Separation of large coal molecules using high-resolution supercritical fluid chromatography. Final report, March 1982-April 1985

Technical Report · Thu Aug 01 00:00:00 EDT 1985

OSTI ID:6174856

Lee, M L

Capillary supercritical fluid chromatography was developed and evaluated for the application to large coal-derived molecules. Chromatographic theory was developed for supercritical fluid mobile phases, and formed the basis for selection of operating parameters for the technique. Capillary columns of less than 100-micrometer i.d. and with stationary phase films up to 1 micrometer in thickness produced chromatographic efficiencies in excess of 3,500 plates/m at ten times the optimum linear velocity. These columns were prepared from fused silica tubing which was deactivated at 450 C with hexamethyldisilazane or hexamethyldisiloxane, coated with various polysiloxane stationary phases, and crosslinked with azo-t-butane in order to render the stationary phase insoluble. Polysiloxanes containing biphenyl, cyanopropyl, and n-octyl side groups were synthesized for use as stationary phases. Hardware and microcomputer software were developed for density programming of the syringe pump during chromatographic analysis. An optical fiber-based scanning fluorescence detector with sub-picogram sensitivity was constructed. The common flamebased gas chromatographic detectors, flame ionization, flame photometric, and thermionic, as well as a mass spectrometer, were successfully interfaced to the supercritical fluid chromatograph. Pure supercritical n-pentane was found to be the best mobile phase for coal-derived materials, and the technique was successfully applied to several samples which were beyond the range of gas chromatography.

• Research Organization: Brigham Young Univ., Provo, UT (USA). Dept. of Chemistry
• OSTI ID: 6174856
• Report Number(s): PB-86-132842/XAB
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
COAL
GAS CHROMATOGRAPHY
MOLECULAR STRUCTURE
LABORATORY EQUIPMENT
MASS SPECTROSCOPY
MOLECULAR WEIGHT
SAMPLING
SILOXANES
CARBONACEOUS MATERIALS
CHROMATOGRAPHY
ENERGY SOURCES
EQUIPMENT
FOSSIL FUELS
FUELS
MATERIALS
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
SEPARATION PROCESSES
SPECTROSCOPY
010600* - Coal
Lignite
& Peat- Properties & Composition