Performance of capillary restrictors in supercritical fluid chromatography

Journal Article · Fri Aug 01 00:00:00 EDT 1986 · Anal. Chem.; (United States)

DOI:https://doi.org/10.1021/ac00122a028· OSTI ID:5403826

Smith, R D; Fulton, J L; Petersen, R C; Kopriva, A J; Wright, B W

The operating characteristics of capillary flow restrictors to control linear velocity and for transport analytes to gas phase analysis devices have been investigated for use in supercritical fluid chromatography (SFC). Expansion of the fluid from too low a temperature can result in formation of a condensed solvent phase and problems in flow regulation. Fluid flow rates for expansions that avoid two-phase regions can be estimated to within approx.30%. The expansion process has been directly observed and solvent droplet size was found to be strongly dependent on fluid temperature, with average droplet size decreasing to under 0.2 ..mu..m above the critical temperature and being negligible for reduced temperatures >1.3. The source of detector noise with flame ionization detectors (FID) and the loss of less volatile compounds in SFC results from precipitation and collection of the analyte on the restrictor during expansion of the fluid. The transport of low volatility analytes is facilitated by heating the fluid prior to the restrictor or, less effectively, by heating in the restrictor. The successful transport and detection of nonvolatile compounds in FID with SFC are demonstrated.

• Research Organization: Battelle, Pacific Northwest Labs., Richland, WA
• OSTI ID: 5403826
• Journal Information: Anal. Chem.; (United States), Journal Name: Anal. Chem.; (United States) Vol. 58:9; ISSN ANCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400105* -- Separation Procedures
42 ENGINEERING
420400 -- Engineering-- Heat Transfer & Fluid Flow
BLOOD VESSELS
BODY
CAPILLARIES
CAPILLARY FLOW
CARDIOVASCULAR SYSTEM
CHROMATOGRAPHY
CRITICAL TEMPERATURE
DATA
EXPANSION
EXPERIMENTAL DATA
FLOW RATE
FLUID FLOW
FLUIDS
GASES
INFORMATION
NUMERICAL DATA
ORGANS
PERFORMANCE
PHASE STUDIES
PHYSICAL PROPERTIES
SEPARATION PROCESSES
SUPERCRITICAL FLUID CHROMATOGRAPHY
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
VELOCITY