polar organic solvents, such as alcohols, is used as mobile phase. Compared to HPLC, SFC offers better selectivity and shorter analysis time due to...

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Since there is an enormous volume of information on the separation of antibiotics in the literature, readers should be able to Rnd HPLC conditions for almost any antibiotic of interest. Readers are also encouraged to consult the ofRcial compendia for analysis of bulk or formulated drugs. For analysis of biological samples, the samples may be directly injected with a column switching technique i...

Supercritical Suid chromatography (SFC) on a preparative scale is of interest because of its advantages over high performance liquid chromatography (HPLC). The high diffusivity and low viscosity of supercritical Suids allow rapid separation. The solvent strength can easily be controlled by changing pressure and/or temperature, so that mobile phases with a Rxed composition can be used to separat...

The basic unit operations in vegetable oil processing are shown in Figure 4. Oil is extracted from plant material (oilseeds) using a solvent, usually hexane. Published research indicates that about 50}70% of the hexane can be recovered and recycled using nanoRltration membranes instead of the evaporators used today, thus reducing energy consumption substantially. The extracted crude oil is most...

NMR probes, and further development in cryoprobe technology along with the use of improved processing procedures, will continue to enhance the sensitivity of HPLC-NMR coupling. As a microanalytical method, HPLC-NMR allows the detection of various groups of natural compounds and other biomolecules in the nanogram or even picogram range and, therefore, can contribute to the solution of problems o...

ganic trace analysis. Pure Applied Chemistry 55: 1943. FiReld FW and Haines PJ (1995) Environmental Analytical Chemistry. London: Chapman and Hall. Luque de CastroMD andDa Silva MP (1997) Strategies for solid sample pretreatment. Trends in Analytical Chemistry 16: 16. Luque de Castro MD and Garcia-Ayuso LE (1998) Soxhlet extraction of solid materials: an outdated techniquewith a promising innov...

Supercritical Fluid properties are of interest as being significantly different from liquids or gases in the area near the critical temperature, T c , and the critical pressure, P c. The primary physical feature of supercritical fluids in the immediate critical point region is the very pronounced change in density with pressure. Critical region shown for carbon dioxide in terms of Pr and Tr, th...