1、Designation:D352504 Designation: D3525 04 (Reapproved 2010)Standard Test Method forGasoline Diluent in Used Gasoline Engine Oils by GasChromatography1This standard is issued under the fixed designation D3525; the number immediately following the designation indicates the year oforiginal adoption or,
2、 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. Scope *1.1This test method covers the use of gas chromatography to determine the amount o
3、f gasoline in used lubricating oils arisingfrom their use in gasoline engines.1.1 This test method covers the use of gas chromatography to determine the amount of gasoline in used lubricating oils arisingfrom their use in gasoline engines.1.2 There is no limitation for the determination of the dilut
4、ion range, provided that the amount of sample plus internal standardis within the linear range of the gas chromatograph detector.1.3 This test method is limited to gas chromatographs equipped with flame ionization detectors and programmable ovens.NOTE 1The use of other detectors and instrumentation
5、has been reported. However, the precision statement applies only when the instrumentationspecified is employed.1.4 The applicability of this method to gelled used engine oils has not been adequately investigated in order to ensurecompliance with the indicated repeatability and reproducibility. Gelle
6、d oils are defined as oils that develop structure on standing,but that return to their original fluidity with light agitation.1.5The values stated in SI units are to be regarded as the standard.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are includ
7、ed in this standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatoryrequirements prior to
8、use.2. Referenced Documents2.1 ASTM Standards:2E260 Practice for Packed Column Gas ChromatographyE355 Practice for Gas Chromatography Terms and RelationshipsE594 Practice for Testing Flame Ionization Detectors Used in Gas or Supercritical Fluid ChromatographyE1510 Practice for Installing Fused Silic
9、a Open Tubular Capillary Columns in Gas Chromatographs3. Terminology3.1 Definitions:3.1.1 For definition of gas chromatography terms, refer to Practice E355.3.2 Definitions of Terms Specific to This Standard:3.2.1 fuel dilutionfuel diluent, nthe amount, expressed as a percentage, of gasoline found i
10、n engine lubricating oil. in usedoil analysis, unburned fuel components that enter the engine crankcase cause dilution of the oil.3.2.1.1 DiscussionFuel dilution may be the result of engine wear or improper performance. In this method, the fuel diluentcomponents being determined originate from gasol
11、ine.3.2.2 fuel diluentfuel dilution, nin used oil analysis, unburned fuel components that enter the engine crankcase cause dilutionof the oil. the amount, expressed as a percentage, of gasoline found in engine lubricating oil.3.2.2.1 DiscussionIn this method, the fuel diluent components being determ
12、ined originate from gasoline. Fuel dilution maybe the result of engine wear or improper performance.1This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.04.0Hon Hydrocarbon Analysis. Chromatographi
13、c Distribution Methods.Current edition approved Nov.Oct. 1, 2004.2010. Published November 2004.2010. Originally approved in 1976. Last previous edition approved in 20022004 asD352593(2002)1.D353204. DOI: 10.1520/D3525-04R10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or con
14、tact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have
15、been made to the previous version. Becauseit 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 versionof the standard as published by ASTM is to be considered the official docum
16、ent.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.3 Abbreviations:3.3.1 Acommon abbreviation of hydrocarbon compounds is to designate the number of carbon atoms in the compound.Aprefixis used to indicate the carbon chain form, whi
17、le a subscripted suffix denotes the number of carbon atoms.Example:normal decane n-C10iso-tetradecane i-C144. Summary of Test Method4.1 A gas chromatographic technique is used for analyzing the samples, by adding a known percentage of n-tetradecane as aninternal standard, in order to determine the w
18、eight percent of gasoline fuel in the lubricating oil. A calibration curve is previouslyconstructed which plots the gasoline fuel to n-tetradecane response ratio versus the weight percent of gasoline fuel in lubricatingoil mixtures containing a constant amount of internal standard. Mass percent of g
19、asoline fuel in the samples is determined byinterpolation from the calibration curve.5. Significance and Use5.1 Some fuel dilution of the engine oil may take place during normal operation. However, excessive fuel dilution is of concernin terms of possible performance problems. This method provides a
20、 means to determine the magnitude of the fuel dilution,providing the user with the ability to predict performance problems and to take appropriate action.6. Apparatus6.1 Gas ChromatographAny gas chromatograph may be used that has the following performance characteristics:6.1.1 DetectorOnly a flame i
21、onization detector can be used in this method. The detector must have sufficient sensitivity todetect 1.0 % n-tetradecane with a peak height of at least 40 % of full scale on the data acquisition devise under the conditionsprescribed in this method. For further guidance on testing flame ionization d
22、etectors, refer to Practice E594. When operating atthis sensitivity level, detector stability must be such that a baseline drift of not more than 1 % full scale per hour is obtained. Thedetector must be capable of operating continuously at a temperature equivalent to the maximum column temperature e
23、mployed.Connection of the column to the detector must be such that no temperature zones exist below the column temperature (cold spots).6.1.2 Column Temperature ProgrammerThe chromatograph must be capable of temperature program operation of the ovenover a range sufficient to establish a retention ti
24、me of 0.25 min (15 s) for the initial peak and to elute the internal standard totally.A retention time repeatability of 0.3 min (18 s) must be achieved.6.1.3 Sample Inlet SystemThe sample inlet system must be capable of operating continuously at a temperature equivalent tothe maximum column temperat
25、ure employed. An on-column inlet with some means of programming the inlet temperature,including the point of sample introduction, up to the maximum temperature required can also be used. Connection of the columnto the sample inlet system must be such that no temperature zones exist below the column
26、temperature (cold spots).6.2 Data Acquisition SystemMeans must be provided for measuring the accumulated area under the chromatogram. This canbe done by means of an electronic integrator or computer based chromatography data system.6.2.1 Integrator/Computer SystemThe integrator/computer system must
27、have chromatographic software capable of measuringthe retention times and areas of eluting peaks (peak detection mode). The electronic range of the integrator/computer (for example,1 V, 10 V) must be within the linear range of the detector/electrometer system used. It is desirable that the system be
28、 capable ofsubtracting each area slice of a blank run from the corresponding area slice of a sample run.NOTE 2Best precision and automatic operation can be achieved with electronic integration.TABLE 1 Typical Operating ConditionsPacked Columns Open Tubular ColumnsColumn length, m (ft) 0.610 (2) 5 10
29、Column outside diameter, mm (in.) 3.2 (1/8) Column inner diameter, mm (in.) 2.36 ( 0.093) 0.53Liquid phase methylsilicone gum or liquids cross-linked, bonded polydimethylsiloxanePercent liquid phase 10 Support material crushed fire brick or diatomaceous earth Treatment acid wash Support mesh size 80
30、/100 Stationary phase thickness, microns 0.88 2.65Column temperature, initial C 30 30Column temperature, final C 255 255Programming rate, C/min 6 6Carrier gas helium or nitrogen helium or nitrogenCarrier gas flow rate, mL/min 30 30Detector flame ionization detector flame ionization detectorDetector
31、temperature, C 300 300Injection port temperature, C 255 255Sample size, L 0.7 0.1 0.2 (from 1/10 dilution in CS2)D3525 04 (2010)2NOTE 3Some gas chromatographs have an algorithm built into their operating software that allows a mathematical model of the baseline profile tobe stored in memory. This pr
32、ofile is automatically subtracted from the detector signal on subsequent sample analyses to compensate for any baseline offset.Some integration systems also store and automatically subtract a blank analysis from subsequent analytical determinations.6.3 ColumnAny column and conditions may be used, pr
33、ovided that, under the conditions of the test, the separations occurin order of increasing boiling points and the column performance requirements described in 8.2.1 are met. The column resolution,R, shall be at least 3 and not more than 8 (see 8.2.1.1). Since a stable baseline is an essential requir
34、ement of this method, electronicsingle column compensation is required to compensate for column bleed, septum bleed, detector temperature control, constancyof carrier gas flow and instrument drift.6.4 Flow ControllersThe gas chromatograph must be equipped with mass flow controllers capable of mainta
35、ining carrier gasflow constant to 61 % over the full operating temperature range of the column. The inlet pressure of the carrier gas supplied tothe gas chromatograph must be sufficiently high to compensate for the increase in column back-pressure as the column temperatureis raised. An inlet pressur
36、e of 550 kPa (80 psig) has been found to be satisfactory with the columns described in Table 1.6.5 Sample Introduction Devices:6.5.1 Micro SyringeA micro syringe, usually 10 L, is used for sample introduction.6.5.2 Automatic sampling devices that reproducibly inject the same volume are highly recomm
37、ended. The sample introductiondevices should operate in a synchronous manner with the gas chromatograph.6.6 Vials, 1-dram (3.7-mL), septum-capped, or those recommended by the manufacturer of the automatic sampling device.7. Reagents and Materials37.1 Purity of ReagentsReagent grade chemicals shall b
38、e used in all tests. Unless otherwise indicated, it is intended that allreagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where suchspecifications are available. Other grades may be used, provided it is first ascertained that the reagent
39、is of sufficiently high purityto permit its use without lessening the accuracy of the determination.7.2 Liquid Phase for ColumnsAny nonpolar liquid phase suitable for column operation above 300C may be used.Methylsilicone gums and liquids have been found to provide the proper chromatographic hydroca
40、rbon elution characteristics forthis test method.7.3 Solid SupportUsually crushed fire brick or diatomaceous earth is used in the case of packed columns. Where solid supportis used, sieve size and support loading should be such as will give optimum resolution and analysis time. In general, particle
41、sizesranging from 60 to 100 sieve mesh, and support loadings of 3 to 10 %, have been found most satisfactory.7.4 Carrier GasHelium or nitrogen (WarningHelium and nitrogen are compressed gases under high pressure), 99.99mole% or greater, shall be used with the flame ionization detector. Additional pu
42、rification is recommended by the use of molecularsieves or other suitable agents to remove water, oxygen, and hydrocarbons. Available pressure must be sufficient to ensure aconstant carrier gas flow rate (see 6.4).7.5 HydrogenHydrogen (WarningHydrogen is an extremely flammable gas under high pressur
43、e), 99.99 mole% purity orgreater, is used as fuel for the flame ionization detector (FID).7.6 AirCompressed air (WarningCompressed air is a gas under high pressure and supports combustion), 99.99 mole%purity or greater, is used as the oxidant for the flame ionization detector (FID).7.7 n-Tetradecane
44、(WarningCombustible liquid; vapor harmful), 95 % minimum purity.7.8 n-Hexadecane(WarningCombustible liquid; vapor harmful), 95 % minimum purity.7.9 n-Octane(Warning Flammable liquid; harmful if inhaled), 95 % minimum purity.7.10 Carbon Disulfide (CS2) (WarningCarbon disulfide is extremely volatile,
45、flammable, and toxic.)8. Preparation of Apparatus8.1 Column Preparation:8.1.1 Packed ColumnsAny satisfactory method used in the practice of gas chromatography (see Practice E260) that willproduce a column meeting the requirements of 6.3 may be used. The column must be conditioned at the maximum oper
46、atingtemperature until baseline drift due to column bleeding has been reduced to less than 1 % per hour.8.1.1.1 The packed column can be conditioned very rapidly and effectively using the following procedure: Connect the columnto the inlet but leave the detector end free. Purge the column thoroughly
47、 at ambient temperature with carrier gas. Turn off the carriergas and allow the column to depressurize completely. Seal off the open end (detector end) of the column with an appropriate fitting.Raise the column temperature to the maximum operating temperature and hold at this temperature for at leas
48、t 1 h with no flowthrough the column. Cool the column to ambient temperature. Then remove the cap from the detector end of the column and turnthe carrier gas back on. Program the column temperature up to the maximum several times with normal carrier gas flow. Connectthe free end of the column to the
49、 detector.3Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D3525 04 (2010)3NOTE 4Difficulty in achieving the baseline drift requirement may indicate column bleed due to insufficient condit
