Supercritical fluid chromatography/supersonic jet spectroscopy: Progress report, 9/15/86-12/15/86

Technical Report · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6989239

Goates, S R; Lee, M L

Supersonic jet (SJ) expansions of gaseous molecules can result in much simplified and highly resolved laser-induced fluorescence spectra, allowing analysis of closely related components in a complex sample. We have previously demonstrated that large polycyclic aromatic hydrocarbon (PAH) molecules of low volatility can also be introduced into the jet by means of supercritical fluid (SF), rather than gaseous, carriers and very good spectral narrowing achieved. Last summer in our first attempts with total fluorescence detection in a coupled capillary SFC/SJ system, selective detection of perylene in an artificial mixture of ten PAH and in the coal tar extract sample was achieved. However, only rather poor chromatographic separation was obtained, due in part to a high linear velocity of the fluid through the chromatographic column with the short capillary nozzle which was employed. The extended pressure gradient with most of the restrictors commonly used with SFC lead to conditions within the restrictor where aggregation of solute molecules can occur which seriously degrade the spectral resolution. Successful SFC/SJ requires large but abrupt restriction. Since then we have worked on the problem of a nozzle design which provides low dead-volume and high restriction for efficient chromatographic separation without leading to solute clustering. Several nozzle types were investigated including pinhole, tapered tubular, and porous frit. Disappointing results were obtained with all three types. During this last quarter we have built a light-scattering apparatus and vacuum chamber which can be devoted to testing new nozzles while pursuing spectroscopic studies in our primary chamber. 8 refs., 3 figs.

• Research Organization: Brigham Young Univ., Provo, UT (USA). Dept. of Chemistry
• DOE Contract Number: FG22-86PC90534
• OSTI ID: 6989239
• Report Number(s): DOE/PC/90534-1; ON: DE87004583
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600* -- Coal
Lignite
& Peat-- Properties & Composition
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
AROMATICS
CHEMICAL ANALYSIS
CHROMATOGRAPHY
COAL EXTRACTS
COAL TAR
CONDENSED AROMATICS
DATA
DESIGN
DISPERSIONS
EXPERIMENTAL DATA
EXTRACTION
FLUID FLOW
FLUORESCENCE
HYDROCARBONS
INFORMATION
JETS
LASERS
LUMINESCENCE
MIXTURES
NOZZLES
NUMERICAL DATA
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
PERYLENE
POLYCYCLIC AROMATIC HYDROCARBONS
QUALITATIVE CHEMICAL ANALYSIS
RESEARCH PROGRAMS
SEPARATION PROCESSES
SPECTROSCOPY
SUPERCRITICAL FLUID CHROMATOGRAPHY
SUPERSONIC FLOW
TAR