ASTM_E_1151_-_93_2011.pdf

Designation:E115193(Reapproved 2011)Standard Practice forIon Chromatography Terms and Relationships1This standard is issued under the fixed designation E1151;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 practice deals primarily with identifying the termsand relationships of those techniques that use ion exchangechromatography to separate mixtures and a conductivity detec-tor to detect the separated components.However,most of theterms should also apply to ion chromatographic techniques thatemploy other separation and detection mechanisms.1.2 Because ion chromatography is a liquid chromato-graphic technique,this practice uses,whenever possible theterms and relationships identified in Practice E682.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety problems,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:2E682 Practice for Liquid Chromatography Terms and Rela-tionships3.Descriptions of Techniques3.1 Ion Chromatography,(IC)a general term for severalliquid column chromatographic techniques for the analysis ofionic or ionizable compounds.Of the many useful separationand detection schemes,those most widely used have been thetwo techniques described in 3.2 and 3.3 in which ion exchangeseparation is combined with conductimetric detection.Bydescribing only these two techniques,this practice does notmean to imply that IC is tied only to ion exchange chroma-tography or conductimetric detection.3.2 Chemically Suppressed Ion Chromatography,(DualColumn Ion Chromatography)In this technique,sample com-ponents are separated on a low capacity ion exchanger anddetected conductimetrically.Detection of the analyte ions isenhanced by selectively suppressing the conductivity of themobile phase through post separation ion exchange reactions.3.3 Single Column Ion Chromatography,(ElectronicallySuppressed Ion Chromatography)In this technique samplecomponents are separated on a low capacity ion exchanger anddetected conductimetrically.Generally,lower capacity ionexchangers are used with electronic suppression than withchemical suppression.Mobile phases with ionic equivalentconductance significantly different from that of the sample ionsand a low electrolytic conductivity are used,permitting analyteion detection with only electronic suppression of the baselineconductivity signal.4.Apparatus4.1 PumpsAny of various machines that deliver the mo-bile phase at a controlled flow rate through the chromato-graphic system.4.1.1 Syringe Pumps,having a piston that advances at acontrolled rate within a cylinder to displace the mobile phase.4.1.2 Reciprocating Pumps,having one or more chambersfrom which mobile phase is displaced by reciprocating pis-ton(s)or diaphragm(s).The chamber volume is normally smallcompared to the volume of the column.4.1.3 Pneumatic Pumps,employing a gas to displace themobile phase either directly from a pressurized container orindirectly through a piston or collapsible container.The vol-ume within these pumps is normally large as compared to thevolume of the column.4.2 Sample Inlet Systems,devices for introducing samplesinto the column.4.2.1 Septum InjectorsThe sample contained in a syringeis introduced directly into the pressurized flowing mobile phaseby piercing an elastomeric barrier with a needle attached to asyringe.The syringe is exposed to pressure and defines thesample volume.4.2.2 Valve InjectorsThe sample contained in a syringe(or contained in a sample vial)is injected into(or drawn into)1This practice is under the jurisdiction of ASTM Committee E13 on MolecularSpectroscopy and Separation Science and is the direct responsibility of Subcom-mittee E13.19 on Separation Science.Current edition approved Nov.1,2011.Published December 2011.Originallyapproved in 1993.Last previous edition approved in 2006 as E1151 93(2006).DOI:10.1520/E1151-93R11.2For 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 States1 an ambient-pressure chamber through which the pressurizedflowing mobile phase is subsequently diverted,after sealingagainst ambient pressure.The displacement is by means ofrotary or sliding motion.The chamber is a section(loop)oftubing or an internal