1、Designation: D8003 15Standard Test Method forDetermination of Light Hydrocarbons and Cut PointIntervals in Live Crude Oils and Condensates by GasChromatography1This standard is issued under the fixed designation D8003; the number immediately following the designation indicates the year oforiginal ad
2、option 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 lighthydrocarbons and cut
3、 point intervals by gas chromatography inlive crude oils and condensates with VPCR4(see Note 1)upto500 kPa at 37.8 C.NOTE 1As described in Test Method D6377.1.2 Methane (C1) to hexane (nC6) and benzene are speciatedand quantitated. Samples containing mass fractions of up to 0.5% methane, 2.0 % ethan
4、e, 10 % propane, or 15 % isobutanemay be analyzed. A mass fraction with a lower limit of 0.001% exists for these compounds.1.3 This test method may be used for the determination ofcut point carbon fraction intervals (see 3.1.2) of live crude oilsand condensates from initial boiling point (IBP) to 39
5、1 C(nC24). The nC24plus fraction is reported.1.4 Dead oils or condensates sampled in accordance with12.1 may also be analyzed.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5.1 ExceptionWhere there is no direct SI equival
6、entsuch as tubing size.1.6 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
7、 to use.2. Referenced Documents2.1 ASTM Standards:2D1265 Practice for Sampling Liquefied Petroleum (LP)Gases, Manual MethodD3700 Practice for Obtaining LPG Samples Using a Float-ing Piston CylinderD4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD5002 Test Method for Den
8、sity and Relative Density ofCrude Oils by Digital Density AnalyzerD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6377 Test Method for Determination of Vapor Pressure ofCrude Oil: VPCRx(Expansion Method)D67
9、92 Practice for Quality System in Petroleum Productsand Lubricants Testing LaboratoriesE1510 Practice for Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs2.2 Other Regulations:CAN/CGSB-3.0 No. 14.3-99 Standard Test Method for theIdentification of Hydrocarbon Components in
10、AutomotiveGasoline using Gas Chromatography33. Terminology3.1 Definitions:3.1.1 D1265 cylinder, na container used for storage andtransportation of a sample obtained at pressures above atmo-spheric pressure as described in Practice D1265.3.1.2 cut point carbon fraction interval, nthe percent massobta
11、ined between two selected n-paraffins of the interval. Thecut point carbon fraction interval as used in this test method isdefined as the percent mass obtained between the end of onen-paraffin peak to the end of the next n-paraffin peak, thus atemperature interval is not used to determine the cut po
12、ints butrather the end points sequential of a n-paraffin peak pair.3.1.3 dead crude oil, na term usually employed for crudeoils that, when exposed to normal atmospheric pressure atroom temperature, will not result in actual boiling of thesample.1This test method is under the jurisdiction of ASTM Com
13、mittee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.04.0L on Gas Chromatography Methods.Current edition approved June 1, 2015. Published July 2015. DOI: 10.1520/D8003-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org
14、, 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 Standards Council of Canada (SCC), 60055 Metcalfe St.,Ottowa, ON K1P 6L5, http:/www.scc.ca.Copyright ASTM Interna
15、tional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.3.1 DiscussionThese crudes will have vapor pressuresbelow atmospheric pressure at room temperature.3.1.4 floating piston cylinder, na high pressure samplecontainer, with a free floating internal piston th
16、at effectivelydivides the container into two separate compartments, asdescribed in Practice D3700.3.1.5 live crude oil, ncrude oil with sufficiently high vaporpressure that it would boil if exposed to normal atmosphericpressure at room temperature.3.1.5.1 DiscussionSampling and handling of live crud
17、eoils requires a pressurized sample system and pressurizedsample containers to ensure sample integrity and prevent lossof volatile components.3.1.6 residue, nthe percent mass of the sample that eitherdoes not elute from the column or elutes after the end of thenC24peak.3.1.7 vapor pressure of crude
18、oil (VPCRx), nthe pressureexerted in an evacuated chamber at a vapor-liquid ratio of X:1by conditioned or unconditioned crude oil, which may containgas, air, or water, or a combination thereof, where X may varyfrom 4 to 0.02.4. Summary of Test Method4.1 This is a gas chromatographic method using a H
19、eatedPressurized Liquid Injection System (HPLIS) (trademarked)4,split/splitless inlet, capillary column, and flame ionizationdetector. A calibration mixture which fully elutes from thecapillary column, consisting of a full range of hydrocarbonsincluding methane, ethane, and normal paraffins up to C2
20、4isused to ensure system performance (Section 7). This calibra-tion mixture serves as an external response standard to deter-mine sample recovery. Samples are introduced to the GCsystem by loading the HPLIS valve under pressure followed bythe pneumatic piston action of the HPLIS injection systemintr
21、oducing the sample into the gas chromatographic injectionport.5. Significance and Use5.1 This test method determines methane (nC1) to hexane(nC6), cut point carbon fraction intervals to nC24and recovery(nC24+) of live crude oils and condensates withoutdepressurizing, thereby avoiding the loss of hig
22、hly volatilecomponents and maintaining sample integrity. This test methodprovides a highly resolved light end profile which can aid indetermining and improving appropriate safety measures andproduct custody transport procedures. Decisions in regards tomarketing, scheduling and processing of crude oi
23、ls may rely onlight end compositional results.5.2 Equation of state calculations can be applied to variablesprovided by this method to allow for additional samplecharacterization.6. Apparatus6.1 Gas ChromatographThe recommended conditions ofthe gas chromatograph are listed in Table 1. The gas chroma
24、to-graph shall be equipped with an electronic pressure control(EPC) or manual split/splitless inlet system. A 4-way 24 VDCsolenoid valve controlled from the gas chromatograph key-board for actuator air pressure control to accommodate theHPLIS is also required. Important features of instrumentcompone
25、nts are listed in section 6.2 to 6.4.6.2 Data SystemA data system capable of measuring theretention time and areas of eluting peaks accurately andrepeatedly as well as possess a data rate to achieve 10 points to20 points per peak.6.3 Flame Ionization Detector (FID)A FID system shallbe connected to t
26、he column to avoid any cold spots and havethe ability to operate at a temperature equivalent to themaximum column temperature used. The detector shall havesufficient sensitivity to detect n-heptane at a mass fraction of0.01 % with a signal-to-noise greater than 5.6.4 High Pressure Liquid Injection S
27、ystem (HPLIS)AHPLIS system that is compatible with a split/splitless inlet andcapable of linearly introducing C1to C24components shouldbe used. The unit should possess an internal dead volume of80 L in sample transfer zone and a 0.5 uL stem volume tocontain the pressurized liquid sample. The sample
28、pressurerating for the unit should be 8300 kPa (1200 psig) at 30 Cusing helium as the test media. Other injection systems may beemployed provided the performance criteria in Section 7 aremet.7. Column and Performance Criteria7.1 A 100 % polydimethylsiloxane (PDMS) phase columnof a 15 m length with a
29、n inside diameter of 0.28 mm and 3 mfilm thickness is recommended. The column shall possess4HPLIS (trademarked) has been found to be a suitable injector. The sole sourceof supply of the HPLIS known to the committee at this time is TranscendentEnterprises Inc., #33: 17715 - 96 Ave Edmonton, Alberta,
30、Canada, T5T 6W9,www.transcendent.ca. If you are aware of alternative suppliers, please provide thisinformation to ASTM International Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.TABLE 1 Gas Chromatograph Parame
31、tersInitial Oven Temperature 35 CInitial Oven Time 2 minOven Temperature Program 20 C/minFinal Oven Temperature 310 CFinal Hold Time 10 minHPLIS Collar Heater Temperature 200 CInlet Temperature 400 CColumn 15m0.28mm3mPDMSColumn Flow (Hydrogen) 2 mL/minCarrier Control Constant FlowDetector FIDDetecto
32、r Temperature 425 CDetector Gases:Hydrogen 40 mL/minAir 450 mL/minMake-Up (N2) 25 mL/minVolume Injected 0.5 LSplit Ratio 30:1Data Acquisition Rate 10 HzHPLIS Valve Timing On 0 minHPLIS Valve Timing Off 0.3 minTotal Acquisition Time 25.75 minD8003 152stability at 380 C. Metal columns have been succes
33、sfully usedfor this test method. The column should be installed accordingto Practice E1510. To prevent column overloading, the skew-ness is measured for nC6. The value shall not be less than 1 ormore than 4. Skewness is determined drawing a straight linedown the apex, as well as one across the lengt
34、h of the nC6peakat 5 % height. The width of the right section of the peak at 5 %height (B) is divided by that of the left section (A) (see Fig. 1).7.2 Baseline resolution for C1,C2,C3, isobutane and butaneshall be achieved (R 1.0). The resolution is calculated asfollows:R 5 2 3 t 2 2 t 1!1.699w 1 1
35、w 2! (1)where:t2 = retention time of peak 1,t1 = retention time of peak 2,w1 = peak width at half height for peak 1, andw2 = peak width at half height for peak 2.7.3 Splitter Linearity VerificationUsing the calibrationstandard (see 8.1.4), inject this sample according to theparameters listed in Tabl
36、e 1. Identify and quantify the normalparaffins C1to C24. Compare the calculated mass % concen-trations to the known standard concentrations after calculatingthe corrected area normalization using the response factorsfrom Table 2 procedures in Section 13. Verify that for eachcomponent selected, its c
37、oncentration does not vary by morethan 3 % relative error.percent relative error5100 3concentration determined 2 concentration known!concentration known(2)7.4 The sensitivity of the system shall be determined byanalyzing a 10 mg kg pentane standard (Practice D4307). Thesignal to noise ratio shall be
38、 greater than 5.8. Reagents and Materials8.1 Gas Chromatograph GasesThe purity of the volumefraction for all gases used in this system should be 99.995 %.8.1.1 Carrier GasHydrogen. Follow proper safety proce-dures. (WarningExtremely flammable under high pressure;use of a safety hydrogen sensor in GC
39、 oven containing thecolumn is highly recommended.)8.1.2 Detector GasesAir, hydrogen and make-up gas(helium or nitrogen) are used for Flame Ionization Detectoroperation (WarningCompressed gas under high pressure.Hydrogen is extremely flammable under high pressure.)8.1.3 Injection system washMethylene
40、 chloride, with apurity of 99 %, used to remove any residual components fromHPLIS sample injection. (WarningToxic material. May becombustible at high temperatures.) Toluene, with a purity of99 %, or other suitable solvents may be used as an alternativeto methylene chloride but caution shall be taken
41、 to eliminateresidual sample and solvent in the HPLIS sample lines.8.1.4 Calibration StandardThe calibration standard mayserve three purposes. A retention time calibration forn-paraffins covering the range of C1to nC24, the determinationof the detector response to enable the sample recovery calcu-la
42、tion and a linearity check sample. A hydrocarbon mixturesuch as a gasoline mid-distillate (diesel or jet fuel) containinga known amount of C1,C2,C3,nC5, and n-paraffins in therange of nC17through nC24is required. All n-paraffins presentup to nC24shall be identifiable. The calibration standard shallc
43、ompletely elute from the column by peak end of nC24underthe conditions of the method. A commercially prepared cali-bration standard or one prepared as described in the Appendixof this method has been found to be successful.9. Preparation of Apparatus9.1 Install the HPLIS system according to supplier
44、 proce-dures. The unit should have one of the sample chamber tubesconnected to an isolation (needle) valve to allow control andtermination of sample flow during the injectcycle. Attach116in. SS tubing to the remaining sample chamber tube. This willbe attached to the sample cylinder. Install the appr
45、opriatecolumn and check for leaks. Set the gas chromatograph to theconditions stated in Table 1.9.2 BaselineObtain a suitable blank baseline prior to anyanalysis or after any system change (Fig. A1.2). A blank runrequires actuation of the HPLIS without a sample injection. Itmay take several blanks t
46、o show a stable plateau at the highesttemperature of the oven with no indication of residual elutionor of carryover. It should also not contain any ghost peaks.Overlay the baseline signal with the sample signal as shown inFig. A1.2. Use only those sample signals that asymptoticallyFIG. 1 Calculation
47、 of Peak SkewnessD8003 153approach the baseline signals. Reject any sample run where thebaseline signal at the end of the run exceeds in value thesample run.10. Calibration10.1 Calibration and performance criteria (Section 7) shallbe performed whenever HPLIS valve or gas chromatographmaintenance is
48、performed.10.1.1 HPLIS valve maintenance includes seal replacement.10.1.2 Gas chromatograph maintenance includes columnreplacement, injection port or detector cleaning.10.1.3 Calibration shall include verification of total areareproducibility. The calibration standard (8.1.4) shall be run ata minimu
49、m interval of every five samples. All sample runsshall be bracketed by a preceding and following calibrationstandard run. The total area of the calibration runs shall notvary more than 63 % absolute from run to run. If it does notmeet this requirement ensure all hardware is operating properlyand all instrument settings are as stated above or recommendedby the manufacturer.10.1.4 Apply statistical quality control techniques (PracticeD6299) to the area percent of the calibration standard peaks C1,C2,C3,iC4,C4,nC20,nC21,nC22,nC2
