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1、INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXAYHAPOAHAR OPrAHM3AMR n0 CTAHAPTkl3Al stopper the flask or measuring cylinder and shake well after each addition. The lower layer of chloroform will be coloured pink. As the end poin
2、t approaches, the emulsions formed during shaking tend to break easily and the coloration of the chloroform layer becomes fainter. From this point, continue the titration drop by drop, shaking after each addition of titrant, until the end-point is reached. This is at the moment when the pink colour
3、is completely discharged from the chloroform layer, which turns a faint greyish blue. With excess of test solution A, the chloroform layer turns blue. Note the volume of test solution A required for the titration. 8 Expression of results 8.1 Calculation The content, expressed as a percentage by mass
4、, of cationic- active matter is given by the formula CM, x 10 x 1000 x loo 1000 Vmo CM, x 1000 = Vm0 where c is the actual concentration, expressed in moles of C12H2aNa04S per litre, of the sodium lauryl sulfate solution (4.3); M, is the relative molecular mass of the cationic-active matter; V is th
5、e volume, in millilitres, of test solution A used for the titration; m. is the mass, in grams, of the test portion (7.1). 8.2 Precision 8.2.1 Repeatability The difference between the results of two determinations car- ried out on the same sample simultaneously or in rapid succes- sion by the same an
6、alyst using the same apparatus should not exceed I,5 % of the mean value. 8.2.2 Reproducibility The difference between the results obtained on the same sam- ple in two different laboratories should not exceed 3 % of the mean value. 9 Test report The test report shall include the following informatio
7、n : a) all the indications necessary for the complete identifica- tion of the sample; b) the method used (reference to this part of IS0 2871); c) the results obtained and the way in which they have been expressed; d) any unusual features noted during the determination; e) any operation not specified
8、 in this part of IS0 2871 or in the International Standards to which reference is made, as well as any operation regarded as optional. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/
9、2007 06:57:55 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 2871-1 : 1987 (E) UDC 661.185 : 543.24 Descriptors : surfactants, detergents, chemical analysis, determination of content, cationic active matter, volumetric analysis. Price based on 2 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 06:57:55 MDTNo reproduction or networking permitted without license from IHS -,-,-