ASTM D8083-2016 7938 Standard Test Method for Total Nitrogen and Total Kjeldahl Nitrogen (TKN) by Calculation in Water by High Temperature Catalytic Combustion and Chemiluminescenc.pdf

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1、Designation: D8083 16Standard Test Method forTotal Nitrogen, and Total Kjeldahl Nitrogen (TKN) byCalculation, in Water by High Temperature CatalyticCombustion and Chemiluminescence Detection1This standard is issued under the fixed designation D8083; the number immediately following the designation i

2、ndicates the year 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 determinati

3、on of totalnitrogen (TN) and total dissolved nitrogen (TDN) in surfacewater, seawater, groundwater, wastewater, and wastewatereffluents in the range from 0.210 mg/L N. Concentrationsfrom 10500 mg/L are possible when used in conjunction withmanual or automatic dilution, or automatic injection of less

4、sample volume. The EPA 40 CFR Part 136 Appendix BMethod Detection Limit (MDL) is 0.05 mg/L N. Higherconcentrations may be determined by sample dilution. Lowerconcentrations may be possible by injecting larger samplevolumes. Follow the manufacturers instructions.1.2 The sample is injected onto a plat

5、inum catalyst heated at720C. The sample converts into a gaseous phase and isforced through a layer of catalyst ensuring conversion of allnitrogen containing compounds to nitrogen oxide (NO). Reac-tion with ozone converts the NO to an exited NO2. As theexcited NO2returns to the ground state, it emits

6、 radiation thatis measured photo-electrically.1.3 Total and dissolved organic carbon analysis by TestMethod D7573 can be analyzed at the same time on the samesample simultaneously using a properly equipped analyzer.(See Appendix X1 for an example of simultaneous TOC data.)1.4 This test method quanti

7、tatively recovers nitrogen from alarge range of organic and inorganic nitrogen compounds (seeTable 1 and Table 2). The test method does not measurenitrogen gas (N2). It is the users responsibility to ensure thevalidity of this test method for waters of untested matrices.1.5 This test method is appli

8、cable only to nitrogenousmatter in the sample that can be introduced into the reactionzone. The syringe needle or injector opening size generallylimits the maximum size of particles that can be so introduced.Optional automatic sample homogenization may be used.1.6 This test method is performance bas

9、ed. You may makemodifications that improve the test methods performance butdo not change the oxidation or detection technique.1.7 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.8 This standard does not purport to address all

10、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 of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Rela

11、ting to WaterD1193 Specification for Reagent WaterD1426 Test Methods for Ammonia Nitrogen In WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD3590 Test Methods for Total Kjeldahl Nit

12、rogen in WaterD3867 Test Methods for Nitrite-Nitrate in WaterD4327 Test Method for Anions in Water by Suppressed IonChromatographyD4448 Guide for Sampling Ground-Water Monitoring WellsD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisD6089 Guide for

13、 Documenting a Groundwater SamplingEventD6538 Guide for Sampling Wastewater With AutomaticSamplersD6759 Practice for Sampling Liquids Using Grab and Dis-crete Depth SamplersD6919 Test Method for Determination of Dissolved Alkaliand Alkaline Earth Cations and Ammonium in Water andWastewater by Ion Ch

14、romatography1This 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.Current edition approved Dec. 1, 2016. Published February 2017. DOI: 10.1520/D8083-16.2For referenced AS

15、TM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoho

16、cken, 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 Organi

17、zation Technical Barriers to Trade (TBT) Committee.1D7573 Test Method for Total Carbon and Organic Carbon inWater by High Temperature Catalytic Combustion andInfrared DetectionD7781 Test Method for Nitrite-Nitrate in Water by NitrateReductase3. Terminology3.1 Definitions:3.1.1 For definitions of ter

18、ms used in this standard, refer toTerminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 dissolved inorganic nitrogen (DIN), nnitrogen in theform of ammonium, nitrate ion, or nitrite ion determined in afiltered sample.3.2.2 dissolved nitrogen (DN), nnitrogen determined in afilter

19、ed sample.3.2.3 dissolved organic nitrogen (DON), norganic nitro-gen determined in a filtered sample.3.2.4 particulate nitrogen (PN), nnitrogen bound to par-ticulate materials that do not pass through a filter.3.2.5 refractory material, nthat which cannot be com-pletely oxidized under the test metho

20、d conditions.3.2.6 total inorganic nitrogen (TIN), nnitrogen in the formof ammonium ion, nitrite ion, or nitrate ion.3.2.7 total Kjeldahl nitrogen (TKN), nthe sum of nitrogencontained in free ammonia and other nitrogen compoundswhich are converted to ammonium sulfate (NH4)2SO4 underthe conditions of

21、 Test Method D3590.3.2.8 total nitrogen (TN), nthe sum of TIN and TON.3.2.9 total organic nitrogen (TON), nnitrogen in the formof organic compounds.4. Summary of Test Method4.1 FundamentalsNitrogen can occur in water as inor-ganic or organic compounds, or both. This test method can beused to measure

22、 TN, and can also determine TON by thedifference of TN and TIN measured by other methods, such asTest Method D4327 plus Test Method D6919, Test MethodD1426 plus Test Method D7781, or Test Methods D1426 plusTest Method D3867. DON is determined on samples that havebeen filtered through a quartz fiber

23、filter.4.2 TON and DON procedures require that samples havebeen preserved with acid before it is analyzed for organicnitrogen content.4.3 TN minus nitrate nitrite nitrogen is equivalent to TKN inmost samples.5. Significance and Use5.1 This test method is used for determination of the total ordissolv

24、ed nitrogen content of water from a variety of natural,domestic, and industrial sources. In its most common form, thistest method is used to measure nitrogen as a means ofmonitoring nutrient pollutant in industrial wastewater, domes-tic wastewater, and ambient water. These measurements mayalso be us

25、ed in monitoring waste treatment processes.5.2 This test method measures oxidized ammonia and or-ganic nitrogen (as nitrate) and soluble nitrate simultaneously,subtracting the nitrate + nitrite value from a non-digestedsample gives total Kjeldhal nitrogen (TKN).TN 5 TKN1NO32 N!1NO22 N!TKN 5 NH32 N1O

26、rganic NWhen using this test method:TN 5 Digested Sample 2 Non-Digested SampleTKN 5 TN 2 NO32 N 1 NO22 N#where:TN = total nitrogen, andTKN = total Kjeldahl nitrogen.6. Interferences6.1 The conversion of dissolved inorganic and organicnitrogen to NO is brought about at high temperatures (720C)in the

27、presence of oxygen. A catalyst promotes the process andthe resulting nitrogen oxide is converted by ozone to nitrogendioxide (NO2). The NO2is measured by a chemiluminescencedetector. Suspended and refractory materials are completelyoxidized under these conditions.6.2 Acid preservation minimizes inte

28、rference that can causeresults to be low.TABLE 1 Nitrogen Recoveries from Various Compounds inPresence of Organic CarbonCompound Nitrogen ppm CarbonPotassium Nitrate (100 ppm N) 100% 0Potassium Hydrogen Phthalate (0 ppm) ND 100Acetonitrile (58.6 ppm N) 104% 100Caffeine (58.9 ppm N) 90% 100Nicotinic

29、Acid (20 ppm N) 99% 100Urea (233 ppm) 91% 100Nicotinic Acid (100 ppm N) 97% 98%TABLE 2 Nitrogen Recoveries for a Range of Nitrogen SourcesCompound TN (mg/L) Recovery (%)Ammonium Chloride 0.01 102Ammonium Sulfate 2 102Ammonium Sulfate 100 100Aniline 0.014 101Arginine 0.007 99Calcium Nitrate 10 99Glut

30、amic Acid 0.013 98Glycine 0.016 103L-glutamic Acid 2 1021,6-Hexanediamine 50 101Imidazole 0.011 100Nitro aniline 50 100Nitro phenol 50 102Potassium Nitrate 10 99Potassium Nitrate 0.009 99Potassium Nitrate 50 105Proline 0.01 99RNA 0.018 103Sodium Nitrite 0.009 101Tri-peptide (Glu-Cys-Gly) 0.014 99Try

31、ptophan 0.009 103Urea 0.013 99D8083 1626.3 Total organic carbon (TOC) up to 300 mg/L does notinterfere. Dissolved salts up to 31 000 mg/L do not interfere.6.4 Homogenizing may be necessary for samples with ahigh particulate loading.6.5 Inorganics dissolved in the sample are not volatilizedinto gas a

32、nd remain on the catalyst or quartz surface of thecombustion tube. High amounts of solids eventually react withthe quartz causing devitrification, or solidify in the catalyst beddecreasing flow rates. Limit sample volume injected to reducethe amount of soluble salts and to reduce cooling of thereact

33、ion chamber. Buildup of salts; reduction of flow rate, orlarge injection volumes could result in peak splitting.7. Apparatus7.1 Sampling Devices, manually operated or automaticallyoperated sampling valves, or syringes are typically used withthis test method.7.2 Apparatus for Nitrogen DeterminationTh

34、is instru-ment consists of reagent and sample introduction mechanism,the high temperature combustion chamber with catalyst, anozone generator, a NO2-specific chemiluminescence detector, acontrol system, and a display. Fig. 1 shows a diagram of suchan arrangement.7.2.1 Combustion ChamberA heated cata

35、lyst contained ina quartz tube, may contain quartz wool, quartz shards, or otheritems to protect the catalyst from dissolved salts to extend itslife.7.2.2 Ozone Generator, converts NO gas emerging from thecombustion chamber to NO2.7.2.3 DetectorThe excited NO2in the gas stream relaxingto ground stat

36、e NO2is detected by a NO2-specific chemilumi-nescence detector.7.2.4 Detector ResponseArea integration accurately quan-tifies nitrogen content in the event of split or overlapping peaksthat result from furnace cooling or variable combustion rates ofdifferent organic molecules contained in a sample.7

37、.2.5 Presentation of ResultsThe detector output is relatedto stored calibration data and then displayed as milligrams ofnitrogen per litre.8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents sha

38、ll conform to the specifications of the commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may beused, provided it is pure enough to be used without lesseningthe accuracy of the determination.8.2 Purity of WaterUnless otherwise in

39、dicated, referencesto water shall be understood to mean reagent water conformingto Specification D1193, Type I or Type II.8.3 AcidAcid is used for sample preservation and inter-ference removal. Follow the manufacturers suggestions foracid and acid concentration. Do not use nitric acid.8.4 Total Nitr

40、ogen Stock Calibration Standard Solution(1000 mg/L)Weigh 3.609 g of potassium nitrate (KNO3) and2.360 g of ammonium sulfate (NH4)2SO4) previously dried fortwo hours at 120C and quantitatively transfer to a 1000-mLvolumetric flask containing about 500 mLof reagent water. Stirto dissolve and add 1 mL

41、of concentrated hydrochloric acid(HCl), dilute to the mark with reagent water and mix. Transferto an amber glass reagent bottle and cap for storage. This stocksolution, or dilutions of it, is used to calibrate and testperformance of the nitrogen analyzer.NOTE 1Alternative nitrogen compounds, such as

42、 glycine, may beused as the stock calibrant providing all QC acceptance criteria is met.8.5 Total Nitrogen, Stock Laboratory Control Sample (LCS)Solution (1000 mg/L)Weigh 7.218 g of potassium nitrate(KNO3) previously dried at 120C for two hours and quanti-tatively transfer to a 1000-mL volumetric fl

43、ask containingabout 500 mL of reagent water. Stir to dissolve and add 1 mLof concentrated hydrochloric acid (HCl), dilute to the mark3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the Ame

44、rican 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 Diagram of ApparatusD8083 163with reagent water and mix. Transfer to an amber

45、 glass reagentbottle and cap for storage. This solution, or dilutions of it, isused to verify calibration accuracy and test performance of thenitrogen analyzer.8.6 Organic Nitrogen, Stock TON Test Solution (1000mg/L)Weigh 7.964 g of glycine (C2H4NO2-HCL) and trans-fer to a 1000-mL volumetric flask c

46、ontaining about 500 mL ofreagent water. Mix to dissolve, dilute to the mark, and mix.8.7 Calibration SolutionsTN.8.7.1 TN Calibration SolutionsAt least four calibrationconcentrations and a calibration blank (CB) are used to preparean initial calibration curve. Standards are prepared to cover theconc

47、entration of interest from the total nitrogen stock calibra-tion solution. Calibration standards are prepared in reagentwater and preserved to pH 2 with concentrated H2SO4.Filtration of these standards is unnecessary. These standardsmay be used for TN and DN calibrations. The calibration blank(CB) s

48、hould be compensated either by running a 0.0 mg N/Lstandard or by blank subtraction. These standards, if stored inthe dark, are stable for about 30 days and may be used torecalibrate the instrument within the 30-day period. See Table3 for an example of calibration standard preparation. Differentcali

49、bration standards may be needed depending upon theconcentration of nitrogen in the samples analyzed.8.8 Gas SupplyHigh-purity compressed air or high purityoxygen free of CO2and of organic matter is required. Use gaspurity as specified by the equipment manufacturer.9. Sampling and Sample Preservation9.1 Collect the sample in accordance with Practices D3370,Guide D4448, Guide D6538, or Practice D6759. Document thefield activities according to Guide D6089.9.2 To preserve samples for this analysis, store samples inhigh density polyethylene or