ASTM D5580-2015 Standard Test Method for Determination of Benzene Toluene Ethylbenzene p m-Xylene o-Xylene C9 and Heavier Aromatics and Total Aromatics in Finished Gasoline by Gas .pdf

1、Designation: D5580 13D5580 15Standard Test Method forDetermination of Benzene, Toluene, Ethylbenzene, p/m-Xylene, o-Xylene, C9 and Heavier Aromatics, and TotalAromatics in Finished Gasoline by Gas Chromatography1This standard is issued under the fixed designation D5580; the number immediately follow

2、ing the designation indicates the year oforiginal adoption 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

3、covers the determination of benzene, toluene, ethylbenzene, the xylenes, C9 and heavier aromatics, andtotal aromatics in finished motor gasoline by gas chromatography.1.2 The aromatic hydrocarbons are separated without interferences from other hydrocarbons in finished gasoline. Nonaromatichydrocarbo

4、ns having a boiling point greater than n-dodecane may cause interferences with the determination of the C9 and heavieraromatics. For the C8 aromatics, p-xylene and m-xylene co-elute while ethylbenzene and o-xylene are separated. The C9 andheavier aromatics are determined as a single group.1.3 This t

5、est method covers the following concentration ranges, in liquid volume %, for the preceding aromatics: benzene, 0.1to 5 %; toluene, 1 to 15 %; individual C8 aromatics, 0.5 to 10 %; total C9 and heavier aromatics, 5 to 30 %, and total aromatics,10 to 80 %.1.4 Results are reported to the nearest 0.01

6、% by either mass or by liquid volume.1.5 This test method includes a relative bias section for U.S. EPA spark-ignition engine fuel regulations reporting for benzenebased on Practice D6708 accuracy assessment between Test Method D5580 and Test Method D3606 as a possible Test MethodD5580 alternative t

7、o Test Method D3606. The Practice D6708 derived correlation equation is only applicable for fuels in thebenzene concentration range from 0.0 % to 2.31 % by volume as measured by Test Method D5580. The applicable Test MethodD3606 range for benzene is from 0.0 % to 2.38 % by volume as reported by Test

8、 Method D3606.1.6 This test method includes a relative bias section for U.S. EPA spark-ignition engine fuel regulations for total aromaticsreporting based on Practice D6708 accuracy assessment between Test Method D5580 and Test Method D5769 as a possible TestMethod D5580 alternative to Test Method D

9、5769. The Practice D6708 derived correlation equation(s) is only applicable for fuelsin the total aromatic concentration range from 5.4 % to 31.6 % by volume as measured by Test Method D5580 and a distillationtemperature T95, at which 95 % of the sample has evaporated, as measured by Test Method D86

10、 is in the range of 149.1 C to196.6 C (300.4 F to 385.9 F).1.6.1 The applicable Test Method D5769 range for total aromatics is from 3.7 % to 29.4 % by volume as reported by TestMethod D5769 and the distillation temperature T95, at which 95 % of the sample has evaporated, when tested according to Tes

11、tMethod D86 ranged from 149.1 C to 196.6 C (300.4 F to 385.9 F).1.7 Many of the common alcohols and ethers that are added to gasoline to reduce carbon monoxide emissions and increaseoctane, do not interfere with the analysis. Ethers such as methyl tert-butylether (MTBE), ethyl tert-butylether (ETBE)

12、,tert-amylmethylether (TAME), and diisopropylether (DIPE) have been found to elute from the precolumn with the nonaromatichydrocarbons to vent. Other oxygenates, including methanol and ethanol elute before benzene and the aromatic hydrocarbons.1-Methylcyclopentene has also been found to elute from t

13、he precolumn to vent and does not interfere with benzene.1 This test method 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 Sept. 15, 20

14、13Dec. 1, 2015. Published October 2013December 2015. Originally approved in 1994. Last previous edition approved in 20072013as D5580 02 (2007).D5580 13. DOI: 10.1520/D5580-13.10.1520/D5580-15.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indica

15、tion of what changes have 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 con

16、sidered the official document.*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 States11.8 The values stated in SI units are to be regarded as standard. The values given in paren

17、theses are for information only.1.8.1 ExceptionThe values given in parentheses are for information only.1.9 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

18、health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D86 Test Method for Distillation of Petroleum Products and Liquid Fuels at Atmospheric PressureD1298 Test Method for Density, Relative Density, or API Gravity of Crude Pe

19、troleum and Liquid Petroleum Products byHydrometer MethodD3606 Test Method for Determination of Benzene and Toluene in Finished Motor and Aviation Gasoline by Gas Chromatog-raphyD4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density MeterD4057 Practice for Man

20、ual Sampling of Petroleum and Petroleum ProductsD4307 Practice for Preparation of Liquid Blends for Use as Analytical StandardsD5769 Test Method for Determination of Benzene, Toluene, and Total Aromatics in Finished Gasolines by GasChromatography/Mass SpectrometryD6708 Practice for Statistical Asses

21、sment and Improvement of Expected Agreement Between Two Test Methods that Purportto Measure the Same Property of a MaterialE355 Practice for Gas Chromatography Terms and Relationships3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 aromaticany organic compound containing a benz

22、ene ring.3.1.2 low-volume connectora special union for connecting two lengths of narrow bore tubing 1.6-mm (0.06-in.)1.6 mm(0.06 in.) outside diameter and smaller; sometimes this is referred to as zero dead volume union.3.1.3 narrow bore tubingtubing used to transfer components prior to or after sep

23、aration; usually 0.5-mm (0.02-in.)0.5 mm(0.02 in.) inside diameter and smaller.3.1.4 split ratioin capillary gas chromatography, the ratio of the total flow of carrier gas to the sample inlet versus the flowof the carrier gas to the capillary column, expressed by:split ratio5S1C!/C (1)where:S = flow

24、 rate at the splitter vent andC = flow rate at the column outlet.3.1.5 1,2,3-tris-2-cyanoethoxypropane (TCEP)a polar gas chromatographic liquid phase.3.1.6 wall-coated open tubular (WCOT)a type of capillary column prepared by coating the inside wall of the capillary witha thin film of stationary pha

25、se.4. Summary of Test Method4.1 A two-column chromatographic system equipped with a column switching valve and a flame ionization detector is used. Areproducible volume of sample containing an appropriate internal standard such as 2-hexanone is injected onto a precolumncontaining a polar liquid phas

26、e (TCEP). The C9 and lighter nonaromatics are vented to the atmosphere as they elute from theprecolumn. A thermal conductivity detector may be used to monitor this separation. The TCEP precolumn is backflushedimmediately before the elution of benzene, and the remaining portion of the sample is direc

27、ted onto a second column containinga nonpolar liquid phase (WCOT). Benzene, toluene, and the internal standard elute in the order of their boiling points and aredetected by a flame ionization detector. Immediately after the elution of the internal standard, the flow through the nonpolar WCOTcolumn i

28、s reversed to backflush the remainder of the sample (C8 and heavier aromatics plus C10 and heavier nonaromatics) fromthe column to the flame ionization detector.4.2 The analysis is repeated a second time allowing the C12 and lighter nonaromatics, benzene and toluene to elute from thepolar TCEP preco

29、lumn to vent. A thermal conductivity detector may be used to monitor this separation. The TCEP precolumn isbackflushed immediately prior to the elution of ethylbenzene and the remaining aromatic portion is directed into the WCOT2 For referencedASTM standards, visit theASTM website, www.astm.org, or

30、contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.D5580 152column. The internal standard and C8 aromatic components elute in the order of their boiling points and are detected by a fl

31、ameionization detector. Immediately after o-xylene has eluted, the flow through the nonpolar WCOT column is reversed to backflushthe C9 and heavier aromatics to the flame ionization detector.4.3 From the first analysis, the peak areas of benzene, toluene, and the internal standard (2-hexanone) are m

32、easured andrecorded. Peak areas for ethylbenzene, p/m-xylene, o-xylene, the C9 and heavier aromatics, and internal standard are measured andrecorded from the second analysis. The backflush peak eluting from the WCOT column in the second analysis contains only C9and heavier aromatics.4.4 The flame io

33、nization detector response, proportional to the concentration of each component, is used to calculate the amountof aromatics that are present with reference to the internal standard.5. Significance and Use5.1 Regulations limiting the concentration of benzene and the total aromatic content of finishe

34、d gasoline have been establishedfor 1995 and beyond in order to reduce the ozone reactivity and toxicity of automotive evaporative and exhaust emissions. Testmethods to determine benzene and the aromatic content of gasoline are necessary to assess product quality and to meet new fuelregulations.5.2

35、This test method can be used for gasolines that contain oxygenates (alcohols and ethers) as additives. It has been determinedthat the common oxygenates found in finished gasoline do not interfere with the analysis of benzene and other aromatics by thistest method.6. Apparatus6.1 Chromatographic Syst

36、emSee Practice E355 for specific designations and definitions. Refer to Fig. 1 for a diagram of thesystem.6.1.1 Gas Chromatograph (GC), capable of operating at the conditions given in Table 1, and having a column switching andbackflushing system equivalent to Fig. 1. Carrier gas pressure and flow co

37、ntrol devices shall be capable of precise control whencolumn head pressures and flow rates are low.6.1.2 Sample Introduction System, capable of introducing a representative sample into the gas chromatographic inlet. Microlitresyringes and automatic syringe injectors have been used successfully.6.1.3

38、 Inlet System, (splitting type)Split injection is necessary to maintain the actual chromatographed sample size within thelimits required for optimum column efficiency and detector linearity.6.1.3.1 Some gas chromatographs are equipped with on-column injectors and autosamplers which can inject submic

39、rolitresample sizes. Such systems can be used provided that column efficiency and detector linearity are comparable to systems with splitinjection.6.1.4 DetectorA flame ionization detector (Detector A) is employed for quantitation of components eluting from the WCOTcolumn. The flame ionization detec

40、tor used for Detector A shall have sufficient sensitivity and stability to detect 0.01 volume %of an aromatic compound.6.1.4.1 It is strongly recommended that a thermal conductivity detector be placed on the vent of the TCEP precolumn (DetectorB). This facilitates the determination of valve BACKFLUS

41、H and RESET times (10.5) and is useful for monitoring the separationof the polar TCEP precolumn.6.1.5 Switching and Backflushing Valve, to be located within a temperature-controlled heated zone and capable of performingthe functions in accordance with Section 10, and illustrated in Fig. 1. The valve

42、 shall be of low internalvolume design and notcontribute significantly to deterioration of chromatographic resolution.FIG. 1 Valve Diagram, Aromatics in GasolineD5580 1536.1.5.1 A 10-port valve with 1.6-mm1.6 mm (0.06) outside diameter fittings is recommended for this test method.Alternately,Alterna

43、tively, and if using columns of 0.32-mm0.32 mm inside diameter or smaller, a valve with 0.8-mm(0.03-in.)0.8 mm (0.03 in.) outside diameter fittings should be used.6.1.5.2 Some gas chromatographs are equipped with an auxiliary oven which can be used to contain the valve. In such aconfiguration, the v

44、alve can be kept at a higher temperature than the polar and nonpolar columns to prevent sample condensationand peak broadening. The columns are then located in the main oven and the temperature can be adjusted for optimum aromaticresolution.6.1.5.3 An automatic valve switching device is strongly rec

45、ommended to ensure repeatable switching times.6.2 Data Acquisition System:6.2.1 Integrator or Computer, capable of providing real-time graphic and digital presentation of the chromatographic data arerecommended for use. Peak areas and retention times can be measured by computer or electronic integra

46、tion.6.2.1.1 It is recommended that this device be capable of performing multilevel internal-standard-type calibrations and be ableto calculate the correlation coefficient (r2) and linear least square fit equation for each calibration data set in accordance with 11.4.6.3 Chromatographic Columns (two

47、 columns are used):6.3.1 Polar Precolumn, to perform a pre-separation of the aromatics from nonaromatic hydrocarbons in the same boiling pointrange. Any column with equivalent or better chromatographic efficiency and selectivity in accordance with 6.3.1.1 can be used.6.3.1.1 TCEP Micro-Packed Column

48、, 560-mm (22-in.)560 mm (22 in.) by 1.6-mm1.6 mm (116-in.) in.) outside diameter by0.76-mm (0.030-in.)0.76 mm (0.030 in.) inside diameter stainless steel tube packed with 0.140.14 g to 0.15 g 0.15 g of 20 %(mass/mass) TCEP on 80/100 mesh Chromosorb P(AW). This column was used in the cooperative stud

49、y to provide the precisionand bias data referred to in Section 15.6.3.2 Nonpolar (Analytical) ColumnAny column with equivalent or better chromatographic efficiency and selectivity inaccordance with 6.3.2.1 can be used.6.3.2.1 WCOT Methyl Silicone Column, 30 m 30 m long by 0.53-mm0.53 mm inside diameter fused silica WCOT column witha 5.0-m5.0 m film thickness of cross-linked methyl siloxane.TABLE 1 Typical Chromatographic Operating Parameters 130TemperaturesInjection port (split injector) 200CInjection port (split injector) 200 CFID (Detector A) 250CFI