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1、g.: “:* .-, “ . ii 6 ,. ; .5.,;1. :I r.: : ,. .i 1:“. 1 c”,” r- I?, j j. j-1 , 1 / .-I(. * A- a .A c, c-4 $3 f%?i v ) Surface active agents - Technical straight-chain sodium alkylbenzenesulfonates - Determination of mean relative molecular mass by gas-liquid chromatography Agents de surface - Alkylb
2、enzane sulfonates de sodium linkaires techniques - Oktermination de la masse mol the relative molecular mass of the respective monosul- fonate or monosulfonic acid can then be calculated by adding the relative molecular mass of the SOsNa group minus Na, or that of the SOsH group minus H. The GLC tec
3、hnique is only applicable to straight-chain alkylbenzenes, since branched- chain types will give chromatograms from which it is impossible to identify and to calculate the relative molecular mass for individual chains. NOTE - Any ortho-fused polycyclic hydrocarbon derivatives of low relative molecul
4、ar mass pre- sent, such as indan, and tetrahydronaphthalene, as well as branched-chain alkylbenzenes, are not taken into account in the calculation of the relative molecular mass of the technical straight- chain sodium alkylbenzenesulfonate analysed. iii Copyright International Organization for Stan
5、dardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 02:09:00 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD IS0 6641 : 1966 (E) Surface active agents - Technical straight-chain
6、sodium alkylbenzenesulfonates - Determination of mean relative molecular mass by gas-liquid chromatography 1 Scope This International Standard specifies a gas-liquid chromatography (GLC) method for the determination of the mean relative molecular mass of technical straight-chain sodium alkylbenzenes
7、ulfonates. 2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based
8、 on this International Standard are encouraged to investigate the possibility of applying the most recent edition of the standard listed below. Members of IEC and IS.0 maintain registers of currently valid International Standards. 4.5 Reference alkylbenzene: mixture of alkylbenzenes of known chain l
9、engths, for example from Cl, to C2, (phenyl group included). A product of known composition can be adopted as reference sample. This reference sample cannot be used for identification purposes but only for checking the proper performance of the chromatograph. 4.6 Carrier gas: nitrogen, helium, argon
10、 or hydrogen. 4.7 Acetone (if necessary). 5 Apparatus Usual laboratory equipment, and IS0 607: 1980, Surface active agents and detergents - Methods of sample division. 5.1 Combustion tube, one end closed, of diameter 12 mm and length 120 mm. (Ready-made tubes are available on the market.) 3 Principl
11、e Desulfonation of a test portion in concentrated phosphoric acid medium and extraction of the liberated alkylbenzene with light petroleum. Determination of the mean relative molecular mass of the ex- tracted alkylbenzene by GLC. 5.2 Test tubes, of similar dimensions to the combustion tube (5.11, fi
12、tted with a ground glass stopper. 5.3 Metallic safety tube, capable of accommodating the sealed combustion tube (5.1). It contains a cushioning disc (see the note) to prevent breakage of the combustion tube and is fit- ted with a screw cap (see figure 1). Calculation of the mean relative molecular m
13、ass of the alkylbenzenesulfonate. 4 Reagents and materials NOTE - To obtain the best cushioning effect, the disc should preferably be made of silicone rubber and polytetrafluoroethylene, although silicone rubber discs, of thickness 3 mm, are suitable. The use of polytetrafluoroethylene discs is not
14、advised. During the analysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 5.4 Heating device: capable of being controlled at a temperature of about 250 OC, for example a silicone oil bath. 4.1 Phosphoric acid, solution, 85 % (m/m). 5.5 Chr
15、omatograph, with the following elements: 4.2 Light petroleum, free from aromatic compounds, distill- ing between 40 and 60 OC. 4.3 Sodium sulfate, anhydrous. 5.5.1 Capillary column, of length 20 to 50 m, in spiral form, of internal diameter 0,25 mm and external diameter I,1 mm, coated with an apolar
16、 stationary phase for high temperatures (for example, a dimethylsiloxane type, such as silicone OV 101). oreconditioned at the test temperature; or a packed 4.4 Sodium hydroxide, 160 g/l solution. column, of length 1 to 6 m, provided that the chromatogram peaks are sufficiently well separated. 1 Cop
17、yright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 02:09:00 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 6= _ A The mean relative molecular mass of the
18、 alkylbenzene is given by the formula 100 c 4 ; M, where ai is the area of the peak corresponding to a chain length or group of isomers: A is the total peak area; IS0 6641 : 1988 (E) M, is the relative molecular mass of the isomers, the number of carbon atoms of which includes those in the phenyl gr
19、oup, as follows: M, Cl5 204 c16 218 Cl7 232 cl8 246 c19 260 c20 274 c21 288 Calculate the mean relative molecular mass of the alkyl- benzenesulfonate by adding 102 to the calculated relative molecular mass of the alkylbenzene. 9.2 Precision Comparative analyses, on a sample of sodium alkylbenzene su
20、lfonate, carried out in 10 laboratories, have given the follow- ing statistical results: - mean (mean relative molecular mass) 340 - standard deviation of repeatability, CT, 4 - standard deviation of reproducibility, oR 418 10 Test report The test report shall include the following information : a)
21、all the information necessary for the complete iden- tification of the sample; b) the reference of the method used (reference to this International Standard); c) the results and the method of expression used; d) details of any operation not specified in this Inter- national Standard, or any operatio
22、n regarded as optional, together with details of any incidents likely to have affected the results. 3 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 02:09:00 MDTNo reproduction
23、or networking permitted without license from IHS -,-,- IS0 6941 : 1999 (El Dimensions in millimetres r Aeration hole I L Seal L Seal Figure 1 - Safety tube with screw cap Badly sealed Figure 2 - Sealing the combustion tube 4 Copyright International Organization for Standardization Provided by IHS un
24、der license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 02:09:00 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 6941 : 1998 (E) a) alkylbenzene - packed column 1 I I b I6 - C 17 C 18 C 19 C 20 b) alkylbenzene - capillary column 16
25、 L,17 ? A J r C 22 18 Figure 3 - Typical chromatograms 5 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 02:09:00 MDTNo reproduction or networking permitted without license from
26、IHS -,-,- IS0 6841 : 1988 (E) UDC 661.186.5 : !543.644.46 : 641.24 Descriptors : surfactants, alkylsulphonates, tests, determination, molecular weight, gas chromatography. Price based on 5 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 02:09:00 MDTNo reproduction or networking permitted without license from IHS -,-,-