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1、INTERNATIONAL STANDARD 3363 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION .MEXflYHAPOLIHAR OPrAHM3AUHII I-IO CTAHItAPTki3AUHH.ORGANISATION INTERNATIONALE DE NORMALlSATlON Fluorochlorinated hydrocarbons for industrial use - Determination of acidity -Titrimetric method Hydrocarbures fluorochlor, ,: -
2、% f - 1 *p.c. “i. ,n ._ I 4. CY 2: ._ * _- ._ i- - 2 CL ., . $9 i, _i ;pg i ; UDC 661.723-13/-16 : 643.2415 Ref. No. IS0 3363-1976 (E) 3 . n ; : Descriptors : fluorochlorinated hydrocarbons, chemical analysis, determination of content, acidity, volumetric analysis. : 5 Price based on J pages Copyrig
3、ht International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:56:20 MDTNo reproduction or networking permitted without license from IHS -,-,- FOREWORD IS0 (the International Organization for Stand
4、ardization) is a worldwide federation of national standards institutes (IS0 Member Bodies). The work of developing International Standards is carried out through IS0 Technical Committees. Every Member Body interested in a subject for which a Technical Committee has been set up has the right to be re
5、presented on that Committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the Technical Committees are circulated to the Member Bodies for approval before their acceptance as International St
6、andards by the IS0 Council. International Standard IS0 3363 was drawn up by Technical Committee ISO/TC 47, Chemistry, and circulated to the Member Bodies in February 1974. It has been approved by the Member Bodies of the following countries : Austria Hungary Belgium India Bulgaria Ireland Chile Isra
7、el Czechoslovakia Italy Egypt, Arab Rep. of Netherlands France Portugal Germany Romania South Africa, Rep. of Spain Switzerland Thailand Turkey United Kingdom U.S.S.R. No Member Body expressed disapproval of the document. 0 International Organization for Standardization, 1976 . Printed in Switzerlan
8、d Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:56:20 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD IS0 3363-1976 (E) Fluo
9、rochlorinated hydrocarbons for industrial use - Determination of acidity -Titrimetric method 1 SCOPE AND FIELD OF APPLICATION This International Standard specifies a titrimetric method for the determination of the acidity of fluorochlorinated hydrocarbons for industrial use. The method is applicable
10、 to products of which the acidity is in the range 2 to 200pmol of univalent acid per kilo- gram. Two procedures are given; one applicable to products that are liquid at ordinary temperatures (R 11, R 113, etc.), and the other to products that are gaseous at ordinary temperatures (R 12, R 22, R 114 e
11、tc.). 2 REFERENCES ISOIR 1393, Liquid halogenated hydrocarbons for industrial use - Determination of acidity. IS0 2209, Liquid halogenated hydrocarbons for industrial use - Sampling. I SO 3427, Gaseous halogenated hydrocarbons (liquefied gases) - Taking of sample. 3 PRINCIPLE Extraction of the acidi
12、ty in the fluorochlorinated hydrocarbon by water. Titration of the acidity of the aqueous phase with a standard volumetric sodium hydroxide solution in the presence of bromocresol green as indicator. 4 SAMPLING The laboratory sample of liquid products shall be collected by the method specified in IS
13、0 2209. The laboratory sample of products which are gaseous at ordinary temperatures shall be collected as a liquefied gas in a stainless steel sample cylinder by the method specified in IS0 3427. 5 REAGENTS During the analysis use only reagents of recognized analytical grade. 5.1 Distilled water, n
14、eutral to bromocresol green. Add to distilled water, or water of equivalent purity, contained in a conical flask with a ground glass stopper, 1 % (V/V) of the bromocresol green solution (5.3) and neutralize with the sodium hydroxide solution (5.2) until the colour changes to clear blue. 5.2 Sodium h
15、ydroxide, 0,Ol N standard volumetric solution. Standardize this solution with 0,Ol N standard volumetric hydrochloric acid solution under the conditions of the determination. 5.3 Bromocresol green, 1 g/l solution in 95 % (V/V) ethanol. 6 APPARATUS Ordinary laboratory apparatus and 6.1 For products g
16、aseous at ordinary temperatures See the figure for the arrangement of apparatus. 6.1.1 Needle valve, of any convenient type, with screw-thread union for connection to the sample cylinder. 6.1.2 Bubble indicator, of glass, capacity about 15 ml. NOTE - The bubble indicator is used empty to check compl
17、ete vaporization of the test portion. 6.1.3 Three tall-form Drechsel-type gas washing bottles, of capacity 100 ml, fitted with sintered glass disks. 6.2 For both liquid and gaseous products. 6.2.1 Microburette, of capacity 2 ml, graduated in 0,Ol ml. 7 PROCEDURE 7.1 Liquid products Use the method sp
18、ecified in ISO/R 1393 with the following modifications appropriate for the products concerned : 7.1.1 Test portion Weigh, to the nearest 0,l g, about 100 g of the laboratory sample. 1 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Techni
19、cal Standards 1/9972545001 Not for Resale, 04/28/2007 07:56:20 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 3363-1976 (E) 7.1.2 Determination In the case of R 11 (boiling point 24 “C), carry out the extraction with the water (5.1) previously cooled to 15 C. For all p
20、roducts, transfer the who/e of the aqueous phase to a 250 ml conical flask and titrate. 8 EXPRESSION OF RESULTS 8.1 The acidity, expressed in micromoles of univalent acid per kilogram, is given by the formula : 1000 looooxv VxO,Ol x 1 000 x-= m m where V is the volume, in millilitres, of the standar
21、d volumetric sodium hydroxide solution (5.2) used for the titration; m is the mass, in grams, of the test portion (equal to the change in mass of the sample cylinder in the case of gaseous products). 7.2 Gaseous products Weigh, to the nearest 1 g, the capped sample cylinder containing the laboratory
22、 sample, remove the cap and connect the needle valve (6.1.1) to the valve of inverted cylinder type (b) (IS0 34271, or to valve A of cylinder type (a) (IS0 3427) (see the figure). Add 50 ml of the water (5.1) to each of the three gas washing bottles (6.1.3). Connect the outlet of the needle valve to
23、 the bubble indicator (6.1.21, connected in turn to the gas washing bottles connected in series as shown in the figure. Open the sample cylinder valve fully and open the needle valve to the extent required to give a steady vaporization rate of about 100 g of sample per hour. NOTES 1 The required set
24、ting is judged by experience and observation of the bubble rate through the gas washing bottles. 2 It may be necessary to warm the bubble indicator and cylinder valves by means of a warm air blower when analysing higher boiling products such as R 114. After about 1 h, close first the cylinder valve
25、and then the needle valve. Disconnect the needle valve and replace the cylinder cap. Allow the cylinder to warm up to room temperature, dry it if necessary, and reweigh it, to the nearest 1 g, under the same conditions as previously. Mix the contents of the first two gas washing bottles; if the samp
26、le is acid, the solution will be coloured yellow. Titrate the acidity (if any) with the standard volumetric sodium hydroxide solution (5.2), using the microburette (6.2.1). until the appearance of a clear blue colour. The water in the third gas washing bottle should remain blue. If this is not the c
27、ase, repeat the test. 8.2 The acidity, expressed in milligrams of hydrogen chloride (HCI) per kilogram, is given by the formula : 365 vx- m where V and m have the same meaning as in 8.1. 8.3 The acid number, expressed in milligrams of potassium hydroxide (KOH) per gram, is given by the formula : 56,
28、l x V x 0,Ol 0,561 x V = m m where V and m have the same meaning as in 8.1. 8.4 Express the result with a precision corresponding to the accuracy of weighing and titration. NOTE - If the concentration of the standard volumetric solution used is not exactly as specified in the list of reagents, an ap
29、propriate correction should be made. 9 TEST REPORT The test report shall include the following particulars : a) the reference of the method used; b) the results and the method of expression used; c) any unusual features noted during the deter- mination; d) any operation not included in this Internat
30、ional Standard or in the International Standards to which reference is made, or regarded as optional. 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:56:20 MDTNo reproductio
31、n or networking permitted without license from IHS -,-,- IS0 3363-1976 (E) Type (b) Needle Flexible couplings of inert material echsel gas washing Type (a) Sample cylinder containing liquefied test sample FIGURE - Apparatus for absorption of acidity for products gaseous at ordinary temperatures ANNE
32、X OTHER IS0 PUBLICATIONS RELATING TO HALOGENATED HYDROCARBONS FOR INDUSTRIAL USE ISO/R 1393 - Determination of acidity liquids. ISO/R 1394 - Determination of cloud point liquids. IS0 2209 - Sampling liquids. IS0 2210 - Determination of residue on evaporation liquids. IS0 3427 - Taking of a sample liquefied gases. 3 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:56:20 MDTNo reproduction or networking permitted without license from IHS -,-,-