1、BRITISH STANDARD BS ISO 10636:1994 Implementation of ISO10636:1994 Photography Processing chemicals Specifications for anhydrous sodium thiosulfate and sodiumthiosulfate pentahydrateBSISO10636:1994 This BritishStandard, having been prepared under the directionof the Consumer Products and Services Se
2、ctor Board (W/-), was published underthe authority of the Standards Board and comesintoeffect on 15 March 1995 BSI 02-2000 The following BSI references relate to the work on this standard: Committee reference CPM/14 Draft for comment91/48774DC ISBN 0 580 23916 0 Committees responsible for this Briti
3、shStandard The preparation of this BritishStandard was entrusted to Technical Committee CPM/14, Photographic chemicals and processing, upon which thefollowing bodies were represented: British Institute of Non-destructive Testing British Photographic Association Chemical Industries Association Depart
4、ment of the Environment (Water Directorate) Royal Photographic Society Amendments issued since publication Amd. No. Date CommentsBSISO10636:1994 BSI 02-2000 i Contents Page Committees responsible Inside front cover National foreword ii Foreword iii Text of ISO10636 1BSISO10636:1994 ii BSI 02-2000 Na
5、tional foreword This BritishStandard reproduces verbatim ISO10636:1994 and implements it as the UK national standard. It supersedes BS3301:1978 and BS3302:1978 which are withdrawn. This BritishStandard is published under the direction of the Consumer Products and Services Sector Board whose Technica
6、l Committee CPM/14 has the responsibility to: aid enquirers to understand the text; present to the responsible international committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them
7、 in the UK. NOTEInternational and European Standards, as well as overseas standards, are available from Customer Services, BSI,389 Chiswick High Road, London W44AL. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible f
8、or their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theISO title page, pagesii toiv, pages1 to4 and a back cover. This standard has bee
9、n updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.ISO10636:1994(E) ii BSI 02-2000 Contents Page Foreword iii Introduction 1 1 Scope 1 2 Normative references 1 3 General 2 3.1 Physical properties 2 3.2 Haza
10、rdous properties 2 3.3 Storage 2 4 Requirements 2 5 Reagents and glassware 2 6 Sampling 3 7 Test methods 3 7.1 Assay 3 7.1.1 Specification 3 7.1.2 Reagents 3 7.1.3 Procedure 3 7.1.4 Expression of results 3 7.2 Insoluble matter 3 7.2.1 Specification 3 7.2.2 Procedure 3 7.3 Heavy metals content 3 7.3.
11、1 Specification 3 7.3.2 Procedure 4 7.4 Iron 4 7.4.1 Specification 4 7.4.2 Procedure 4 7.5 Alkalinity 4 7.5.1 Specification 4 7.5.2 Procedure 4 7.6 Acidity 4 7.6.1 Specification 4 7.6.2 Procedure 4 7.7 Sulfide content 4 7.7.1 Specification 4 7.7.2 Procedure 4 7.8 pH value 4 7.8.1 Specification 4 7.8
12、.2 Apparatus 4 7.8.3 Procedure 4 7.9 Appearance of solution 4 7.9.1 Specification 4 7.9.2 Procedure 4 Table 1 Summary of requirements 2ISO10636:1994(E) BSI 02-2000 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member
13、 bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental
14、 and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member
15、 bodies for voting. Publication as an InternationalStandard requires approval by at least75% of the member bodiescasting a vote. International Standard ISO10636 was prepared by Technical Committee ISO/TC42, Photography. This first edition cancels and replaces ISO419:1972 and ISO3300:1976.iv blankISO
16、10636:1994(E) BSI 02-2000 1 Introduction 0.1 This International Standard is one of a series that establishes criteria of purity for chemicals usedin processing photographic materials. Generaltest methods and procedures cited in this International Standard are compiled in parts1,3,5,7 and10 ofISO1034
17、9. 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 chemicals requires the u
18、se of safety glasses or goggles, rubber gloves and other protective apparel such as face masks or aprons where appropriate. Normal precautions required in the performance of any chemical procedure are to be exercised at all times but care has been taken to provide warnings for hazardous materials. H
19、azard warnings designated by a letter enclosed in angle brackets, are used as a reminder in those steps detailing handling operations and are defined in ISO10349-1. More detailed information regarding hazards, handling and use of these chemicals may be available from the manufacturer. 0.2 This Inter
20、national Standard provides chemical and physical requirements for the suitability of a photographic-grade chemical. The tests correlate with undesirable photographic effects. Purity requirements are set as low as possible consistent with these photographic effects. These criteria are considered the
21、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, the purity requirements have been
22、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 received” to reflect the condit
23、ion 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. Assay procedures have been inclu
24、ded 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 another chemical or mixture of chem
25、icals could pass the other tests. All requirements listed in clause4 are mandatory. The physical appearance of the material and any footnotes are for general information only and are not part of the requirements. 0.3 Efforts have been made to employ tests which are capable of being run in any normal
26、ly 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 satisfactory method is available. Over the past few years, great improve
27、ments 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 alternative procedures with the given method is the responsibility of the use
28、r. 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. 1 Scope This International Standard specifies the purity requirements and describes the tests for photographic-g
29、rade anhydrous sodium thiosulfate and sodium thiosulfate pentahydrate. 2 Normative references The following 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 sta
30、ndards are subject to revision, and parties to agreements based on this International Standard are 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. IS
31、O10349-1:1992, Photography Photographic-grade chemicals Test methods Part1: General. ISO10636:1994(E) 2 BSI 02-2000 ISO10349-3:1992, Photography Photographic-grade chemicals Test methods Part3: Determination of matter insoluble in ammonium hydroxide solution. ISO10349-5:1992, Photography Photographi
32、c-grade chemicals Test methods Part5: Determination of heavy metals and iron content. ISO10349-7:1992, Photography Photographic-grade chemicals Test methods Part7: Determination of alkalinity or acidity. ISO10349-10:1992, Photography Photographic-grade chemicals Test methods Part10: Determination of
33、 sulfide content. 3 General 3.1 Physical properties Anhydrous sodium thiosulfate (Na 2 S 2 O 3 ) exists in the form of a white powder and has a relative molecular mass of158,09. Sodium thiosulfate pentahydrate (Na 2 S 2 O 3 5H 2 O) exists in the form of colourless crystals and has a relative molecul
34、ar mass of248,14. 3.2 Hazardous properties Sodium thiosulfate is not hazardous when handled with normal precautions. Refer to the manufacturer for additional information. 3.3 Storage Store in closed containers away from heat and moisture. 4 Requirements A summary of the requirements is shown in Tabl
35、e 1. 5 Reagents and glassware All reagents, materials and glassware shall conform to the requirements specified in ISO10349-1 unless otherwise noted. The hazard warning symbols used as a reminder in those steps detailing handling operations are defined in ISO10349-1. These symbols are used to provid
36、e information to the user and are not meant to provide conformance with hazardous labelling requirements as these vary from country to country. Table 1 Summary of requirements Test Limit Subclause International Standard in which test method is given Assay Na 2 S 2 O 3 Na 2 S 2 O 3 5H 2 O Insoluble m
37、atter (as precipitate of calcium, magnesium and ammonium hydroxides) Heavy metals (as Pb) Iron (as Fe) Alkalinity (as NaOH) Acidity (as H 2 SO 4 ) Sulfide (as S 2 ) pH value Appearance of solution 97%(m/m)min. 99%(m/m)min. 101%(m/m)max. 0,4%(m/m)max. (Na 2 S 2 O 3 ) 0,2%(m/m)max. (Na 2 S 2 O 3 5H 2
38、O) 0,002%(m/m)max. (Na 2 S 2 O 3 ) 0,001%(m/m)max. (Na 2 S 2 O 3 5H 2 O) 0,005%(m/m)max. (Na 2 S 2 O 3 ) 0,003%(m/m)max. (Na 2 S 2 O 3 5H 2 O) 0,06%(m/m)max. 0,01%(m/m)max. 0,0006%(m/m)max. (Na 2 S 2 O 3 ) 0,0004%(m/m)max. (Na 2 S 2 O 3 5H 2 O) 6,5 to9,5 Clear and free from insoluble matter except f
39、or a slight flocculence 7.1 7.1 7.1 7.2 7.2 7.3 7.3 7.4 7.4 7.5 7.6 7.7 7.7 7.8 7.9 ISO10636 ISO10636 ISO10636 ISO10349-3 ISO10349-3 ISO10349-5 ISO10349-5 ISO10349-5 ISO10349-5 ISO10349-7 ISO10349-7 ISO10349-10 ISO10349-10 ISO10636 ISO10636 NOTEm/m =mass/massISO10636:1994(E) BSI 02-2000 3 6 Sampling
40、 SeeISO10349-1. 7 Test methods 7.1 Assay 7.1.1 Specification For anhydrous sodium thiosulfate, the content of Na 2 S 2 O 3shall be97% (m/m)min. For sodium thiosulfate pentahydrate, the content ofNa 2 S 2 O 3 5H 2 O shall be99% (m/m)min. and101% (m/m)max. 7.1.2 Reagents 7.1.2.1 Neutral formaldehyde s
41、olution (DANGER: ) 1) ,37%. 7.1.2.2 Iodine, standard volumetric solution of0,05mol/l(12,7g/l) 2) . Weigh, to the nearest0,001g,12,7g of freshly sublimed iodine into a tared weighing flask. Add36g of potassium iodide and100ml of water. After solution is complete, add three drops of hydrochloric acid,
42、 and dilute to1litre in a volumetric flask at20 C. From the mass of iodine, m, calculate the concentration, c I : c I = m/254 7.1.2.3 Salicylic acid solution,1%(10g/l). Prepare a solution of1g of salicylic acid in100ml ofwater. 7.1.2.4 Starch indicator solution,5g/l. Stir5g of soluble starch with100
43、ml of1% salicylic acid solution(7.1.2.3). Then add300ml to400ml of boiling water and boil until the starch dissolves. Finally, dilute to1litre with water. 7.1.3 Procedure Weigh, to the nearest0,001g, a test portion of about0,6g of Na 2 S 2 O 3or1,0g of Na 2 S 2 O 3 5H 2 O. Transfer to a conical flas
44、k and dissolve in about50ml of water. Add5ml of formaldehyde solution(7.1.2.1) () and titrate with the standard iodine solution(7.1.2.2). Add5ml of the starch indicator solution(7.1.2.4) near the end of the titration (slow discharges of yellow iodine colour) and continue titrating until the blue col
45、our produced at the endpoint remains for at least1min. 7.1.4 Expression of results The assay for anhydrous sodium thiosulfate, expressed as a percentage by mass of Na 2 S 2 O 3 , is given by 31,6c I V/m The assay for sodium thiosulfate pentahydrate, expressed as a percentage by mass of Na 2 S 2 O 3
46、5H 2 O, is given by 49,6c I V/m 7.2 Insoluble matter (as a precipitate of calcium, magnesium and ammonium hydroxides) 7.2.1 Specification Maximum content of insoluble matter for anhydrous sodium thiosulfate shall be0,4% (m/m). Maximum content of insoluble matter for sodium thiosulfate pentahydrate s
47、hall be0,2% (m/m). 7.2.2 Procedure Determine the percentage of insoluble matter in accordance with ISO10349-3. 7.3 Heavy metals content 7.3.1 Specification Maximum content of heavy metals for anhydrous sodium thiosulfate shall be0,002% (m/m). Maximum content of heavy metals for sodium thiosulfate pe
48、ntahydrate shall be0,001% (m/m). 1) Hazard warning codes are defined in ISO10349-1:1992, clause4. 2) Commercially available analysed reagent is recommended. If solutions are to be prepared, seeany quantitative analytical chemistry text. It is recommended that self-prepared iodine solutions be standa
49、rdized before use. where c I is the actual concentration, in moles per litre, of the iodine solution(7.1.2.2); V is the volume, in millilitres, of the iodine solution(7.1.2.2) used for titrations; m is the mass, in grams, of the test portion; 31,6 is the conversion factor of the equivalent mass of anhydrous sodium thiosulfate (Na 2 S 2 O 3 ) per mole of iodine (i.e.158,1 2) theconversion factor for millilitres to litres (i.e.0,001) 100(for percentage); 49,6 is the conversion factor of the equivalent mass of sodium thiosulfate pentah
