1、Designation: D5806 95 (Reapproved 2009)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 SyntheticAnionicActive Ingredientin Detergents by Cationic Titration Procedur
8、eD3049 Test Method for Synthetic Anionic Ingredient byCationic TitrationE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals33. Terminology3.1 DefinitionsSee Terminology D459.4. Summary of Test Method4.1 Disinfectant type quaterna
9、ry 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). In this potentiometr
10、ic 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 potential change l
11、arge enough to give awell defined inflection in the titration curve.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 Componen
12、ts.Current edition approved Oct. 1, 2009. Published March 2010. Originallyapproved in 1995. Last previous edition approved in 2003 as D5806-95(2003). DOI:10.1520/D5806-95R09.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For
13、Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 194
14、28-2959, United States.5. Significance and Use5.1 This test method is used to determine the percent activesin each type of the disinfectant quaternary ammonium salts,and also in the disinfectant products. Quaternary ammoniumcompounds being the active ingredients in disinfectant-typeproducts require
15、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 autoti-tration system.6.2 Nitrat
16、e Specific Ion Electrode,8or surfactant elec-trode,9or equivalent. Silver/silver chloride reference elec-trode.106.3 Metrohm Coaxial Adaptor, required for indicator elec-trode.11Banana plug adaptor, required for reference electrode.NOTE 1To ensure electrical continuity (after assembly), shake downel
17、ectrode 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 recommended. Alsoapplies to the ni
18、trate 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 use. Therefore, a ground
19、-glass sleeveelectrode12is suggested.7. Reagents7.1 Sodium Lauryl Sulfate,13primary standard (see Note3).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 D3049 before using as a p
20、rimarystandard.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.)7.7 Sodium Hydroxide, (NaOH)
21、, 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 well.7.9 Borate Buffer Solu
22、tionDissolve 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 Solution, 1 %Pipet 1 mL of the o
23、ctoxynol-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/E-535 and Dosimat/E-459, or
24、 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 Brinkmann Instruments Inc.8
25、Orion 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 found satisfactory.Availab
26、lefrom 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.13Available from British Drug
27、 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-alkyldimethylbenzylammonium
28、 chloride and n-alkyldimethylethylbenzylammonium chloridewhere:X= chloride, andR = aliphatic, normal C8C22.FIG. 2 Dialkyldimethyl quaternariesD5806 95 (2009)27.12 Sodium Lauryl Sulfate Solution, 8 3 103NWeighaccurately 2.42 6 0.01 g of sodium lauryl sulfate to nearest 0.1mg; dissolve in water and di
29、lute to a final volume of 1 L.Determine the normality of the solution with the followingequation:Normality of sodium lauryl sulfate 5W 3 P288.38! 100!(1)where:P = purity of the sodium lauryl sulfate, weight %, andW = weight of sodium lauryl sulfate, g.Keep the solution no longer than 1 month before
30、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 DisinfectantQuaternary Ammonium Salt or D
31、isinfectant 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 corresponding aliquot, then add a
32、pproximately150 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, reduce the addition ra
33、te 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 titration of 0.0056 meq use
34、the following equation:W 50.0056 3 MD(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 sample, it isconvenien
35、t 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 200-mLvolumetric flas
36、k, 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. Theendpoint is marked by the p
37、oint 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 quaternary ammonium com
38、pound weight % 5 (3)A 3 N3 M 3 D 3 100S 3 1000 3 A1where: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 sample, g,D = init
39、ial 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 to be 0.25 %abso
40、lute 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 of duplicates),o
41、btained 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 (each the average
42、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-decyldimethyl Am
43、monium 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 level) if they diff
44、er 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-octyldecyldimeth
45、ylammonium chloride, di-n-octyldimethylammoniumchloride, and di-n-decyldimethylammonium chloride (335),n-alkyldimethylbenzylammonium chloride (358), cetyltrimethylammo-nium chloride (320).D5806 95 (2009)3ASTM International takes no position respecting the validity of any patent rights asserted in co
46、nnection 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 time by the respo
47、nsible 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 receive careful
48、 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,
49、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 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).FIG. 3 Sample: n-alkyldimethylbenzylammonium chlorideTitrant: 0.008N Sodium lauryl sulfate. Using nitrate ion selective electr
