1、Designation: D1607 91 (Reapproved 2018)1Standard Test Method forNitrogen Dioxide Content of the Atmosphere (Griess-Saltzman Reaction)1This standard is issued under the fixed designation D1607; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、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.This standard has been approved for use by agencies of the U.S. Department of Defense.1NOTEWarning notes wer
3、e editorially updated throughout in July 2018.1. Scope1.1 This test method2covers the manual determination ofnitrogen dioxide (NO2) in the atmosphere in the range from 4to 10 000 g/m3(0.002 to 5 ppm(v) when sampling isconducted in fritted-tip bubblers.1.2 For concentrations of NO2in excess of 10 mg/
4、m3(5ppm(v), as occur in industrial atmospheres, gas burner stacks,or automotive exhaust, or for samples relatively high in sulfurdioxide content, other methods should be applied. See forexample Test Method D1608.1.3 The maximum sampling period is 60 min at a flow rateof 0.4 L/min.1.4 The values stat
5、ed in SI units are to be regarded asstandard. The values given in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its u
6、se. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.See also 7.2.2 for other precautions.1.6 This international standard was developed in accor-dance wit
7、h 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 TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards
8、:3D1071 Test Methods for Volumetric Measurement of Gas-eous Fuel SamplesD1193 Specification for Reagent WaterD1356 Terminology Relating to Sampling and Analysis ofAtmospheresD1357 Practice for Planning the Sampling of the AmbientAtmosphereD1608 Test Method for Oxides of Nitrogen in GaseousCombustion
9、 Products (Phenol-Disulfonic Acid Proce-dures)D3195 Practice for Rotameter CalibrationD3609 Practice for Calibration Techniques Using Perme-ation TubesD3631 Test Methods for Measuring Surface AtmosphericPressureE1 Specification for ASTM Liquid-in-Glass ThermometersE128 Test Method for Maximum Pore D
10、iameter and Perme-ability of Rigid Porous Filters for Laboratory Use3. Terminology3.1 For definitions of terms used in this test method, refer toTerminology D1356.4. Summary of Test Method4.1 The NO2is absorbed in an azo-dye-forming reagent(1).4Ared-violet color is produced within 15 min, the intens
11、ityof which is measured spectrophotometrically at 550 nm.5. Significance and Use5.1 Nitrogen dioxide plays an important role in photochemi-cal smog-forming reactions and, in sufficient concentrations, isdeleterious to health, agriculture, materials, and visibility.1This test method is under the juri
12、sdiction of ASTM Committee D22 on AirQuality and is the direct responsibility of Subcommittee D22.03 on AmbientAtmospheres and Source Emissions.Current edition approved July 1, 2018. Published July 2018. Originally approvedin 1958. Last previous edition approved in 2011 as D1607 91 (2011). DOI:10.15
13、20/D1607-91R18E01.2Adapted from “Selected Methods for the Measurement ofAir Pollutants,” PHSPublication No 999-AP-11, May 1965. A similar version has been submitted to theIntersociety Committee.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at s
14、erviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4The boldface numbers in parentheses refer to a list of references at the end ofthis standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Co
15、nshohocken, PA 19428-2959. United StatesThis international 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
16、Organization Technical Barriers to Trade (TBT) Committee.15.2 In combustion processes, significant amounts of nitricoxide (NO) may be produced by combination of atmosphericnitrogen and oxygen; at ambient temperatures NO can beconverted to NO2by oxygen and other atmospheric oxidants.Nitrogen dioxide
17、may also be generated from processes involv-ing nitric acid, nitrates, the use of explosives, and welding.6. Interferences6.1 Aten-fold ratio of sulfur dioxide (SO2)toNO2producesno effect. A thirty-fold ratio slowly bleaches the color to aslight extent. The addition of acetone to the reagent retards
18、 thefading by forming a temporary addition product with SO2. Thispermits reading the color intensity within 4 to 5 h (instead ofthe 45 min required without the acetone) without appreciablelosses.6.2 A five-fold ratio of ozone to NO2will cause a smallinterference, the maximal effect occurring in 3 h.
19、 The reagentassumes a slightly orange tint.6.3 Peroxyacetyl nitrate (PAN) can produce a color changein the absorbing reagent. However, in ordinary ambient air, theconcentration of PAN is too low to cause any significant errorin the measurement of NO2.6.4 Interferences may exist from other nitrogen o
20、xides andother gases that might be found in polluted air.7. Apparatus7.1 Sampling ProbeA glass or TFE-fluorocarbon (pre-ferred) tube, 6 to 10 mm in diameter provided with adownwind facing intake (funnel or tip).The dead volume of thesystem should be kept minimal to avoid losses of NO2on thesurfaces
21、of the apparatus.7.2 AbsorberAn all-glass bubbler with a 60-m maximumpore diameter frit, similar to that illustrated in Fig. 1.7.2.1 The porosity of the fritted bubbler, as well as thesampling flow rate, affect absorption efficiency. An efficiencyof over 95 % may be expected with a flow rate of 0.4
22、L/min orless and a maximum pore diameter of 60 m. Frits having amaximum pore diameter less than 60 m will have a higherefficiency but will require an inconvenient pressure drop forsampling. Considerably lower efficiencies are obtained withcoarser frits.7.2.2 Measure the porosity of an absorber in ac
23、cordancewith Test Method E128. If the frit is clogged or visiblydiscolored, carefully clean with concentrated chromic-sulfuricacid mixture, and rinse well with water and redetermine themaximum pore diameter. (WarningDo not dispose of thisreagent in the drain system.)7.2.3 Rinse the bubbler thoroughl
24、y with water and allow todry before using.7.3 Mist Eliminator or Gas Drying Tube, filled with acti-vated charcoal or soda lime is used to prevent damage to theflowmeter and pump.7.4 Air-Metering DeviceA calibrated, glass, variable-areaflowmeter, or dry gas meter coupled with a flow indicatorcapable
25、of accurately measuring a flow of 0.4 L/min.7.5 ThermometerASTM Thermometer 33C, meeting therequirements of Specification E1, will be suitable for mostapplications of this test method.7.6 Manometer, accurate to 670 Pa (0.20 in. Hg). See TestMethods D3631.7.7 Air PumpA suction pump capable of drawing
26、 therequired sample flow for intervals of up to 60 min is suitable.7.8 Spectrophotometer or ColorimeterAn instrument suit-able for measuring the intensity of absorption at 550 nm, withstoppered tubes or cuvettes. The wavelength band-width is notcritical for this determination.7.9 Stopwatch or Timer.
27、8. Reagents and Materials8.1 Reagent grade chemicals shall be used in all tests. Allreagents shall conform to the specifications of the Committeeon Analytical Reagents of the American Chemical Society,where such specifications are available.5Other grades may beused, provided it is first ascertained
28、that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.8.2 Purity of WaterUnless otherwise indicated, water shallbe deionized water in accordance with Specification D1193 forType I or II reagent water. Water shall be free of nitrite.8.3 Ab
29、sorbing ReagentDissolve5gofanhydrous sulfa-nilic acid (or 5.5 g of sulfanilic acid monohydrate) in almost aL of water containing 140 mL of glacial acetic acid. Gentle5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing
30、 of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Fritted Bubbler for Sampling Nitrogen Dioxid
31、eD1607 91 (2018)12heating is permissible to speed up the process. To the cooledmixture, add 20 mL of the 0.1 % stock solution of N-(1-naphthyl)-ethylenediamine dihydrochloride, and 10 mL ofacetone. Dilute to 1 L. The solution will be stable for severalmonths if kept well-stoppered in a brown bottle
32、in therefrigerator. The absorbing reagent shall be at room tempera-ture before use. Avoid lengthy contact with air during prepa-ration and use since discoloration of reagent will result becauseof absorption of NO2.8.4 N-(1-Naphthyl)-Ethylenediamine Dihydrochloride,Stock Solution (0.1 %)Dissolve 0.1
33、g of the reagent in 100mL of water. Solution will be stable for several months if keptwell-stoppered in a brown bottle in the refrigerator.(Alternatively, preweighed amounts of the solid reagent maybe stored.)8.5 Sodium Nitrite, Standard Solution (0.0246 g/L)OnemL of this working solution of sodium
34、nitrite (NaNO2)produces a color equivalent to that of 20 g of NO2in1Lofair at 101 kPa (29.92 in. Hg) and 25C (see 10.1). Prepare freshjust before use by dilution from a stock solution containing2.46 g of the reagent grade granular solid per litre. Assay thesolid reagent. The stock solution is stable
35、 for 90 days at roomtemperature, and for 1 year in a brown bottle under refrigera-tion.8.6 NO2Permeation DeviceWith a permeation rate of 0.1to 0.2 g/min.9. Sampling9.1 Sampling procedures are described in Section 11. Dif-ferent combinations of sampling rates and time may be chosento meet specific ne
36、eds, but sample volumes and air flow ratesshall be adjusted so that linearity is maintained betweenabsorbance and concentration over the dynamic range.9.2 See Practice D1357 for sampling guidelines.10. Calibration and Standardization10.1 Sampling Equipment:10.1.1 FlowmeterCalibrate flowmeter prior t
37、o use, usingPractice D3195.10.1.2 Gas MeterCalibrate gas meter prior to use, usingTest Methods D1071.10.2 Analysis:10.2.1 Recommended Procedure:10.2.1.1 The recommended procedure for preparation ofcalibration standards is by the use of permeation devices (2).Analysis of known concentrations gives ca
38、libration curves thatsimulate all of the operational conditions performed duringsampling and analytical procedures.10.2.1.2 Using the apparatus described in Practice D3609,generate a gas stream of known concentration. Sample it asdescribed in 11.1, five times, adjusting the sample times so thatthe a
39、mount of NO2in each collected sample solution covers thedynamic range of this test method. Analyze each as describedin 11.2, and prepare a calibration curve using regressionanalysis by this test method of least squares. Determine thereciprocal of the slope of the line, and denote it as K, thevolume
40、of NO2, in L, intercepted at an absorbance of 1.0.10.2.2 Alternate Procedure:10.2.2.1 Standardization is based upon the empirical obser-vation (1, 3)6that 0.82 mol of NaNO2produces the same coloras 1 mol of NO2. One mL of the working standard solutioncontains 24.6 g of NaNO2. Since the molecular wei
41、ght ofNaNO2is 69.1, this is equivalent to (24.6/69.1) (46.00.82) = 20 g NO2.10.2.2.2 For convenience, standard conditions are taken as101 kPa (29.92 in. Hg) and 25C, at which the molar gasvolume is 24.47 L. This is very close to the standard conditionsused for air-handling equipment101 kPa (29.92 in
42、. Hg), 70F(21.1C), and 50 % relative humidity, at which the molar gasvolume is 24.76 L, or 1.2 % greater. Ordinarily, the correctionof the sample volume to these standard conditions is slight andmay be omitted, however, for greatest bias, it may be made bymeans of the perfect gas equation.10.2.2.3 A
43、dd graduated amounts of NaNO2solution up to 1mL(measured accurately in a graduated pipet or small buret) toa series of 25-mL volumetric flasks, and dilute to the markswith absorbing reagent. Mix, allow 15 min for complete colordevelopment, and read the absorbance (see 11.2).10.2.2.4 Good results can
44、 be obtained with these smallvolumes of standard solution if they are carefully measured.Making the calibration solutions up to 25-mL total volume,rather than the 10-mL volume used for samples, increasesaccuracy.10.2.2.5 Plot absorbances of the standards against micro-grams of NO2per mL of absorbing
45、 reagent. The plot followsBeers law. Find the standardization factor, K, as described in10.2.1.1.11. Procedure11.1 Assemble in order as shown in Fig. 2, a sampling probe(optional), fritted-tip absorber, mist eliminator or trap,flowmeter, and pump. Measure temperature and pressuredifference from atmo
46、spheric so that corrections for gas volumemay be applied. Keep the flowmeter free from spray or dust.Use ground-glass connections. Butt-to-butt glass connectionswith vinyl tubing also may be used for connections withoutlosses if lengths are kept minimal.11.2 Pipet 10.0 mL of absorbing reagent into a
47、 dry frittedbubbler. Draw an air sample through it at the rate of 0.4 L/min,long enough to develop sufficient final color (about 10 to 60min). Note the total air volume sampled. Measure and recordair temperature and pressure. After using the bubbler, rinsewell with water and dry. If fritted tip is v
48、isibly discolored, cleanin accordance with the procedure in 7.2.2.11.3 After sampling, development of the red-violet color iscomplete within 15 min at room temperatures. Transfer to astoppered cuvette and read in a spectrophotometer at 550 nm,using distilled water as a reference. Deduct the absorban
49、ce ofthe reagent blank from that of the sample.6Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D22-1019. ContactASTM CustomerService at serviceastm.org.D1607 91 (2018)1311.4 Colors too dark to read may be quantitatively dilutedwith unexposed absorbing reagent. Then multiply the mea-sured absorbance by the dilution factor.12. Calculation12.1 Air VolumeConvert the volume of air sampled to thevolume at standard conditions of 25C and 101.3 kPA (1 atm),as follows:VR5 V 3 P
