1、Designation: D5197 09Standard Test Method forDetermination of Formaldehyde and Other CarbonylCompounds in Air (Active Sampler Methodology)1This standard is issued under the fixed designation D5197; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e 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. Scope1.1 This test method covers a procedure for the determina-tion of formaldehyde (HCHO) and other
3、 carbonyl compounds(aldehydes and ketones) in air. Other carbonyl compounds thathave been validated for determination by this method includeacetaldehyde, acetone, propanal (propionaldehyde), methac-rolein, 2-butanone (methyl ethyl ketone), butyraldehyde, ben-zaldehyde, isovaleraldehyde, valeraldehyd
4、e, o-tolualdehyde,m-tolualdehyde, p-tolualdehyde, hexanal, and 2,5-dimethylbenzaldehyde. Acrolein and crotonaldehyde can notbe determined quantitatively using the analytical proceduredescribed in 10.2 due to the formation of multiple derivativepeaks and the instability of the peak ratios2, 3. Howeve
5、r, theprocedure described in theAnnexAhas been used by the U. S.Environmental Protection Agency to estimate acrolein andcrotonaldehyde concentrations in standard atmospheres fol-lowing special precautions.1.2 This test method involves drawing air through a car-tridge containing silica gel coated wit
6、h 2,4-dinitrophenylhydrazine (DNPH) reagent. Carbonyl compoundsreadily form stable derivatives with the DNPH reagent. TheDNPH derivatives are analyzed for parent aldehydes andketones utilizing high performance liquid chromatography(HPLC). The sampling procedure is a modification of U.S.EPA Method TO
7、-11A (see 2.2).1.3 This test method is based on the specific reaction ofcarbonyl compounds with DNPH in the presence of an acid toform stable derivatives according to the reaction shown in Fig.1, (where: both R and R1are alkyl or aromatic groups(ketones), or both, or either R or R1is a hydrogen atom
8、(aldehydes). The determination of formaldehyde and othercarbonyl compounds, as DNPH derivatives, is similar to that ofU.S. EPA Method TO-11A in that it utilizes HPLC with UVdetection as the analytical finish. The detection limits havebeen extended to other carbonyl compounds that can bedetermined as
9、 outlined in Section 10.2.4. This test method issuitable for determination of formaldehyde and other carbonylcompounds in the concentration range from approximately 10ppb to 1 ppm (v/v).1.4 The sampling method gives a time-weighted average(TWA) sample. It can be used for long-term (1 to 24 h) orshor
10、t-term (5 to 60 min) sampling of air for formaldehyde.1.5 This test method instructs the user on how to preparesampling cartridges from commercially available chromato-graphic grade silica gel cartridges4by the application ofacidified DNPH to each cartridge.1.6 The sampling flow rate, as described i
11、n this test method,has been validated for sampling rates up to 1.5 L/min. Thisflow rate limitation is principally due to the high pressure drop(8 kPa at 1.0 L/min) across the user prepared silica gelcartridges which have a particle size of 55 to 105 m. Thesecartridges are not generally compatible wi
12、th battery-poweredpumps used in personal sampling equipment (for example,those used by industrial hygienists.1.7 Alternatively, pre-coated DNPH silica gel cartridges arealso commercially available and may be substituted providedthey can be demonstrated to perform equivalently.5Some ofthese use silic
13、a gel of a larger particle size that results in alower pressure drop across the cartridge. These low pressuredrop cartridges may be more suitable for sampling air usingbattery-powered personal sampling pumps.1.8 The values stated in SI units are to be regarded as thestandard.1This test method is und
14、er the jurisdiction of ASTM Committee D22 on AirQuality and is the direct responsibility of Subcommittee D22.05 on Indoor Air.Current edition approved Nov. 1, 2009. Published December 2009. Originallyapproved in 1991. Last previous edition approved in 2003 as D5197 03. DOI:10.1520/D5197-09.2Levin, J
15、. O., and Lindahl, R., “Aldehyde Measuring Methods Using DNPH-coated FiltersSummary and Conclusions,” Proceedings of the Workshop “Sam-pling Project”, Mol, Belgium, June 2728, 1986.3Clark, W. L., Biller, W. F., Tejada, S. B., Siegl, W. O., Rosenhamer, D.,Newkirk, M. S., and Crowley, R. J., “Round Ro
16、bin Analysis of Alcohol andCarbonyl Synthetic Exhaust Samples,” SAE Technical Paper Series, Paper 941944,1994, pp. 71-87.4The cartridge used in the development and performance evaluation of this testmethod was the Sep-Pak Plus Silica cartridge. The sole source of supply of thecartridge known to the
17、committee at this time is WatersAssociates, 34 Maple Street,Milford, MA 01757. If you are aware of alternative suppliers, please provide thisinformation to ASTM Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.5
18、Tejada, S. B., “Evaluation of Silica Gel Cartridges Coated in situ withAcidified2,4-Dinitrophenylhydrazine for Sampling Aldehydes and Ketones in Air,” Interna-tional Journal of Environmental Analytical Chemistry, Vol 26, 1986, pp. 167185.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C
19、700, West Conshohocken, PA 19428-2959, United States.1.9 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 practices and determine the applica-bility o
20、f regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:6D1193 Specification for Reagent WaterD1356 Terminology Relating to Sampling and Analysis ofAtmospheresD3195 Practice for Rotameter CalibrationD3631 Test Methods for Measuring Surface AtmosphericPressureD3686 Practice fo
21、r Sampling Atmospheres to Collect Or-ganic Compound Vapors (Activated Charcoal Tube Ad-sorption Method)E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE682 Practice for Liquid Chromatography Terms and Rela-tionships2.2 EPA Methods:Method TO-11A, EPA-625/R-96/010b, Compendium
22、 ofMethods for the Determination of Toxic Organic Com-pounds in Ambient Air, U.S. Environmental ProtectionAgency, Research Triangle Park, NC, January 19997EPA-600/R-98/004, Quality Assurance Handbook for AirPollution Measurement Systems, Volume 2, Part1Ambient Air Quality Monitoring Program QualityS
23、ystem Development, U.S. Environmental ProtectionAgency, Research Triangle Park, NC, August 19987EPA-600/4-83-027, Technical Assistance Document forSampling and Analysis of Toxic Organic Compounds inAmbient Air, U.S. Environmental Protection Agency,Research Triangle Park, NC, June 1983 (PB90-187 014/
24、AS)73. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method, referto Terminology D1356 and Practice E682.3.2 Definitions of Terms Specific to This Standard:3.2.1 All other pertinent abbreviations and symbols aredefined when first cited in this test method.4. Summary of
25、Test Method4.1 A known volume of indoor air is drawn through aprepacked silica gel cartridge coated with acidified DNPH, at asampling rate of 0.5 to 1.2 L/min for an appropriate period oftime. Both sampling rate and time are dependent upon carbonylconcentrations in the test atmosphere.4.2 After samp
26、ling, the sample cartridges are individuallycapped and placed in individual bottles or other sealablecontainers. Sample identifying tags or labels are attached andthe individual sample containers are then placed in a friction-top can or other suitable sealable secondary container with apouch of char
27、coal for transport to the laboratory for analysis.The cartridges are placed in cold storage until analysis.Alternatively, the cartridges may be desorbed, diluted to aknown volume, and refrigerated until analysis.NOTE 1A heat-sealable foil-lined plastic pouch of the type includedwith some commercial
28、pre-coated DNPH cartridges may be used forstoring a DNPH-coated cartridge after sampling, if appropriate.4.3 The DNPH-carbonyl derivatives are determined using agradient HPLC system, equipped with a C-18 reverse phasecolumn and an ultraviolet (UV) absorption detector operated at360 nm.4.4 A blank ca
29、rtridge is likewise desorbed and analyzed inaccordance with 4.3.4.5 Formaldehyde and other carbonyl compounds in thesample are identified and quantified by comparison of theirretention times and peak heights or peak areas of theircorresponding DNPH derivatives with those of standard solu-tions.5. Si
30、gnificance and Use5.1 This test method provides an analytical procedure formeasuring formaldehyde and other carbonyl compounds inindoor or outdoor air.6. Interferences6.1 The solid sorbent sampling procedure is specific forsampling and analysis of carbonyl compounds. Interferences inthis test method
31、 are certain isomeric aldehydes or ketones thatmay be unresolved by the HPLC system or coelute with DNPHderivatives of other aldehydes and ketones in the sample.Organic compounds that have the same retention time andsignificant absorbance at 360 nm as the DNPH derivatives ofsome carbonyl compounds w
32、ill interfere. Such interferencescan often be overcome by altering the separation conditions(for example, using alternative HPLC columns or mobile phasecompositions).6For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual B
33、ook of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.7Available from the U.S. Environmental Protection Agency, http:/www.epa.gov/ttn/amtic/airtox.html, or the U.S. Department of Commerce, NationalTechnical Information Service, 5285 Port Royal Rd.,
34、Springfield, VA 22161.FIG. 1 Reaction of Carbonyl CompoundsD5197 0926.2 Formaldehyde contamination of the DNPH reagent is afrequently encountered problem. The DNPH must be purifiedby multiple recrystallizations in UV-grade acetonitrile. Recrys-tallization is accomplished, at 40 to 60C, by slow evapo
35、rationof the solvent to maximize crystal size. The purified DNPHcrystals are stored under UV-grade acetonitrile until use.Impurity levels of carbonyl compounds in the DNPH aredetermined prior to use by HPLC and should be less than 0.15g per cartridge.6.3 Exposure of the DNPH-coated sampling cartridg
36、es todirect sunlight may produce artifacts and should be avoided.86.4 Ozone at high concentrations (120 ppb and above) hasbeen shown to interfere negatively by reacting with both theDNPH and its carbonyl derivatives (hydrazones) in the car-tridge.9The extent of interference depends on the temporalva
37、riations of both the ozone and the carbonyl compounds andthe duration of sampling. Significant (45 %) negative inter-ference from ozone was observed even at concentrations offormaldehyde and ozone typical of clean ambient air (2 and 40ppbv, respectively) when air was sampled for three hours at 1L/mi
38、n. It is highly recommended that ozone be removed bymeans of the devices described in 6.4.2 and 6.4.4 before thesample reaches the cartridge.106.4.1 The presence of ozone in the sample stream is readilyinferred from the appearance of new compounds with retentiontimes shorter than that of the hydrazo
39、ne of formaldehyde. Fig.2 shows chromatograms of samples of a formaldehyde-spikedair stream with and without ozone.6.4.2 The most direct solution to the ozone interference is toremove the ozone before the sample stream reaches thecartridge. This process entails constructing an ozone denuderor scrubb
40、er and placing it in front of the cartridge. The denuderis constructed of1mof0.64-cm outside diameter by 0.46-cminside diameter copper tubing, that is filled with a saturatedsolution of KI in water, allowed to stand for a few minutes(;5), drained and dried with a stream of clean air or nitrogenfor a
41、bout 1 h. The capacity of the ozone denuder as describedis about 100 ppm(v)-hour of ozone.6.4.3 Test aldehydes (formaldehyde, acetaldehyde, propi-onaldehyde, benzaldehyde, and p-tolualdehyde) that were dy-namically spiked into an ambient sample air stream passedthrough the denuder with practically n
42、o losses.6.4.4 Ozone scrubbers (cartridge filled with granular potas-sium iodide) are also commercially available from suppliers ofpre-coated DNPH cartridges.7. Apparatus7.1 Sampling System, capable of accurately and preciselysampling 0.1 to 1.50 L/min.NOTE 2An example of a sampling system for ambie
43、nt air consistingof a heated manifold/sample inlet, a denuder/cartridge assembly, a flowmeter, a vacuum gage/pump, a timer and a power supply is shown in Fig.3. In operation, ambient air is drawn through the denuder/cartridgeassembly with a vacuum pump at a fixed flow rate between 0.1 to 2 Lpm.NOTE
44、3Apressure drop through the user-prepared sample cartridge ofabout 19 kPa at a sampling rate of 1.5 L/min has been observed. Somecommercially available pre-coated cartridges may exhibit lower pressuredrops, which will permit the use of battery-operated personal samplingpumps.7.2 HPLC System, consist
45、ing of two or more mobile phasereservoirs; a single or a dual high-pressure pump systemequipped with a mobile phase gradient programmer, an injec-tion valve (automatic sampler with a 25-Lor other convenientloop volume (10 L, 20 L); a C18 reverse phase (RP) column(25-cm by 4.6-mm inside diameter); a
46、UV detector operating at360 nm; and a data system or strip chart recorder. A typicalgradient HPLC system configuration is shown in Fig. 4.NOTE 4Most commercial HPLC analytical systems will be adequatefor this application.7.3 Stopwatch.7.4 Friction-Top Metal Can (for example, 4-L Paint Can) orOther S
47、uitable Container, with polyethylene air bubble pack-ing or other suitable padding, to hold and cushion sample vials.7.5 Thermometer, to record temperature.7.6 Barometer, (Refer to Test Methods D3631).7.7 Suction Filtration Apparatus, for filtering HPLC mobilephase.7.8 Volumetric Flasks, various siz
48、es, 5 to 2000 mL.7.9 Pipets, various sizes, 1 to 50 mL.7.10 Helium Purge Line, for degassing HPLC mobile phase(optional).7.11 Erlenmeyer Flask, 1 L, for preparing HPLC mobilephase.7.12 Graduated Cylinder, 1 L, for preparing HPLC mobilephase.8Grosjean, D., “Ambient Levels of Formaldehyde, Acetaldehyd
49、e, and FormicAcid in Southern California: Results of a One-Year Base-Line Study,” Environmen-tal Science air; carbonyl compounds; DNPH car-tridge; formaldehyde; HPLC analysis15Details for the precision and bias studies summarized in this section are on fileat ASTM Headquarters.D5197 0913ANNEX(Mandatory Information)A1. DETERMINATION OF ACROLEIN AND CROTONALDEHYDEA1.1 Determination of Acrolein and CrotonaldehydeA1.1.1 Special procedures must be followed if this testmethod is to be used for determination of acrolein or crotonal-dehyde in air since the hydrazones of
