ASTM G120-95

Standard Practice for Determination of Soluble Residual Contamination in by Soxhlet Extraction

SCOPE
1.1 This practice describes a procedure for the determination of residual contamination in systems and components requiring a high level of cleanliness, such as oxygen, 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 wipes, contaminated test specimens or control coupons, small pieces of hardware, component softgoods, etc. When used with proposed cleaning materials (wipes, gloves, etc.), this practice may be used to determine the potential of the proposed solvent to extract contaminants (plasticizers, residual detergents, brighteners, etc.) 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. Values in parentheses are for information only.  
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Sep-2001
• Technical Committee: G04 - Compatibility and Sensitivity of Materials in Oxygen Enriched Atmospheres
• Drafting Committee: G04.01 - Test Methods

Relations

• Replaced By: ASTM G120-95(2001) - Standard Practice for Determination of Soluble Residual Contamination in by Soxhlet Extraction
• Effective Date: 10-Sep-2001
• Referred By: ASTM G126-16(2023) - Standard Terminology Relating to the Compatibility and Sensitivity of Materials in Oxygen Enriched Atmospheres
• Effective Date: 10-Sep-2001
• Referred By: ASTM E1731-11(2018) - Standard Test Method for Gravimetric Determination of Nonvolatile Residue from Cleanroom Gloves
• Effective Date: 10-Sep-2001
• 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-Sep-2001

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NOTICE: This standard has either been superseded and replaced by a new version or discontinued.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: G 120 – 95
Standard Practice for
Determination of Soluble Residual Contamination in
Materials and Components by Soxhlet Extraction
This standard is issued under the fixed designation G 120; 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 Oxygen-Enriched Environments
1.1 This practice describes a procedure for the determina-
3. Terminology
tion of residual contamination in systems and components
3.1 Definitions:
requiring a high level of cleanliness, such as oxygen, by
3.1.1 contaminant, n—unwanted molecular and particulate
Soxhlet extraction.
matter that could affect or degrade the performance of the
1.2 This practice may be used for extracting nonvolatile and
components upon which they reside.
semivolatile residues from solids such as new and used gloves,
3.1.2 contamination, n—a process of contaminating.
new and used wipes, contaminated test specimens or control
3.1.3 nonvolatile residue (NVR), n—residual molecular and
coupons, small pieces of hardware, component softgoods, etc.
particulate matter remaining following the filtration of a
When used with proposed cleaning materials (wipes, gloves,
solvent containing contaminants and complete evaporation of
etc.), this practice may be used to determine the potential of the
the solvent at a specified temperature.
proposed solvent to extract contaminants (plasticizers, residual
3.1.4 particle (particulate contaminant), n—a piece of mat-
detergents, brighteners, etc.) and deposit them on the surface
ter in a solid state with observable length, width, and thickness.
being cleaned.
3.1.4.1 Discussion—The size of a particle is usually defined
1.3 This practice is not suitable for the evaluation of
by its greatest dimension and is specified in micrometres.
particulate contamination.
3.1.5 molecular contaminant (non-particulate contamina-
1.4 The values stated in SI units are standard. Values in
tion), n—the molecular contaminant may be in a gaseous,
parentheses are for information only.
liquid, or solid state.
1.5 This standard does not purport to address all of the
3.1.5.1 Discussion—It may be uniformly or nonuniformly
safety concerns, if any, associated with its use. It is the
distributed, or be in the form of droplets. Molecular contami-
responsibility of the user of this standard to establish appro-
nants account for most of the NVR.
priate safety and health practices and determine the applica-
3.1.6 control coupon (witness coupon), n—a coupon made
bility of regulatory limitations prior to use.
from the same material and prepared in exactly the same way
2. Referenced Documents as the test coupons, which is used to verify the validity of the
method or part thereof.
2.1 ASTM Standards:
3.1.6.1 Discussion—In this test method, the control coupon
D 1193 Specification for Reagent Water
will be contaminated in the same manner as the test coupons
E 1235 Test Method for Gravimetric Determination of Non-
and will be subjected to the identical extraction procedure.
volatile Residue (NVR) in Environmentally Controlled
Areas for Spacecraft
4. Summary of Practice
F 324 Test Method for Nonvolatile Residue of Volatile
4 4.1 The sample is placed in an extraction thimble or
Cleaning Solvents Using the Solvent Purity Meter
between two plugs of glass wool and extracted using an
F 331 Test Method for Nonvolatile Residue of Halogenated
appropriate solvent (see Practice G 93 for recommendations) in
Solvent Extract from Aerospace Components (Using Ro-
4 a Soxhlet extractor. The solvent is brought to the boiling point;
tary Flash Evaporator)
the pure solvent vapors travel to the condenser where they
G 93 Practice for Cleaning Methods and Equipment Used in
condense and drip into the thimble. When the liquid level in the
thimble reaches the top of the Soxhlet siphon, the solvent and
This practice is under the jurisdiction of ASTM Committee G-4 on Compat-
extracted soluble contaminant are siphoned back into the
ibility and Sensitivity of Materials in Oxygen Enriched Atmospheres and is the
boiler. This process is allowed to continue for several hours.
direct responsibility of Subcommittee G04.01 on Test Methods.
The solvent and extract are then concentrated or dried for
Current edition approved Oct. 10, 1995. Published November 1995. Originally
published as G120 – 93. Last previous edition G 120 – 93.
analysis.
Annual Book of ASTM Standards, Vol 11.01.
Annual Book of ASTM Standards, Vol 15.03.
Annual Book of ASTM Standards, Vol 10.05.
Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
G 120
5. Significance and Use
5.1 It is expected that this test method 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 oxygen. Softgoods such as seals
and valve seats can be tested as received. Gloves and wipes, 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 and deposit chemicals on the surface to
be cleaned.
5.2 Wipes or other cleaning equipment can be tested after
use to determine the amount of contaminant removed from a
surface. This procedure can be used to obtain samples for NVR
analysis using contaminated control coupons that were sub-
jected to the cleaning process as controls to validate cleaning
operations.
5.3 The selection of the solvent requires some knowledge of
the contaminant. If a nonvolatile residue (NVR) analysis is to
be performed on the molecular contaminant, the boiling point
of the solvent shall be significantly lower than that of the
contaminant. For other analytical methods, the tester must
know the accuracy of the analytical methods, and the solvent
shall be chosen so as not to interfere with the selected
analytical method. To identify the composition of the NVR,
analytical methods such as infrared spectroscopy or gas
chromatography/mass spectroscopy have been used satisfacto-
rily.
6. Apparatus
6.1 Soxhlet extractor—500 mL evaporation flask and asso-
FIG. 1 Soxhlet Extraction Apparatus
ciated equipment as shown in Fig. 1.
highly flammable. The reader should refer to appropriate safe handling
6.2 Boiling chips—solvent extracted.
procedures.
6.3 Water bath—heated with temperature control of 65°C.
6.4 Thimbles—glass or paper. 7.3 Water—shall meet the requirements of D 1193, Type II.
6.5 Heating mantle—rheostat controlled.
8. Procedure
6.6 Balance—range to a minimum of 50 g with an accuracy
8.1 Prepare the sample for placement in the extractor.
of 0.1 mg.
8.1.1 To determine the amount of extractable material in a
6.7 Evaporator—rotary.
wiping cloth (new or used), cut out a test section approximately
7. Reagents
30 centimetres (cm) square, accurately measure and calculate
the area (A) in square centimetres, and weigh the section in
7.1 Solvents that can be used to prepare standard contami-
grams to the nearest tenth of a milligram (W ). Record the area
nant solutions include the following: 2-propanol, 2-butanone, 1
and weight.
hexane, methylene chloride
...