ASTM D874-23

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: D874 − 13a (Reapproved 2018) D874 − 23 British Standard 4716
Standard Test Method for
Sulfated Ash from Lubricating Oils and Additives
This standard is issued under the fixed designation D874; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope Scope*
1.1 This test method covers the determination of the sulfated ash from unused lubricating oils containing additives and from
additive concentrates used in compounding. These additives usually contain one or more of the following metals: barium, calcium,
magnesium, zinc, potassium, sodium, and tin. The elements sulfur, phosphorus, and chlorine can also be present in combined form.
1.2 Application of this test method to sulfated ash levels below 0.02 % by mass is restricted to oils containing ashless additives.
The lower limit of the test method is 0.005 % by mass sulfated ash.
NOTE 1—This test method is not intended for the analysis of used engine oils or oils containing lead. Neither is it recommended for the analysis of
nonadditive lubricating oils, for which Test Method D482 can be used.
NOTE 2—There is evidence that magnesium does not react the same as other alkali metals in this test. If magnesium additives are present, the data is
interpreted with caution.
NOTE 3—There is evidence that samples containing molybdenum can give low results because molybdenum compounds are not fully recovered at the
temperature of ashing.
1.3 Fatty acid methyl ester (FAME) conforming to EN 14213 EN 14213 and EN 14214, when tested using this test method, were
shown to meet its precision.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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.
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 April 1, 2018March 1, 2023. Published June 2018April 2023. Originally approved in 1946. Last previous edition approved in 20132018 as
D874 – 13a.D874 – 13a (2018). DOI: 10.1520/D0874-13AR18.10.1520/D0874-23.
In the IP, this test method is under the jurisdiction of the Standardization Committee. This test method has been approved by the sponsoring committees and accepted by
the cooperating societies in accordance with established procedures.
*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
D874 − 23
2. Referenced Documents
2.1 ASTM Standards:
D482 Test Method for Ash from Petroleum Products
D1193 Specification for Reagent Water
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-
ment System Performance
2.2 CEN Standards:
EN 14213 Heating Fuels—Fatty Acid Methyl Esters (FAME)—Requirements and Test Methods
EN 14214 Automotive Fuels—Fatty Acid Methyl Esters (FAME) for Diesel Engines—Requirements and Test Methods
3. Terminology
3.1 Definitions:
3.1.1 sulfated ash, n—the residue remaining after the sample has been carbonized, and the residue subsequently treated with
sulfuric acid and heated to constant weight.
4. Summary of Test Method
4.1 The sample is ignited and burned until only ash and carbon remain. After cooling, the residue is treated with sulfuric acid and
heated at 775 °C until oxidation of carbon is complete. The ash is then cooled, re-treated with sulfuric acid, and heated at 775 °C
to constant weight.
5. Significance and Use
5.1 The sulfated ash can be used to indicate the concentration of known metal-containing additives in new oils. When phosphorus
is absent, barium, calcium, magnesium, sodium and potassium are converted to their sulfates and tin (stannic) and zinc to their
oxides (Note 4). Sulfur and chlorine do not interfere, but when phosphorus is present with metals, it remains partially or wholly
in the sulfated ash as metal phosphates.
NOTE 4—Since zinc sulfate slowly decomposes to its oxide at the ignition temperature specified in the test method, samples containing zinc can give
variable results unless the zinc sulfate is completely converted to the oxide.
5.2 Because of above inter-element interferences, experimentally obtained sulfated ash values may differ from sulfated ash values
calculated from elemental analysis. The formation of such non-sulfated species is dependent on the temperature of ashing, time
ashed, and the composition of metal compounds present in oils. Hence, sulfated ash requirement generally should not be used in
product specifications without a clear understanding between a buyer and a seller of the unreliability of an ash value as an indicator
of the total metallic compound content.
6. Apparatus
6.1 Evaporating Dish or Crucible;Crucible, 50 mL to 100 mL for samples containing more than 0.02 % by mass sulfated ash, or
120 mL to 150 mL for samples containing less than 0.02 % by mass sulfated ash, and made of porcelain, fused silica, or platinum.
(Warning—Do not use platinum when the sample is likely to contain elements such as phosphorus, which attack platinum under
the conditions of the test.)
NOTE 5—For best results on samples containing less than 0.1 % by mass sulfated ash, platinum dishes are used. The precision values shown in Section
13 for this type of sample were so obtained.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from European Committee for Standardization (CEN), Avenue Marnix 17, B-1000, Brussels, Belgium, http://www.cen.eu.
Further discussion of these interferences can be found in Nadkarni, R. A., Ledesma, R. R., and Via, G. H., “Sulfated Ash TM: Limitations of Reliability and
Reproducibility,” SAE Technical Paper No. 952548, available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001, U.S.A.
D874 − 23
6.2 Electric Muffle Furnace—The furnace shall be capable of maintaining a temperature of 775 °C 6 25 °C and preferably have
apertures at the front and rear to allow a slow natural draft of air to pass through the furnace.
6.3 Balance, capable of weighing to 0.1 mg.
7. Reagents
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where
such specifications are available, or to other recognized standards for reagent chemicals. Other grades may be used, provided it
is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.
7.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean reagent water defined by Types
II or III of Specification D1193.
7.3 Low-Ash Mineral Oil—White oil having a sulfated ash lower than the limit capable of being determined by this test method.
NOTE 6—Determine the sulfated ash of this oil by the procedure given in 9.1 – 9.11 below using 100 g of white oil weighed to the nearest 0.5 g in a 120 mL
to 150 mL platinum dish. Deduct the sulfuric acid blank as described in 9.11.
7.4 Sulfuric Acid (relative density 1.84)—Concentrated sulfuric acid (H SO ). (Warning—Poison. Corrosive. Strong oxidizer.)
2 4
7.5 Sulfuric Acid (1 + 1)—Prepare by slowly adding 1 volume of concentrated sulfuric acid (relative density 1.84) to 1 volume
of water with vigorous stirring. (Warning—Mixing this acid into water generates considerable heat. When necessary, cool the
solution before adding more acid. Do not allow the solution to boil.)
7.6 Propan-2-ol, (Warning—Flammable, can be explosive when evaporated to or near dryness.) 99 % minimum purity.
7.7 Toluene, (Warning—Flammable, toxic.) 99 % minimum purity.
7.8 Quality Control (QC) Samples, preferably are portions of one or more liquid petroleum materials that are stable and
representative of the samples of interest. These QC samples can be used to check the validity of the testing process as described
in Section 12.
8. Sampling
8.1 Obtain samples in accordance with the instructions in Practice D4057 or D4177. The sample shall be thoroughly mixed before
removal of the laboratory test portion.
9. Procedure
9.1 Select the size of the evaporating dish or crucible according to the quantity of sample necessary (see 9.3).
9.2 Heat the evaporating dish or crucible that is used for the test at 775 °C 6 25 °C for a minimum of 10 min. Cool to room
temperature in a suitable container and weigh to the nearest 0.1 mg.
NOTE 7—The container in which the dish is cooled does not contain a desiccating agent.
9.3 Weigh into the dish a quantity of sample given as follows:
ACS Reagent Chemicals, American Chemical Society Specifications Specifications and Procedures for Reagents and Standard-Grade Reference Materials, , American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by the American Chemical Society, see Analar Standards for Laboratory Chemicals,
BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
D874 − 23
W 5 10/a (1)
where:
W = mass of test specimen, g, and
a = expected sulfated ash, mass %.
However, do not take a quantity in excess of 80 g. In the case of lubricating oil additives yielding a sulfated ash of 2 % by mass
or more, dilute the weighed sample in the dish with approximately 10 times its weight of low-ash mineral oil. If the amount of
sulfated ash found differs from the expected amount by more than a factor of two, repeat the analysis with a different weight of
sample calculated from the first analysis unless the calculated sample size >80 g.
9.4 Heat the dish or crucible and sample carefully until the contents can be ignited with a flame. Maintain at such a temperature
that the sample continues to burn at a uniform and moderate rate. When burning ceases, continue to heat gently until no further
smoke or fumes are evolved.
9.4.1 If the samp
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