ASTM_D_5806_-_95_2009.pdf

Designation:D580695(Reapproved 2009)Standard Test Method forDisinfectant Quaternary Ammonium Salts by PotentiometricTitration1This standard is issued under the fixed designation D5806;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 a potentiometric titration pro-cedure for determining active matter in disinfectant quaternaryammonium salts.This test method is intended for the analysisof quaternary ammonium salts used as disinfectants,and onlyapplies to the following commonly used quaternary ammoniumsalts:n-alkyldimethylbenzylammonium chloride(see Fig.1),cetyltrimethylammonium chloride,and a blend of n-octyldecyldimethylammonium chloride,di-n-octyl dimethylammoniumchloride,and di-n-decyldimethyl ammonium chloride(see Fig.2).Also,this test method can be applied to the analysis ofdisinfectant type products where the formula ingredients areknown and the quaternary ammonium salt is one of the above.Interferences such as amines oxides and betaines present indisinfectant formulations were not tested.1.2 This disinfectant quaternary ammonium salt conformsto the structures in Fig.1 and Fig.2.1.3 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 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.For specificprecautionary information,see Section 8.2.Referenced Documents2.1 ASTM Standards:2D459 Terminology Relating to Soaps and Other DetergentsD1193 Specification for Reagent WaterD1681 Test Method for Synthetic Anionic Active Ingredientin Detergents by Cationic Titration ProcedureD3049 Test Method for Synthetic Anionic Ingredient byCationic TitrationE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)33.Terminology3.1 DefinitionsSee Terminology D459.4.Summary of Test Method4.1 Disinfectant type quaternary ammonium compoundspresent,as the active materials in disinfectant type products aretitrated potentiometrically in an aqueous medium with astandard solution of sodium lauryl sulphate using a nitrateion-selective electrode or a surfactant electrode(see also TestMethod D1681).In this potentiometric titration,the reactioninvolves the formation of a complex between the disinfectantquaternary ammonium compound and the anionic surfactantwhich then precipitates.At the end point,the nitrate ionelectrode or surfactant electrode appears to respond to anexcess of titrant with a potential change large enough to give awell defined inflection in the titration curve.5.Significance and Use5.1 This test method is used to determine the percent activesin each type of the disinfectant quaternary ammonium salts,1This test method is under the jurisdiction of ASTM Committee D12 on Soapsand Other Detergents and is the direct responsibility of Subcommittee D12.12 onAnalysis and Specifications of Soaps,Synthetics,Detergents and their Components.Current edition approved Oct.1,2009.Published March 2010.Originallyapproved in 1995.Last previous edition approved in 2003 as D5806-95(2003).DOI:10.1520/D5806-95R09.2For 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 and also in the disinfectant products.Quaternary ammoniumcompounds being the active ingredients in disinfectant-typeproducts require accurate determination to assess the cost andantimicrobial performance of such products.6.Apparatus6.1 Autotitration System,4with 10-mL buret capacity,or20-mL buret capacity,magnetic stirrer,5evaluating ruler,6titroprocessor7with 10-mL buret capacity or equivalent auto-titration system.6.2 Nitrate Specific Ion Electrode,8or surfactant electrode,9or equivalent.Silver/silver chloride reference electrode.106.3 Metrohm Coaxial Adaptor,required for indicator elec-trode.11Banana plug adaptor,required for reference electrode.NOTE1To ensure electrical continuity(after assembly),shake downelectrode in the manner of a clinical thermometer.Also,the conditioningof the electrode is essential for obtaining a good break in the titrationcurve.Conditioning new electrodes in 0.004 M sodium lauryl sulfate,aqueous solution for 60 min(or more)prior to use is re