1、Designation: D 3606 07An American National StandardStandard Test Method forDetermination of Benzene and Toluene in Finished Motorand Aviation Gasoline by Gas Chromatography1This standard is issued under the fixed designation D 3606; the number immediately following the designation indicates the year
2、 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of benzenean
3、d toluene in finished motor and aviation gasolines by gaschromatography.1.2 Benzene can be determined between the levels of 0.1and 5 volume % and toluene can be determined between thelevels of 2 and 20 volume %.1.3 The precision for this test method was determined usingconventional gasoline as well
4、as gasolines containing oxygen-ates (ethers such as methyl tert-butyl ether, ethyl tert-butylether and tert-amyl methyl ether).1.4 Methanol may cause interference. Appendix X1 pro-vides an option for modifying the test method for analyzingsamples containing ethanol.1.5 The values stated in SI units
5、are to be regarded as thestandard. The values given in parentheses are for informationonly.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 practi
6、ces and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsE 694 Specification for Laboratory Glass Volumetric Appa-ratusE 969 Specification for Glass Volumetric (Transfe
7、r) PipetsE 1044 Specification for Glass Serological Pipets (GeneralPurpose and Kahn)E 1293 Specification for Glass Measuring Pipets3. Summary of Test Method3.1 An internal standard, methyl ethyl ketone (MEK), isadded to the sample which is then introduced into a gaschromatograph equipped with two co
8、lumns connected inseries. The sample passes first through a column packed with anonpolar phase such as dimethylpolysiloxane (8.1.1) whichseparates the components according to boiling point. Afteroctane has eluted, the flow through the nonpolar column isreversed, flushing out the components heavier t
9、han octane. Theoctane and lighter components then pass through a columnpacked with a highly polar phase such as 1,2,3-tris(2-cyanoethoxy) propane (8.1.2) which separates the aromatic andnonaromatic compounds. The eluted components are detectedby a thermal conductivity detector. The detector response
10、 isrecorded, the peak areas are measured, and the concentration ofeach component is calculated with reference to the internalstandard.4. Significance and Use4.1 Benzene is classed as a toxic material. A knowledge ofthe concentration of this compound can be an aid in evaluatingthe possible health haz
11、ard to persons handling and using thegasoline. This test method is not intended to evaluate suchhazards.5. Apparatus5.1 ChromatographAny chromatographic instrument thathas a backflush system and thermal conductivity detector, andthat can be operated at the conditions given in Table 1, can beemployed
12、. Two backflush systems are shown. Fig. 1 is apressure system and Fig. 2 is a switching valve system. Eitherone can be used.5.2 Columns:1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.04.0L on G
13、as Chromatography Methods.Current edition approved Nov. 1, 2007. Published January 2008. Originallyapproved in 1977. Last previous edition approved in 2006 as D 360606e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annu
14、al Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Copyright
15、by ASTM Intl (all rights reserved); Wed Mar 12 02:49:04 EST 2008Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.5.2.1 Column AOne 0.8-m (2.5-ft) by 3.2-mm (18-in.)outside diameter stainless steel column packed with 10 mass %dimethylpolysiloxan
16、e (for example, OV-101) on ChromosorbW, 60 to 80 mesh.5.2.2 Column BOne 4.6-m (15-ft) by 3.2-mm outsidediameter stainless steel column packed with 20 mass % TCEPon Chromosorb P, 80 to 100 mesh.5.3 Recorder, a strip chart recorder. An electronic integrat-ing device or a computer capable of graphical
17、presentation ofthe chromatogram. The electronic integrating device or com-puter must be capable of measuring 0.1 volume % MEK withsatisfactory signal-to-noise. If a strip chart recorder is to beused, a 0 to 1mV range recording potentiometer with aresponse time of 2 s or less and a maximum noise leve
18、l of 60.3% of full scale is recommended. The detector strip chartrecorder combination must produce a 4mm deflection for a2L sample containing 0.1 volume % MEK when operated atmaximum sensitivity.5.4 Microsyringe, 5-L capacity.5.5 Volumetric Pipets, Class A, 0.5, 1, 5, 10, 15, and 20-mLcapacities (se
19、e Specification E 694 and E 969).5.6 Measuring Pipets, 1 and 2mL capacities calibrated in0.01 mL; 5mL calibrated in 0.1mL, for use in dispensingvolumes of benzene and toluene not covered by the volumetricpipets (see Specification E 1044 and E 1293) during prepara-tion of standard samples (see 11.1).
20、NOTE 1Other volume dispensing equipment capable of delivering thespecified volumes within the stated tolerance limits may be used as analternative to the requirements stated in 5.5 and 5.6.5.7 Flasks, volumetric, 25 and 100-mL capacity.5.8 Vibrator, electric.5.9 Vacuum Source.5.10 Evaporator, vacuum
21、, rotary.5.11 Flask, boiling, round-bottom, short-neck, with2440standard taper joint, 500-mL capacity. Suitable for use withevaporator (5.10).5.12 Lamp, infrared.5.13 Burets, automatic, with integral reservoir, 25-mL ca-pacity.6. Materials6.1 Carrier GasHelium, 99.99 % pure. (WarningCompressed gas u
22、nder high pressure.)6.2 SupportCrushed firebrick, acid-washed, 60 to 80-mesh and 80 to 100-mesh.6.3 Liquid Phases1,2,3-Tris(2-cyanoethoxy) propane(TCEP) and methyl silicone.36.4 Solvents:6.4.1 Methanol, reagent grade. (WarningFlammable. Va-por harmful. Can be fatal or cause blindness if swallowed or
23、inhaled.)6.4.2 Chloroform, reagent grade. (WarningCan be fatal ifswallowed. Harmful if inhaled.)6.4.3 Methylene Chloride, for cleaning columns.(WarningHarmful if inhaled. High concentrations can causeunconsciousness or death.)6.4.4 Acetone, for cleaning columns. (WarningExtremely flammable. Vapors c
24、an cause flash fires.)6.5 Internal Standard:6.5.1 Methyl Ethyl Ketone (MEK), 99.5% minimum purity.(WarningFlammable. Vapor can be harmful.)6.6 Calibration Standards:6.6.1 Benzene,99+mol %. (WarningPoison. Carcinogen.Harmful or fatal if swallowed. Extremely flammable. Vaporscan cause flash fires.)6.6
25、.2 Isooctane (2,2,4trimethyl pentane),99+mol %.(WarningExtremely flammable. Harmful if inhaled.)6.6.3 Toluene,(WarningFlammable. Vapor harmful.)6.6.4 n-Nonane,99+mol %. (WarningFlammable. Vaporharmful.)7. Sampling7.1 Gasoline(WarningExtremely flammable. Vaporsharmful if inhaled.) Samples to be analy
26、zed by this test methodshall be obtained using the procedures outlined in PracticeD 4057.8. Preparation of Column Packings8.1 Prepare two packing materials (one packing materialconsists of 10 mass % dimethylpolysiloxane on ChromosorbW; the other, 20 mass % TCEP on Chromosorb P) in accor-dance with t
27、he following procedures:8.1.1 Dimethylpolysiloxane PackingWeigh 45 g of theChromosorb W, 60 to 80 mesh and pour into the 500-mL flask(5.11). Dissolve5gofthedimethylpolysiloxane in approxi-mately 50 mL of chloroform. (WarningCan be fatal ifswallowed. Harmful if inhaled.) Pour the methyl silicone-chlo
28、roform solution into the flask containing the ChromosorbW. Attach the flask to the evaporator (5.10), connect thevacuum, and start the motor. Turn on the infrared lamp andallow the packing to mix thoroughly until dry.3Packed column liquid phases such as OV 101 are considered to be of thedimethylpoly
29、siloxane type. Other equivalent phases can also be used. Consult withthe column manufacturer or phase supplier for information.TABLE 1 Instrument ParametersDetector thermal conductivityColumns: two, stainless steelLength, m (A) 0.8; (B) 4.6Outside diameter, mm 3.2Stationary phase (A) dimethylpolysil
30、oxane, 10 mass %(B) TCEP, 20 mass %Support (A) Chromosorb W, 60 to 80-mesh(B) Chromosorb P, 80 to 100-meshReference column Any column or restriction may beused.Temperature:Sample inlet system, C 200Detector, C 200Column, C 145Carrier Gas: heliumLinear Gas Rate, cm/s 6Volume flow rate, cm3/min approx
31、imately 30Column head pressure, kPa (psi) approximately 200 (30)Recorder range, mV 0 to 1Chart speed, cm/min 1Sample size, L 2Total cycle time, min 8Backflush, min approximately 0.75AAThis back flush time must be determined for each column system.D3606072Copyright by ASTM Intl (all rights reserved);
32、 Wed Mar 12 02:49:04 EST 2008Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.8.1.2 1,2,3-Tris(2-cyanoethoxy) Propane (TCEP)PackingWeigh 80 g of Chromosorb P, 80 to 100 mesh andpour into the 500-mL flask (5.11). Dissolve 20 g of TCEP in200 mL o
33、f methanol and pour into the flask containing theChromosorb P. Attach the flask to the evaporator (5.10),connect the vacuum, and start the motor. Turn on the infraredlamp and allow the packing to mix thoroughly until dry. (Donot heat the packing over 180C.)9. Preparation of Column9.1 Cleaning Column
34、Clean the stainless steel tubing asfollows. Attach a metal funnel to one end of the steel tubing.Hold or mount the stainless steel tubing in an upright positionand place a drain beaker under the outlet end of the tubing.Pour about 50 mL of methylene chloride (WarningHarmfulif inhaled. High concentra
35、tions can cause unconsciousness orFIG. 1 Pressure BackflushD3606073Copyright by ASTM Intl (all rights reserved); Wed Mar 12 02:49:04 EST 2008Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.death) into the funnel and allow it to drain through t
36、he steeltubing and into the drain beaker. Repeat the washing procedurewith 50 mL of acetone. (WarningHarmful if inhaled. Highconcentrations can cause unconsciousness or death.) Removethe funnel and attach the steel tubing to an air line, using vinyltubing to make the connection. Remove all solvent f
37、rom thesteel tubing by blowing filtered, oil-free air through or pullinga vacuum.9.2 Packing ColumnsPreform Columns A and B sepa-rately to fit the chromatograph. Pack the 0.8-m tubing (ColumnA) with the dimethylpolysiloxane packing (8.1.1) and the4.6-m tubing (Column B) with the TCEP packing (8.1.2)
38、 usingthe following procedure. Close one end of each tubing with asmall, glass wool plug, and connect this end to a vacuumsource by means of a glass wool-packed tube. To the other endconnect a small polyethylene funnel by means of a short lengthof vinyl tubing. Start the vacuum and pour the appropri
39、atepacking into the funnel until the column is full. While fillingeach column, vibrate the column with the electric vibrator tosettle the packing. Remove the funnel and shut off the vacuumsource. Remove the top 6 mm (14-in.) of packing and insert aglass wool plug in this end of the column.FIG. 2 Val
40、ve BackflushD3606074Copyright by ASTM Intl (all rights reserved); Wed Mar 12 02:49:04 EST 2008Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.10. Configuration of Apparatus and Establishment ofConditions10.1 Conditioning ColumnInstall Columns
41、A and B asshown in Fig. 1 or Fig. 2 in accordance with the systempreferred (5.1). Do not connect the exit end of Column B to thedetector until the columns have been conditioned. Pass heliumgas through the column at approximately 40 cm3/min. Condi-tion the column at the listed temperatures for the sp
42、ecified timeperiods.Temperature, C Hours at Temperature501210012150 1170 310.2 AssemblyConnect the outlet of Column B to thedetector port. Adjust the operating conditions to those listed inTable 1, but do not turn on the detector circuits. Check thesystems for leaks.10.3 Flow Rate Adjustment:10.3.1
43、Column System Setup for Pressure Backflushing(Fig. 1):10.3.1.1 Open Tap A and B and close C; set the primarypressure regulator to give the desired flow (Table 1) throughthe column system (at an approximate gage pressure of 205kPa (30 psi). Measure the flow rate at the detector vent,sample side. Obse
44、rve the pressure on gage GC.10.3.1.2 Close Tap A and open B and C. The pressurereading on gage GAshould fall to zero immediately. If not,open the needle valve until the pressure falls to zero.10.3.1.3 Close Tap B. Adjust the secondary pressure regu-lator until the reading of gage GCis 3.5 to 7 kPa (
45、0.5 to 1 psi)higher than observed in 10.3.1.1.10.3.1.4 Open Tap B and adjust the backflush vent controlneedle valve until the pressure recorded on GAapproximates agage pressure of 14 to 28 kPa (2 to 4 psi).10.3.1.5 Forward FlowOpen Taps A and C and close TapB (Fig. 1 B1).10.3.1.6 BackflushClose Tap
46、A and open Tap B. (Thereshould be no baseline shift on switching from forward flow tobackflush. If there is a baseline shift increase the secondarypressure slightly.) (Fig. 1)10.3.2 Column System Setup for Valve Backflushing (Fig.2):10.3.2.1 Set the valve in the forward flow mode (Fig. 2 B1),and adj
47、ust flow control A to give the desired flow (Table 1).Measure the flow rate at the detector vent, sample side.10.3.2.2 Set the valve in the backflush position (Fig. 2 B2),measure the flow rate at the detector vent, sample side. If theflow has changed, adjust flow control B to obtain the correctflow.
48、 (Flows should match to within 61cm3/min).10.3.2.3 Change the valve from forward flow to the back-flush position several times and observe the baseline. Thereshould be no baseline shift or drift after the initial valve kickthat results from the pressure surge. If there is a baseline shift,increase o
49、r decrease flow control B slightly to balance thebaseline. (A persistent drift could indicate leaks somewhere inthe system.)10.4 Determine Time to BackflushThe time to backflushwill vary for each column system and must be determinedexperimentally as follows. Prepare a mixture of 5 volume %isooctane in n-nonane. Using the injection technique describedin 11.4 and with the preferred system (10.3)intheforward flowmode, inject 1 L of the isooctane n-nonane mixture. Allowthe chromatogram to run until the n-nonane has eluted and the
