1、Designation:D87407D87413 British Standard 4716 Standard Test Method for Sulfated Ash from Lubricating Oils and Additives 1 This standard is issued under the xed designation D874; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the
2、 year of last revision.Anumber 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 Department of Defense. 1. Scope* 1.1 This test method covers th
3、e determination of the sulfated ash from unused lubricating oils containing additives and from additiveconcentratesusedincompounding.Theseadditivesusuallycontainoneormoreofthefollowingmetals:barium,calcium, magnesium,zinc,potassium,sodium,andtin.Theelementssulfur,phosphorus,andchlorinecanalsobeprese
4、ntincombinedform. 1.2 Application of this test method to sulfated ash levels below 0.02 mass% is restricted to oils containing ashless additives. The lower limit of the test method is 0.005 mass% sulfated ash. NOTE 1This test method is not intended for the analysis of used engine oils or oils contai
5、ning lead. Neither is it recommended for the analysis of nonadditive lubricating oils, for which Test Method D482 can be used. NOTE 2There 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.
6、 NOTE 3There is evidence that samples containing molybdenum can give low results because molybdenum compounds are not fully recovered at the temperature of ashing. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This
7、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. 2. Referenced Documents
8、 2.1 ASTM Standards: 2 D482Test Method for Ash from Petroleum Products D1193Specication for Reagent Water D4057Practice for Manual Sampling of Petroleum and Petroleum Products D4177Practice for Automatic Sampling of Petroleum and Petroleum Products D6299Practice for Applying Statistical Quality Assu
9、rance and Control Charting Techniques to Evaluate Analytical Measure- ment System Performance 3. Terminology 3.1 Denitions: 3.1.1 sulfated ashthe residue remaining after the sample has been carbonized, and the residue subsequently treated with sulfuric acid and heated to constant weight. 4. Summary
10、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 andheatedat775Cuntiloxidationofcarboniscomplete.Theashisthencooled,re-treatedwithsulfuricacid,andheatedat775C to constant weight. 1 This test method is under
11、the jurisdiction ofASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.03 on Elemental Analysis. Current edition approved Nov. 1, 2007Aug. 1, 2013. Published November 2007August 2013. Originally approved in 1946. Last previous edition approved
12、 in 20062007 as D874D87407.06. DOI: 10.1520/D0874-07.10.1520/D0874-13. 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 proc
13、edures. 2 ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatserviceastm.org.ForAnnualBookofASTMStandards volume information, refer to the standards Document Summary page on the ASTM website. This document is not anASTM standard and is intended only to provide
14、the user of anASTM 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 stan
15、dard as published by ASTM is to be considered the official document. *ASummary of Changes section appears at the end of this standard Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States 15. Signicance and Use 5.1 The sulfated ash can be us
16、ed to indicate the concentration of known metal-containing additives in new oils. When phosphorusisabsent,barium,calcium,magnesium,sodiumandpotassiumareconvertedtotheirsulfatesandtin(stannic)andzinc to their oxides (Note 54). Sulfur and chlorine do not interfere, but when phosphorus is present with
17、metals, it remains partially or wholly in the sulfated ash as metal phosphates. NOTE 4Since zinc sulfate slowly decomposes to its oxide at the ignition temperature specied in the test method, samples containing zinc can give variable results unless the zinc sulfate is completely converted to the oxi
18、de. 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, timeashed,andthecompositionofmetalcompoundspr
19、esentinoils.Hence,sulfatedashrequirementgenerallyshouldnotbeused in product specications 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. 3 6. Apparatus 6.1 EvaporatingDishorCrucible;50to100-mLfors
20、amplescontainingmorethan0.02mass%sulfatedash,or120to150-mL for samples containing less than 0.02 mass% sulfated ash, and made of porcelain, fused silica, or platinum. (WarningDo not useplatinumwhenthesampleislikelytocontainelementssuchasphosphorus,whichattackplatinumundertheconditionsofthe test.) NO
21、TE 5For best results on samples containing less than 0.1 mass % sulfated ash, platinum dishes are used. The precision values shown in Section 13 for this type of sample were so obtained. 6.2 Electric Muffle FurnaceThe furnace shall be capable of maintaining a temperature of 775 6 25C and preferably
22、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 ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall
23、conform to the specications of the Committee on Analytical Reagents of the American Chemical Society, where such specications are available, or to other recognized standards for reagent chemicals. 4 Other grades may be used, provided it isrstascertainedthatthereagentisofsufficientlyhighpuritytopermi
24、titsusewithoutlesseningtheaccuracyofthedetermination. 7.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean reagent water dened by Types II or III of Specication D1193. 7.3 Low-AshMineralOilWhiteoilhavingasulfatedashlowerthanthelimitcapableofbeingdeterminedby
25、thistestmethod. NOTE 6Determine 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 to 150-mL platinum dish. Deduct the sulfuric acid blank as described in 9.11. 7.4 SulfuricAcid(relativedensity1.84)Concentratedsulfuric
26、acid(H 2 SO 4 ).(WarningPoison.Corrosive.Strongoxidizer.) 7.5 SulfuricAcid (1+1)Prepare by slowly adding 1 volume of concentrated sulfuric acid (relative density 1.84) to 1 volume of water with vigorous stirring. ( WarningMixing this acid into water generates considerable heat. When necessary, cool
27、the solution before adding more acid. Do not allow the solution to boil.) 7.6 Propan-2-ol. (WarningFlammable, can be explosive when evaporated to or near dryness.) 7.7 Toluene. (WarningFlammable, toxic.) 7.8 Quality Control (QC) Samples , preferably are portions of one or more liquid petroleum mater
28、ials 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 mixe
29、d before removal of the laboratory test portion. 3 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, W
30、arrendale, PA 15096-0001, U.S.A. 4 Reagent Chemicals, American Chemical Society Specications ,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
31、., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD. D87413 29. 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 tha
32、t is used for the test at 775 6 25C for a minimum of 10 min. Cool to room temperature in a suitable container and weigh to the nearest 0.1 mg. NOTE 7The 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: W510/a (
33、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 mass% or more, dilute the weighed sample in the dish with approximately 10 times its weight of low-a
34、sh 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 rst analysis unless the calculated sample size 80 g. NOTE8Iftheamountofsulfatedashfounddiffersfromtheexpectedam
35、ountbymorethanafactoroftwo,repeattheanalysiswithadifferentweight of sample calculated from the rst analysis. 9.4 Heatthedishorcrucibleandsamplecarefullyuntilthecontentscanbeignitedwithaame.Maintainatsuchatemperature that the sample continues to burn at a uniform and moderate rate. When burning cease
36、s, continue to heat gently until no further smoke or fumes are evolved. 9.4.1 If the sample contains sufficient moisture to cause foaming and loss of material from the dish, discard the sample and to an additional sample add 1 to 2 mL of 99% propan-2-ol (Warning Flammable) before heating. If this is
37、 not satisfactory, add 10 mL of a mixture of equal volumes of toluene (Warning Flammable, Vapor harmful.) and propan-2-ol and mix thoroughly. Placeseveralstripsofashlesslterpaperinthemixtureandheat;whenthepaperbeginstoburn,thegreaterpartofthewaterwill have been removed. 9.5 Allow the dish to cool to
38、 room temperature, then completely moisten the residue by the dropwise addition of sulfuric acid (relative density 1.84). Carefully heat the dish at a low temperature on a hot plate or over a gas burner, avoiding spattering, and continue heating until fumes are no longer evolved. 9.6 Place the dish
39、in the furnace at 7756 25C and continue heating for 306 5 min until oxidation of the carbon is complete or almost complete. 9.7 Allow the dish to cool to room temperature.Add 3 drops of water and 10 drops of sulfuric acid (1+1). Move the dish so as to moisten the entire residue. Again heat the dish
40、in accordance with 9.5. 9.8 Againplacethedishinthefurnaceat775625Candmaintainatthattemperaturefor30min65min(seeNote98).Cool the dish to room temperature in a suitable container (see Note 7). Zinc dialkyl or alkaryl dithiophosphates and blends containing theseadditivescangivearesiduethatispartiallybl
41、ackatthisstage.Inthiscase,repeat9.7and9.8untilawhiteresidueisobtained. NOTE8Astudyconductedbytwoseparatelaboratoriesinvestigatingwhetherheatingsulfatedashresiduesforextendedperiodsoftime(forexample, overnight) in a furnace at 7756 25C as opposed to 30 min as required in 9.8 revealed that a signicant
42、 difference in sulfated ash results can exist.The study indicated that lower sulfated ash results were obtained on the samples left in the furnace overnight versus those that were heated in 30min cycles. Athermogravimetric analysis also conrmed that the samples evaluated continued to lose weight at
43、775C as a function of time.As such, it is essential that the 30min heating time requirement be adhered to in performing the test method. Details concerning the study can be found in ASTM Research Report RR:D02-1597. NOTE 10Zinc dialkyl or alkaryl dithiophosphates and blends containing these additive
44、s can give a residue which is partially black at this stage. In this case, repeat 9.7 and 9.8 until a white residue is obtained. 9.9 Weigh the dish and residue to the nearest 0.1 mg. 9.10 Repeat 9.8 and 9.9 until two successive weighings differ by no more than 1.0 mg. NOTE 9Normally one repeat will
45、suffice, unless a high proportion of zinc is present, when three or four heating periods can be required. 9.11 For samples expected to contain 0.02 mass% or less of sulfated ash, determine a sulfuric acid blank by adding 1 mL of the concentrated sulfuric acid to a tared platinum dish or crucible, he
46、ating until fumes are no longer evolved and then heating in the furnace at 7756 25C for 306 5 min. Cool the dish or crucible to room temperature in a suitable container (see Note 7) and weigh to the nearest 0.1 mg. If any ash is found in the sulfuric acid, make an adjustment to the weight of sulfate
47、d ash obtained by subtracting the weight of ash contributed by the sulfuric acid, determined from the total volume of sulfuric acid used and the weight of ash found for the 1-mL blank, from the total grams of sulfated ash for the sample. Use this corrected weight, w, in calculating the percent sulfa
48、ted ash. D87413 310. Calculation 10.1 Calculate the sulfated ash as a percentage of the original sample as follows: Sulfatedash,mass%5w/W!3100 (2) where: w = grams of sulfated ash, and W = grams of sample used. 11. Report 11.1 Report the result to the nearest 0.001 mass% for samples below 0.02 mass%
49、 and to the nearest 0.01 mass% for higher levels as the sulfated ash, Test Method D874. 12. Quality Control 12.1 Conrm the performance of the instrument or the test procedure by analyzing a QC sample (see 7.8). 12.1.1 WhenQC/QualityAssurance(QA)protocolsarealreadyestablishedinthetestingfacility,thesemaybeusedtoconrm the reliability of the test result. 12.1.2 When there is no QC/QA protocol established in the testing facility, Appendix X1 can be used as the QC/QA system. 13. Precision and Bias 5 13.1 The precision of this test
