ASTM D3016-97

Standard Practice for Use of Liquid Exclusion Chromatography Terms and Relationships

SCOPE
1.1 This practice covers the definitions of terms and symbols most often used in liquid exclusion chromatography. Wherever possible, these terms and symbols are consistent with those used in other chromatographic techniques. As additional terms and relationships are developed, they will be incorporated.
Note 1- There is no similar or equivalent ISO standard.

General Information

• Status: Historical
• Publication Date: 09-Apr-1997
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.70 - Analytical Methods

Relations

• Replaced By: ASTM D3016-97(2003) - Standard Practice for Use of Liquid Exclusion Chromatography Terms and Relationships
• Effective Date: 10-Mar-2003
• Referred By: ASTM D5296-19 - Standard Test Method for Molecular Weight Averages and Molecular Weight Distribution of Polystyrene by High Performance Size-Exclusion Chromatography
• Effective Date: 10-Apr-1997
• Referred By: ASTM D6579-11(2020) - Standard Practice for Molecular Weight Averages and Molecular Weight Distribution of Hydrocarbon, Rosin and Terpene Resins by Size-Exclusion Chromatography
• Effective Date: 10-Apr-1997
• Referred By: ASTM F2150-19 - Standard Guide for Characterization and Testing of Biomaterial Scaffolds Used in Regenerative Medicine and Tissue-Engineered Medical Products
• Effective Date: 10-Apr-1997
• Referred By: ASTM E682-92(2019) - Standard Practice for Liquid Chromatography Terms and Relationships
• Effective Date: 10-Apr-1997
• Referred By: ASTM F561-19 - Standard Practice for Retrieval and Analysis of Medical Devices, and Associated Tissues and Fluids
• Effective Date: 10-Apr-1997
• Referred By: ASTM D6474-20 - Standard Test Method for Determining Molecular Weight Distribution and Molecular Weight Averages of Polyolefins by High Temperature Gel Permeation Chromatography
• Effective Date: 10-Apr-1997

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 3016 – 97
Standard Practice for
Use of Liquid Exclusion Chromatography Terms and
Relationships
This standard is issued under the fixed designation D 3016; 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.
INTRODUCTION
Liquid exclusion chromatography (LEC) began as “gel filtration chromatography” which is
2 3
attributed to Porath and Flodin. With the invention of new column packings by Moore for
organic-phase work a new form of LEC developed which commonly became known as gel permeation
chromatography or GPC. Liquid exclusion chromatography is a form of liquid chromatography (some
other forms being partition, ion-exchange, and adsorption) and as such is the preferred name for the
technique; however, the reader must be aware that other names are common in the literature, the most
prevalent being those cited above. LEC differs from all other chromatographic techniques in that only
the exclusion mechanism may be operative if meaningful data are to result. Most other chromato-
graphic mechanisms operate in essentially the opposite way, that is, with small molecules exiting first.
Any combination of mechanisms causes confusion and is misleading.
Liquid exclusion chromatography as used for the analysis of polymers has grown and matured since
the first issuance of this practice in 1972. Therefore, some infrequently used or “outdated” terms have
been deleted and some modern practices (or terms) have been included. Modern developments include
the use of constant-volume pumps, use of “microparticle” column packings and much smaller
columns, and automated data-handling procedures. In addition, SI units as recommended in ASTM
Standard E 380 for Metric Practice are now used.
1. Scope * 2.3 by-pass or loop injector—the injector most common in
liquid exclusion chromatography and which utilizes a sample
1.1 This practice covers the definitions of terms and sym-
chamber that can be filled with sample while it is temporarily
bols most often used in liquid exclusion chromatography.
external to the flowing liquid stream. It can be manipulated by
Wherever possible, these terms and symbols are consistent
5 means of a valving device to sweep the sample with eluent into
with those used in other chromatographic techniques. As
the column.
additional terms and relationships are developed, they will be
2.4 columns—tubes that contain the column packing.
incorporated.
2.5 column end-fittings—devices that prevent the column
NOTE 1—There is no similar or equivalent ISO standard.
packing from passing through them but which are permeable to
the eluent (solvent or solution).
2. Terminology Apparatus Definitions
2.6 detectors—devices that sense and measure the concen-
2.1 sample inlet system—a means of introducing samples
tration or other physical property of solute components in the
onto the column.
solution (eluate) passing through.
2.2 direct injector—a device for introducing a sample from
2.7 differential detectors—devices that sense and measure
a source external to the column directly onto the column (for
the difference in a physical or chemical property between a
example, septum-syringe injector).
solution (solvent containing solute components) and a refer-
ence liquid (for example, solvent alone).
2.8 absolute detectors—devices that sense and measure the
This practice is under the jurisdiction of the ASTM Committee D-20 on Plastics
absolute concentration or other physical property of solute
and is the direct responsibility of Subcommittee D 20.70 on Analytical Methods
(Section D20.70.02).
components contained in the eluate.
Current edition approved April 10, 1997. Published April 1998. Originally
2.9 collection devices—devices used to collect discrete
published as D 3016 – 72. Last previous edition D 3016 – 78 (1992)e .
2 portions of an eluate according to a preset cycle (for example,
Porath, J., and Flodin, P., Nature, NTRWA, Vol 183, 1959, p. 1657.
Moore, J. C., Journal of Polymer Science, JPYAA, Part A, Vol 2, 1964, p. 835. times, volume, etc.).
Annual Book of ASTM Standards, Vol 14.02; excerpts in all volumes.
Journal of Gas Chromatography, JCHSB, Vol 66, 1968.
*A Summary of Changes section appears at the end of this standard.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D3016–97
2.10 pump—any device that causes mobile phase to flow
through the columns.
3. Reagent Definitions
3.1 eluent—the mobile phase or solvent used to sweep or
elute the sample (solute) components into, through, and out of
the column. Its composition is the same as the stationary liquid
phase.
3.2 eluate—the liquid emerging from the column.
3.3 solutes—dissolved substances that, in LEC, are caused
to pass through the column and to influence the detector
response.
3.4 column packing—the stationary phase which consists of
FIG. 1 Typical Chromatogram
microporous material and the stationary liquid phase contained
in the pores.
5.2 The definitions that follow apply to chromatograms
4. Performance in Terms of Resolution, Column
obtained directly by means of differential detectors:
Efficiency, and Precision
5.2.1 baseline—the portion of the chromatogram recording
4.1 Resolution is the resultant of two effects, the separating the detector response when only eluent emerges from the
column.
power of the column packing and the efficiency or peak
broadening. The separating power of the column packing is 5.2.2 peak—the portion of the chromatogram recording the
detector response while a single component or a single
dependent on pore size and pore volume. Peak broadening
depends on the nature of the column packings, on how well the distribution (two or more sample components that emerge
together as a single peak) is eluted from the column.
columns are packed, and on instrumental components external
to the columns. The equations used in LEC (GPC) are similar 5.2.3 peak base, BC—an interpolation of the baseline be-
to those used in other chromatographic techniques. Reference tween extremities of the peak.
may be made to any standard chromatography text. Resolution 5.2.4 peak area, BGDHCAB—the area enclosed between
for any two samples is defined by the following equation: the peak and the peak base.
5.2.5 peak height, AD—the dimension from the peak maxi-
R 5 2@~V 2 V !/~W 1 W ! (1)
1,2 R R 1 2
1 2
mum to the base measured in the direction of detector
where subscripts 1 and 2 refer to samples 1 and 2. (See tables
response.
for symbols used in this equation.) For complete separation,
5.2.6 peak width, EF—the retention volume interval of the
R must be 1.25 or greater.
segment of peak base intercepted by tangents to the inflection
1,2
4.2 Column efficiency is a measure of peak spreading or the
points on either side of the peak.
rate of generation of variance with column length. For a
5.2.7 half width, GH—the retention volume interval of a
monodisperse material, efficiency is the number of theoretical
line parallel to the peak base, bisecting the peak height, and
plates, N, for the entire system defined as follows: (See tables
terminating at the sides of the peak.
for symbols used in this equation.)
6. Volume Parameters
N 5 16~V /W! ors5 N/V (2)
R R
6.1 Volume parameters expected to be involved in LEC are
This expression includes all contributions to peak broaden-
listed in the glossary of terms found in Tables 1 and 2. These
ing.
terms are intended for use where the primary mechanism of
4.3 Precision and accuracy are used according to their
separation depends on the size of the solute molecules. The
accepted definitions. Precision is inherent to the system. Both
hydrodynamic volume of polymers usually may be related to
precision and accuracy are dependent on the method of
V independent of molecular weight and structure, for example,
calibration and treatment of the data as well as on the resolving R
in describing the exclusion limit. Hydrodynamic volume is
power of the columns. The accuracy must be determined by
related to the product of intrinsic viscosity and molecular
comparison with other methods. For example, the molecular-
weight. For small molecules, molar volume is a generally
weight distribution can be compared with that obtained from
applicable parameter for correlation with retention volume.
equilibrium ultracentrifugation. More commonly the weight-
Molar volumes can be readily calculated from experimentally
and number-average molecular weights computed from the
measured densities or estimated at any temperature of interest
LEC (GPC) trace are compared with those measured by light
by use of critical properties. Of course, determination of the
scattering, (both static and on-line), osmometry, and on-line
molecular weight distribution of a polymer by LEC requires a
viscometry.
known relationship between molecular weight of the polymer
5. Readout Definitions
and retention volume.
5.1 chromatogram—a plot of detector response against
7. Presentation of Data
volume of eluate emerging from the system. An idealized
chromatogram obtained with a detector providing differential 7.1 Calibration procedures and data should be included in
response is shown in Fig. 1. all LEC publications as follows:
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D3016–97
TABLE 1 Recommended List of Terms and Symbols for Use in LEC—Part I
PART I—LEC PARAMETERS
A
Units
No. Parameter Symbol Definitions
SI Common
...