ASTM_D_2023_-_89_2016.pdf

Designation:D202389(Reapproved 2016)Standard Test Method ofAnalysis for Sodium Toluene Sulfonate in Detergents1This standard is issued under the fixed designation D2023;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 analysis for the apparentsodium toluene sulfonate(NaTS)content of detergents.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 and health practices and determine the applica-bility of regulatory limitations prior to use.Material SafetyData sheets are available for reagents and materials.Reviewthem for hazards prior to usage.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent Water3.Summary of Test Method3.1 This test method is based on the separation of the lowmolecular weight sulfonate from interfering higher molecularweight sulfonates and determination by ultraviolet absorption.The higher molecular weight sulfonates are extracted assulfonic acids in a hydrochloric acid solution using ethyl etheras the solvent.4.Significance and Use4.1 This test method is of use to anyone engaged incompositional analysis of detergent formulations.This wouldinclude formulators,and analysts employed by companies thatmanufacture the components usually included in such formu-lations.5.Interferences5.1 Any low molecular weight substituted benzene sul-fonate or benzene sulfonate(NaBS)itself will interfere andgive an apparent toluene sulfonate figure.Since the method isstandardized using p-toluene sulfonate,o-sulfonate will not beassayed correctly.When contamination is suspected,it shouldbe checked by running a complete absorption curve andcomparing with known samples.6.ApparatusNOTE1Absolute cleanliness of apparatus is essential.Use glassapparatus only.Contact with rubber,cork,or hands will introduceabsorbance errors.6.1 Separatory Funnels,500-mL capacity,glass-stoppered,pear-shaped.6.2 Balance,analytical.6.3 Spectrophotometer(Note 2),with necessary ultravioletaccessories for working in the range from 230 to 300 nm.These include 1.00 and 5.00-cm absorption cells with quartzwindows.NOTE2Details of the test method as written are based on the use ofthe Beckman DU or Cary recording spectrophotometers.Equivalentspectrophotometers also may be used,provided suitable modifications canbe made in the details of the method.7.Reagents7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water conformingto Specification D1193.1This 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 July 1,2016.Published August 2016.Originallyapproved in 1962 as D2023 62 T.Last previous edition approved in 2009 asD2023 89(2009).DOI:10.1520/D2023-89R16.2For 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.3Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,see Analar Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.3 Ethyl Ether.7.4 Hydrochloric Acid(sp gr 1.19)Concentrated hydro-chloric acid(HCl).7.5 Hydrochloric Acid(1+3)Mix 1 volume of concen-trated HCl with 3 volumes of water.7.6 p-Toluenesulfonic Acid Sodium Salt(NaTS)4Dry for24 h at 105C and store in a desiccator.Use for preparation ofstandards.7.7 Sodium Sulfate(Na2SO4),anhydrous.8.Precaution8.1 This test method includes ethyl ether extraction from anacidic solution.Appropriate safety practices,such as those