1、Designation: D8098 17Standard Test Method forPermanent Gases in C2and C3Hydrocarbon Products byGas Chromatography and Pulse Discharge HeliumIonization Detector1This standard is issued under the fixed designation D8098; 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 hydrogen,nitrogen, oxygen
3、, methane, carbon monoxide, and carbondioxide in the parts per billion mole (nmol/mol) to parts permillion mole (mol/mol) range in C2and C3hydrocarbons.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 n
4、ot 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 some specifichazard statements, se
5、e Annex A1.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization Technical
6、Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D2505 Test Method for Ethylene, Other Hydrocarbons, andCarbon Dioxide in High-Purity Ethylene by Gas Chroma-tographyD4175 Terminology Relating to Petroleum Products, LiquidFuels, and LubricantsD6300 Practice for Determinati
7、on of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsD7915 Practice for Application of Generalized ExtremeStudentized Deviate (GESD) Technique to Simultane-ously Identify Multiple Outliers in a Data SetE260 Practice for Packed Column Gas ChromatographyF307 Practic
8、e for Sampling Pressurized Gas for Gas Analy-sis2.2 Other Standards:3G-4 and G-4.1, Compressed Gas Association Booklet on theUse of Oxygen3. Terminology3.1 For definitions of terms used in this standard, seeTerminology D4175.4. Summary of Test Method4.1 The sample is separated in a gas chromatograph
9、icsystem using gas chromatography columns. Hydrogen,oxygen, nitrogen, methane, carbon monoxide, and carbondioxide (also known as the permanent gases) are detected on apulse discharge detector. The concentration of the gases to bedetermined is calculated from the peak areas relative to anexternal sta
10、ndard. Helium is the required carrier gas for thisdetector. Ultra-high purity carrier gases and leak-free gaschromatography (GC) systems with getters are essential due tothe extreme sensitivity of the detector. Argon, if present in thesample, may interfere with oxygen determination.5. Significance a
11、nd Use5.1 The presence of trace amounts of hydrogen, oxygen,carbon monoxide, and carbon dioxide can have deleteriouseffects in certain processes using hydrocarbon products as feedstock. This test method is suitable for setting specifications, foruse as an internal quality control tool, and for use i
12、n develop-ment and research work.6. Apparatus6.1 ChromatographAny gas chromatograph capable ofmaintaining the temperatures, pressures, and flows necessary1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibil
13、ity ofSubcommittee D02.D0.02 on Ethylene.Current edition approved July 15, 2017. Published September 2017. DOI:10.1520/D8098-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informatio
14、n, refer to this standards Document Summary page onthe ASTM website.3Available from Compressed Gas Association (CGA), 14501 George CarterWay, Suite 103, Chantilly, VA 20151, http:/.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis i
15、nternational standard was developed in 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)
16、 Committee.1for this analyses. The GC should also be capable of tempera-ture programming of the oven to obtain optimum separation ofthe components. A typical configuration is shown in Fig. 1.6.2 Detectors(PDHID Pulse Discharge Detector HeliumIonization)The PDHID detector is very sensitive to mostorg
17、anic or inorganic chemicals, thus requiring separation of theproduct gases from the permanent gas components.6.2.1 Alternative DetectorsThis test method is written forthe pulsed discharge helium detector (PDHID), but otherdetectors can be used provided they have sufficient sensitivity,respond to all
18、 of the species in the scope, do not suffer frominterferences, and satisfy quality assurance criteria. Regulatoryagencies may require demonstration of equivalency of alterna-tive detection systems to the PDHID.6.3 Gas Sample ValveAny valve that allows for columnand/or sample inlet system selection.
19、This valve may be purgedwith helium to minimize atmospheric air contamination intothe valve rotor and column system.6.4 Helium PurifierUltra-high purity carrier gas with aninline helium purifier installed to remove impurities is recom-mended. The purifier should be able produce gas with outletimpuri
20、ties less than 10 nmol/mol of H2O, H2,O2,N2, NO,NH3, CO, and CO2, based on 100 mol/mol total inletimpurities. A leak-free GC system is essential due to the highsensitivity of the detector.6.5 Constant-volume Gas Sampling ValveAny gas sam-pling valve capable of delivering a consistent volume of gas.6
21、.5.1 Liquefied Petroleum Gas SamplesSamples shouldbe vaporized to allow introduction to the constant-volume gassampling valve. The vaporization technique used must bevalidated to ensure that sample discrimination is avoided.Pressure sampling devices may be used to inject a smallamount of the liquid
22、directly into the carrier gas.6.6 Materials of ConstructionThe sample inlet systemshall be constructed of materials that are inert and non-adsorptive with respect to the components in the sample. Thepreferred material of construction is stainless steel. Copper,brass, and other copper-bearing alloys
23、are unacceptable. Theanalysis of oxygen and carbon monoxide may benefit from theuse of treated metal surfaces.6.7 ColumnAny column may be used provided it willresolve the trace compound peaks present in concentrations of20 ppmv or more so that the resolution ratio, A/B, will not beless than 0.4, whe
24、re A is the depth of the valley on either sideof peak B and B is the height above the baseline of the smallerof any two adjacent peaks (see Fig. 2). For compounds presentin concentrations of less than 20 ppm, the ratio A/B may be lessthan 0.4. In the case where the small-component peak isadjacent to
25、 a large one, it may be necessary to construct thebaseline of the small peak tangent to the curve as shown in Fig.3.6.7.1 Columns used to obtain the results in Fig. 4 usinginstrument conditions in Table 1:6.7.1.1 Column 1, Porous divinylbenzene homopolymer,30 m 0.53 mm6m.6.7.1.2 Column 2, Porous div
26、inylbenzene homopolymer,30 m 0.53 mm6m.6.7.1.3 Column 3, Molecular sieve, 30 m 0.53 mm 25 m.6.7.1.4 Restrictor, Fused silica open tube, 0.60m5m,restrictor should be sized as such to provide the same restric-tion as the molecular sieve column as to balance the flowacross the six port bypass valve.6.8
27、 Data SystemAny analytical data system that is capableof storing the retention time, integrating peak areas, andnaming peaks is acceptable.7. Reagents and Materials7.1 Gases for CalibrationPure or research-gradehydrogen, oxygen, nitrogen, carbon monoxide, and carbondioxide will be needed to prepare
28、synthetic standard samples asFIG. 1 Typical GC ConfigurationD8098 172described in Test Method D2505.(WarningFlammablegases. Hazardous pressure. See A1.1 through A1.5.)(WarningFlammable. Poison. Harmful if inhaled. Danger-ous when exposed to flame. See A1.5.) (WarningHazardouspressure. See A1.2.) Cer
29、tified calibration blends are commer-cially available from numerous sources and can be used as thesynthetic standard samples.7.2 Carrier GasesHelium, ultra-high purity (99.999 %pure, also known as 5.0 grade).NOTE 1Practice E260 contains information that will be helpful tothose using this test method
30、.8. Sampling8.1 Samples shall be supplied to the laboratory in high-pressure sample cylinders, obtained using the proceduresdescribed in Practice F307 or similar methods. All cylindersshould meet all applicable safety requirements.8.2 Sample system purging may require the use of anautomated sampling
31、 system which provides for suitable samplesystem purge to eliminate atmospheric air contamination.Non-reproducible oxygen and nitrogen results relative tomethane (refer to Table 1) indicate air contamination.9. Calibration9.1 Bring the equipment and columns to equilibrium andmaintain a constant carr
32、ier gas rate and temperature.9.2 Inject a known volume of the standard blends (preparedor purchased).NOTE 2The use of stripper columns, valves, and reverse-flow arrange-ment will facilitate removal of heavier gases and decrease the elapsed timeof analysis.9.3 Identify all of the desired peaks from t
33、he preparedsynthetic blend. Multiple levels of blends can be used forgeneration of calibration tables.9.4 The recommended method of measuring peak areas iselectronic integration with capabilities of changing integrationparameters. For each component present in the calibrationstandard, calculate the
34、response factor according to Eq 1.RFi 5 CiAi (1)where:RFi = the response factor for component i,Ci = the known concentration of i, andAi = the integrated area of peak i.9.5 A data system may be used to automate these calcula-tions and to plot peak areas versus concentrations of eachcompound in parts
35、 per million, by mole (mol/mol).10. Procedure10.1 Connect the sample cylinder containing a gaseoussample to the gas sample valve inlet. Sample inlet system shallbe purged thoroughly to eliminate ambient air. Either manualor automated purging may be used and shall be determined tobe reliable when the
36、 lowest calibration standard containingoxygen and nitrogen are repeatable to less than 2 % relativestandard deviation and the concentration is not decreasing fromfive successive injections.10.2 Close the cylinder valve and allow the pressure of thesample in the tube to stabilize.10.3 Inject the samp
37、le into the instrument using the gassampling valve. The same valve should be used for calibrationstandard and sample (pressure of sample and calibration gasmust be the same in the sample loop at injection time).11. Calculation11.1 The data system will automatically record the peakretention times and
38、 areas of the desired components. Thedetector response varies with the component being detected (donot assume equal response).11.2 Using the area of the compound in the sample the datasystem will determine the concentration in mol/mol of thecompound from the calibration table.Atypical characterizati
39、onshowing hydrogen, oxygen, nitrogen, methane, carbonmonoxide, and carbon dioxide in ethylene is presented in Fig.4.12. Precision and Bias12.1 The precision of this test method is based on anintralaboratory study of Test Method D8098, conducted in2017.Asingle laboratory participated in this study, t
40、esting fourconcentration levels of two gas mixtures. Every “test result”represents an individual determination. The laboratory reported16 replicate test results for each compound analyzed. PracticeFIG. 2 Illustration of A/B RatioFIG. 3 Illustration of A/B Ratio for Small-component PeakD8098 173D6300
41、 was followed for the design and analysis of this interimrepeatability study; the details are given in ASTM ResearchReport No. RR:D02-1866.412.1.1 Repeatability (r)The difference between repetitiveresults obtained by the same operator in a given laboratoryapplying this same test method with the same
42、 apparatus underconstant operating conditions on identical test material withinshort intervals of time would, in the long run, in the normal andcorrect operation of this test method, exceed the followingvalues only in one case in 20.12.1.1.1 Repeatability can be interpreted as maximum dif-ference be
43、tween two results, obtained under repeatabilityconditions, that is accepted as plausible due to random causesunder normal and correct operation of this test method.12.1.1.2 Repeatability limits are listed in Table 2 and Table3. The data listed in Table 2 and Table 3 are based on 16separate results f
44、or each compound.12.1.2 It is not feasible to provide a complete precisionstatement covering repeatability and reproducibility for thistest method at this time since test results from differentlaboratories and test samples meeting the required ASTMprotocol are not available. This information is bein
45、g deter-mined and will be available on or before May 31, 2022.4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D02-1866. ContactASTM CustomerService at serviceastm.org.FIG. 4 Typical Chromatogram for Hydrogen, Oxygen, Nitrogen, M
46、ethane, Carbon Monoxide, and Carbon DioxideTABLE 1 Instrument ConditionsTemperaturesValve Box 100 CColumn 50 C (hold 5 min), ramp 20 C/min to 85 C (hold 1 min)PDHID 200 CFlowsColumn 1, 2, 3 15 mL/minValve TimingValve 1 (10 port) On 0.01 min, Off 2.00 minValve2(6port) On3.20min,Off3.80minD8098 174TAB
47、LE 2 Concentration of Various Compounds in Ethylene (ppm)CompoundCertifiedConcentrationAverageXVariancevRepeatabilityStandardDeviationSrRepeatabilityLimitrRSD%AverageRecovery%Number ofOutliersRejected perD7915CO21 0.774 0.0007 0.0273 0.0764 3.53 77.4 011.4 12.959 0.0029 0.0521 0.1459 0.40 113.7 026.
48、5 25.990 0.0011 0.0331 0.0927 0.13 98.1 044 45.185 0.0319 0.1785 0.4998 0.40 102.7 0H21.1 0.860 0.0004 0.0194 0.0543 2.26 78.2 010.8 8.702 0.0056 0.0740 0.2072 0.85 80.6 026.2 20.467 0.0092 0.0961 0.2691 0.47 78.1 044 46.694 0.6109 0.7816 2.1885 1.67 106.1 0O26 3.642 0.0058 0.0760 0.2128 2.09 60.7 0
49、14.6 12.999 0.0188 0.1325 0.3710 1.02 89.0 029.1 28.974 0.0306 0.1748 0.4894 0.60 99.6 053.7 54.833 0.3519 0.5932 1.6610 1.08 102.1 0N217.8 28.376 0.1482 0.3849 1.0777 1.36 159.4 025.4 31.097 0.2781 0.5273 1.4764 1.70 122.4 044.6 50.296 0.2781 0.5273 1.4764 1.05 112.8 068.7 79.767 1.5678 1.2521 3.5059 1.57 116.1 0CH41 0.982 0.0004 0.0192 0.0538 1.96 98.2 011.1 10.575 0.0026 0.0503 0.1408 0.48 95.3 026.5 24.136 0.0018 0.0429 0.1201 0.18 91.1 044.4 42.704 0.0015 0.0384 0.1075 0.09 96.2 2CO 1 0.857 0.0003 0.0046 0.0129
