1、Designation: D7845 17Standard Test Method forDetermination of Chemical Species in Marine Fuel Oil byMultidimensional Gas Chromatography/Mass Spectrometry1This standard is issued under the fixed designation D7845; the number immediately following the designation indicates the year oforiginal adoption
2、 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. Scope*1.1 This test method covers the quantitative determinationof a variety of chemi
3、cal species in marine fuel oil (bunker fueloil) by gas chromatography/mass spectrometry. By using thesame conditions and by selecting required mass spectralselected ions, the test method may be used for the determina-tion of other species than those for which precision statementsand limits of detect
4、ion have been established.1.2 An example list of chemical species for which a limit ofquantification has been determined by means of this testmethod is given in Table 1.1.3 Other refinery hydrocarbon fractions and their mixturesmay be tested using the same test method conditions. However,the precisi
5、on of this test method reflects the compounds inTable 1.1.4 Results are reported to the nearest 1.0 mg kg.1.5 The values stated in SI units are to be regarded asstandard.1.5.1 ExceptionNon-SI values are given for psig.1.6 This standard does not purport to address all of thesafety concerns, if any, a
6、ssociated 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:2D4307 Practice for Preparation of Liquid Blends for Us
7、e asAnalytical StandardsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System Performance2.2 Other Standards:ISO 8217:2010 Petroleum ProductsFuels (Class F)Specifications of Marine Fuels33. Terminology3.1 Definitions:3.1.1 d
8、irect or open split interface, nany GC/MS interfaceused to maintain atmospheric pressure at capillary columnoutlet.3.1.2 reconstructed ion chromatogram (RIC), na limitedmass chromatogram representing the intensities of ion massspectrometric currents for only those ions having particularmass to charg
9、e ratios used in this test method to selectivelyextract and identify components in the presence of a complexhydrocarbon matrix.3.1.3 total ion chromatogram (TIC), nmass spectrometercomputer output representing either the summed intensities ofall scanned ion currents or a sample of the current in the
10、 ionbeam for each spectrum scan plotted against the correspondingspectrum number.3.1.4 wall coated open tubular (WCOT), na type ofcapillary column prepared by coating or bonding the insidewall of the capillary with a thin film of stationary phase.4. Summary of Test Method4.1 A suitable internal stan
11、dard, ethylbenzene d-10 is addedto the sample, which is then introduced into a gas chromato-graph equipped with two columns configured with a Deansswitching system between the two columns. The sample firstpasses through the polydimethylsiloxane (WCOT) pre-columnwhich then performs a separation of th
12、e light hydrocarbonfraction and eliminates the high boiling hydrocarbon fraction tovent. The compounds of interest and internal standard aretransferred to the high resolution polydimethylsiloxane(WCOT) analytical column for chromatographic separation.1This test method is under the jurisdiction of AS
13、TM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.04.0M on Mass Spectroscopy.Current edition approved Jan. 15, 2017. Published February 2017. Originallyapproved in 2013. Last previous edition approved in 2016 as D7845 16. DOI:10.1
14、520/D7845-17.2For 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.3Available from American National Standards Inst
15、itute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.*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 standard was developed i
16、n 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.1An auxiliary carrier gas
17、is used to elute higher boilinghydrocarbons from the pre-column in back flush mode in orderto prepare for the next analysis cycle. The resulting chromato-gram is then processed by mass spectral analysis based onselected or extracted ion monitoring.5. Significance and Use5.1 The test method allows th
18、e quantitation of chemicalspecies at low levels in marine fuel oils and cutter stocks. Agreat many types and concentrations of chemical species arefound in marine fuel oils.Aroot cause relationship between thepresence of such species or their concentration in fuels and anyfailure modes allegedly ind
19、uced by the use of these fuels hasnot been established. This test method is necessary to establishtest conditions required for future ISO 8217:2010 as defined insection 5.5 and Annex B item (d). Additional compounds maybe determined by using the same conditions and by selectingrequired mass spectral
20、 selected ions, accordingly.6. Apparatus6.1 Gas Chromatography:6.1.1 Gas ChromatographAny gas chromatographequipped with a flame ionization detector (FID) and havingsensitivity of 0.01 mg kg. The gas chromatograph must becapable of linear temperature control from 50 C to 320 C forthe capillary colum
21、n oven. The gas chromatograph must becapable of controlling multiple valve events. Carrier gas flowcontrollers and or electronic pressure control modules shall becapable of precise control where the required flow rates arelow. Pressure control devices and gauges shall be capable ofprecise control fo
22、r the typical pressures required. The tempera-ture program rate must repeat to within 0.1 C and provideretention time repeatability of 0.05 min throughout the tem-perature program.6.1.2 Pre-Column ColumnWCOT Column, 25 m long by0.53 mm inside diameter fused silica WCOT column with a1.0 micron film t
23、hickness of polydimethyl siloxane or anycolumn with suitable chromatographic resolution.6.1.3 Analytical ColumnWCOT Column, 100 m by0.25 mm inside diameter fused silica WCOT column with a0.5 micron film thickness of polydimethyl siloxane or anycolumn with suitable chromatographic resolution.6.1.4 Pu
24、rged Packed InjectorAn injection port that allowscontrolled injection of the sample at a temperature sufficient topass the high boiling point fraction to the pre-column or anygas chromatographic injector system to perform the samefunction.6.1.4.1 The injection port liner shall be replaced to removen
25、on-volatile materials.6.1.5 Electronic Pressure ControlElectronic pneumaticcontrol of carrier gas flows. It can be flow or pressureprogrammed to speed up elution of components.6.1.6 Low-Volume Connector and TeesA special union ortee for connecting two lengths of tubing 1.6 mm insidediameter and smal
26、ler; sometimes referred to as a zero dead-volume union, tee, or an active splitting device.6.1.7 Pre-ColumnApolydimethylsiloxane WCOT columnused to isolate the light hydrocarbons to include methane ton-hexadecane from the higher boiling portion of the sample fortransfer to the analytical column for
27、further separation andquantification.6.1.8 Deans Switching Backflush Configuration4(Fig.1)A column backflush configuration utilizing dynamic pres-sure differential which provides suitable means to remove theheavier hydrocarbon fraction from the pre-column or anysimilar configuration that allows for
28、controlled chromato-graphic separation of components of interest and heavierhydrocarbon fraction. An alternative Deans switching back-flush configuration is shown on Fig. 2.6.2 Mass Spectrometry:6.2.1 Mass Spectrometer, capable of producing electronionization spectra at 70 electron volts or higher,
29、and capable ofscanning the range of the specified quantitation masses or(m/e). The mass scan range shall cover the masses of interestfor quantitation and should yield at least 5 scans across thepeak width at half peak width for a 1 mg kg to 3 mg/kgethylbenzene d10 peak and cover the masses of intere
30、st forquantitation. A scan range set for specific ions is defined inTable 2.6.2.1.1 The mass spectrometer shall be capable of beinginterfaced to a gas chromatograph and WCOT columns. Theinterface shall be at a high enough temperature to preventcondensation of components boiling up to 350 C. Usually,
31、20 C above the final column temperature is adequate. Directcolumn interface to the mass spectrometer may be used. Anopen split interface with computer controlled programmableflow controller(s) may also be used, to maintain all components4Deans, D. R., Chromatographia, Vol 1, 18-22, 1968.TABLE 1 Comp
32、onent TableLimit of Quantitationmg/kgn-butyl alcohol 10Cyclohexanol 10n-butyl ether 10n-butyl acrylate 10Styrene 10alpha-pinene 10Phenol 20alpha-methyl styrene 10beta-pinene 104-methyl styrene 10trans-B-methyl styrene 103-methyl styrene 102-methyl styrene 10Dicyclopentadiene 10Limonene 10Indene 201-
33、phenyl ethanol 20para, alpha-Dimethyl styrene 202,5 dimethyl styrene 202,4 dimethyl styrene 202-phenyl ethanol (phenylethanol) 202-Ethyl Phenol 502,4 Dimethyl Phenol 204-Ethyl Phenol (co elutes with 3-ethylphenol) 202-Phenoxy-1-propanol 502-Phenoxy ethanol 504-isopropylphenol 501-Phenoxy-2-Propanol
34、20Styrene Glycol 50D7845 172within the linearity of the mass spectrometer and at the sametime maintain detectability of lower concentration chemicalcomponents.6.2.1.2 Acquistion mode selected ion monitoring (SIM)extracted ion mode or full scan mode using the quantitative andqualitative ions referenc
35、ed in Table 2. Additional compoundsmay be added by selecting and collecting data in full scanmode.6.2.1.3 Tuning shall be performed for low mass resolutionusing perfluorotributylamine mass fragment ions at m/z 69,131, and 219 amu. The mass spectrometer is tuned eitherautomatically or manually for op
36、timum performance.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals should beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specificati
37、ons are available.5Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.7.2 Carrier GasHelium and hydrogen have been usedsuccessfully. The recommended minimum purity of the carrie
38、rgas used is 99.999 mol %. Additional purification usingcommercially available scrubbing reagents may be necessaryto remove trace oxygen, which may deteriorate the perfor-mance of the GC WCOT.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For
39、Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Deans Switching Ba
40、ckflush, Configuration AFIG. 2 Deans Switching Backflush, Configuration BD7845 1737.3 Calibration StandardThis standard shall be preparedby adding the chemicals to include those in Table 1 preparedfrom high (99+ %) purity reagent grade materials.7.4 Standards for Calibration and IdentificationChemic
41、alcompounds used to prepare standards should be 99 % orgreater purity (see Table 1). If reagents of high purity are notavailable, an accurate assay of the reagent shall be performedusing a properly calibrated GC or other techniques. Theconcentration of the impurities that overlap the other calibra-t
42、ion components shall be known and used to correct theconcentration of the calibration components. The use of onlyhigh purity reagents is strongly recommended because of theerror that may be introduced from impurity corrections. Stan-dards are used for calibration as well as for establishing theident
43、ification by retention time in conjunction with massspectral match.7.5 n-hexadecane99+ % purity or better.7.6 Dilution SolventsReagent grade toluene, 99.9 % (orsuitable dilution solvent).7.7 Internal StandardsDeuterated analog of ethylbenzene,as specified, shall be used as internal standard because
44、of thesimilar chromatographic characteristics as the componentsanalyzed.8. Preparation of Apparatus8.1 AssemblyConfigure the GC system in a multidimen-sional configuration as described in Table 3 and Table 4.Connect the WCOT columns to the chromatographic system,including the multidimensional switch
45、ing device, using lowvolume connectors and inert narrow bore tubing. It is importantto minimize the volume of the chromatographic system thatcomes in contact with the sample; otherwise, peak broadeningwill occur.8.2 This section provides details to establish the configura-tions described in Fig. 1.
46、For other column configurations,adjust backflush and or cut times, accordingly.8.3 It is essential that the appropriate backflush time bedetermined to prevent heavy contaminants from reaching theanalytical column and potentially interfering with the determi-nation of compounds of interest.8.4 Settin
47、g the Backflush Time for Configuration AThepre-column connected to the analytical column and the massspectrometer as shown in Fig. 1 inject the calibration standardand record the chromatogram. Identify the peaks. The retentiontime data are used to set the valve on time to assure thecompound peaks ar
48、e not backflushed. The retention timesshould be incorporated into the software timed events beforecontinuing with sample analysis. Assure all of the compoundsof interest are present and high boiling hydrocarbons arebackflushed consistently. Assure the retention time data isrepeatable. If retention t
49、ime shifts are encountered check forleaks to include replacing septum and that all column and valveconnections are leak free.8.4.1 The procedure used is as follows:8.4.1.1 Prepare a timing standard containing all of thecompounds of interest.8.4.1.2 Inject the timing standard into the GC in the fore-flush position with no backflush.TABLE 2 Mass Spectrometer Compound Quantitation Ions (Retention Time Data Based on Configuration A)RetentionTimeCompound CAS # Quantifying Qualifier 1 Qualifier 2 Qualifier 321.55 Ethylbenzene-d10 25837-05-2 116 11513.55
