1、Designation: D4839 03 (Reapproved 2011)Standard Test Method forTotal Carbon and Organic Carbon in Water by Ultraviolet, orPersulfate Oxidation, or Both, and Infrared Detection1This standard is issued under the fixed designation D4839; 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of totalcarb
3、on (TC), inorganic carbon (IC), and total organic carbon(TOC) in water, wastewater, and seawater in the range from 0.1mg/L to 4000 mg/L of carbon.1.2 This test method was used successfully with reagentwater spiked with sodium carbonate, acetic acid, and pyridine.It is the users responsibility to ens
4、ure the validity of this testmethod for waters of untested matrices.1.3 This test method is applicable only to carbonaceousmatter in the sample that can be introduced into the reactionzone. The syringe needle or injector opening size generallylimit the maximum size of particles that can be so introd
5、uced.1.4 In addition to laboratory analyses, this test method maybe applied to stream monitoring.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any
6、, 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 of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1192 Guide for
7、Equipment for Sampling Water and Steamin Closed Conduits3D1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD4129 Test Method for Total and Organic Carbo
8、n in Waterby High Temperature Oxidation and by Coulometric De-tectionD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water Analysis3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method, referto Terminology D1129.3.2 Definitions o
9、f Terms Specific to This Standard:3.2.1 inorganic carbon (IC)carbon in the form of carbondioxide, carbonate ion, or bicarbonate ion.3.2.2 total organic carbon (TOC)carbon in the form oforganic compounds.3.2.3 total carbon (TC)the sum of IC and TOC.3.2.4 refractory materialthat which cannot be oxidiz
10、edcompletely under the test method conditions.4. Summary of Test Method4.1 FundamentalsCarbon can occur in water as an inor-ganic and organic compound. This test method can be used tomake independent measurements of IC, TOC, and TC, and canalso determine IC by the difference of TC and TOC, and TOCas
11、 the difference of TC and IC.4.2 The essentials of this test method are: (a) removal of IC,if desired, by acidification of the sample and sparging bycarbon-free gas; (b) conversion of remaining carbon to CO2byaction of persulfate, aided either by elevated temperature orultraviolet (UV) radiation; (c
12、) detection of CO2that is sweptout of the reactor by a gas stream; and (d) conversion ofdetector signal to a display of carbon concentration in mg/L. Adiagram of suitable apparatus is given in Fig. 1.5. Significance and Use5.1 This test method is used for determination of the carboncontent of water
13、from a variety of natural, domestic, andindustrial sources. In its most common form, this test methodis used to measure organic carbon as a means of monitoring1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.06 on Methods
14、forAnalysis forOrganic Substances in Water.Current edition approved May 1, 2011. Published June 2011. Originallyapproved in 1988. Last previous edition approved in 2003 as D4839 03. DOI:10.1520/D4839-03R11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer
15、Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box
16、 C700, West Conshohocken, PA 19428-2959, United States.organic pollutants in industrial wastewater. These measure-ments are also used in monitoring waste treatment processes.5.2 The relationship of TOC to other water quality param-eters such as chemical oxygen demand (COD) and total oxygendemand (TO
17、D) is described in the literature.46. Interferences and Limitations6.1 The oxidation of dissolved carbon to CO2is broughtabout at relatively low temperatures by the chemical action ofreactive species produced by hot or UV-irradiated persulfateions. Even if oxygen is used as the sparging gas, it make
18、s amuch lower contribution to oxidation than in high-temperature(combustive) systems. Not all suspended or refractory materialmay be oxidized under these conditions; analysts should takesteps to determine what recovery is being obtained. This maybe done by several methods: (a) by monitoring reaction
19、progress to verify that oxidation has been completed; (b)byrerunning the sample under more vigorous reaction conditions;(c) by analyzing the sample by an alternative method, such asTest Method D4129, known to result in full recovery; or (d)byspiking samples with known refractories and determiningrec
20、overy.6.2 Chloride ion tends to interfere with oxidative reactionmechanisms in this test method, prolonging oxidation timesand sometimes preventing full recovery. Follow manufactur-ers instructions for dealing with this problem. See AppendixX1 for supporting data.6.3 Homogenizing or sparging of a sa
21、mple, or both, maycause loss of purgeable organic compounds, thus yielding avalue lower than the true TOC level. (For this reason, suchmeasurements are sometimes known as nonpurgeable organiccarbon (NPOC). The extent and significance of such lossesmust be evaluated on an individual basis. This may b
22、e done bycomparing the TOC by difference (TC-IC) with the direct TOCfigure, that is, that obtained from a sparged sample. Thedifference, if any, between these TOC figures representspurgeable organic carbon (POC) lost during sparging. Alterna-tively, direct measurement of POC can be made duringspargi
23、ng, using optional capabilities of the analyzer.6.4 Note that error will be introduced when the method ofdifference is used to derive a relatively small level from twolarge levels. For example, a ground water high in IC and lowin TOC will give a poorer TOC value as (TC-IC) than by directmeasurement.
24、7. Apparatus7.1 Homogenizing ApparatusA household blender is gen-erally satisfactory for homogenizing immiscible phases inwater.7.2 Sampling DevicesMicrolitre-to-millilitre syringes aretypically required for this test method. Alternatives includemanually operated or automatically operated sampling v
25、alves.Sampling devices with inside diameters as small as 0.15 mmmay be used with samples containing little or no particulatematter. Larger inside dimensions such as 0.4 mm will berequired for samples with particulate matter.NOTE 1See 6.1 concerning oxidation of particulate matter.7.3 Apparatus for C
26、arbon DeterminationThis instrumentconsists of reagent and sample introduction mechanism, agas-sparged reaction vessel, a gas demister or dryer, or both, anoptional CO2trap, a CO2-specific infrared detector, a controlsystem, and a display. Fig. 1 shows a diagram of such anarrangement.7.3.1 Sparging r
27、equires an inert vessel with a capacity of atleast double the sample size with provision for sparging with50 to 100 mL/min of carbon free gas. This procedure willremove essentially all IC in 2 to 10 min, depending on design.7.3.2 OxidationThe reaction assembly contains reagentand sample introduction
28、 devices, and a reactor vessel withsparging flow of carbon-free gas. The vessel may be heated byan external source, and may contain a UV lamp. The reactionvessel and sparging vessel (see 6.3) may be combined.7.3.3 Gas ConditioningThe gas passing from the reactoris dried, and the CO2produced is eithe
29、r trapped and laterreleased to the detector, or routed directly to the detectorthrough a chlorine-removing scrubber.7.3.4 DetectorThe CO2in the gas stream is detected by aCO2-specific nondispersive infrared (NDIR) detector.7.3.5 Presentation of ResultsThe NDIR detector output isrelated to stored cal
30、ibration data and then displayed as milli-grams of carbon per litre.8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended that4Handbook for Monitoring Industrial Wastewater, Section 5.3, U.S. Environ-ment Protecti
31、on Agency, August 1973, pp. 512.FIG. 1 Diagram of ApparatusD4839 03 (2011)2all reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society,5where such specifications are available. Other grades may beused, provided it is first ascertained that the r
32、eagent is ofsufficient purity to permit its use without lessening the accu-racy of the determination.8.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Specification D1193, Type I or Type II. The indicatedspecification does not ac
33、tually specify inorganic carbon ororganic carbon levels. These levels can affect the results of thistest method, especially at progressively lower levels of thecarbon content in the samples to be measured. Where inorganiccarbon in reagent water is significant, CO2-free water may beprepared from reag
34、ent water by acidifying to pH 2, thensparging with fritted-glass sparger using CO2-free gas (timewill depend on volume and gas flow rate, and should bedetermined by test). Alternatively, if the carbon contribution ofthe reagent water is known accurately, its effect may beallowed for in preparation o
35、f standards and other solutions.CO2-free water should be protected from atmospheric contami-nation. Glass containers are required for storage of water andstandard solutions.8.3 AcidVarious concentrated acids may be used foracidification of samples and of the oxidizing reagent. Acidssuch as phosphori
36、c (sp gr 1.69), nitric (sp gr 1.42), or sulfuric(sp gr 1.84) are suitable for most applications. Sulfuric acidshould be used in the form of a 1 + 1 dilution, for safetyreasons. Hydrochloric acid is not recommended.8.4 Organic Carbon, Standard Solution (2000 mg/L)Choose a water-soluble, stable reagen
37、t grade compound, suchas benzoic acid or anhydrous potassium hydrogen phthalate(KHC8H4O4). Calculate the weight of compound required tomake 1 L of organic carbon standard solution; for example,KHC8H4O4= 0.471 g of carbon per gram, so one litre of 2 g/Lof standard requires 2/0.471, or 4.25, grams of
38、KHP. Dissolvethe required amount of standard in some CO2-free water in a1-L volumetric flask, add 1 mL of acid, and dilute to volume.This stock solution, or dilutions of it, may be used to calibrateand test performance of the carbon analyzer.8.5 Persulfate SolutionPrepare by dissolving the appro-pri
39、ate weight of potassium or sodium persulfate in 1 Lof water,to produce the concentration specified by the instrumentmanufacturer. If specified, add 1 mL of phosphoric acid (sp gr1.69) and mix well. Store in a cool, dark place. Recipes for thisreagent solution may be modified by manufacturers to meet
40、 theneeds of specific applications, for example, high chloridesamples.8.6 Gas SupplyA gas free of CO2and of organic matter isrequired. Use a purity as specified by the equipment manufac-turer. The use of oxygen is preferred for the UV-persulfatemethod, and nitrogen or helium is preferred if a CO2tra
41、p isused between reactor and detector.9. Sampling and Sample Preservation9.1 Collect the sample in accordance with SpecificationD1192 and Practice D3370.9.2 To preserve samples for this analysis, store samples inglass at 4C. To aid preservation, acidify the samples to a pHof 2. It should be noted th
42、at acidification will enhance loss ofinorganic carbon. If the purgeable organic fraction is important,fill the sample bottles to overflowing with a minimum ofturbulence and cap them using a fluoropolymer-lined cap,without headspace.9.3 For monitoring of waters containing solids or immis-cible liquid
43、s that are to be injected into the reaction zone, usea mechanical homogenizer or ultrasonic disintegrator. Filteringor screening may be necessary after homogenization to rejectparticle sizes that are too large for injection. Volatile organicsmay be lost. See 6.3.9.4 For wastewater streams where carb
44、on concentrations aregreater than the desired range of instrument operation, dilutethe samples as necessary.10. Instrument Operation10.1 Follow the manufacturers instructions for instrumentwarm-up, gas flows, and liquid flows.11. Calibration11.1 Use the stock solution of 2000 mg/L of carbon, andvari
45、ous dilutions of it, for calibration.NOTE 2Dilutions should be made with CO2-free water (see 8.2).11.2 Calibration protocols may vary with equipment manu-facturers. However, in general, calibrate the instrument inaccordance with the manufacturers instructions, and usestandards to verify such calibra
46、tion in the specific range ofinterest for actual measurements. Plots of standard concentra-tion versus instrument reading may be used for calibration or toverify linearity of response.11.3 Establish instrument blank according to the manufac-turers instructions.12. Procedure12.1 Mix or blend each sam
47、ple thoroughly and carry out anynecessary dilution to bring the carbon content within range ofthe instrument.12.2 If inorganic carbon is to be measured directly, injectthe sample into the analyzer under appropriate conditions.12.3 If inorganic carbon is to be removed by sparging priorto sample intro
48、duction, acidify to approximately pH 2 withconcentrated acid (if not already done) and sparge with anappropriate flow of gas. Samples with high alkali content orbuffer capacity may require larger amounts of acid. In suchcases, incorporate this dilution into the calculation. If incom-plete sparging o
49、f CO2from IC is suspected, sparge and analyzethe sample and then repeat the procedure until appropriateconditions are established. In difficult conditions, use of afritted-glass sparger may help.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing 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. Pharmaceutical Convention, Inc. (US
