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 Luque de Castro MD and Garcia-Ayuso LE (1998) Soxhlet extraction of solid materials: an outdated techniquewith a promising innov...

Ultra-supercritical circulating fluidized bed (CFB) boiler combustion technology has the advantages of environmental protection and good commercialization. As one key aspects in ultra-supercritical CFB technology, water wall system directly determines whether can safely effectively transform heat energy. This paper studies thermal–hydraulic characteristics designed a 700 MWe boiler, largest tha...

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...

chrmatography and Suorescence detection. Journal of High Resolution Chromatography 21: 667}670. Leeming R andHamerW (1990)Determination of polycyclic aromatic hydrocarbons in lake sediments. Organic Geochemistry 15: 469}476. Messer DC and Taylor LT (1995)Method development for the quantitation of trace polyaromatic from water via solid-phase extraction with supercritical Suid elution. Journal o...

Calophyllum brasiliense is a rich source of bioactive coumarins, xanthones and biflavonoids. The aim of the study was to compare the phenol contents and the antioxidant activity of C. brasiliense extracts obtained by conventional and supercritical fluid extraction (SFE) methods, as well as the quantification of crude extracts and (-)-mammea A/BB yields. Dichloromethane and hexane were used as s...