ASTM_D_3231_-_13.pdf

Designation:D323113Standard Test Method forPhosphorus in Gasoline1This standard is issued under the fixed designation D3231;the number immediately following the designation indicates the year oforiginal adoption or,in 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 Department of Defense.1.Scope*1.1 This test method covers the determination of phospho-rus generally present as pentavalent phosphate esters or salts,or both,in gasoline.This test method is applicable for thedetermination of phosphorus in the range from 0.2 to 40 mgP/litre or 0.0008 to 0.15 g P/U.S.gal.1.2 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with 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.For specificwarning statements,see Section 6 and 9.5.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceE832 Specification for Laboratory Filter Papers3.Summary of Test Method3.1 Organic matter in the sample is decomposed by ignitionin the presence of zinc oxide.The residue is dissolved insulfuric acid and reacted with ammonium molybdate andhydrazine sulfate.The absorbance of the Molybdenum Bluecomplex is proportional to the phosphorus concentration in thesample and is read at approximately 820 nm in a 5-cm cell.4.Significance and Use4.1 Phosphorus in gasoline will damage catalytic convertorsused in automotive emission control systems,and its leveltherefore is kept low.5.Apparatus5.1 Buret,10-mL capacity,0.05-mL subdivisions.5.2 Constant-Temperature Bath,equipped to hold several100-mL volumetric flasks submerged to the mark.Bath musthave a large enough reservoir or heat capacity to keep thetemperature at 82.2 to 87.8C(180 to 190F)during the entireperiod of sample heating.NOTE1If the temperature of the hot water bath drops below 82.2C(180F),the color development cannot be complete.5.3 Cooling Bath,equipped to hold several 100-mL volu-metric flasks submerged to the mark in ice water.5.4 Filter Paper,for quantitative analysis,Class G for fineprecipitates as defined in Specification E832.5.5 Ignition DishCoors porcelain evaporating dish,glazedinside and outside,with pourout(Size No.00A,diameter 75mm,capacity 70 mL).5.6 Spectrophotometer,equipped with a tungsten lamp,ared-sensitive phototube capable of operating at 830 nm andwith absorption cells that have a 5-cm light path.5.7 Thermometer,ASTM 34C or 34F,range from 25 to105C(77 to 221F).NOTE2Other temperature measuring devices,such as thermocouplesor resistance thermometers,may be used when the temperature readingsobtained by these devices are determined to produce the same results thatare obtained when mercury-in-glass thermometers are used.The precisionand bias given in Section 12 may or may not apply in such cases since thepublished precision is based on an interlaboratory study where onlymercury-in-glass thermometers were used.No information on the effecton precision when using alternative temperature measuring devices isavailable.5.8 Volumetric Flask,100-mL with ground-glass stopper.5.9 Volumetric Flask,1000-mL with ground-glass stopper.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.03 on Elemental Analysis.Current edition approved June 15,2013.Published July 2013.Originallyapproved in 1973.Last previous edition approved in 2011 as D3231 11.DOI:10.1520/D3231-13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual 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 States1 5.10 Syringe,Luer-Lok,10-mL equipped with 5-cm,22-gauge needle.5.11 Pipets,or equivalent volume dispensing devices,fordelivering the necessary volumes of dilute sulfuric acid(6.8)and molybdate-hydrazine reagent used in this test.6.Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications