1、Designation: D5297 95 (Reapproved 2014)Standard Test Methods forRubber Chemical AcceleratorPurity by High PerformanceLiquid Chromatography1This standard is issued under the fixed designation D5297; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e 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 These test methods cover the determination of the purityof present commercially available r
3、ubber chemical acceleratorsin the range from 80 to 100 % by high performance liquidchromatography (HPLC) using ultraviolet detection and exter-nal standard calculations.1.2 Expertise in HPLC is necessary to the successful appli-cation of these test methods.1.3 The values stated in SI units are to be
4、 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 de
5、termine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D3853 Terminology Relating to Rubber and RubberLaticesAbbreviations for Chemicals Used in Com-poundingD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon
6、 Black ManufacturingIndustriesD4571 Test Methods for Rubber Compounding MaterialsDetermination of Volatile MaterialD4936 Test Method for Mercaptobenzothiazole SulfenamideAssay by Reduction/Titration2.2 ISO Standard:3ISO 6472 Rubber Compounding IngredientsAbbreviations3. Terminology3.1 Definitions:3.
7、1.1 external standard calculationa method of calculat-ing the percent composition by measuring the area of theanalyte peak, multiplying by a response factor, and dividing bythe sample concentration. All components are assumed to beresolved from the component of interest.3.1.2 lot samplea production
8、sample representative of astandard production unit, normally referred to as the sample.3.1.3 specimenalso known as the test portion, it is theactual material used in the analysis. It must be representative ofthe lot sample.3.2 Abbreviations:3.2.1 The following abbreviations are in accordance withTer
9、minology D3853 and ISO 6472:3.2.2 MBTSBenzothiazyl disulfide.3.2.3 MBS2-(morpholinothio)benzothiazole.3.2.4 CBSN-cyclohexyl-2-benzothiazolesulfenamide.3.2.5 TBBSN-t-butyl-2-benzothiazolesulfenamide.3.2.6 DIBSN,N- diisopropyl-2-benzothiazolesulfena-mide.3.2.7 DCBSN,N - dicyclohexyl-2-benzothiazolesul
10、fe-namide.3.2.8 DPGdiphenylguanidine.3.2.9 DOTGdi-o-tolylguanidine.4. Summary of Test Methods4.1 A specimen is dissolved in the appropriate solvent and afixed loop volume is analyzed by isocratic HPLC using athermostated C18 reversed phase column for materials 3.2.2 1These test methods are under the
11、 jurisdiction of ASTM Committee D11 onRubber and are the direct responsibility of Subcommittee D11.11 on ChemicalAnalysis.Current edition approved Aug. 1, 2014. Published November 2014. Originallyapproved in 1992. Last previous edition approved in 2009 as D5297 95 (2009).DOI: 10.1520/D5297-95R14.2Fo
12、r 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.3Available from American National Standards Institute (ANSI), 25
13、 W. 43rd St.,4th Floor, New York, NY 10036.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.7 and a silica normal phase column for materials 3.2.8 and3.2.9, and an ultraviolet (UV) detector. Peak areas are deter-mined using a chrom
14、atographic integrator or laboratory datasystem with the amount of analyte being determined byexternal calibration.5. Significance and Use5.1 These test methods are designed to determine the purityof rubber chemical accelerators.5.2 Since the results of these test methods are based on anintegrated pe
15、ak area, it is assumed that all analytes of interestare resolved from interfering peaks.6. Interferences6.1 Components co-eluting with the analyte of interest willcause erroneous results; thus it is required that the system becapable of providing a minimum of 10 000 theoretical plates.7. Apparatus7.
16、1 Liquid Chromatograph, consisting of the following:7.1.1 Precision chromatographic pump,7.1.2 Variable wavelength UV detector,7.1.3 A method for thermostating the column at 35 6 1C,for example, a column oven or water jacket, and7.1.4 A fixed loop injector with a nominal volume of 10mm3(L) or less.7
17、.2 HPLC Column:7.2.1 A C18 (ODS) reversed phase column packed withspherical, totally porous monomolecular 5-m particles ca-pable of providing 40 000 theoretical plates per metre. (Aminimum of 10 000 plates is required for this analysis.) Thiscolumn should be reserved for this analysis.7.2.2 For mate
18、rials 3.2.8 and 3.2.9, use a silica normal phasecolumn packed with spherical, totally porous 5-m particlescapable of providing 40 000 theoretical plates per metre. (Aminimum of 10 000 plates is required for this analysis.) Thiscolumn should be reserved for this analysis.7.3 Integrator/Data System, c
19、apable of determining abso-lute amounts of analyte of interest by means of integration ofdetector output versus time.7.4 Analytical Balance, capable of measuring within 60.01mg.8. Reagents and Materials8.1 Acetic Acid, glacial.8.2 Acetonitrile, HPLC grade.8.3 Chloroform, AR grade.8.4 Ethanol, HPLC g
20、rade.8.5 Ethanolamine.8.6 n-Hexane, HPLC grade.8.7 Methanol, HPLC grade.8.8 Water, HPLC grade.9. Calibration and Standardization9.1 Aprimary standard of known purity is used to determinethe response factor for each analyte.TEST METHOD ASULFENAMIDEACCELERATORPURITY10. Procedure10.1 Chromatographic Co
21、nditions:10.1.1 Determine the mobile phase composition and theflow rate by adjusting the chromatographic parameters for theparticular column chosen. The mobile phase consists of theappropriate mixture of HPLC grade acetonitrile and HPLCgrade or equivalent water, both containing 0.001 M glacialacetic
22、 acid or less depending on the particular column chosen.(HPLC grade methanol may be added to the acetonitrile/watereluent to achieve the necessary separation for DIBS andMBTS.)10.1.2 For the analysis of the sulfenamides, adjust the flowrate and mobile phase composition to provide a capacity factor,k
23、, in the range from 4 to 6 for the analyte of interest, and aminimum resolution, Rs, of 2 between the MBTS impurity andthe analyte of interest.NOTE 1Different liquid chromatography columns may exhibit differ-ent elution characteristics. Suggested chromatographic starting parametersfor analysis are a
24、s follows:PercentH2OAPercentAcetonitrileAPercentMethanolAFlow rate(cm3/min)DCBS 5 95 0 2.5CBS 20 80 0 2.0TBBS 30 70 0 1.7MBS 45 55 0 1.4DIBS 15 0 85 1.0AContaining 0.001 M glacial acetic acid.10.1.3 The capacity factor, k, is defined as the retentiontime of the analyte, tA, minus the retention time
25、of anunretained solute (solvent peak), to, divided by to:k 5 tA2 to!/to(1)10.1.4 The resolution, Rs, is a function of the capacityfactor, selectivity, and the theoretical plates of the column:Rs5t22 t1!1/2 tw11tw2!(2)where:t1,t2= retention times of the analyte and MBTS, andtw1,tw2= peak widths at 10
26、 % of the peak height.10.2 DetectorMonitor the absorbance of all componentsat 275 nm. The detector sensitivity should be set to 1absorbance unit full scale (AUFS).10.3 Integrator/Data SystemThe integrator settingsshould be adjusted to give a full-scale response to 1 absorbanceunit (AU).10.4 Standard
27、 PreparationWeigh at least 50 mg to thenearest 0.01 mg of the standard in a 50-cm3volumetric flaskand dilute to volume with acetonitrile. Adjust the standardconcentration if necessary by serial dilution with acetonitrile togive a maximum absorbance (peak height) between 0.4 and 0.8D5297 95 (2014)2AU
28、 (the linear range of the chromatographic system). Thestandard must be analyzed within4hofbeing diluted.NOTE 2Preparation of StandardsThe analytical standards areprepared by multiple recrystallizations of the sulfenamides. Dissolve 100g of the sulfenamide in 200 cm3of analytical reagent (AR) grade t
29、oluenewith slight warming.Add2gofactivated carbon and stir for 30 min. Filterthe hot solution by gravity and cool in an ice/acetone bath. Filter thecrystals with suction. Repeat this crystallization. Dissolve the analytecrystals from the second toluene crystallization in hot methanol, cool in anice/
30、acetone bath, and filter with suction. Repeat the alcohol recrystalliza-tion and dry at low pressure at 50C overnight. The procedure can berepeated until the desired purity is obtained. The purity of the standard isestimated by gradient HPLC analysis of the impurities and differentialthermal analysi
31、s (DTA). The purity of the standard should be reestimatedby HPLC of the impurities every 90 days. The standard should be storedat 5C or lower. Volatile matter and free amine content can be measuredusing Test Methods D4571 and Test Method D4936, respectively.10.5 Test PreparationTo ensure specimen ho
32、mogeneity, 5g of the lot sample should be ground with a mortar and pestle.10.6 Analysis:10.6.1 Weigh at least 50 mg to the nearest 0.01 mg of thespecimen into a 50-cm3volumetric flask. Dissolve in acetoni-trile (a sonic bath is recommended) and dilute to volume withacetonitrile. Adjust the concentra
33、tion, if necessary, by serialdilution with acetonitrile to give a maximum absorbance within10 % of the standard absorbance. Filter through a chemicallyresistant filter with a nominal pore size less than or equal to 0.5m. Analyze within4hofdilution. Chromatograph thestandard and measure the area.TEST
34、 METHOD BBENZOTHIAZOLEACCELERATORPURITY11. Procedure11.1 Chromatographic Conditions:11.1.1 Determine the mobile phase composition and theflow rate by adjusting the chromatographic parameters for theparticular column chosen. The mobile phase consists of theappropriate mixture of HPLC grade acetonitri
35、le and HPLCgrade or equivalent water, both containing 0.001 M glacialacetic acid or less depending on the particular column chosen.11.1.2 For the analysis of the benzothiazoles, adjust the flowrate and mobile phase composition to provide a capacity factor,k, in the range from 4 to 6 for the analyte
36、of interest, and aminimum resolution, Rs, of 2 between the MBTS impurity andthe analyte of interest.NOTE 3Different liquid chromatography columns may exhibit differ-ent elution characteristics. Suggested chromatographic starting parametersfor analysis are as follows:PercentH2OAPercentAcetonitrileAPe
37、rcentMethanolAFlow rate(cm3/min)MBT 65 35 0 2.0MBTS 20 80 0 2.0AContaining 0.001 M glacial acetic acid.11.1.3 The capacity factor, k, is defined as the retentiontime of the analyte, tA, minus the retention time of anunretained solute (solvent peak), to, divided by to:k 5 tA2 to!/to(3)11.1.4 The reso
38、lution, Rs, is a function of the capacityfactor, selectivity, and the theoretical plates of the column:Rs5t22 t1!1/2 tw11tw2!(4)where:t1,t2= retention times of the analyte and MBTS, andtw1,tw2= peak widths at 10 % of the peak height.11.2 DetectorMonitor the absorbance of all componentsat 275 nm. The
39、 detector sensitivity should be set to 1absorbance unit full scale (AUFS).11.3 Integrator/Data SystemThe integrator settingsshould be adjusted to give a full-scale response to 1 absorbanceunit (AU).11.4 Standard PreparationWeigh at least 50 mg to thenearest 0.01 mg of the standard in a 50-cm3volumet
40、ric flaskand dilute to volume with acetonitrile for MBT and chloroformfor MBTS. Adjust the standard concentration if necessary byserial dilution with acetonitrile to give a maximum absorbance(peak height) between 0.4 and 0.8 AU (the linear range of thechromatographic system). The standard must be an
41、alyzedwithin4hofbeing diluted.NOTE 4Preparation of StandardsThe analytical standards may beprepared by multiple recrystallizations of the benzothiazoles. The purity ofthe standard is estimated by gradient HPLC analysis of the impurities anddifferential thermal analysis (DTA). The purity of the stand
42、ard should bereestimated by HPLC of the impurities every 90 days. The standard shouldbe stored at 5C or lower.11.5 Test PreparationTo ensure specimen homogeneity, 5g of the lot sample should be ground with a mortar and pestle.11.6 Analysis:11.6.1 Weigh at least 50 mg to the nearest 0.01 mg of thespe
43、cimen into a 50-cm3volumetric flask. Dissolve MBT inacetonitrile and MBTS in chloroform (a sonic bath is recom-mended) and dilute to volume with acetonitrile for MBT andchloroform for MBTS. Adjust the concentration, if necessary,by serial dilution with acetonitrile to give a maximum absor-bance with
44、in 10 % of the standard absorbance. Filter with achemically resistant filter with a nominal pore size less than orequal to 0.5 m. Analyze within4hofbeing diluted.Chromatograph the standard and measure the area.TEST METHOD CGUANIDINE ACCELERATORPURITY12. Procedure12.1 Chromatographic Conditions:12.1.
45、1 Determine the mobile phase composition and theflow rate by adjusting the chromatographic parameters for theparticular column chosen. The mobile phase consists of theappropriate mixture of HPLC grade n-hexane, ethanol, andmethanol containing 0.01 M ethanolamine or less depending onthe particular co
46、lumn chosen.12.1.2 For the analysis of the guanidines, adjust the flowrate and mobile phase composition to provide a capacity factor,k, in the range from 6 to 8 for the analyte of interest.D5297 95 (2014)3NOTE 5Different liquid chromatography columns may exhibit differ-ent elution characteristics. S
47、uggested chromatographic starting parametersfor analysis are as follows:Percentm-HexanePercentEthanolAPercentMethanolAFlow rate(cm3/min)DPG 91 4 5 2.0DOTC 91 4 5 2.0AContaining 0.01 M ethanolamine.12.1.3 The capacity factor, k, is defined as the retentiontime of the analyte, tA, minus the retention
48、time of anunretained solute (solvent peak), to, divided by to:k 5 tA2 to!/to(5)12.2 DetectorMonitor the absorbance of all componentsat 240 nm. The detector sensitivity should be set to 1absorbance unit full scale (AUFS).12.3 Integrator/Data SystemThe integrator settingsshould be adjusted to give a f
49、ull-scale response to 1 absorbanceunit (AU).12.4 Standard PreparationWeigh at least 50 mg to thenearest 0.01 mg of the standard in a 50-cm3volumetric flaskand dilute to volume with 45/55 (v/v) ethanol/methanol.Adjustthe standard concentration if necessary by serial dilution withm-hexane to give a maximum absorbance (peak height) be-tween 0.4 and 0.8 AU (the linear range of the chromatographicsystem). The standard must be analyzed within4hofbeingdiluted.NOTE 6Preparation of StandardsThe analytical standards arepre
