1、Designation: D 3606 06e1An 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 ye
2、ar 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.e1NOTEUpdated 1.4 editorially in November 2006.1. Scope*1.1 This
3、test method covers the determination of benzeneand 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 w
4、as determined usingconventional gasoline as well 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 cont
5、aining ethanol.1.5 The values stated in SI units 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 t
6、o establish appro-priate safety and health practices 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-ratus
7、E 969 Specification for Glass Volumetric (Transfer) 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 introd
8、uced into a gaschromatograph equipped with two columns 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
9、isreversed, flushing out the components heavier than 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 the
10、rmal conductivity detector. The detector response 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 c
11、an be an aid in evaluatingthe possible health hazard 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 a
12、t the conditions given in Table 1, can beemployed. 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 di
13、rect responsibility of SubcommitteeD02.04.0L on Gas Chromatography Methods.Current edition approved May 1, 2006. Published June 2006. Originallyapproved in 1977. Last previous edition approved in 2004 as D 360604a.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM C
14、ustomer Service at serviceastm.org. For Annual 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 Conshohoc
15、ken, PA 19428-2959, United States.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 %dimethylpolysiloxane (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
16、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 presentation ofthe chromatogram. The electronic integrating device or com-puter must be capable of measuring 0.1 volume % MEK withsatis
17、factory 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 level of 60.3% of full scale is recommended. The detector strip chartrecorder combination must produce a 4mm deflection for a2L sample cont
18、aining 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 (see 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 d
19、ispensingvolumes 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).NOTE 1Other volume dispensing equipment capable of delivering thespecified volumes within the stated tolerance limits may be used as an
20、alternative 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, rotary.5.11 Flask, boiling, round-bottom, short-neck, with2440standard taper joint, 500-mL capacity. Suitable for use withevaporator
21、(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 under 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-cyanoetho
22、xy) 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 orinhaled.)6.4.2 Chloroform, reagent grade. (WarningCan be fatal ifswallowed. Harmful if inhaled.)6.4.3 Methylene Chloride, for cleaning
23、columns.(WarningHarmful if inhaled. High concentrations can causeunconsciousness or death.)6.4.4 Acetone, for cleaning columns. (WarningExtremely flammable. Vapors can cause flash fires.)6.5 Internal Standard:6.5.1 Methyl Ethyl Ketone (MEK), 99.5% minimum purity.(WarningFlammable. Vapor can be harmf
24、ul.)6.6 Calibration Standards:6.6.1 Benzene,99+mol %. (WarningPoison. Carcinogen.Harmful or fatal if swallowed. Extremely flammable. Vaporscan cause flash fires.)6.6.2 Isooctane (2,2,4trimethyl pentane),99+mol %.(WarningExtremely flammable. Harmful if inhaled.)6.6.3 Toluene,(WarningFlammable. Vapor
25、harmful.)6.6.4 n-Nonane,99+mol %. (WarningFlammable. Vaporharmful.)7. Sampling7.1 Gasoline(WarningExtremely flammable. Vaporsharmful if inhaled.) Samples to be analyzed by this test methodshall be obtained using the procedures outlined in PracticeD 4057.8. Preparation of Column Packings8.1 Prepare t
26、wo packing materials (one packing materialconsists of 10 mass % dimethylpolysiloxane on ChromosorbW; the other, 20 mass % TCEP on Chromosorb P) in accor-dance with the following procedures:8.1.1 Dimethylpolysiloxane PackingWeigh 45 g of theChromosorb W, 60 to 80 mesh and pour into the 500-mL flask(5
27、.11). Dissolve5gofthedimethylpolysiloxane in approxi-mately 50 mL of chloroform. (WarningCan be fatal ifswallowed. Harmful if inhaled.) Pour the methyl silicone-chloroform solution into the flask containing the ChromosorbW. Attach the flask to the evaporator (5.10), connect thevacuum, and start the
28、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 thedimethylpolysiloxane type. Other equivalent phases can also be used. Consult withthe column manufacturer or phase supplier for information.TABLE 1
29、Instrument ParametersDetector thermal conductivityColumns: two, stainless steelLength, m (A) 0.8; (B) 4.6Outside diameter, mm 3.2Stationary phase (A) dimethylpolysiloxane, 10 mass %(B) TCEP, 20 mass %Support (A) Chromosorb W, 60 to 80-mesh(B) Chromosorb P, 80 to 100-meshReference column Any column o
30、r restriction may beused.Temperature:Sample inlet system, C 200Detector, C 200Column, C 145Carrier Gas: heliumLinear Gas Rate, cm/s 6Volume flow rate, cm3/min approximately 30Column head pressure, kPa (psi) approximately 200 (30)Recorder range, mV 0 to 1Chart speed, cm/min 1Sample size, L 2Total cyc
31、le time, min 8Backflush, min approximately 0.75AAThis back flush time must be determined for each column system.D360606e128.1.2 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 of methanol a
32、nd 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 ColumnClean the st
33、ainless 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 concentrations can ca
34、use unconsciousness orFIG. 1 Pressure BackflushD360606e13death) into the funnel and allow it to drain through the steeltubing and into the drain beaker. Repeat the washing procedurewith 50 mL of acetone. (WarningHarmful if inhaled. Highconcentrations can cause unconsciousness or death.) Removethe fu
35、nnel and attach the steel tubing to an air line, using vinyltubing to make the connection. Remove all solvent from 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 (Colu
36、mnA) with the dimethylpolysiloxane packing (8.1.1) and the4.6-m tubing (Column B) with the TCEP packing (8.1.2) 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 endconnec
37、t a small polyethylene funnel by means of a short lengthof vinyl tubing. Start the vacuum and pour the appropriatepacking 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 vacuums
38、ource. Remove the top 6 mm (14-in.) of packing and insert aglass wool plug in this end of the column.FIG. 2 Valve BackflushD360606e1410. Configuration of Apparatus and Establishment ofConditions10.1 Conditioning ColumnInstall Columns A and B asshown in Fig. 1 or Fig. 2 in accordance with the systemp
39、referred (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 specified timeperiods.Temperature, C Hours at Temperature50121001215
40、0 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 Column System Setup for Pressure Backflushing(Fig. 1):10.3.1.1 Ope
41、n 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. Observe the pressure on gage GC.10.3.1.2 Close Tap A and open B and C.
42、 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 (0.5 to 1 psi)higher than observed in 10.3.1.1.10.3.1.4 Open Tap B
43、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 A and open Tap B. (Thereshould be no baseline shift on switching f
44、rom 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 adjust flow control A to give the desired flow (Table 1).Measure the
45、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. (Flows should match to within 61cm3/min).10.3.2.3 Change the valv
46、e 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 or decrease flow control B slightly to balance thebaseline. (A pers
47、istent 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 wi
48、th 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 thedetector signal has returned to baseline. Measure the time inseconds, from the injection until the detector signal returns tobaseline b
49、etween the isooctane and n-nonane peaks. At thispoint all of the isooctane, but essentially none of the n-nonane,should have eluted. One half of the time determined shouldapproximate the “time to backflush” and should be from 30 to60 s. Repeat the run, including the injection, but switching thesystem to the backflush mode at the predetermined “time tobackflush.” This should result in a chromatogram of isooctanewith little or no n-nonane visible. If necessary, make additionalruns, adjusting the “time to backflush” until this cond
