ASTM_D_3605_-_00_2011.pdf

Designation:D360500(Reapproved 2011)Standard Test Method forTrace Metals in Gas Turbine Fuels by Atomic Absorptionand Flame Emission Spectroscopy1This standard is issued under the fixed designation D3605;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.1.Scope1.1 This test method covers the determination of sodium,lead,calcium,and vanadium in Specification D2880 GradeNos.1-GT and 2-GT fuels in the range from 0.1 to 2.0 mg/L.This test method is intended for the determination of oil-soluble metals and not waterborne contaminants in oil-watermixtures.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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.2.Referenced Documents2.1 ASTM Standards:2D2880 Specification for Gas Turbine Fuel OilsD4057 Practice for Manual Sampling of Petroleum andPetroleum Products3.Summary of Test Method3.1 The samples are prepared to conform with the require-ments of the method of standard additions,which is selected toobviate problems encountered with the direct analysis oftypical gas turbine fuels that exhibit significant variations inphysical properties.Different,but known,amounts of analyteare added to two portions of sample.These,together with theunaltered sample,are burned in the flame of an atomicabsorption instrument that measures light absorption by theatomized metals.The analysis of the sample portions withadded analyte provides the calibration information necessary tocalculate the analyte content of the unaltered sample.3.2 Lead is determined by atomic absorption in a premixedair-acetylene flame,and sodium is determined by atomicabsorption or atomic emission in a premixed air-acetyleneflame.Calcium and vanadium are determined by atomicabsorption or atomic emission in a premixed nitrous oxide-acetylene flame.3.3 Most experience with this test method has been in theatomic absorption mode,although flame emission has beenused successfully.Details in the subsequent sections arewritten for the atomic absorption mode.If the flame emissionmode is used,minor details in the subsequent sections must bealtered to conform to standard practice for flame emissionspectroscopy.The precision statement applies only to theatomic absorption mode.NOTE1Some GT fuel users may wish to determine potassium inaddition to other metals included in this method.Potassium can bedetermined in a manner similar to that for sodium using a potassiumhollow cathode lamp,(unless flame emission mode is used)a wavelengthof 766.4 mm,and an appropriate organo-potassium standard.Precisiondata for potassium have not been determined.4.Significance and Use4.1 Knowledge of the presence of trace metals in gas turbinefuels enables the user to predict performance and,whennecessary,to take appropriate action to prevent corrosion.5.Apparatus5.1 Atomic Absorption Spectrophotometer,capable of mea-suring radiation over the wavelength range from 280 to 600nm.The instrument must be capable of measuring low-levelsignals(approximately 1%absorption or 0.004 absorbanceunit per mg/L vanadium).The instrument should also beequipped as follows.5.1.1 Burner,with variable nebulizer and auxiliary oxidantsupply to reduce non-atomic absorption from unburned hydro-carbons which cause interferences.5.1.1.1 Burner Head,capable of supporting a nitrous oxide-acetylene flame.5.1.1.2 Burner Head,single-or multiple-slot,capable ofsupporting an air-acetylene flame.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricantsand is the direct responsibility of SubcommitteeD02.03 on Elemental Analysis.Current edition approved May 1,2011.Published May 2011.Originallyapproved in 1977.Last previous edition approved in 2005 as D3605 00(2005).DOI:10.1520/D3605-00R11.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.1.2 Electronic Detection System,capable of reading to thenearest 0.1%absorption or 0.0004 absorbance.5.1.2.1 The text describes the measurement of absorptionsignals that is,either percent absorption or absorbance.Forinstruments reading in percent absorption,absorption signalsof 0.1%absorption must be measurable.For instrumentsreading in absorbance,signals of 0.0004 absorbance must beme