1、DEUTSCHE NORM March 1997 Surface active agents Determination of the amine oxide content of fatty alkyl dimethyl amine oxides English version of DIN EN 1791 I DIN I EN 1791 ICs 71.1 00.40 Descriptors: Surface active agents, amine oxide content, testing. Grenzflchenaktive Stoffe - Fettalkyldimethylami
2、noxide - Bestimmung des Aminoxidgehalts European Standard EN 1791:1997 has the status of a DIN Standard. A comma is used as the decimal marker. National foreword This standard has been prepared by CEN/TC 276. The responsible German body involved in its preparation was the Normenausschu Materialprfun
3、g (Materials Testing Standards Committee). DIN IS0 607 is the standard corresponding to International Standard IS0 607 referred to in clause 2 of the EN. EN comprises 8 pages. O No part of this standard may be reproduced without the prior permission of DIN Deutsches Institut fr Normung e.V., Berlin.
4、 Beutb Verlag GmbH, Berlin, has the exclusive right of sale for German Standards (DIN-Normen). Ref. No. DIN EN 1791: 1997-03 Sales No. 1706 11.97 English price group 06 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1791 February 1997 ICs 71.1 00.40 Descriptors: Surface active agents, amine ox
5、ide content, testing. English version Surface active agents Fatty alkyl dimethyl amine oxides Determination of the amine oxide content Agents de surface - Oxydes dalkyldimthylamine grasses - Dtermination de la teneur en oxyde damine Grenzflchenaktive Stoffe - Fettalkyldimethylaminoxide - Bestimmung
6、des Aminoxidgehalts This European Standard was approved by CEN on 1997-01-05. CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibli
7、ographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. The European Standards exist in three official versions (English, French, German). A version in any other language made by translation under the responsibility of
8、a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Por- tugal,
9、 Spain, Sweden, Switzerland, and the United Kingdom. GEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-IO50 Brussels O 1997. GEN - All rights of exploitation in any form and by any means reserved worldw
10、ide for CEN national members. Ref. No. EN 1791 : 1997 E Page 2 EN1791:1997 Contents Forword . 2 1 . Scope . 3 2 Normative references . 3 3 Principle 3 4 Reagents. 4 5 Apparatus . 4 6 Sampling 4 7 Procedure . 5 7.1 Titration of the sum : Amine oxide and tertiary amine 5 7.2 8 Expression of results 6
11、8.1 Calculation . 6 8.2 Precision 6 9 Test report 7 Annex A (informative) Instrument settings . 7 Annex B (informative) . 8 Polonovski reaction and titration of tertiary amine 5 Foreword This European Standard has been prepared by Technical Committee CENTTC 276 “Surface active agents. the secretaria
12、t of which is held by AFNOR . This European Standard shall be given the status of a national standard. either by publication of an identical text or by endorsement. at the latest by August 1997. and conflicting national standards shall be withdrawnat the latest by August 1997 . According to the CENI
13、CENELEC Internal Regulations. the national standards organizations of the following countries are bound to implement this European Standard: Austria. Belgium. Denmark. Finland. France. Germany. Greece. Iceland. Ireland. Italy. Luxembourg. Netherlands. Norway. Portugal. Spain. Sweden. Switzerland and
14、 the United Kingdom . Annexes A and 6 are informative . Page 3 EN 1791 : 1997 1 Scope This draft European Standard specifies a method for the determination of up to approximately 2 milli-equivalents of tertiary amine oxide. Components which lose their basicity in reaction with acetic anhydride by fo
15、rming an amide (e.9. primary and secondary amines) interfere. If present, these primary and secondary amines should be determined by a different procedure e.g. reaction with carbonsulfide. The method is applicable lo solids or to aqueous solutions of ?he aciive material. The molecular mass of the am
16、ine oxide shall be known if its content is expressed as a percsntage of mass. 2 Nonnative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications
17、are listed hereafter. For dated references, subsequent amendments to or revisions or any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the Iitest edition of the publication referred to applies. IS0 607 1980 Surface
18、 active agents and detergents - Methods of sample division IS0 1042 1983 Laboratory glassware - One-mark volumetric flasks 3 Principle This draft European Standard is based on the Polonovski reaction in which the fatty alkyldimethylamine oxide reacts with acetic anhydride to form a N,Ndisubstituted
19、acetamide and an aldehyde (see equation 1). Free tertiary amine, residual raw material of technical amine oxide, remains unreacted and after dissolution of the sample in mixture of acetic acid and acetic anhydride 2:l (as a volume fraction) is titrated with a perchloric acid solution (see equation 2
20、). In this medium the acetamide is not titrated. In a second titration the sum of amine oxide and tertiary amine is determined by potentiometric titration in acetic acid medium with a perchloric acid solution (see equation 3). R - N(CH3)zO + (CH3CO)zO + R - N(CH3)COCH3 + HCHO + CH3COOH .( I) R - N(C
21、H3)2 i HC104+ R - NH(CH3),CiO, .( 2) R-N(CH)O+R-N(CHJ) +2HC104 - R-N (CH3)2OH+CIO$ + R-NH(CH3)iCIOi .( 3) The difference between these two titrations (3 - 2) gives the amine oxide content. Page 4 EN 1791 :1997 4 Reagents During the analysis, use only reagents of recognized analytical grade and only
22、distilled water or water of equivalent purity. 4.1 Perchloric acid standard volumetric solution of known titre, c = 0,l mol/l in acetic acid. 4.2 Acetic acid, glacial (purity 99 O/O as a mass fraction (minimum), density 1 ,O5 g/ml at 20 OC). 4.3 Acetic anhydride (purity 99 % as a mass fraction (mini
23、mum), density 1,08 g/ml at 20 OC). 5 Apparatus Ordinary laboratory apparatus and the following : 5.1 Recording potentiometer equipped with a 20 ml plunger burette and stirrer NOTE : An example of instrument settings is given in annex A. 5.2 Combined glass electrode. 5.3 Magnetic stirrer with electri
24、cally heated hct plate, capable of maintaining a temperature of (100 f 5) OC. 5.4 Beaker, 150 ml capacity. 5.5 Measuring cylinder, 100 rnl capacity. 5.6 Conical flask, 100 ml capacity. 5.7 Reflux condenser. 5.8 Analytical balance. 6 Sampling The laboratory sample of the detergent shall be prepared a
25、nd stored in accordance with instructions given in IS0 607. Page 5 EN 1791 :I997 7 Procedure 7.1 Titration of the sum : Amine oxide and tertiary amine Weigh (rn?), to the nearest 0,l mg, a portion of the laboratory sample containing approximately 13 rnilli-equivalent of amine oxide into a 150 mi bea
26、ker (see 5.4j. Add 50 rnl acetic acid (see 4.2) with a measuring cylinder (see 5.5) and dissolve the sample. Place the beaker on the potentiometer (see 5.1) and insert a stimng bar. Insert the combined glass electrode (see 5.2) and start stirring. Titrate with the perchloric acid standard volumetric
27、 solution (see 4.1) until slightly beyond the potential jump and record the volume of perchloric acid solution necessary to reach equivalent point (V7) (see annex B). 7.2 Polonovski reaction and titration of tertiary amine Weigh (md, approximately 5 g to the nearest 1 O mg of the laboratory sample i
28、nto a conical flask (see 5.6). Add 25 ml of acetic anhydride (see 4.3) with a measuring cylinder and dissolve the sample. Insert a stirring Dar, place the flask on the the hot plate (see 5.3) and connect the reflux condenser (see 5.7). Heat to the boiling point and maintain a moderate reflux for 1 O
29、 min while stirring. Cool to room temperature and add 50 mi of acetic acid . Place the flask on the potentiometer (see 5.1). Insert the combined glass electrode (see 5.2) and start stirring. Titrate with the perchloric acid standard volumetric solution (see 4.1) until slightly beyond the potential j
30、ump and record the volume of perchloric acid solution necessary to reach the equivalent point (V2) (see annex B). Page 6 EN 1791 : 1997 8 Expression of results 8.1 Calculation The amine oxide content (A) expressed as a percentage by mass is given by the following equation : M xi00 1 O00 xcx- YO . .
31、. (4) where : V7 is the volume of the perchloric acid standard volumetric solution (see 4.1) necessary to reach the equivalence point in 7.1, in millilitres ; V2 is the volume of the perchloric acid standard volumetric solution necessary to reach the equivalence point in 7.2, in millilitres ; m7 is
32、the mass of the laboratory sample, weighed in 7.1, in grams ; m2 is the mass of the laboratory sample, weighed in 7.2, in grams ; C is the concentration of the perchloric acid standard volcmetric solution ; M is the mean molecular mass of the amine oxide. Express the result to one decimal place. 8.2
33、 Precision 8.2.1 Repeatability 0,8 % at a level of approximately 31 % tertiary amine oxide. In the normal and correct operation of the method, the difference between two individual results obtained within the shortest feasible time interval by the same operator using the same apparatus and identical
34、 test material will exceed the repeatability value on average not more than once in 20 cases. 8.2.2 Reproducibility 0,9 % at a level of approximately 31 % tertiary amine oxide. In the normal and correct operation of the method, individual results obtained by two different laboratories using identica
35、l test material will differ by more than reproducibility value on average no! more than once in 20 cases. Page 7 EN 1791 :i997 9 Testreport The test report shall include the following particulars : a) all information necessary for the complete identification of the sample ; b) the method used (a ref
36、erence to this European Standard) ; c) the results obtained and the way in which they have been expressed ; d) details of any operations not specified in this European Standard or in the International Standards to which reference is made, and any operations regarded as optional, as well as any incid
37、ents likely to have affected the results. Annex A (informative) instrument settings Data given are settings for the Metrohrn Potentiograph type E 536 and are intended to act as guide only : stop % u Autocontrol Min/lo0 % vol mVx 100 mV scale Recording mVlpH Tem perat Ure Scan speed Off 10 5 500 mVpH 100 Yo 25 OC 400 mm/l00 % vol. Page 8 EN 1791 :1997 1 Annex B (informative) nV Equivalent point - Figure B.l: Titration of the sum: Amine oxide and tertiary amine (see 7.1) Figure B.2: Titration of tertiary amine after Polonovski reaction (see 7.2)
