Based on the solubility in supercritical CO2,two strategies in which CO2 plays different roles are used to make quercetine and astaxanthin particles by supercritical fluid technologies.The experimental results showed ...Based on the solubility in supercritical CO2,two strategies in which CO2 plays different roles are used to make quercetine and astaxanthin particles by supercritical fluid technologies.The experimental results showed that micronized quercetine particles with mean particle size of 1.0-1.5 μm can be made via solution enhanced dispersion by supercritical fluids(SEDS) process,in which CO2 worked as turbulent anti-solvent;while for astaxanthin,micronized particles with mean particle size of 0.3-0.8 μm were also made successfully by rapid expansion supercritical solution(RESS) process.展开更多
Several recently developed analytical techniques, based on high-end mass spectrometry and chromatography, for dealing with challenges in petroleum characterization are reported. Folded flight path time-of-flight mass ...Several recently developed analytical techniques, based on high-end mass spectrometry and chromatography, for dealing with challenges in petroleum characterization are reported. Folded flight path time-of-flight mass spectrometry provides resolving power up to 100000, enabling accurate mass measurement for molecular formula determination with high confidence. Atmos- pheric pressure chemical ionization （APCI） can be used in both gas chromatography （GC, as APGC） and liquid chromatog- raphy （LC） for analyzing non-polar hydrocarbons as well as polar compounds. The improvement in chromatography facilitates the mass spectrometric analysis through online coupling. Comprehensive two-dimensional gas chromatography （GCxGC） re- solves overlapping components, rendering accurate identification and quantitation. Supercritical fluid extraction has been de- veloped as an alternative method to replace traditional solvent extraction methods and eliminate the use of large volumes of solvents that can be harmful to health and environment. Supercritical fluid chromatography （SFC） has been developed as a convergence of GC and LC chromatographic techniques. The use of SFC for heavy oils and residua has been demonstrated. Prospective developments in the use of mass spectrometric and chromatographic methods for petroleum characterization are also described.展开更多
基金Supported partially by the China Ministry of Science and Technology for the China’s Agenda 21 Strategic Research (MOST,2008IM021900)the General Administration of Quality Supervision Inspection and Quarantine of the People’s Republic of China for the 4th Food Safety Research (AQSIQ 2008:ASPAQ0809)
文摘Based on the solubility in supercritical CO2,two strategies in which CO2 plays different roles are used to make quercetine and astaxanthin particles by supercritical fluid technologies.The experimental results showed that micronized quercetine particles with mean particle size of 1.0-1.5 μm can be made via solution enhanced dispersion by supercritical fluids(SEDS) process,in which CO2 worked as turbulent anti-solvent;while for astaxanthin,micronized particles with mean particle size of 0.3-0.8 μm were also made successfully by rapid expansion supercritical solution(RESS) process.
文摘Several recently developed analytical techniques, based on high-end mass spectrometry and chromatography, for dealing with challenges in petroleum characterization are reported. Folded flight path time-of-flight mass spectrometry provides resolving power up to 100000, enabling accurate mass measurement for molecular formula determination with high confidence. Atmos- pheric pressure chemical ionization （APCI） can be used in both gas chromatography （GC, as APGC） and liquid chromatog- raphy （LC） for analyzing non-polar hydrocarbons as well as polar compounds. The improvement in chromatography facilitates the mass spectrometric analysis through online coupling. Comprehensive two-dimensional gas chromatography （GCxGC） re- solves overlapping components, rendering accurate identification and quantitation. Supercritical fluid extraction has been de- veloped as an alternative method to replace traditional solvent extraction methods and eliminate the use of large volumes of solvents that can be harmful to health and environment. Supercritical fluid chromatography （SFC） has been developed as a convergence of GC and LC chromatographic techniques. The use of SFC for heavy oils and residua has been demonstrated. Prospective developments in the use of mass spectrometric and chromatographic methods for petroleum characterization are also described.
