1、Designation:D359011Standard Test Methods forTotal Kjeldahl Nitrogen in Water1This standard is issued under the fixed designation D3590;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses
2、indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 These test methods cover the determination of totalKjeldahl nitrogen.The following test methods are included:SectionsTest Method AManual Digestion/Distillation8
3、 13Test Method BSemiautomated Colorimetric Bertholt15 221.2 The analyst should be aware that precision and biasstatements included may not necessarily apply to the waterbeing tested.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstan
4、dard.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 determine the applica-bility of regulatory limitations prior to use.2.Referenced
5、Documents2.1 ASTM Standards:2D1129 Terminology Relating 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 Close
6、d ConduitsD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water Analysis3.Terminology3.1 DefinitionsFor definitions of terms used in these testmethods,refer to Terminology D1129.3.2 Definitions of Terms Specific to Th
7、is Standard:3.2.1 total Kjeldahl nitrogen,nthe sum of the nitrogencontained in the free ammonia and other nitrogen compounds,which are converted to ammonium sulfate(NH4)2SO4 underthe specified digestion conditions.4.Significance and Use4.1 These test methods are useful for measuring organicnitrogen
8、and ammoniacal nitrogen,which are essential growthnutrients.4.2 Nitrogen compounds are widely distributed in the envi-ronment.Sources of nitrogen include surface-appliedfertilizers,cleaning products,and drinking water treatmentaids.Because nitrogen is a nutrient for photosyntheticorganisms,it may be
9、 important to monitor and control dis-charge into the environment.5.Interferences5.1 Nitrate is known to cause a serious negative interferencein the test.Reportedly,a concentration of 250 mg/L NO3results in zero recovery of some level of N added as some Ncompound.5.2 The analyst is cautioned that am
10、monia in the laboratorymay easily become an interference in these test methods fromcontamination of reagents,caps,or from the laboratory atmo-sphere.Care should be taken that ammonium hydroxide,eitheras a reagent or as a cleaning substance,is not used in the sameroom.6.Purity of Reagents6.1 Reagent-
11、grade chemicals shall be used in all tests.Unless otherwise indicated,it is intended that all reagents shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society,where suchspecifications are available.3Other grades may be used,pro-vided it is first asc
12、ertained that the reagent is of sufficient highpurity to permit its use without lessening the accuracy of thedetermination.1These test methods are under the jurisdiction of ASTM Committee D19 onWater and are the direct responsibility of Subcommittee D19.05 on InorganicConstituents in Water.Current e
13、dition approved April 1,2011.Published April 2011.Originallyapproved in 1977.Last previous edition approved in 2006 as D3590 02(2006).DOI:10.1520/D3590-11.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStan
14、dards volume information,refer to the standards Document Summary page onthe ASTM website.3Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,and the United States Phar
15、macopeia andNational Formulary,U.S.Pharmaceutical Convention,Inc.(USPC),Rockville,MD.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.2 Purity of WaterUnless otherwise indi
16、cated,referenceto water shall be understood to mean reagent water conformingto Specification D1193,Type I.Other reagent water types maybe used 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 IIIwater was specified at the time of round-robin testing of thistest method.7.Sampling and Preservation7.1 Collect the sample in accordance with applicable Prac-tices D3370.7.2 Samples m