ASTM_D_5997_-_15.pdf

Designation:D599715Standard Test Method forOn-Line Monitoring of Total Carbon,Inorganic Carbon inWater by Ultraviolet,Persulfate Oxidation,and MembraneConductivity Detection1This standard is issued under the fixed designation D5997;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 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 on-line determination oftotal carbon(TC),inorganic carbon(IC),and total organiccarbon(TOC)in water in the range from 0.5 g/L to 50 000g L of carbon.Higher carbon levels may be determined bysuitable on-line dilution.This test method utilizes ultraviolet-persulfate oxidation of organic carbon coupled with a CO2selective membrane to recover the CO2into deionized water.The change in conductivity of the deionized water is measuredand related to carbon concentration in the oxidized sampleusing calibration data.Inorganic carbon is determined in asimilar manner without the requirement for oxidation.In bothcases,the sample is acidified to facilitate CO2recovery throughthe membrane.The relationship between the conductivitymeasurement and carbon concentration can be described by aset of chemometric equations for the chemical equilibrium ofCO2,HCO3,H+,and OH,and the relationship between theionic concentrations and the conductivity.The chemometricmodel includes the temperature dependence of the equilibriumconstants and the specific conductances resulting in linearresponse of the method over the stated range of TOC.See TestMethod D4519 for a discussion of the measurement of CO2byconductivity.1.2 This test method has the advantage of a very highsensitivity detector that allows very low detection levels onrelatively small volumes of sample.Also,the use of twomeasurement channels allows determination of IC in thesample independently of organic carbon.Isolation of theconductivity detector from the sample by the CO2selectivemembrane results in a very stable calibration with minimalinterferences.1.3 This test method was used successfully with reagentwater spiked with sodium carbonate and various organiccompounds.This test method is effective with both deionizedwater samples and samples of high ionic strength.It is theusers responsibility to ensure the validity of this test methodfor waters of untested matrices.1.4 This test method is applicable only to carbonaceousmatter in the sample that can be introduced into the reactionzone.The inlet system generally limits the maximum size ofparticles that can be introduced.Filtration may also be used toremove particles,however,this may result in removal oforganic carbon if the particles contain organic carbon.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,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 Equipment for Sampling Water and Steamin Closed Conduits(Withdrawn 2003)3D1193 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 ConduitsD4519 Test Method for On-Line Determination of Anionsand Carbon Dioxide in High Purity Water by CationExchange and Degassed Cation Conductivity3.Terminology3.1 Definitions:1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.03 on Sampling Water andWater-Formed Deposits,Analysis of Water for Power Generation and Process Use,On-Line Water Analysis,and Surveillance of Water.Current edition approved May 1,2015.Published August 2015.Originallyapproved in 1996.Last previous edition approved in 2009 as D5997 96(2009).DOI:10.1520/D5997-15.2For referenced ASTM 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.1 For definitions of terms used in this test method,referto Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 inorganic carbon(IC),ncarbon in the form ofcarbon dioxide,carbonate ion,or bicarbonate ion.3.2.2 refractory material,nthat which cannot be oxidizedcompletely under the test method conditions.3.2.3total carbon(TC),nthe