ASTM_D_2357_-_11.pdf

Designation:D235711Standard forQualitative Classification of Surfactants by InfraredAbsorption1This standard is issued under the fixed designation D2357;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 standard covers the qualitative classification ofsynthetic detergent products or mixtures of synthetic deter-gents.It is applicable to built detergent formulations as well asindividual surfactant compositions.NOTE1The organic active ingredient must be isolated from builtsyndet compositions in accordance with Test Method D2358.1.2 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:2D2358 Test Method for Separation ofActive Ingredient fromSurfactant and Syndet Compositions3.Summary of Classification3.1 A portion of the active ingredient is scanned in theinfrared region of the spectrum from at least 2.5 to 15 m(4000 to 667 cm1).Qualitative identification of surfactant typeis based on the presence of infrared absorption bands attribut-able to specific functional groups.3.2 A listing of absorbance bands corresponding to thecharacteristic functional groups of some of the more commontypes of commercial surfactants is included in this method.Useof available detergent reference spectra may provide additionalinformation.4.Apparatus4.1 Spectrophotometer,recording,infrared,or Fourier trans-form Infrared(FTIR if available).4.2 Dies and Press,for preparation of KBr disks.4.3 Detergent Reference Spectra.4.4 Appropriate Sampling AccessoriesATR,Diffuse re-flectance and others as appropriate.5.Reagents5.1 Potassium Bromide(KBr),infrared quality,powdered.5.2 Additional Reagents,as specified in Test MethodD2358.6.Preparation of Sample6.1 Sample in Pure FormIf the sample is in pure form orcontains only volatile solvents,dry the sample in accordancewith 5.8 of Test Method D2358,and obtain the infraredspectrum of the dried sample.6.2 ForBuiltSurfactantsandSyntheticDetergentCompositionsObtain the infrared spectrum of the activeingredient(s)separated in accordance with Test Method D2358.7.Procedure7.1 Whenever possible,the infrared spectrum should beobtained directly from the organic material,by formation of afilm between salt blocks,and by recording the spectrumbetween 2.5 and 15 m(4000 and 667 cm1).The film issatisfactory if the spectrum shows 10 to 30%transmittance inthe strongest absorbance region.7.2 Alternatively,the sample may be applied to an ATRcrystal and the spectrum collected according to the manufac-turers instructions.Care should be taken to use an appropriateATR crystal material as different crystals will produce inter-ference in different regions of the spectrum.Diamond crystalsare generally preferred for durability but they will produceinterference in the 3.85 to 5.5 m(2600 to 1800 cm1)regionof the spectrum.A correction factor may need to be applied tothe spectrum to change the absorbance values to what would beexpected in a transmission spectrum.most software packageshave algorithms to perform this correction.7.3 If the sample can be obtained in dry,powdered form,thediffuse reflectance or KBr pressed-disk method may be used.Grind the sample sufficiently fine to prevent radiation scatter,1This classification 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 Sept.1,2011.Published October 2011.Originallyapproved in 1965 as D2357 65 T.Last previous edition approved in 2003 asD2357 74(2003).DOI:10.1520/D2357-11.2For 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 and add approximately 1 part sample to 19 parts of drypowdered KBr.For diffuse reflectance load this mixture intothe accessory according to the manufacturers instructions.Toprepare a KBr disk,using suitable equipment,form the disk atroom temperature in vacuum,under pressure of 10 to 30tons/in.2(150 to 450 MPa).Obtain the spectrum of the samplebetween 2.5 and 15 m(4000 and 667 cm1)as in 7.1.37.4 Other sample accessories may be used to collect spectraprovided they work in the appropriate wavelength/frequencyrange and any interferences are known and accounted for in theinterp