1、Designation: D5599 15D5599 17Standard Test Method forDetermination of Oxygenates in Gasoline by GasChromatography and Oxygen Selective Flame IonizationDetection1This standard is issued under the fixed designation D5599; the number immediately following the designation indicates the year oforiginal a
2、doption 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 a gas chromatographic procedure for the quan
3、titative determination of organic oxygenatedcompounds in gasoline having a final boiling point not greater than 220 C and oxygenates having a boiling point limit of 130 C.It is applicable when oxygenates are present in the 0.1 % to 20 % by mass range.1.2 This test method is intended to determine the
4、 mass concentration of each oxygenate compound present in a gasoline. Thisrequires knowledge of the identity of each oxygenate being determined (for calibration purposes). However, the oxygen-selectivedetector used in this test method exhibits a response that is proportional to the mass of oxygen. I
5、t is, therefore, possible to determinethe mass concentration of oxygen contributed by any oxygenate compound in the sample, whether or not it is identified. Totaloxygen content in a gasoline may be determined from the summation of the accurately determined individual oxygenatedcompounds. The summed
6、area of other, uncalibrated or unknown oxygenated compounds present, may be converted to a massconcentration of oxygen and summed with the oxygen concentration of the known oxygenated compounds.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are includ
7、ed in this standard.1.4 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 regulatorylimitations prior to u
8、se.1.5 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to
9、 Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1298 Test Method for Density, Relative Density, or API Gravity of Crude Petroleum and Liquid Petroleum Products byHydrometer MethodD1744 Test Method for Determination of Water in Liquid Petroleum Products by Karl Fischer Reagent (Wit
10、hdrawn 2016)3D4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density MeterD4175 Terminology Relating to Petroleum Products, Liquid Fuels, and LubricantsD4307 Practice for Preparation of Liquid Blends for Use as Analytical StandardsE594 Practice for Testing Flam
11、e Ionization Detectors Used in Gas or Supercritical Fluid ChromatographyE1064 Test Method for Water in Organic Liquids by Coulometric Karl Fischer TitrationE1510 Practice for Installing Fused Silica Open Tubular Capillary Columns in Gas Chromatographs3. Terminology3.1 Definitions:1 This test method
12、is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.04.0L on Gas Chromatography Methods.Current edition approved June 1, 2015May 1, 2017. Published July 2015June 2017. Originally approved in 1994. Last
13、 previous edition approved in 20102015 asD5599 00 (2010).D5599 15. DOI: 10.1520/D5599-15.10.1520/D5599-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standar
14、ds Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version.
15、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 document.*A Summary of Changes section a
16、ppears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.1 independent reference standardsstandards, ncalibration samples of the oxygenates which are purchased or preparedfrom materials independent of the
17、quality control check standards and used for intralaboratory accuracy.3.1.2 oxygenate, nan oxygen-containing compound, such as an alcohol or ether, which may be used as a fuel or fuelsupplement.3.1.3 quality control check standardsstandards, ncalibration samples of the oxygenates for intralaboratory
18、 repeatability.4. Summary of Test Method4.1 An internal standard of a noninterfering oxygenate, for example, 1,2-dimethoxyethane (ethylene glycol dimethyl ether) isadded in quantitative proportion to the gasoline sample.Arepresentative aliquot of the sample and internal standard is injected intoa ga
19、s chromatograph equipped with a capillary column operated to ensure separation of the oxygenates. Hydrocarbons andoxygenates are eluted from the column, but only oxygenates are detected with the oxygen-selective flame ionization detector(OFID). A discussion of this detector is presented in Section 6
20、.4.2 Calibration mixtures are used for determining the retention times and relative mass response factors of the oxygenates ofinterest. Suggested calibrant materials are listed in 8.2.4.3 The peak area of each oxygenate in the gasoline is measured relative to the peak area of the internal standard.
21、A quadraticleast-squares fit of the calibrated data of each oxygenate is applied and the concentration of each oxygenate calculated.NOTE 1While 1,2-dimethoxyethane has been found to be an appropriate internal standard, other oxygenates may be used provided they are not presentin the sample and do no
22、t interfere with any compound of interest.5. Significance and Use5.1 In gasoline blending, the determination of organic oxygenated compounds is important. Alcohols, ethers, and otheroxygenates are added to gasoline to increase the octane number and to reduce tailpipe emissions of carbon monoxide. Th
23、ey mustbe added in the proper concentration and ratios to meet regulatory limitations and to avoid phase separation and problems withengine performance or efficiency.5.2 This test method provides sufficient oxygen-to-hydro-carbon selectivity and sensitivity to allow determination of oxygenatesin gas
24、oline samples without interference from the bulk hydrocarbon matrix.6. Theory of OFID Operation6.1 The detection system selective for organic oxygen consists of a cracking reactor, hydrogenating reactor (methanizer), anda flame ionization detector (FID). The cracking reactor, connected immediately a
25、fter the gas chromatographic capillary column,consists of a Pt/Rh capillary tube. Carbon monoxide (CO) is formed from compounds containing oxygen according to thefollowing reaction:CxHyOzzCO1y/2!H 21x2z!C (1)6.2 An excess layer of carbon is created in the Pt/Rh tube of the cracking reactor from the
26、introduction of hydrocarbons fromthe sample or, if so designed, from a hydrocarbon (for example, pentane or hexane) doping system, or both. This layer of carbonfacilitates the cracking reaction and suppresses hydrocarbon response.6.3 The carbon monoxide formed in the cracking reactor is converted to
27、 methane in the hydrogenating reactor according to thefollowing reaction:CO13H 2CH41H2O (2)The CH4 is subsequently detected with an FID.6.4 The methanizer consists either of a short porous layer open tubular (PLOT) glass capillary tube internally coated withaluminum oxide with adsorbed nickel cataly
28、st or stainless steel tubing containing a nickel-based catalyst. It is installed within orbefore the FID and is operated in the range from 350 C to 450 C, depending on the instruments manufacturer.NOTE 2Gasolines with high sulfur content may cause a loss in detector sensitivity thereby limiting the
29、number of samples that can be analyzed beforethe catalyst needs replacement.7. Apparatus7.1 Gas ChromatographAny gas chromatograph can be used having the following performance characteristics:7.1.1 Column Temperature ProgrammerThe chromatograph must be capable of reproducible linear temperature prog
30、rammingover a range sufficient for separation of the components of interest.7.1.2 Sample Introduction SystemAny system capable of introducing a representative 0.1 L to 1.0 L liquid sample into thesplit inlet device of the gas chromatograph. Microlitre syringes, autosamplers, and liquid sampling valv
31、es have been usedsuccessfully. The split injector should be capable of accurate split control in the range from 10:1 to 500:1.7.1.3 Carrier and Detector Gas ControlConstant flow control of carrier and detector gases is critical to optimum andconsistent analytical performance. Control is best provide
32、d by the use of pressure regulators and fixed flow restrictors.The gas flowD5599 172rates are measured by any appropriate means. The supply pressure of the gas delivered to the gas chromatograph must be at least70 kPa (10 psig) greater than the regulated gas at the instrument to compensate for the s
33、ystem back pressure. In general, a supplypressure of 550 kPa (80 psig) will be satisfactory.7.2 OFID Detector System, consisting of a cracking reactor, methanizer, and FID. A schematic of a typical OFID system isshown in Fig. 1.7.2.1 The detector must meet or exceed the typical specifications given
34、in Table 1 of Practice E594 while operating in thenormal FID mode as specified by the manufacturer.7.2.2 In the OFID mode, the detector shall meet or exceed the following specifications: (a) equal to or greater than 103 linearity,(b) less than 100 ppm mass oxygen (1 ng Os) sensitivity, (c) greater t
35、han 106 selectivity for oxygen compounds overhydrocarbons, (d) no interference from coeluting compounds when 0.1 L to 1.0 L sample is injected, (e) equimolar response foroxygen.7.3 ColumnA 60 m by 0.25 mm inside diameter fused silica open tubular column containing a 1.0 m film thickness ofbonded met
36、hyl silicone liquid phase is used. Equivalent columns which provide separation of all oxygenates of interest may beused.7.4 IntegratorUse of an electronic integrating device or computer is required. The device and software should have thefollowing capabilities:7.4.1 Graphic presentation of the chrom
37、atogram,7.4.2 Digital display of chromatographic peak areas,7.4.3 Identification of peaks by retention time,7.4.4 Calculation and use of response factors, and7.4.5 Internal standard calculation and data presentation.8. Reagents and Materials8.1 Purity of ReagentsReagents grade chemicals shall be use
38、d in all tests. Unless otherwise indicated, it is intended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, wheresuch specifications are available.4 Other grades may be used, provided it is first ascertained that the reage
39、nt is of sufficiently highpurity to permit its use without lessening the accuracy of the determination.8.2 Calibrant MaterialsThe following compounds may be used for calibrating the detector: methanol, ethanol, n-propanol,iso-propanol, n-butanol, tert-butanol, sec-butanol, iso-butanol, tert-pentanol
40、, methyl tert-butylether (MTBE), tert-amylmethylether(TAME), ethyl tert-butylether (ETBE), di-iso-propylether (DIPE). (WarningThese materials are very flammable and may beharmful or fatal when ingested, inhaled, or allowed to be absorbed through the skin.)8.3 Internal StandardUse one of the compound
41、s listed in 8.2 that is not present in the sample. If all of the materials in 8.2are likely to be present in the test sample, use another organic oxygenate of high-grade purity that is separated from all otheroxygenates present (for example, 1,2-dimethoxyethane).4 Reagent Chemicals, American Chemica
42、l Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pha
43、rmacopeial Convention, Inc. (USPC), Rockville, MD.FIG. 1 Schematic of an OFIDD5599 1738.4 DopantIf the OFID is so designed, reagent-grade pentane is used as a hydrocarbon dopant for the cracking reactor.(WarningPentane is extremely flammable and harmful when inhaled.)8.5 Instrument GasesThe gases su
44、pplied to the gas chromatograph and detector are:8.5.1 Air, zero grade. (WarningCompressed air is a gas under high pressure and supports combustion.)8.5.2 Hydrogen, pure grade, 99.9 % mol minimum purity. (WarningHydrogen is an extremely flammable gas under highpressure.)8.5.3 Helium or nitrogen as c
45、olumn carrier gas, 99.995 % mol minimum purity, or a blend of 95 % helium/5 % hydrogen,depending on the instruments manufacturer. (WarningHelium and nitrogen are compressed gases under high pressure.)8.5.4 Additional purification of the carrier, air, and hydrogen is recommended. Use molecular sieves
46、, Drierite, charcoal, or othersuitable agents to remove water, oxygen, and hydrocarbons from the gases.8.6 Sample ContainerGlass vials with crimp-on or screw-down sealing caps with self-sealing polytetrafluoroethylene(PTFE)-faced rubber membranes are used to prepare calibration standards and samples
47、 for analysis.9. Preparation of Apparatus9.1 Chromatograph and OFIDPlace instrument and detector into operation in accordance with the manufacturersinstructions. Install the capillary column according to Practice E1510. Adjust the operating conditions to provide for separation ofall oxygenates of in
48、terest. Typical conditions used with the column specified in 7.3 are listed in Table 1.9.2 System PerformanceAt the beginning of each day of operation, inject an oxygenate-free gasoline sample into thechromatograph to ensure minimum hydrocarbon response. If hydrocarbon response is detected, the OFID
49、 is not operatingeffectively and must be optimized according to the manufacturers instructions before the sample can be analyzed.10. Calibration and Standardization10.1 Retention Time IdentificationDetermine the retention time of each oxygenate component by injecting small amountseither separately or in known mixtures. Table 2 gives typical retention times for the oxygenates eluting from a 60 m methyl siliconecolumn temperature programmed according to conditions given in Table 1. A chromatogram of a blend of oxygenates is given inFi
