ASTM E1772-95

Standard Test Method for Particle Size Distribution of Chromatography Media by Electric Sensing Zone Technique

SCOPE
1.1 This test method is valuable for the measurement of particle size and covers determination of the particle size distribution of chromatography media in the overall size range of approximately 1 to 450 μm using the electric sensing zone (ESZ) apparatus. This instrument uses an electric current path of small dimensions that is modulated by individual particle passage through an aperture and produces individual pulses of amplitude proportional to the particle volume (1).²  
1.2 The values stated in SI units are to be regarded as the standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Nov-1995
• Technical Committee: E48 - Bioenergy and Industrial Chemicals from Biomass

Relations

• Replaced By: ASTM E1772-95(2001) - Standard Test Method for Particle Size Distribution of Chromatography Media by Electric Sensing Zone Technique (Withdrawn 2010)
• Effective Date: 10-Nov-1995

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E 1772 – 95
Standard Test Method for
Particle Size Distribution of Chromatography Media by
Electric Sensing Zone Technique
This standard is issued under the fixed designation E 1772; 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 3.1.2.1 Discussion—From n (d), the corresponding volume
distribution can be calculated:
1.1 This test method is valuable for the measurement of
particle size and covers determination of the particle size p
3 3 C 3
f~d ! 5 n~d ! d /V 5 n~d !d / n~d !d (1)
(
i i i i i i 5 1 i i
distribution of chromatography media in the overall size range
of approximately 1 to 450 μm using the electric sensing zone
where:
(ESZ) apparatus. This instrument uses an electric current path
p
C 3
of small dimensions that is modulated by individual particle
V 5 n~d !d (2)
(
i 5 1 i i
passage through an aperture and produces individual pulses of
is the total particle volume.
amplitude proportional to the particle volume (1).
A cumulative volume distribution, F(d ), is defined by
1.2 The values stated in SI units are to be regarded as the i
standard.
F d ! 5 f x ! (3)
~ ~
i ( i
x #d
i i
1.3 This standard does not purport to address all of the
The volume weighted (mass) median diameter is the diam-
safety concerns, if any, associated with its use. It is the
eter, d , given by
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
F~d ! 5 0.5 (4)
i
bility of regulatory limitations prior to use.
that is, the diameter that divides the particle volume into two
equally sized halves.
2. Referenced Documents
2.1 ASTM Standards:
4. Summary of Test Method
D 1193 Specification for Reagent Water
4.1 A carefully dispersed, dilute suspension of the particles
E 177 Practice for Use of the Terms Precision and Bias in
in a beaker filled with electrolyte is placed in the counting
ASTM Test Methods
position on the instrument sample stand. The suspension is
E 456 Terminology Relating to Quality and Statistics
forced through a restricting aperture. Each particle passing is
2.2 Other Document:
recorded on an electronic counter according to selected particle
Manufacturer’s Operating Manual for Particle Size Distri-
size levels.
bution Analyzer
4.2 The instrument determines the particle volume (liquid
displacement); therefore, the equivalent spherical diameter is
3. Terminology
commonly used to express the particle size.
3.1 Definitions:
3.1.1 equivalent volume diameter—the diameter of a sphere
5. Significance and Use
with a volume equal to that of the actual particle.
5.1 It is important to recognize that the results obtained by
3.1.2 volume weighted (mass) median diameter—a number
this test method or any other test method for particle size
C
distribution, n (d), is measured, and N 5 n (d)isthe
(i 5 1 i
determination using different physical principles may disagree.
total number of particles in the C classes and n (d)isthe
i
The results are strongly influenced by physical principles used
number of particles in class i (corresponding to diameter d ).
i
by each method of particle size analysis. The results of any
particle sizing method should be used only in a relative sense
This test method is under the jurisdiction of ASTM Committee E-48 on
and should not be regarded as absolute when comparing results
Biotechnology and is the direct responsibility of Subcommittee E48.03 on Unit
obtained by other methods.
Processes and Their Control.
5.2 Both sellers and purchasers of chromatography media
Current edition approved Nov. 10, 1995. Published January 1996.
The boldface numbers in parentheses refer to the list of references at the end of
will find the test method useful if mutually acceptable to all
this test method.
parties concerned to determine the particle size distributions
Annual Book of ASTM Standards, Vol 11.01.
4 for materials specifications, manufacturing control, and devel-
Annual Book of ASTM Standards, Vol 14.02.
opment and research.
Available from Coulter Corp., Scientific Instruments, P.O. Box 169015, MC
195-10, Miami, FL 33116-9015.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
E 1772
TABLE 1 Coincidence Chart
6. Apparatus
Aperture Manometer Maximum Count for 5 %
6.1 Electronic Particle Counter, using the ESZ technique,
Diameter, μm Volume, mL Coincidence
for example, Multisizer II from Coulter Electronics Ltd.,
50 0.05 16000
Elzone 280 from Particle Data Inc., or their equivalent.
70 0.05 5830
6.1.1 The apertures are selectable from 50, 70, 100, 140,
100 0.5 20000
140 0.5 7290
280, 400, and 560-μm diameter. The measuring range for each
280 2.0 3640
sensor is approximately 2 to 80 % of the aperture diameter (2).
400 2.0 1250
6.2 Microscope—Zeiss Axioplan from Carl Zeiss, Germany,
560 2.0 455
or similar microscope.
6.3 Filtering Device—Peristalic pump with 0.22-μm mem-
brane filters (Sterivex-GS Millipore Corp.).
the suspension. Shake the container vigorously until the entire
6.4 Ultrasonic Bath, 50 to 100 W and 60 to 80 kHz.
suspension is homogenous. Immediately withdraw approxi-
mately 5 mL of suspension using a Pasteur pipette. Place the
7. Reagents
suspension in a round-bottomed sample beaker, and dilute
7.1 Purity of Reagents—Reagent grade chemicals shall be
slowly with electrolyte solution. Sonicate for 1 min. Check the
used in all tests. Unless otherwise indicated, it is intended that
particle concentration. Adjust if necessary.
all reagents conform to the specifications of the Committee on
8.2 Calibration for Particles in Suspension—Wet sieve a
Analytical Reagents of the American Chemical Society where
portion of the material under test in water with sieves that are
such specifications are available. Other grades may be used,
as close as possible together in size and with a size range that
provided it is first ascertained that the reagent is of sufficiently
covers the peak of the particle size distribution. Transfer the
high purity to permit its use without lessening the accuracy of
sieved material to a suitable container, and substitute the water
the determination.
for that electrolyte solution that shall be used when measuring
7.2 Purity of Water—Unless otherwise indicated, references
the material using the ESZ instrument. Transfer a suitable
to water shall be understood to m
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