1、Designation:E231308Standard Test Method forAldehydes in Mono-,Di-,and Triethylene Glycol(Spectrophotometric Method)1This standard is issued under the fixed designation E2313;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of
2、 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.Scope*1.1 This test method describes the spectrophotometric de-termination of total aldehyde carbonyl content in the range of0.5 to
3、 50 mg/kg(as acetaldehyde)or 0.3 to 35 mg/kg(asformaldehyde)in mono-,di-,and triethylene glycol(MEG,DEG and TEG).Alkoxyalcohols(hemiacetals),if present,areco-determined,whereas dialkoxyalkanes(acetals),if present,are not.The results provide a measure of the purity of thesample with respect to total
4、aldehyde carbonyl content.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 Review the current material Safety Data Sheets(MSDS)for detailed information concerning toxicity,first aid proce-dures and safety precautions.1.4 T
5、his 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
6、.1 ASTM Standards:2D1193 Specification for Reagent WaterD2194 Test Method for Concentration of FormaldehydeSolutionsE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)3E275 Practice for Describing and Measuring Pe
7、rformance ofUltraviolet and Visible SpectrophotometersE288 Specification for Laboratory Glass Volumetric FlasksE300 Practice for Sampling Industrial ChemicalsE969 Specification for Glass Volumetric(Transfer)Pipets2.2 Other Document:Manufacturers Instruction Manual of Spectrophotometer3.Summary of Te
8、st Method3.1 The total aldehyde carbonyl content of the sample isdetermined spectrophotometrically.The aldehydes present arereacted with excess 3-methyl-2-benzothiazolinone hydrazone(MBTH)to form azines.An aqueous solution of iron(III)chloride is added,causing the oxidation of the excess MBTH toa re
9、active cation,which reacts with the previously formedazines producing bluish-green cations.Acetone or methanol isadded to stop the oxidation reaction,to mask the excess MBTHand to obtain a clear solution.The absorbance of the testsolution is measured spectrophotometrically at 635 nm.Theamount of ald
10、ehyde present in the test solution is derived froma previously prepared calibration graph.The aldehyde contentofthesample,expressedaseitheracetaldehydeorformaldehyde,is calculated from the data obtained.4.Significance and Use4.1 Knowledge of the aldehyde content of Monoethyleneglycol is required to
11、establish whether the product meets therequirements of its quality specifications.5.Apparatus5.1 Spectrophotometer,suitable for measurement at a wave-length of 635 nm,provided with cells with a pathlength of 10mm.NOTE1Further information on spectrophotometers can be obtainedfrom Practice E275.5.2 An
12、alytical Balance,readable to 0.1 mg,calibrated.Calibrate and verify at regular intervals.5.3 Stopwatch,measuring accuracy 61 s or better.Calibrateor verify at regular intervals.5.4 Apparatus,as described in Test Method D2194.5.4.1 Buret,calibrated,100-mL,with a 50 or 75-mL reser-voir on top of a low
13、er portion calibrated in 0.1-mL divisions.APTFE-fluorocarbon resin stopcock is suitable for this purpose.1This test method is under the jurisdiction of ASTM Committee E15 onIndustrial and Specialty Chemicalsand is the direct responsibility of SubcommitteeE15.02 on Product Standards.Current edition a
14、pproved April 1,2008.Published May 2008.Originallyapproved in 2003.Last previous edition approved in 2004 as E2313 04.DOI:10.1520/E2313-08.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume inf
15、ormation,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohock
16、en,PA 19428-2959.United States1 5.4.2 Erlenmeyer Flask,approximately 5-mL capacity.5.4.3 Vials,specimen,short,style,approximately 5-mLcapacity.5.5 Glassware:NOTE2In cases where volumetric glassware is to be used,it shallconform to Grade(or Class)A specifications as described in,for example,Specification E288 for volumetric flasks,or Specification E969 forone-mark pipettes.5.5.1 Graduated Pipettes,capable of quantitatively transfer-ring between 0.5 and 5 mL,or5.5.2 Volumetric Pipette,0.5,1.0,2.0,
