1、INTERNATIONAL ISO STANDARD 3623 Second edition 1994-12-15 Photography - Processing chemicals - Specifications for anhydrous potassium carbonate Photographie - Produkts chimiques de traitement - Spkifications pour Ie carbona te de po tassium anh ydre Reference number ISO 3623:1994( E) ISO 3623: 1994(
2、E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national Standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Esch member body interested in a subject for which
3、a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matt
4、ers of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 3623
5、was prepared by Technical Committee lSO/TX 42, Photography. This second edition cancels and replaces the first edition (ISO 3623:1976), which has been technically revised. Annex A of this International Standard is for information only. 0 ISO 1994 All rights reserved. Unless otherwise specified, no p
6、art of this publication may be reproduced or utilized in any form or by any means, electronie or mechanical, including photocopying and microfilm, without Permission in writing from the publisher. International Organi zation for Standardization Case postale 56 l CH-l 2 11 Geneve 20 l Switzerland Pri
7、nted in Switzerland 0 ISO ISO 3623:1994(E) Introduction 0.1 This International Standard is one of a series that establishes criteria of purity for chemicals used in processing photographic materials. General test methods and procedures cited in this International Standard are compiled in Parts 1, 5,
8、 6, 7, 8 and 9 of ISO 10349. This International Standard is intended for use by individuals with a working knowledge of analytical techniques which may not always be the case. Some of the procedures utilize caustic, toxic or otherwise hazardous chemicals. Safe laboratory practice for the handling of
9、 chemicals requires the use of safety glasses or goggles, rubber gloves and other protective apparel such as face masks or aprons where appropriate. Normal pre- cautions required in the Performance of any Chemical procedure are to be exercised at all times but care has been taken to provide warnings
10、 for hazardous materials. Hazard warnings designated by a letter enclosed in angle brackets, , are used as a reminder in those Steps detailing handling operations and are defined in ISO 10349-1. More detailed information regarding hazards, handling and use of these chemicals may be available from th
11、e manufacturer. 8.2 This International Standard provides Chemical and physical require- ments for the suitability of a photographit-grade Chemical. The tests correlate with undesirable photographic effects. Purity requirements are set as low as possible consistent with these photographic effects. Th
12、ese criteria are considered the minimum requirements necessary to assure sufficient purity for use in photographic processing solutions, except that if the purity of a commonly available grade of Chemical exceeds photographic processing requirements and if there is no economic penalty in its use, th
13、e purity requirements have been set to take advantage of the availability of the higher-quality material. Every effort has been made to keep the number of requirements to a minimum. Inert impurities are limited to amounts which will not unduly reduce the assay. All tests are performed on samples “as
14、 received” to reflect the condition of materials furnished for use. Although the ultimate criterion for suitability of such a Chemical is its successful Performance in an appropriate use test, the shorter, more economical test methods described in this International Standard are generally adequate.
15、Assay procedures have been included in all cases where a satisfactory method is available. An effective assay requirement serves not only as a safeguard of Chemical purity but also as a valuable complement to the identity test. Identity tests have been included whenever a possibility exists that ano
16、ther Chemical or mixture of chemicals could pass the other tests. All requirements listed in clause 4 are mandatory. The physical appearance of the material and any footnotes are for general information only and are not part of the requirements. . . . Ill ISO 3623: 1994(E) 0 ISO 0.3 Efforts have bee
17、n made to employ tests which are capable of being run in any normally equipped laboratory and, wherever possible, to avoid tests which require highly specialized equipment or techniques. Instrumental methods have been specified only as alternative methods or alone in those cases where no other satis
18、factory method is available. Over the past few years, great improvements have been made in instrumentation for various analyses. Where such techniques have equivalent or greater precision, they may be used in place of the tests described in this International Standard. Correlation of such alternativ
19、e procedures with the given method is the responsibility of the User. In case of disagreement in results, the method called for in the specification shall prevail. Where a requirement states “to pass test”, however, alternative methods shall not be used. INTERNATIONAL STANDARD o ISO ISO 3623: 1994(E
20、) Photography - Processing chemicals - Specifications for anhydrous potassium carbonate 1 Scope This International Standard establishes criteria for the purity of photographit-grade anhydrous potassium carbonate and specifies the tests to be used to determine the purity. 2 Normative references The f
21、ollowing Standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All Standards are subject to revision, and Parties to agreements based on this International Standard are
22、encouraged to investigate the possibility of applying the most recent editions of the Standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 10349-1: 1992, Photography - Photographic- grade chemicals - Test methods - Part 1: General. ISO
23、10349-5: 1992, Photography - Photographic- grade chemicals - Test methods - Part 5: Determi- nation of heavy metals and iron content. ISO 10349-6: 1992, Photography - Photographic- grade chemicals - Test methods - Part 6: Determi- nation o f halide con tent. ISO 10349-7: 1992, Photography - Photogra
24、phic- grade chemicals - Test methods - Part 7: Determi- nation of alkalinity or acidity. ISO 10349-8: 1992, Photography - Photographic- grade chemicals - Test methods - Part 8: Determi- na tion of volatile matter. ISO 10349-9: 1992, Photography - Photographic- grade chemicals - Test methods - Part 9
25、: Determi- nation of reaction to ammoniacal silver nitrate. 3 General 3.1 Physical properties Anhydrous potassium carbonate, K2COs, exists in the form of colourless white granules or powder. lt has a relative molecular mass of 138,Zl. 3.2 Hazardous properties Potassium carbonate is irratating to the
26、 eyes, skin and throat. 3.3 Storage Potassium carbonate should be stored in a closed Container at room temperature. 4 Requirements A summary of the requirements is shown in table 1. 5 Reagents and glassware All reagents, materials and glassware shall conform to the requirements specified in ISO 1034
27、9-1 unless otherwise noted. The hazard warning Symbols used as a reminder in those Steps detailing handling oper- ations are defined in ISO 10349-1. These Symbols are used to provide information to the user and are not meant to provide conformance with hazardous labelling requirements as these vary
28、from country to country. 6 Sampling See ISO 10349-1. 7 Test methods 7.1 Assay 7.1.1 Specification Content of K2C03 shall be 97,0 % (HZ/LV) min. ISO 3623: 1994(E) 0 ISO Table 1 - Summary of requirements Test Limit Subclause International Standard in which test method is given Assay (as K2C0s) 97,0 %
29、(m/m) min. 7.1 ISO 3623 Heavy metals (as Pb) 0,001 % (m/m) max. 7.2 ISO 10349-5 Iran (Fe) 0,001 % (m/m) max. 7.3 ISO 10349-5 Halides (as Cl-) 0,l % ( 7.121 Hydrochlorit acid, HCI, Standard volumetric Solution of 1,OO mol/1 l) *). 7.1.2.2 Methyl orange indicator, 0,4 g/l. 7.1.3 Apparatus 7.1.3.1 Bure
30、tte, of 50 ml capacity. 7.1.4 Procedure Weigh, to the nearest 0,001 g, a test Portion of about 2,5 g and dissolve it in 50 ml of water. Add two drops of the methyl orange indicator (7.1.2.2) and titrate with the hydrochloric acid (7.1.2.1) to the endpoint when the colour changes from yellow to red.
31、7.15 Expression of results The assay, expressed as a percentage by mass, for K2C03, is given by 6,91 -em Vlm where c is the actual concentration, expressed in moles per litre, of the hydrochloric acid (7.1.2.1); V is the volume, in millilitres, of the hydro- chloric acid used to resch the endpoint (
32、7.1.4); 6,91 is the conversion factor obtained from the mass of potassium carbonate equivalent to 1 mole of hydrochloric acid (i.e. 138,2/2) x the conversion factor for millilitres to litres (i.e. 0,001) x 100 (for percentage). 7.2 Heavy metals content 72.1 Specification Maximum content of heavy met
33、als shall be 0,001 % (mlm). 7.2.2 Procedure NOTE 1 The Standard for the iron test (7.3) is prepared in the same way as the heavy metals Standard. Determine the percentage of heavy metals in accord- ante with ISO 10349-5. Use a test Portion of 4,90 g to 5,lO g prepared in accordance with ISO 10349-5:
34、 1992, 7.3. Use 5 ml of the heavy metals Standard prepared in accordance with ISO 10349-5:1992, 8.1.2. 7.3 Iron content 7.3.1 Specification Maximum content of iron shall be 0,001 % (m/m). 7.3.2 Procedure Determine the percentage of iron in accordance with ISO 10349-5. Use a test Portion of 4,90 g to
35、 5,lO g of 1) Commercially available analysed reagent solution is recommended. If solutions are to be prepared, see any quantitative analytical chemistry text. 2) This Solution tan be prepared from concentrated hydrochloric acid, p = 1 ,18 (DANGER: cB). 2 0 ISO ISO 3623: 1994(E) the Sample prepared
36、in accordance with ISO 10349-5: 1992, 7.3. Use 5 ml of the iron Standard prepared in accordance with ISO 10349-5:1992, 8.12. 7.4 Halides content (as Cl-). 7.4.1 Specification Maximum content of halides shall be 0,l % (L 7.9.2.3 EDTA Solution, Standard volumetric Solution of 0,Ol mol/1 (3,36 g/l of t
37、he disodium salt, C,0H14Na2N208)2) 5). v2 is the volume, in millilitres, of the EDTA Solution (7.9.2.3) used to resch the endpoint of the blank; 7.9.2.4 Hydrochlorit acid, HCI I p= 1,18 g/ml (DANGER: ). 7.9.2.5 Magnesium Standard Solution (1 ml = 1 mg Mg). Dissolve IO,1 41 g of magnesium sulfate hep
38、tahydrate (MgS04.7HZO) in water containing 1 ml of hydro- chloric acid (7.9.2.4) () in a 1 litre volumetric flask. Dilute to the mark with water and mix. m is the mass, in grams, of the test Portion; 0,024 3 is the conversion factor obtained from the mass of magnesium equivalent to 1 mole of EDTA (i
39、.e. 24,3) x the concentration of the EDTA Solution (i.e. 0,Ol) x the con- Version factor for millilitres to litres (i.e. 0,001) x 100 (for percentage). 7.10 Appearance of Solution 7.10.1 Specification 7.9.2.6 Mordant black indicator Grind 0,25 g of Mordant black 11 6, with 25 g of sodium chloride (N
40、aCI) in a mortar. The Solution shall be clear and free from insoluble matter except for a slight flocculence. 7.10.2 Procedure 7.9.3 Apparatus 7.9.3.1 One-mark volumetric flask, of 1 litre capacity. Dissolve a test Portion of 200 g of the test Sample and dissolve in 1 litre of water. Observe the Sol
41、ution for colour and clarity. 5) A procedure for the preparation and standardization of EDTA solution is given in annex A. 6) Cisted in colour index as C.P. 14645. Chrome Fast Black CAT, KIT*TS, Eriochrome Black DW, T and TDW, and Potting Black C are examples of suitable products available commercially. This information is given for the convenience of users of the International Standard and does not constitute an endorsement by ISO of these products. 4
