1、Designation: D5806 95 (Reapproved 2017)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 revis
2、ion, 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 disinf
3、ectant 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
4、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 th
5、e 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 ar
6、e 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 p
7、rior 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 Proced
8、ureD3049 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Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals (Withdrawn 2009)33.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 Disinfe
9、ctant 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). I
10、n 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
11、 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 S
12、oapsand Other Detergents and is the direct responsibility of Subcommittee D12.12 onAnalysis and Specifications of Soaps, Synthetics, Detergents and their Components.Current edition approved Jan. 1, 2017. Published February 2017. Originallyapproved in 1995. Last previous edition approved in 2009 as D
13、5806-95(2009). DOI:10.1520/D5806-95R17.2For 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 ver
14、sion 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization establi
15、shed in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1and also in the disinfectant products. Quaternary ammoniumcompounds being the active ingredients in disinfe
16、ctant-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-
17、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.NOTE 1To ensure electrical continuity (afte
18、r 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 recommend
19、ed. Alsoapplies to the nitrate or surfactant electrode.NOTE 2Other electrodes (for example, calomel electrodes) are suit-able as the reference electrode provided they give a stable referencepotential during the titration. Reference electrodes having a ceramic or anasbestos junction tend to clog with
20、 use. Therefore, a ground-glass sleeveelectrode12is suggested.7. Reagents7.1 Sodium Lauryl Sulfate,13primary standard (see Note 3).7.2 Standardize with Hyamine 1622, dried previously at105C for 1 h.NOTE 3Sodium lauryl sulfate must be analyzed for purity accordingto the Reagent section of Test Method
21、 D3049 before using as a primarystandard.7.3 Water, Type III, reagent water conforming to Specifica-tion D1193.7.4 Isopropanol, reagent grade. (WarningHighly flam-mable.)7.5 Sodium Borate Decahydrate, (Na2B4O710H2O), re-agent grade.7.6 Boric Acid, (H3BO3), reagent grade. (WarningCauses irritation.)7
22、.7 Sodium Hydroxide, (NaOH), reagent grade.(WarningCauses severe burns on contact with skin.)7.8 Sodium Hydroxide, 2N SolutionDissolve 40 g ofsodium hydroxide in approximately 300 mLof deionized waterwith stirring. Transfer to a 500-mL volumetric flask, dilute tovolume with deionized water, and mix
23、well.7.9 Borate Buffer SolutionDissolve 1.5 g Na2B4O710H2O and 1.0 g H3BO3in approximately 200 mL deionizedwater, with stirring; adjust pH to 9.5 with 2N HaOH, transferto a 1000-mL volumetric flask, mix and dilute to volume withdeionized water.7.10 Octoxynol-9 Nonionic Surfactant.147.11 Triton Solut
24、ion, 1 %Pipet 1 mL of the octoxynol-9nonionic surfactant and transfer to a 100-mL volumetric flaskdiluted to volume with deionized water.4Metrohm-Brinkmann E-536, or equivalent, has been found satisfactory. Avail-able from Brinkmann Instruments Inc., Cantiague Rd., Westbury, NY 11590.5Potentiograph/
25、E-535 and Dosimat/E-459, or equivalent, have been foundsatisfactory. Available from Brinkmann Instruments Inc.6Evaluating Ruler EA-893, or equivalent, has been found satisfactory. Availablefrom Brinkmann Instruments Inc.7Metrohm-Brinkmann Titroprocessor 670 has been found satisfactory.Availablefrom
26、Brinkmann Instruments Inc.8Orion Model 93.07, or equivalent, has been found satisfactory. Available fromOrion Research Inc., 529 Main St., Boston, MA 02129.9Orion Model 93.42, or equivalent, has been found satisfactory. Available fromOrion Research Inc.10Metrohm Model EA-440, or equivalent, has been
27、 found satisfactory.Availablefrom Brinkmann Instruments Inc.11The Metrohm coaxial adaptor, or equivalent, has been found satisfactory forthis purpose. Available from Brinkmann Instruments Inc.12The Metrohm WA-440, or equivalent, has been found satisfactory. Availablefrom Brinkmann Instruments Inc.13
28、Available from British Drug House, LTD, or in the U.S.A. from GallardSchlesinger Chemical Manufacturing Corp., 584 Mineola Ave., Carle Place, NY11514.14Triton-X-100 has been found satisfactory.Available from Fisher Scientific Cat.#BP151-100.where:X= chloride, andR = aliphatic, normal C8C22.FIG. 1 n-
29、alkyldimethylbenzylammonium chloride and n-alkyldimethylethylbenzylammonium chloridewhere:X= chloride, andR = aliphatic, normal C8C22.FIG. 2 Dialkyldimethyl quaternariesD5806 95 (2017)27.12 Sodium Lauryl Sulfate Solution, 8 103NWeighaccurately 2.42 6 0.01 g of sodium lauryl sulfate to nearest 0.1mg;
30、 dissolve in water and dilute to a final volume of 1 L.Determine the normality of the solution with the followingequation:Normality of sodium lauryl sulfate 5W 3P288.38!100!(1)where:P = purity of the sodium lauryl sulfate, weight %, andW = weight of sodium lauryl sulfate, g.Keep the solution no long
31、er than 1 month before making afresh solution.8. Hazards8.1 Handle all reagents and chemicals with care. Beforeusing any chemical, read and follow all safety precautions andinstructions of the manufacturer label or MSDS (MaterialSafety Data Sheet).9. Procedure for Determination of DisinfectantQuater
32、nary Ammonium Salt or Disinfectant TypeProduct9.1 Weigh accurately a quantity of sample to contain ap-proximately 0.056 meq/10 mL of disinfectant quaternaryammonium compound active material into a 200-mL volumet-ric flask (Note 4). Dilute to volume with deionized water. Mixwell. Pipet the correspond
33、ing aliquot, then add approximately150 mL of water and stir. While stirring, pipet in 10 mL of theborate buffer solution, 2 mL of isopropanol, and 2 mL of 1 %octoxynol-9 nonionic surfactant. Titrate potentiometricallywith standard sodium lauryl sulfate solution. As the inflectionpoint is approached,
34、 reduce the addition rate and continuetitrating well past the inflection in the titration curve. (Auto-matic titrators can be preset to automatically slow down theaddition rate as the inflection point is approached.)NOTE 4To determine the amount of sample needed for an approxi-mately 5 to 7 mL titra
35、tion of 0.0056 meq use the following equation:W 50.0056 3MD(2)where:W = weight of sample to be taken for analysis, g,M = average molecular weight of the anionic active matter present,andD = approximate concentration of anionic active matter expected,weight %.9.2 To obtain accurate sample weights of
36、sample, it isconvenient to dissolve the disinfectant quaternary ammoniumcompound in deionized water and take an aliquot correspond-ing to a known meq of active matter. For example, for adisinfectant quaternary ammonium compound containing28.0 % actives molecular weight 335, weigh 1.3 of sample intoa
37、 200-mLvolumetric flask, dilute with water, and take a 10-mLaliquot.Add 150 mL of water, 10 mL of borate buffer solution,2 mL of 1 % Triton solution, and 2 mL of isopropanol. Titratewith the standard 0.008 N solution of sodium lauryl sulfate.9.3 Record the titration volume at the end point. Theendpo
38、int is marked by the point of inflection on “S” shapedcurve and it is determined by the use of metrohm evaluatingruler. A typical titration curve of a disinfectant quaternaryammonium compound is shown in Fig. 3.10. Calculation10.1 Calculate the percent actives in the sample as follows:Disinfectant q
39、uaternary ammonium compound weight %5 (3)A 3N 3M 3D 3100S 31000 3A1where:A = standard sodium lauryl sulphate solution consumedduring titration, mL,N = normality of standard sodium lauryl sulfate solution,M = average equivalent weight of the disinfectant quater-nary ammonium compound,S = weight of sa
40、mple, g,D = initial sample dilution, mL (that is, 200 mL), andA1= aliquot taken for titration (that is, 10 mL).11. Precision and Bias11.1 Repeatability (Single Analyst)The standard deviationof results (each the average of duplicates), obtained by thesame analyst on differed days, has been estimated
41、to be 0.25 %absolute at 23 df. Two such averages should be consideredsuspect (95 % confidence level) if they differ by more than0.80 % absolute. (See Practice E180.)11.2 Reproducibility (Multilaboratory):11.2.1 n-Alkyldimethylbenzylammonium ChlorideThestandard deviation of results (each the average
42、of duplicates),obtained by analysts in different laboratories, has been esti-mated to be 0.24 % absolute at 23 df. Two such averagesshould be considered suspect (95 % confidence level) if theydiffer by more than 0.8 % absolute.11.2.2 Cetyltrimethylammonium ChlorideThe standarddeviation of results (e
43、ach the average of duplicates), obtainedby analysts in different laboratories, has been estimated to be0.38 % absolute at 23 df. Two such averages should beconsidered suspect (95 % confidence level) if they differ bymore than 1.4 % absolute.11.2.3 Blend of n-octyldecyldimethylammonium Chloride,Di-n-
44、decyldimethyl Ammonium Chloride and Di-n-decyldimethylammonium ChlorideThe standard deviation ofresults (each the average of duplicates), obtained by analysts indifferent laboratories, has been estimated to be 1.9 % absoluteat 23 df. Two such averages should be considered suspect(95 % confidence lev
45、el) if they differ by more than 4.4 %absolute.NOTE 5The precision data were derived from results of the coopera-tive tests by six laboratories on the following disinfectant quaternaryammonium salts: (equivalent weights in parentheses are based on com-mercial disinfectant quaternary ammonium salts)n-
46、octyldecyldimethylammonium chloride, di-n-octyldimethylammoniumchloride, and di-n-decyldimethylammonium chloride (335),n-alkyldimethylbenzylammonium chloride (358), cetyltrimethylammo-nium chloride (320).D5806 95 (2017)3ASTM International takes no position respecting the validity of any patent right
47、s asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any t
48、ime by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will
49、 receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555
