ASTM E1449-92(2000)
(Guide)Standard Guide for Supercritical Fluid Chromatography Terms and Relationships
Standard Guide for Supercritical Fluid Chromatography Terms and Relationships
SCOPE
1.1 This guide deals primarily with the terms and relationships used in supercritical fluid chromatography.
1.2 Since many of the basic terms and definitions also apply to gas chromatography and liquid chromatography, this guide is using, whenever possible, symbols identical to Practices E355 and E682.
General Information
Relations
Standards Content (Sample)
Designation: E 1449 – 92 (Reapproved 2000)
Standard Guide for
Supercritical Fluid Chromatography Terms and
1
Relationships
This standard is issued under the fixed designation E 1449; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.4 In supercritical fluid chromatography, the temperature
may be constant, or changing during a chromatographic
1.1 This guide deals primarily with the terms and relation-
separation.
ships used in supercritical fluid chromatography.
3.4.1 Isothermal Supercritical Fluid Chromatography is
1.2 Since many of the basic terms and definitions also apply
the version of the technique in which the column temperature
to gas chromatography and liquid chromatography, this guide
is held constant during the passage of the sample components
is using, whenever possible, symbols identical to Practices
through the separation column.
E 355 and E 682.
3.4.2 Programmed Temperature Supercritical Fluid Chro-
2. Referenced Documents matography is the version of the technique in which the
column temperature is changed with time during the passage of
2.1 ASTM Standards:
the sample components through the separation column. Iso-
E 355 Practice for Gas Chromatography Terms and Rela-
2
thermal intervals may be included in the temperature program.
tionships
3.5 In supercritical fluid chromatography, the density may
E 682 Practice for Liquid Chromatography Terms and Re-
2
be constant or changing during the chromatographic separa-
lationships
tion.
3. Names of Techniques
3.5.1 Isoconfertic is a term used when the density of the
mobile phase is kept constant for a specified time or for the
3.1 Supercritical Fluid Chromatography, abbreviated as
entire chromatographic separation.
SFC, comprises all chromatographic methods in which both
3.5.2 Programmed Density Supercritical Fluid Chromatog-
the mobile phase is supercritical under the conditions of
raphy is the version of the technique in which the column
analysis and where the solvating properties of the fluid have a
density is changed with time during the passage of the sample
measurable affect on the separation. Early work in the field was
components through the separation column. Isoconfertic inter-
performed under a broader heading–dense gas chromatogra-
vals may be included in the density program.
phy. Related work in the field uses subcritical or near-critical
3.5.3 Flow Programming is a technique where the mobile
conditions to affect separation.
phase linear velocity is changed during the chromatographic
3.2 Separation is achieved by differences in the distribution
procedure. However, with fixed orifice restrictors, flow pro-
of the components of a sample between the mobile and
gramming is more complex requiring an increase in pressure to
stationary phases, causing them to move through the column at
effect an increase in linear velocity.
different rates (differential migration).
3.6 In supercritical fluid chromatography, the composition
3.3 In supercritical fluid chromatography, the pressure may
of the mobile phase may be constant or changing during a
be constant or changing during a chromatographic separation.
chromatographic separation.
3.3.1 Isobaric is a term used when the mobile phase is kept
3.6.1 The term Isocratic is used when the composition of
at constant pressure. This may be for a specified time interval
the mobile phase is kept constant during a chromatographic
or for the entire chromatographic separation.
separation.
3.3.2 Programmed Pressure Supercritical Fluid Chroma-
3.6.2 The term Gradient Elution is used to specify the
tography is the version of the technique in which the column
technique when a deliberate change in the mobile phase
pressure is changed with time during the passage of the sample
composition is made during the chromatographic procedure.
components through the separation column. Isobaric intervals
Isocratic intervals may be included in the gradient program.
may be included in the pressure program.
4. Apparatus
1
4.1 Pumps—The function of the pumps is to deliver the
This guide is under the jurisdiction of ASTM Committee E13 on Molecular
Spectroscopy and is the direct responsibility of Subcommittee E13.19 on Chroma-
mobile phase at a controlled flow rate to the chromatographic
tography.
column.
Current edition approved Jan. 15, 1992. Published March 1992.
2 4.1.1 Syringe Pumps have a piston that advances at a
Annual Book of ASTM Standards, Vol 14.01.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
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E 1449
controlled rate within a smooth cylinder to displace the mobile tors (for example, UV).
phase. 4.4.1 A Linear Restrictor is a length of small i.d. tubing of
uniform bore. Linear rest
...
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