1、BRITISH STANDARD BS ISO 5990:2000 Photography Processing chemicals Specifications for potassium sulfite, 650 g/l solution ICS 37.040.30 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS ISO 5990:2000 This British Standard, having been prepared under the direction of the Consum
2、er Products and Services Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 21 May 2002 BSI 21 May 2002 ISBN 0 580 39674 6 National foreword This British Standard reproduces verbatim ISO 5990:2000 and implements it as the UK nati
3、onal standard. It supersedes BS ISO 5990:1996 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee CPW/42, Photography, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cros
4、s-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electroni
5、c Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand
6、the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a fr
7、ont cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 7, and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsReference number ISO 5990:2000(E
8、) INTERNATIONAL STANDARD ISO 5990 Third edition 2000-12-15 Photography Processing chemicals Specifications for potassium sulfite, 650 g/l solution Photographie Produits chimiques de traitement Spcifications relatives au sulfite de potassium en solution 650 g/lISO 5990:2000(E) ihTs PDF file mya ctnoa
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12、 aveneG 02 leT. + 41 22 947 10 11 xaF + 14 22 947 90 74 eWb www.iso.ch ii ISO 5990:2000(E)iii Contents Page Foreword.iv Introduction.v 1 Scope 1 2 Normative references 1 3 General1 3.1 Physical properties1 3.2 Hazardous properties1 3.3 Storage1 4 Requirements.2 5 Reagents and glassware.2 6 Sampling.
13、2 7 Test methods2 7.1 Assay 2 7.2 Mass fraction of heavy metals5 7.3 Mass fraction of iron .5 7.4 Reaction to ammoniacal silver nitrate.5 7.5 Specific gravity or density 5 7.6 pH value6 7.7 Mass fraction of thiosulfate (as S 2 O 3 2 ) 6 7.8 Appearance of solution.7ISO 5990:2000(E) iv Foreword ISO (t
14、he 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. Each member body interested in a subject for which a technical commit
15、tee 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 matters of electrotech
16、nical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approva
17、l by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 5990
18、 was prepared by Technical Committee ISO/TC 42, Photography. This third edition cancels and replaces the second edition (ISO 5990:1996), of which it constitutes a technical revision.ISO 5990:2000(E)v Introduction This International Standard is one of a series that establishes criteria of purity for
19、chemicals used in processing photographic materials. General test methods and procedures cited in this International Standard are compiled in ISO 10349-1. This International Standard is intended for use by individuals with a working knowledge of analytical techniques, which may not always be the cas
20、e. Some of the procedures utilize caustic, toxic or otherwise hazardous chemicals. Safe laboratory practice for the handling of chemicals requires the use of safety glasses or goggles and, in some cases, other protective apparel such as rubber gloves, face masks or aprons. Normal precautions for the
21、 safe performance of any chemical procedure must be exercised at all times, but specific details have been provided for hazardous materials. Hazard warnings designated by a letter enclosed in angle brackets “ ” a r eu s e da sa reminder in those steps detailing handling operations and are defined in
22、 ISO 10349-1. More detailed information regarding hazards, handling and use of these chemicals may be available from the manufacturer. This International Standard provides chemical and physical requirements for the suitability of a photographic-grade chemical. The tests correlate with undesirable ph
23、otographic effects. Purity requirements are set as low as possible, consistent with these photographic effects. These criteria are considered to be the minimum requirements necessary to ensure sufficient purity for use in photographic processing solutions, except that if the purity of a commonly ava
24、ilable grade of chemical exceeds photographic processing requirements and if there is no economic penalty in its use, the 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
25、. Inert impurities are limited to amounts that will not unduly reduce the assay. All tests are performed on samples “as 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 appropriat
26、e use test, the shorter, more economical test methods described in this International Standard are generally adequate. 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
27、 as a valuable complement to the identity test. Identity tests have been included whenever a possibility exists that another 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 f
28、or general information only and are not part of the requirements. Efforts have been made to employ tests that are capable of being run in any normally equipped laboratory and, wherever possible, to avoid tests that require highly specialized equipment or techniques. Instrumental methods have been sp
29、ecified only as alternative methods or alone in those cases where no other satisfactory 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 th
30、e tests described in this International Standard. Correlation of such alternative procedures with the given method is the responsibility of the user. In the case of disagreement in results, the method called for in the specification should prevail. Where a requirement states “to pass test”, however,
31、 alternative methods should not be used.INTERNATIONAL STANDARD ISO 5990:2000(E)1 Photography Processing chemicals Specifications for potassium sulfite, 650 g/l solution 1 Scope This International Standard establishes criteria for the purity of photographic-grade potassium sulfite, 650 g/I aqueous so
32、lution, and specifies the tests to be used to determine the purity. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of
33、, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative doc
34、ument referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 10349-1:1992, Photography Photographic-grade chemicals Test methods Part 1: General. ISO 10349-5:1992, Photography Photographic-grade chemicals Test methods Part 5: Determination of h
35、eavy metals and iron content. ISO 10349-9:1992, Photography Photographic-grade chemicals Test methods Part 9: Reaction to ammoniacal silver nitrate. ISO 10349-11:1992, Photography Photographic-grade chemicals Test methods Part 11: Determination of specific gravity. ISO 10349-12:1992, Photography Pho
36、tographic-grade chemicals Test methods Part 12: Determination of density. 3 General 3.1 Physical properties Potassium sulfite (K 2 SO 3 ), 650 g/l aqueous solution, is a clear, colourless or almost colourless liquid. Potassium sulfite has a relative molecular mass of 158,27. 3.2 Hazardous properties
37、 Potassium sulfite, 650 g/l aqueous solution, is not hazardous when handled with normal precautions. Avoid contact with acids. 3.3 Storage Potassium sulfite solution shall be stored in a closed container at room temperature.ISO 5990:2000(E) 2 4 Requirements A summary of the requirements is shown in
38、Table 1. Table 1 Summary of requirements Test Limit Subclause International Standard in which test method is given Assay Minimum: 44,5 % Maximum: 46,0 % 7.1 ISO 5990 Mass fraction of heavy metals (as Pb) Maximum: 0,002 % 7.2 ISO 10349-5 Mass fraction of iron (Fe) Maximum: 0,002 % 7.3 ISO 10349-5 Rea
39、ction to ammoniacal silver nitrate To pass test 7.4 ISO 10349-9 Specific gravity or density: specific gravity Minimum: 1,445 Maximum: 1,460 7.5.1 ISO 10349-11 density Minimum: 1,441 g/ml Maximum: 1,457 g/ml 7.5.2 ISO 10349-12 pH value of (1 + 9) solution 8,0 to 10,0 7.6 ISO 5990 Mass fraction of thi
40、osulfate (as S 2 O 3 2 ) Maximum: 0,006 % 7.7 ISO 5990 Appearance of solution Clear and free from insoluble matter except for a slight flocculence 7.8 ISO 5990 5 Reagents and glassware All reagents, materials and glassware shall conform to the requirements specified in ISO 10349-1 unless otherwise n
41、oted. The hazard warning symbols, used as a reminder in those steps detailing handling operations, 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 from country to count
42、ry. 6 Sampling See ISO 10349-1. 7 Test methods 7.1 Assay 7.1.1 Specification The mass fraction of potassium sulfite shall be between 44,5 % and 46,0 %. 7.1.2 Reagents 7.1.2.1 Hydrochloric acid (HCI), 1,18 g/ml (DANGER: B C ) 1) . 1) Hazard warning codes are defined in ISO 10349-1.ISO 5990:2000(E)3 7
43、.1.2.2 Potassium iodide (KI). 7.1.2.3 Iodine, c(I 2 ) = 0,05 mol/l (12,7 g/l) 2) 3) . Weigh, to the nearest 0,001 g, 12,7 g of freshly sublimed iodine (DANGER: C O ) into a tared weighing flask. Add 36 g of potassium iodide (7.1.2.2) and 100 ml of water. After solution is complete, add three drops o
44、f hydrochloric acid (7.1.2.1) (DANGER: B C ), and dilute to 1 litre at 20 C in a volumetric flask. From the mass of iodine, m, calculate the concentration, c, in moles per litre, from 254 m c 7.1.2.4 Sodium thiosulfate, c(Na 2 S 2 O 3 ) = 0,100 mol/l (15,8 g/l) 2) . NOTE This solution is not require
45、d for the direct-titration method (7.1.4.3). 7.1.2.5 Salicylic acid, c(HOC 6 H 4 COOH) = 1 % (10 g/l). 7.1.2.6 Starch indicator, 5 g/l solution. Stir 5 g of soluble starch into 100 ml of 1 % salicylic acid solution (7.1.2.5). Add 300 ml of this solution to 400 ml of boiling water. Boil until the sta
46、rch dissolves and dilute to 1 litre with water. 7.1.3 Apparatus 7.1.3.1 Burette, of capacity 50 ml. 7.1.3.2 Pipette, of capacity 25 ml. 7.1.3.3 Pipette, of capacity 50 ml. 7.1.3.4 Magnetic stirrer and bar, for the direct-titration method (7.1.4.3). 7.1.4 Procedure 7.1.4.1 Introduction Use either the
47、 back-titration method (7.1.4.2) or the direct-titration method (7.1.4.3). 7.1.4.2 Back-titration method Using a pipette (7.1.3.2), transfer 25,00 ml of the iodine solution (7.1.2.3) to a glass-stoppered flask. Weigh, to the nearest 0,000 1 g, a test portion of about 0,25 g and wash this into the fl
48、ask. Add 5 ml of the hydrochloric acid (7.1.2.1) (DANGER: B C ) and, using a burette (7.1.3.1), titrate with the sodium thiosulfate solution (7.1.2.4), adding 2 ml of the starch indicator (7.1.2.6) just before the endpoint. 7.1.4.3 Direct-titration method Weigh, to the nearest 0,000 1 g, a test port
49、ion of 0,90 g. Using a pipette (7.1.3.3), transfer 50,00 ml of the iodine solution (7.1.2.3) to a completely dry 250 ml beaker that contains a magnetic stirring bar (7.1.3.4). While stirring the 2) Commercially available analysed reagent solution is recommended. If the solution is to be prepared, see any quantitative analytical chemistry text. 3) It is recommended that self-prepared iodine solutions be standardized before use.ISO 5990:2000(E) 4 iodine solution in the beaker, add the test portion to th
