ASTM_D_5904_-_02_2009.pdf

Designation:D590402(Reapproved 2009)Standard Test Method forTotal Carbon,Inorganic Carbon,and Organic Carbon inWater by Ultraviolet,Persulfate Oxidation,and MembraneConductivity Detection1This standard is issued under the fixed designation D5904;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 determination of totalcarbon(TC),inorganic carbon(IC),and total organic carbon(TOC)in water in the range from 0.5 to 30 mg/L of carbon.Higher levels may be determined by sample dilution.The testmethod utilizes ultraviolet-persulfate oxidation of organiccarbon,coupled with a CO2selective membrane to recover theCO2into deionized water.The change in conductivity of thedeionized water is measured and related to carbon concentra-tion in the oxidized sample.Inorganic carbon is determined ina similar 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 is described by a set ofchemometric equations for the chemical equilibrium of CO2,HCO3,H+,and the relationship between the ionic concentra-tions and the conductivity.The chemometric model includesthe temperature dependence of the equilibrium constants andthe specific conductances.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,use of two measure-ment channels allows determination of CO2in the sampleindependently of organic carbon.Isolation of the conductivitydetector from the sample by the CO2selective membraneresults in a very stable calibration,with minimal interferences.1.3 This test method was used successfully with reagentwater spiked with sodium bicarbonate and various organicmaterials.It is the users responsibility to ensure the validity ofthis test method for 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 injector opening size generally limits the maximumsize of particles that can be introduced.1.5 In addition to laboratory analyses,this test method maybe applied to on line monitoring.1.6 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.7 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 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 this testmethod,refer to Terminology D1129.3.2 Definitions of 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 potassium hydrogen phthalate(KHP)KHC8H4O4.3.2.3 refractory materialthat which cannot be oxidizedcompletely under the test method conditions.1This 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 Oct.1,2009.Published November 2009.Originallyapproved in 1996.Last previous edition approved in 2002 as D590402.DOI:10.1520/D5904-02R09.2For 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 3.2.4 total carbon(TC)the sum of IC and TOC.3.2.5 total organic carbon(TOC)carbon in the form oforganic compounds.4.Summary of Test Method4.1 FundamentalsCarbon can occur in water as inorganicand organic compounds.This test method can be used to makeindependent measurements of IC and TC and can also deter-mine TOC as the difference of TC and IC.If IC is high relativeto TOC it is desirable to use a vacuum degass