ASTM G120-15(2023)
(Practice)Standard Practice for Determination of Soluble Residual Contamination by Soxhlet Extraction
Standard Practice for Determination of Soluble Residual Contamination by Soxhlet Extraction
SIGNIFICANCE AND USE
5.1 It is expected that this practice will be suitable to identify and quantify contaminants found in systems, system materials, and components used in systems requiring a high level of cleanliness, such as components for oxygen service. Nonmetallic piece parts such as seals and valve seats can be tested as received. Warning—If parts being tested are to be subsequently installed in an oxygen-enriched system, residual extraction solvent remaining in the part due to inadequate drying may increase the susceptibility of the system to ignition. The extraction solvent shall be thoroughly removed from the parts prior to service.
5.2 Processing materials such as gloves and wipers, or samples thereof, to be used in the cleaning operation can be evaluated prior to use to ensure that the proposed cleaning solvent does not extract contaminants that may be deposited as residues on the surface to be cleaned.
Note 1: Test methods that do not require Soxhlet equipment, such as Test Methods E1560 and E1731, may be suitable alternatives for evaluation of processing materials. Test Method G144 with Practice G136 may be suitable for use when the material to be tested is not degraded by sonication. However, results from this test method cannot be directly compared to results from other test methods. Soxhlet extraction may be more aggressive than other extraction methods.
5.3 Wipers or other cleaning supplies can be tested before and after use to determine the amount of contaminant removed from a surface. The type of contaminant removed from the surface may also be determined by qualitative analysis of the extracted NVR using analytical methods such as Fourier Transform Infrared (FTIR). This procedure can be used to obtain samples for NVR analysis using contaminated control coupons that were subjected to the cleaning process as controls to validate cleaning operations.
5.4 The selection of the solvent requires some knowledge of the contaminant (see Practice G93 for recommenda...
SCOPE
1.1 This practice describes a procedure for the determination of residual contamination in materials to be used within or in contact with hardware requiring a high level of cleanliness, such as components for oxygen service, by Soxhlet extraction.
1.2 This practice may be used for extracting nonvolatile and semivolatile residues from solids such as new and used gloves, new and used wipers, contaminated test specimens or control coupons, small piece parts (metallic or nonmetallic), etc. When used with proposed consumable cleaning materials (wipers, gloves, etc.), this practice may be used to determine the potential of the proposed solvent to extract contaminants (plasticizers, residual detergents, brighteners, etc.) from the cleaning material and deposit them on the surface being cleaned.
1.3 This practice is not suitable for the evaluation of particulate contamination.
1.4 The values stated in SI units are standard.
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: G120 − 15 (Reapproved 2023)
Standard Practice for
Determination of Soluble Residual Contamination by
Soxhlet Extraction
This standard is issued under the fixed designation G120; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice describes a procedure for the determina-
D1193 Specification for Reagent Water
tion of residual contamination in materials to be used within or
E1235 Test Method for Gravimetric Determination of Non-
in contact with hardware requiring a high level of cleanliness,
volatile Residue (NVR) in Environmentally Controlled
such as components for oxygen service, by Soxhlet extraction.
Areas for Spacecraft
1.2 This practice may be used for extracting nonvolatile and
E1560 Test Method for Gravimetric Determination of Non-
semivolatile residues from solids such as new and used gloves,
volatile Residue From Cleanroom Wipers
new and used wipers, contaminated test specimens or control
E1731 Test Method for Gravimetric Determination of Non-
coupons, small piece parts (metallic or nonmetallic), etc. When volatile Residue from Cleanroom Gloves
used with proposed consumable cleaning materials (wipers, F331 Test Method for Nonvolatile Residue of Solvent Ex-
tract from Aerospace Components (Using Flash Evapora-
gloves, etc.), this practice may be used to determine the
potential of the proposed solvent to extract contaminants tor)
G93 Guide for Cleanliness Levels and Cleaning Methods for
(plasticizers, residual detergents, brighteners, etc.) from the
Materials and Equipment Used in Oxygen-Enriched En-
cleaning material and deposit them on the surface being
vironments
cleaned.
G127 Guide for the Selection of Cleaning Agents for
1.3 This practice is not suitable for the evaluation of
Oxygen-Enriched Systems
particulate contamination.
G136 Practice for Determination of Soluble Residual Con-
taminants in Materials by Ultrasonic Extraction
1.4 The values stated in SI units are standard.
G144 Test Method for Determination of Residual Contami-
1.5 This standard does not purport to address all of the
nation of Materials and Components by Total Carbon
safety concerns, if any, associated with its use. It is the
Analysis Using a High Temperature Combustion Analyzer
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter- 3. Terminology
mine the applicability of regulatory limitations prior to use.
3.1 Definitions:
1.6 This international standard was developed in accor-
3.1.1 contaminant, n—unwanted molecular and particulate
dance with internationally recognized principles on standard-
matter that could affect the performance of the components or
ization established in the Decision on Principles for the
materials upon which they reside.
Development of International Standards, Guides and Recom-
3.1.2 contamination, n—a process of contaminating.
mendations issued by the World Trade Organization Technical
3.1.3 control coupon (witness coupon), n—a coupon made
Barriers to Trade (TBT) Committee.
from the same material and prepared in exactly the same way
as the test coupons, and which is used to verify the validity of
the method or part thereof.
3.1.3.1 Discussion—In this test method, the control coupon
will be contaminated in the same manner as the test coupons
and will be subjected to the identical extraction procedure.
This practice is under the jurisdiction of ASTM Committee G04 on Compat-
ibility and Sensitivity of Materials in Oxygen Enriched Atmospheres and is the
direct responsibility of Subcommittee G04.02 on Recommended Practices. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved March 1, 2023. Published March 2023. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1993. Last previous edition approved in 2015 as G120 – 15. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/G0120-15R23. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G120 − 15 (2023)
3.1.4 molecular contaminant, n—non-particulate contami- obtain samples for NVR analysis using contaminated control
nation. coupons that were subjected to the cleaning process as controls
3.1.4.1 Discussion—A molecular contaminant may be in a to validate cleaning operations.
gaseous, liquid, or solid state and may be uniformly or
5.4 The selection of the solvent requires some knowledge of
non-uniformly distributed.
the contaminant (see Practice G93 for recommendations). If a
3.1.4.2 Discussion—Molecular contaminants account for
nonvolatile residue (NVR) analysis is to be performed on the
most of the NVR.
molecular contaminant, the boiling point of the solvent shall be
3.1.5 nonvolatile residue (NVR), n—residual molecular and
significantly lower than that of the contaminant. For other
particulate matter remaining following the filtration of a
analytical methods, the tester must know the accuracy of the
solvent containing contaminants and complete evaporation of
analytical methods, and the solvent shall be chosen so as not to
the solvent at a specified temperature.
interfere with the selected analytical method. To identify the
composition of the NVR, analytical methods such as infrared
3.1.6 particle (particulate contaminant), n—a piece of mat-
spectroscopy or gas chromatography/mass spectroscopy have
ter in a solid state with observable length, width, and thickness.
been used satisfactorily.
3.1.6.1 Discussion—The size of a particle is usually defined
by its greatest dimension and is specified in micrometres.
6. Apparatus
4. Summary of Practice
6.1 Soxhlet extractor—500 mL evaporation flask and asso-
ciated equipment as shown in Fig. 1.
4.1 The specimen is placed in an extraction thimble or
between two plugs of glass wool and contaminants are ex-
6.2 Boiling chips—solvent extracted.
tracted using an appropriate solvent in a Soxhlet extractor. The
6.3 Water bath—heated with temperature control of 65 °C.
solvent is brought to the boiling point and the pure solvent
6.4 Thimbles—glass or paper.
vapors travel to the condenser where they condense and drip
into the thimble. When the liquid level in the thimble reaches
6.5 Heating mantle—rheostat controlled.
the top of the Soxhlet siphon, the solvent and extracted soluble
6.6 Balance—range to a minimum of 50 g with an accuracy
contaminant are siphoned back into the boiler. This process is
of 0.1 mg.
allowed to continue for several hours. The solvent and extract
are then concentrated or dried for analysis.
5. Significance and Use
5.1 It is expected that this practice will be suitable to
identify and quantify contaminants found in systems, system
materials, and components used in systems requiring a high
level of cleanliness, such as components for oxygen service.
Nonmetallic piece parts such as seals and valve seats can be
tested as received. Warning—If parts being tested are to be
subsequently installed in an oxygen-enriched system, residual
extraction solvent remaining in the part due to inadequate
drying may increase the susceptibility of the system to ignition.
The extraction solvent shall be thoroughly removed from the
parts prior to service.
5.2 Processing materials such as gloves and wipers, or
samples thereof, to be used in the cleaning operation can be
evaluated prior to use to ensure that the proposed cleaning
solvent does not extract contaminants that may be deposited as
residues on the surface to be cleaned.
NOTE 1—Test methods that do not require Soxhlet equipment, such as
Test Methods E1560 and E1731, may be suitable alternatives for evalu-
ation of processing materials. Test Method G144 with Practice G136 may
be suitable for use when the material to be tested is not degraded by
sonication. However, results from this test method cannot be directly
compared to results from other test methods. Soxhlet extraction may be
more aggressive than other extraction methods.
5.3 Wipers or other cleaning supplies can be tested before
and after use to determine the amount of contaminant removed
from a surface. The type of contaminant removed from the
surface may also be determined by qualitative analysis of the
extracted NVR using analytical methods such as Fourier
Transform Infrared (FTIR). This procedure can be used to FIG. 1 Soxhlet Extraction Apparatus
G120 − 15 (2023)
6.7 Evaporator—rotary. such specifications are available. Other grades may be used,
provided it is first ascertained that the reagent is of sufficiently
6.8 500 mL concentrator flask.
high purity to permit its use without lessening the accuracy of
NOTE 2—Larger extraction systems may be used for batch extraction of
the determination. Alternatively, the solvent may be purified by
wipers to be used to sample NVR on surfaces or to extract NVR from
distillation prior to use.
larger components. The item to be extracted must be small enough to be
fully immersed in solvent within the extraction chamber. 7.3 Water for extraction—shall meet the requirements of
D1193, Type II.
7. Reagents
8. Procedure
7.1 Examples of solvents commonly used for Soxhlet ex-
8.1 Prepare the specimen for placement in the extractor.
traction are ethanol, 2-propanol, 2-butanone, hexane,
8.1.1 To determine the amount of extractable material in a
dichloromethane, propanone, ethyl acetate, and the azeotrope
wiping cloth (new or used), cut out a test section approximately
of ethyl acetate/cyclohexane. Different solvents will vary in
2 2
30 cm , accurately measure and calculate the area (A) in cm ,
removal efficiency for different types of contaminants and
and weigh the section in grams to the nearest tenth of a
should be selected based on the contaminants of greatest
milligram (W ). Record the area and weight.
concern. The solvent used shall be recorded in the test report.
8.1.1.1 If the NVR is to be determined on a used wiping
Warning—Solvents such a
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.