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

Technical Report · Wed Jan 01 00:00:00 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
• Resource Relation: Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

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