1、Designation:D462816Standard Test Method forAnalysis of Barium,Calcium,Magnesium,and Zinc inUnused Lubricating Oils by Atomic AbsorptionSpectrometry1This standard is issued under the fixed designation D4628;the number immediately following the designation indicates the year oforiginal adoption or,in
2、the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript 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*1.1 This
3、 test method is applicable for the determination ofmass percent barium from 0.005%to 1.0%,calcium andmagnesium from 0.002%to 0.3%,and zinc from 0.002%to0.2%in lubricating oils.1.2 Higher concentrations can be determined by appropriatedilution.Lower concentrations of metals such as barium,calcium,mag
4、nesium,and zinc at about 10 ppm level can alsobe determined by this test method.Use of this test method forthe determination at these lower concentrations should be byagreement between the buyer and the seller.1.3 Lubricating oils that contain viscosity index improversmay give low results when calib
5、rations are performed usingstandards that do not contain viscosity index improvers.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with
6、 its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.Specific warningstatements are given in 3.1,6.3,and 8.1.2.Referenced Documents2.1 ASTM Standards:2D6299 Practice
7、 for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System Performance3.Summary of Test Method3.1 A sample is weighed and base oil is added to 0.25 g 60.01 g total mass.Fifty millilitres of a kerosene solution,containing potassium as an ioniza
8、tion suppressant,are added,and the sample and oil are dissolved.(WarningHazardous.Potentially toxic and explosive.)Standards are similarlyprepared,always adding oil if necessary to yield a total mass of0.25 g.These solutions are burned in the flame of an atomicabsorption spectrophotometer.An acetyle
9、ne/nitrous oxideflame is used.(WarningCombustible.Vapor harmful.)4.Significance and Use4.1 Some oils are formulated with metal-containing addi-tives that act as detergents,antioxidants,antiwear agents,etc.Some of these additives contain one or more of these metals:barium,calcium,zinc,and magnesium.T
10、his test methodprovides a means of determining the concentration of thesemetals that gives an indication of the additive content in theseoils.4.2 Several additive metals and their compounds are addedto the lubricating oils to give beneficial performance.(SeeTable 1.)5.Apparatus5.1 Atomic Absorption
11、Spectrophotometer.5.2 Analytical Balance.5.3 Automatic Measuring Pipet or Volumetric Class A Pipet,50 mL capacity.5.4 Bottles with Screw Caps,60 mL.NOTE1Suitable volumetric flasks or plastic bottles may be substi-tuted.5.5 Shaker,Mechanical Stirrer,or Ultrasonic Bath,capableof handling 60 mL bottles
12、.6.Reagents6.1 Base Oil,metal-free,with a viscosity of about 4 cSt at100 C.A 100 neutral oil which provides good solvency for1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.03 on El
13、emental Analysis.Current edition approved Dec.1,2016.Published January 2017.Originallyapproved in 1986.Last previous edition approved in 2014 as D4628 14.DOI:10.1520/D4628-16.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Ann
14、ual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international
15、 standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 st
16、andards and additive concentrate is satisfactory.Highlyparaffinic oils should be avoided.6.2 2-Ethyl Hexanoic Acid,which has been determined to befree of interfering metals.6.3 Kerosene,Metal-FreeSee Notes 2-4.(WarningCombustible.Vapor harmful.)Distillation range from 170 Cto 280 C at 100 kPa(1 atm).When the kerosene solvent iscontaminated,it may be purified metal-free by running throughattapulgus clay.NOTE2Solvents other than kerosene,such as xylene MEK and soforth,may be used in this test meth
