1、Designation: D 4129 05Standard Test Method forTotal and Organic Carbon in Water by High TemperatureOxidation and by Coulometric Detection1This standard is issued under the fixed designation D 4129; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of total andorganic carbon in water and waste wa
3、ter, including brackishwaters and brines in the range from 2 to 20 000 mg/L. This testmethod has the advantages of a wide range of concentrationwhich may be determined without sample dilution and theprovision for boat or capillary introduction of samples contain-ing sediments and particulate matter
4、where syringe injection isinappropriate.1.2 This procedure is applicable only to that carbonaceousmatter in the sample that can be introduced into the reactionzone. When syringe injection is used to introduce samples intothe combustion zone, the syringe needle opening size limits themaximum size of
5、particles that can be present in samples.Sludge and sediment samples must be homogenized prior tosampling with a micropipetor or other appropriate sampler andladle introduction into the combustion zone is required.1.3 The precision and bias information reported in this testmethod was obtained in col
6、laborative testing that includedwaters of the following types: distilled, deionized, potable,natural, brine, municipal and industrial waste, and waterderived from oil shale retorting. Since the precision and biasinformation reported may not apply to waters of all matrices, itis the users responsibil
7、ity to ensure the validity of this testmethod on samples of other matrices.1.4 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 determin
8、e the applica-bility of regulatory limitations prior to use. For specificprecautionary statements, see 9.1 and 10.2.1.2. Referenced Documents2.1 ASTM Standards:2D 513 Test Methods for Total and Dissolved Carbon Diox-ide in WaterD 1129 Terminology Relating to WaterD 1193 Specification for Reagent Wat
9、erD 3370 Practices for Sampling Water from Closed ConduitsD 3856 Guide for Good Laboratory Practices in Laborato-ries Engaged in the Sampling and Analysis of WaterD 4210 Practice for Interlaboratory Quality Control Proce-dures and a Discussion on Reporting Low-Level Data3D 5789 Practice for Writing
10、Quality Control Specificationsfor Standard Test Methods for Organic Constituents33. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D 1129.4. Summary of Test Method4.1 The sample is homogenized or diluted, or both, asnecessary. If the sample does not
11、contain suspended particlesor high-salt level a 0.200-mL portion is injected into thereaction zone. For samples containing solids or high salt levels,portions are placed in combustion boats containing tungstentrioxide (WO3) or quartz capillaries and introduced into thereaction zone using a ladle. In
12、 the reaction zone the heat,oxidation catalyst and oxygen atmosphere convert carbon-aceous matter to carbon dioxide (CO2). The oxygen gas streamsweeps the gaseous reaction products through a series ofscrubbers for potentially interfering gases and then to theabsorption/titration cell. The CO2is dete
13、rmined by automaticcoulometric titration. Calibration by testing known carboncontent standards is not required, however, standards areanalyzed periodically to confirm proper operation.4.2 Carbon dioxide is liberated from carbonates as well asfrom organic matter under the reaction conditions. Organic
14、carbon is determined by difference between the total carbonand the inorganic carbon determined separately or by acidify-ing a portion of the sample to a pH of 2 or less and spargingwith carbon dioxide-free gas to remove carbonates, bicarbon-ates, and dissolved carbon dioxide prior to total carbondet
15、ermination. To determine organic carbon by difference theinorganic carbon is determined by acid release of carbon1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.06 on Methods forAnalysis forOrganic Substances in Water.Cur
16、rent edition approved March 1, 2005. Published March 2005. Originallyapproved in 1982. Last previous edition approved in 2003 as D 4129 98 (2003).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards
17、 volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.dioxide from a portion of the sample or other methods as givenin Test Methods D 513. For
18、discussion of the limitations andguidelines for the use of the sparge technique see 5.4 and thepaper by Van Hall.44.3 Because of the various properties of carbon-containingcompounds in water, any preliminary treatment of a sampleprior to injection dictates a definition of the carbon measured.Filtrat
19、ion of the sample prior to injection will limit the carbonmeasured to dissolved carbonates and dissolved organic matter.Homogenizing permits determination of the carbon in in-soluble carbonates and insoluble organic materials.5. Significance and Use5.1 This test method is necessary because of the ne
20、ed forrapid reliable tests for carbonaceous material in waters andsediments.5.2 It is used for determining the concentration of organiccarbon in water that comes from a variety of natural, domestic,and industrial sources. Typically, these measurements are usedto monitor organic pollutants in domesti
21、c and industrial wastewater.5.3 When a sample is homogenized so that particulate,immiscible phases, and dissolved carbon from both organicand inorganic sources is determined, the measurement is calledtotal carbon (TC). When inorganic carbon response is elimi-nated by removing the dissolved CO2prior
22、to the analysis orthe dissolved CO2concentration subtracted from the totalcarbon concentration, the measurement is called total organiccarbon (TOC). When particulates and immiscible phases areremoved prior to analysis the measurement is called dissolvedcarbon (DC), or dissolved organic carbon (DOC)
23、if inorganiccarbon response has been eliminated.5.4 Homogenizing or sparging of a sample, or both, maycause loss of volatile organics, thus yielding a negative error.The extent and significance of such losses must be evaluated onan individual basis. If significant quantities of volatile carbon-aceou
24、s materials are present or may be present in samplesorganic carbon should be determined by the difference betweenthe total carbon and the inorganic carbon concentrations. Whenorganic carbon determined both by difference and by spargingagree it is acceptable to determine organic carbon by spargingfor
25、 similar samples.5.5 The relationship of TOC to other water quality param-eters such as COD and BOD is described in the literature.56. Interferences6.1 Any acidic or basic gas formed in the oxidation of thesample and not removed by the scrubbers will interfere withthe test. Potentially interfering g
26、ases that are removed by thescrubbers include hydrogen sulfide (H2S), hydrogen chloride(HCl), hydrogen bromide (HBr), hydrogen iodide (HI), sulfurdioxide (SO2), sulfur trioxide (SO3) free halogens, halogenoxides, and nitrogen oxides. Hydrogen fluoride (HF) may beremoved by bubbling the gas stream th
27、rough water in the watervapor condenser.6.2 The capacity of the scrubbers for potentially interferinggases may vary with the type of samples being analyzed. If thescrubber capacity is exceeded it can be recognized by thetitration continuing beyond the normal analysis time at a higherrate than the bl
28、ank and high results for known carbon contentstandards as well as by appearance changes in the scrubbers. Ifthe scrubber capacity is exceeded during an analysis thescrubbers should be replaced and the analysis repeated.Samples containing all concentrations of the potentially inter-fering species can
29、 be analyzed if the analyst uses great care toensure that the scrubbers are and remain effective for hissamples. The frequency of replacing the scrubbers will dependon the nature of the samples.7. Apparatus7.1 Apparatus for total carbon, organic carbon, and inor-ganic carbon determinationscombustion
30、 furnace with gassupply, gas purification train, flow control, acid reaction train,and carbon dioxide coulometer.6Fig. 1 and Fig. 2 show blockdiagrams of the apparatus.7.2 Sampling Devices A spring-loaded .200-mL syringe7(carbon analyzer syringe) having an all metal tip and a 50 mm4Van Hall, C. E.,
31、Barth, D., and Stenger, V. A., “Elimination of Carbonates fromAqueous Solutions Prior to Organic Carbon Determinations,” Analytical Chemistry,Vol 37, 1965, pp. 769771.5Handbook for Monitoring Industrial Wastewater, U.S. Environment ProtectionAgency, August 1973, pp. 510 to 512.6Instruments marketed
32、by Coulometrics, Inc., a subsidiary of UIC Inc., P.O. Box563, Joliet, IL, 60434, or an equivalent, have been found satisfactory.7Syringes manufactured by Hamilton Co., P.O. Box 10030, Reno, NV 89510, oran equivalent, have been found satisfactory for this purpose.FIG. 1 Total Carbon and TOC Apparatus
33、D 4129 052long, 0.5-mm inside diameter needle with a square end isrecommended for water samples containing little or no particu-late matter.7.3 Homogenizing ApparatusA household blender withglass mixing chamber is generally satisfactory for homogeniz-ing immiscible phases in water.8. Reagents8.1 Pur
34、ity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the commit-tee onAnalytical Reagents of theAmerican Chemical Society.8Other grades may be used provided it is first ascertained thatthe
35、 reagent is of sufficiently high purity to permit its usewithout lessening the accuracy of the determination.8.2 Purity of Water Unless otherwise indicated, referenceto water shall be understood to mean reagent water conformingto the Specification D 1193, Type I. Other reagent water typesmay be used
36、, provided it is first ascertained that the water is ofsufficiently high purity to permit its use without adverselyaffecting the precision and bias of the test method. Type IIwater was specified at the time of round robin testing of thistest method. If necessary, carbon dioxide-free water is to bepr
37、epared by boiling distilled water in a conical flask for 20 min.The boiled water is cooled in the flask stoppered with aone-hole rubber stopper fitted to a soda lime-Ascarite dryingtube. For large (10 to 20 L) volumes of carbon dioxide-freewater, the absorbed carbon dioxide may be removed byinsertin
38、g a fritted-glass gas-dispersion tube to the bottom of thecontainer and vigorously bubbling nitrogen through the waterfor at least 1 h. Carbon dioxide-free water may be stored ifproperly protected from atmospheric contamination.NOTE 1Glass containers are preferred for the storage of reagent waterand
39、 most standard solutions. It is necessary to provide protection againstchanges in quality due to the absorption of gases or water vapor from thelaboratory air. As volumes of fluid are withdrawn from the container, thereplacement air should be passed through a drying tube filled with equalparts of 8
40、to 20-mesh soda lime, oxalic acid, and 4 to 8-mesh anhydrouscalcium chloride, each product being separated from the other by aglass-wool plug.8.3 Gas SupplyUse oxygen of at least 99.6 % purity.8.4 Scrubber Tubes and Catalyst Packings as well as in-structions for their preparation are available from
41、the equip-ment manufacturer.9Fig. 1 illustrates the flow diagram andnames the reagents used.8.5 Carbon Dioxide Coulometer ReagentsCell solutionsto absorb CO2from the gas stream and convert it to a titratableacid and permit 100 % efficient coulometric titration.98.6 AcidVarious acids may be used for
42、acidification ofsamples. Hydrochloric acid is recommended. Phosphoric andsulfuric acids are suitable if they do not cause materials toprecipitate from the sample. Nitric acid is not recommendedbecause it may cause premature oxidation of organics in thesample.8.7 Organic Carbon Standard SolutionsAlth
43、ough themethod does not require sample standardization, proper opera-tion of the instrument should be confirmed by injection ofstandards of similar composition and concentration to theunknown. Standards should be stable water soluble compoundssuch as KHP or benzoic acid of suitable purity.9. Hazards
44、9.1 Injection of samples containing over 25 000 mg/L TOCor 0.5 mL water may cause explosion of the combustion tube.10. Sampling10.1 Collect the sample in accordance with PracticesD 3370 or other applicable ASTM method(s).10.2 Preservation:10.2.1 To preserve samples for this analysis, store or shipsa
45、mples in glass at or below 4C. Caution Head space in thesample bottle or freezing the sample may contribute to the lossof volatile organics from some samples.10.3 For monitoring of waters containing solids or immis-cible liquids of interest, use a mechanical homogenizer orultrasonic disintegrator to
46、 homogenize samples.10.4 For waste water streams where carbon concentrationsare greater than the desired range of instrument operation,provide on-stream dilution of the sample if possible.10.5 A1.1 gives additional guidelines for preparing heavilycontaminated water samples when using the sparge tech
47、nique.10.6 A1.2 gives additional guidelines for samples contain-ing solids and immiscible liquids.8Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar
48、Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.9Satisfactory reagents available from Coulometrics, Inc., a subsidiary of UICInc., P.O. Box 563, Joliet, IL, 60434 use
49、 ethanolamine to absorb CO2forminghydroxethylcarbamic acid that is titrated coulometrically using a color indicator forend-point detection.FIG. 2 CO2Evolution ApparatusD 4129 05311. Calibration and Standardization11.1 Set up the analyzer and fill coulometer cell in accor-dance with the manufacturers specifications. Adjust the gasflow to 80 to 100 mL/min. Set the readout to milligrams perlitre except when other than 0.200-mL samples are used inwhich case set the readout to micrograms.11.2 Analyze samples of carbon dioxide-free water asinstructed in Section 12 for s
