ASTM E355-96
(Practice)Standard Practice for Gas Chromatography Terms and Relationships
Standard Practice for Gas Chromatography Terms and Relationships
SCOPE
1.1 This practice deals primarily with the terms and relationships used in gas elution chromatography. However, most of the terms should also apply to other kinds of gas chromatography and are also valid in the various liquid column chromatographic techniques, although at this time they are not standardized for the latter usage.
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Designation: E 355 – 96
Standard Practice for
1
Gas Chromatography Terms and Relationships
This standard is issued under the fixed designation E 355; 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 components to emerge in the normal order, that is, least-to-
most strongly absorbed.
1.1 This practice covers primarily the terms and relation-
2.7 Isothermal Gas Chromatography is the version of the
ships used in gas elution chromatography. However, most of
technique in which the column temperature is held constant
the terms should also apply to other kinds of gas chromatog-
during the passage of the sample components through the
raphy and are also valid in the various liquid column chro-
separation column.
matographic techniques, although at this time they are not
2.8 Programmed Temperature Gas Chromatograp-
standardized for the latter usage.
hy (PTGC), is the version of the technique in which the
2. Names of Techniques
column temperature is changed with time during the passage of
the sample components through the separation column. In
2.1 Gas Chromatography, abbreviated as GC, comprises all
linear PTGC the program rate is constant during analysis.
chromatographic methods in which the moving phase is
Isothermal intervals may be included in the temperature
gaseous. The stationary phase may be either a dry granular
program.
solid or a liquid supported by the granules or by the wall of the
2.9 Programmed Flow, Pressure, or Velocity Gas Chroma-
column, or both. Separation is achieved by differences in the
tography is the version of the technique in which the carrier
distribution of the components of a sample between the mobile
gas flow, pressure, or velocity is changed during analysis.
and stationary phases, causing them to move through the
2.10 Reaction Gas Chromatography is the version of the
column at different rates and from it at different times. In this
technique in which the composition of the sample is changed
recommended practice gas elution chromatography is implied.
between sample introduction and the detector. The reaction can
2.2 Gas-Liquid Chromatography, abbreviated as GLC, uti-
take place upstream of the column when the chemical compo-
lizes a liquid as the stationary phase, which acts as a solvent for
sition of the individual components passing through the col-
the sample components.
umn differs from that of the original sample, or between the
2.3 Gas-Solid Chromatography, abbreviated as GSC, uti-
column and the detector when the original sample components
lizes an active solid (adsorbent) as the stationary phase.
are separated in the column but their chemical composition is
2.4 Gas Elution Chromatography utilizes a continuous in-
changed prior to entering the detection device.
ert gas flow as the carrier gas and the sample is introduced as
2.11 Pyrolysis Gas Chromatography is the version of reac-
a gas or a liquid with a finite volume into the carrier gas stream.
tion gas chromatography in which the original sample is
If the sample is introduced as a liquid, it is vaporized in the
decomposed by heat to more volatile components prior to
system prior to or during passage through the separation
passage through the separation column.
column.
2.5 Gas-Frontal Chromatography is a technique in which a
3. Apparatus
continuous stream of carrier gas mixed with sample vapor is
3.1 Sample Inlet Systems, represent the means for introduc-
instantaneously replaced by a continuous stream of carrier gas
ing samples into the separation column, including the heated
containing sample vapor at a different concentration. The
zones permitting the vaporization of the introduced liquid
concentration profile is therefore step-shaped at the column
samples prior to their passage through the column. Sample
inlet.
introduction can be carried out by introduction of a liquid,
2.6 Gas-Displacement Chromatography employs a desor-
solid, or gas into the carrier-gas stream. The sample may be
bent as the carrier gas or in the carrier gas to displace a less
vaporized before or after introduction into the column.
strongly held solute from the stationary phase which in turn
3.1.1 Direct Inlets, rapidly vaporize the sample prior to
displaces the next less strongly held one etc., causing the
entering the column. All of the sample vapor enters the column.
3.1.2 On-Column Inlets, introduce a liquid sample into the
column. The sample vaporizes as the column section contain-
1
This practice is under the jurisdiction of ASTM Committee E13 on Molecular
ing the liquid heats up after injection.
Spectroscopy and is the direct resp
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