ASTM D7303-23
(Test Method)Standard Test Method for Determination of Metals in Lubricating Greases by Inductively Coupled Plasma Atomic Emission Spectrometry
Standard Test Method for Determination of Metals in Lubricating Greases by Inductively Coupled Plasma Atomic Emission Spectrometry
SIGNIFICANCE AND USE
5.1 Lubricating greases are used in almost all bearings used in any machinery. Lubricating grease is composed of ~90 % additized oil and soap or other thickening agent. There are over a dozen metallic elements present in greases, either blended as additives for performance enhancements or as thickeners, or in used greases present as contaminants and wear metals. Determining their concentrations can be an important aspect of grease manufacture. The metal content can also indicate the amount of thickeners in the grease. Additionally, a reliable analysis technique can also assist in the process of trouble shooting problems with new and used grease in the field.
5.2 Although widely used in other sectors of the oil industry for metal analysis, ICP-AES based Test Methods D4951 or D5185 cannot be used for analyzing greases because of their insolubility in organic solvents used in these test methods. Hence, grease samples need to be brought into aqueous solution by acid decomposition before ICP-AES measurements.
5.3 Test Method D3340 has been used to determine lithium and sodium content of lubricating greases using flame photometry. This technique is no longer widely used. This new test method provides a test method for multi-element analysis of grease samples. This is the first D02 standard available for simultaneous multi-element analysis of lubricating greases.
SCOPE
1.1 This test method covers the determination of a number of metals such as aluminum, antimony, barium, calcium, iron, lithium, magnesium, molybdenum, phosphorus, silicon, sodium, sulfur, and zinc in unused lubricating greases by inductively coupled plasma atomic emission spectrometry (ICP-AES) technique.
1.1.1 The range of applicability for this test method, based on the interlaboratory study conducted in 2005,2 is aluminum (10 to 600), antimony (10 to 2300), barium (50 to 800), calcium (20 to 50 000), iron (10 to 360), lithium (300 to 3200), magnesium (30 to 10 000), molybdenum (50 to 22 000), phosphorus (50 to 2000), silicon (10 to 15 000), sodium (30 to 1500), sulfur (1600 to 28 000), and zinc (300 to 2200), all in mg/kg. Lower levels of elements may be determined by using larger sample weights, and higher levels of elements may be determined by using smaller amounts of sample or by using a larger dilution factor after sample dissolution. However, the test precision in such cases has not been determined, and may be different than the ones given in Table 3.
1.1.2 It may also be possible to determine additional metals such as bismuth, boron, cadmium, chromium, copper, lead, manganese, potassium, titanium, etc. by this technique. However, not enough data is available to specify the precision for these latter determinations. These metals may originate into greases through contamination or as additive elements.
1.1.3 During sample preparation, the grease samples are decomposed with a variety of acid mixture(s). It is beyond the scope of this test method to specify appropriate acid mixtures for all possible combination of metals present in the sample. But if the ash dissolution results in any visible insoluble material, the test method may not be applicable for the type of grease being analyzed, assuming the insoluble material contains some of the analytes of interest.
1.2 Elements present at concentrations above the upper limit of the calibration curves can be determined with additional appropriate dilutions of dissolved samples and with no degradation of precision.
1.3 The development of the technique behind this test method is documented by Fox.3
1.4 The values stated in SI units are to be regarded as the standard. The values given 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, health, and environmental practices and dete...
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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: D7303 − 23
Standard Test Method for
Determination of Metals in Lubricating Greases by
1
Inductively Coupled Plasma Atomic Emission Spectrometry
This standard is issued under the fixed designation D7303; 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* 1.2 Elements present at concentrations above the upper limit
of the calibration curves can be determined with additional
1.1 This test method covers the determination of a number
appropriate dilutions of dissolved samples and with no degra-
of metals such as aluminum, antimony, barium, calcium, iron,
dation of precision.
lithium, magnesium, molybdenum, phosphorus, silicon,
sodium, sulfur, and zinc in unused lubricating greases by 1.3 The development of the technique behind this test
3
inductively coupled plasma atomic emission spectrometry method is documented by Fox.
(ICP-AES) technique.
1.4 The values stated in SI units are to be regarded as the
1.1.1 The range of applicability for this test method, based
standard. The values given in parentheses are for information
2
on the interlaboratory study conducted in 2005, is aluminum
only.
(10 to 600), antimony (10 to 2300), barium (50 to 800),
1.5 This standard does not purport to address all of the
calcium (20 to 50 000), iron (10 to 360), lithium (300 to 3200),
safety concerns, if any, associated with its use. It is the
magnesium (30 to 10 000), molybdenum (50 to 22 000),
responsibility of the user of this standard to establish appro-
phosphorus (50 to 2000), silicon (10 to 15 000), sodium (30 to
priate safety, health, and environmental practices and deter-
1500), sulfur (1600 to 28 000), and zinc (300 to 2200), all in
mine the applicability of regulatory limitations prior to use.
mg/kg. Lower levels of elements may be determined by using
Specific warning statements are given in Sections 8 and 10.
larger sample weights, and higher levels of elements may be
1.6 This international standard was developed in accor-
determined by using smaller amounts of sample or by using a
dance with internationally recognized principles on standard-
larger dilution factor after sample dissolution. However, the
ization established in the Decision on Principles for the
test precision in such cases has not been determined, and may
Development of International Standards, Guides and Recom-
be different than the ones given in Table 3.
mendations issued by the World Trade Organization Technical
1.1.2 It may also be possible to determine additional metals
Barriers to Trade (TBT) Committee.
such as bismuth, boron, cadmium, chromium, copper, lead,
manganese, potassium, titanium, etc. by this technique.
2. Referenced Documents
However, not enough data is available to specify the precision
4
2.1 ASTM Standards:
for these latter determinations. These metals may originate into
D1193 Specification for Reagent Water
greases through contamination or as additive elements.
D3340 Test Method for Lithium and Sodium in Lubricating
1.1.3 During sample preparation, the grease samples are
5
Greases by Flame Photometer (Withdrawn 2013)
decomposed with a variety of acid mixture(s). It is beyond the
D4057 Practice for Manual Sampling of Petroleum and
scope of this test method to specify appropriate acid mixtures
Petroleum Products
for all possible combination of metals present in the sample.
D4175 Terminology Relating to Petroleum Products, Liquid
But if the ash dissolution results in any visible insoluble
Fuels, and Lubricants
material, the test method may not be applicable for the type of
D4951 Test Method for Determination of Additive Elements
grease being analyzed, assuming the insoluble material con-
in Lubricating Oils by Inductively Coupled Plasma
tains some of the analytes of interest.
1 3
This test method is under the jurisdiction of ASTM Committee D02 on Fox, B. S.,“Elemental Analysis of Lubricating Grease by Inductively Coupled
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Plasm Atomic Emission Spectrometry (ICP-AES),” J. ASTM International, Vol 2,
Subcommittee D02.03 on Elemental Analysis. No. 8, 2005, pp. 12966.
4
Current edition approved July 1, 2023. Published July 2023. Originally approved For referenced ASTM standards, visit the ASTM website, www.astm.org, or
in 2006. Last previous edition approved in 2017 as D7303 – 17. DOI: 10.1520/ contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
D7303-23. St
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7303 − 17 D7303 − 23
Standard Test Method for
Determination of Metals in Lubricating Greases by
1
Inductively Coupled Plasma Atomic Emission Spectrometry
This standard is issued under the fixed designation D7303; 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*
1.1 This test method covers the determination of a number of metals such as aluminum, antimony, barium, calcium, iron, lithium,
magnesium, molybdenum, phosphorus, silicon, sodium, sulfur, and zinc in unused lubricating greases by inductively coupled
plasma atomic emission spectrometry (ICP-AES) technique.
2
1.1.1 The range of applicability for this test method, based on the interlaboratory study conducted in 2005, is aluminum (10 to
600), antimony (10 to 2300), barium (50 to 800), calcium (20 to 50 000), iron (10 to 360), lithium (300 to 3200), magnesium (30
to 10 000), molybdenum (50 to 22 000), phosphorus (50 to 2000), silicon (10 to 15 000), sodium (30 to 1500), sulfur (1600 to
28 000), and zinc (300 to 2200), all in mg/kg. Lower levels of elements may be determined by using larger sample weights, and
higher levels of elements may be determined by using smaller amounts of sample or by using a larger dilution factor after sample
dissolution. However, the test precision in such cases has not been determined, and may be different than the ones given in Table
1.Table 3.
1.1.2 It may also be possible to determine additional metals such as bismuth, boron, cadmium, chromium, copper, lead,
manganese, potassium, titanium, etc. by this technique. However, not enough data is available to specify the precision for these
latter determinations. These metals may originate into greases through contamination or as additive elements.
1.1.3 During sample preparation, the grease samples are decomposed with a variety of acid mixture(s). It is beyond the scope of
this test method to specify appropriate acid mixtures for all possible combination of metals present in the sample. But if the ash
dissolution results in any visible insoluble material, the test method may not be applicable for the type of grease being analyzed,
assuming the insoluble material contains some of the analytes of interest.
1.2 Elements present at concentrations above the upper limit of the calibration curves can be determined with additional
appropriate dilutions of dissolved samples and with no degradation of precision.
3
1.3 The development of the technique behind this test method is documented by Fox.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.03 on Elemental Analysis.
Current edition approved June 1, 2017July 1, 2023. Published June 2017July 2023. Originally approved in 2006. Last previous edition approved in 20122017 as
D7303 – 12.D7303 – 17. DOI: 10.1520/D7303-17.10.1520/D7303-23.
2
Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D02-1608. Contact ASTM Customer
Service at service@astm.org.
3
Fox, B. S., “Elemental S.,“Elemental Analysis of Lubricating Grease by Inductively Coupled Plasm Atomic Emission Spectrometry (ICP-AES),” J. ASTM International,
Vol 2, No. 8, 2005, pp. 12966.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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D7303 − 23
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 healthsafety, health, and environmental practices and determine
the applicability of regulatory limitations prior to use. Specific warning statements are given in Sections 8 and 10.
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 Organi
...
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