ASTM_D_4548_-_11_2019.pdf

Designation:D454811(Reapproved 2019)Standard Test Method forAnion-Cation Balance of Mixed Bed Ion-Exchange Resins1This standard is issued under the fixed designation D4548;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 determines the ratio between theequivalents of anion-exchange capacity and the equivalents ofcation-exchange capacity present in a physical mixture ofsalt-splitting anion-exchange material and salt-splitting cation-exchange material.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2187 Test Methods and Practices for Evaluating Physicaland Chemical Properties of Particulate Ion-ExchangeResins3.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard,refer toTerminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 anion-exchange material,nan ion-exchange mate-rial capable of the reversible exchange of negatively chargedions.3.2.2 cation-exchange material,nan ion-exchange mate-rial capable of the reversible exchange of positively chargedions.3.2.3 ion-exchange material,nan insoluble material thathas the ability to exchange reversibly certain ions in itsstructure or attached to its surface as functional groups withions in a surrounding medium.3.2.4 ion-exchange resin,na synthetic organic ion-exchange material.3.2.5 mixed bed,na physical mixture of anion-exchangematerial and cation-exchange material.3.2.6 salt-splitting,adjthe ability of anion-exchange orcation-exchange materials to exchange hydroxide or hydrogenions respectively for the ions in neutral salts.4.Summary of Test Method4.1 This test method consists of simultaneous conversion ofthe cation-exchange component to the hydrogen form and theanion-exchange component to the chloride form with hydro-chloric acid.After rinsing to remove the excess acid,thehydrogen ion from the cation resin and the chloride ion fromthe anion resin are simultaneously eluted with neutral sodiumnitrate,and the amount eluted is determined by titration of theeffluent for both ions.5.Significance and Use5.1 This test method is applicable to the analysis of newmaterials that are sold as mixtures and to samples taken fromregenerable units containing mixtures of anion-exchanging andcation-exchanging materials.It is used to determine the ratio ofthe components without separating them from each other.5.2 This test method is intended for mixtures of ion-exchange materials that have salt-splitting capacity as mea-sured by Test Method E of Test Methods and Practices D2187for cation-exchange resins,and Test Method H for anion-exchange resins.In the case of cation-exchange resins,theseare styrene-based polymers with sulfonic acid functionalgroups.The anion-exchanging materials in this class are1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.08 on Membranes and IonExchange Materials.Current edition approved Nov.1,2019.Published January 2020.Originallyapproved in 1986.Last previous edition approved in 2011 as D4548 11.DOI:10.1520/D4548-11R19.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,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 Organization Technical Barriers to Trade(TBT)Committee.styrene-based materials with quaternary ammonium functionalgroups.The test method will determine the amount of anion-exchange material of any functionality present in the mixture.However,when anionic groups that are not sal