1、BRITISH STANDARD BS ISO 3629:2000 Photography Processing chemicals Specifications for potassium metabisulfite ICS 37.040.30 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS ISO 3629:2000 This British Standard, having been prepared under the direction of the Consumer Products
2、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 39675 4 National foreword This British Standard reproduces verbatim ISO 3629:2000 and implements it as the UK national standar
3、d. It supersedes BS ISO 3629:1996 which is withdrawn.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. Cross-references
4、 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 Electronic Catalogue.
5、 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 the text; pr
6、esent 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 front cover, a
7、n inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 6, an inside back cover 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 36
8、29:2000(E) INTERNATIONAL STANDARD ISO 3629 Third edition 2000-12-15 Photography Processing chemicals Specifications for potassium metabisulfite Photographie Produits chimiques de traitement Spcifications relatives au mtadisulfite de potassiumISO 3629:2000(E) DPF dlcsiremia ihTs PDF file mya ctnoain
9、emdeddeb tyfepcaes. In acccnadroe with Aebods licnesign lopic,y this file may be pirntde ro ivwede tub slahl ton eb ideted lnuess teh tyfepacse which aer emdeddeb era licnesed to dna intslaled on teh computre frepomring teh idetign. In wodlnidaogn this f,eli trapies accept tniereh teh sersnoptilibiy
10、 of ton nifrgnigni Asebod licsnegni ilopcy. ehT ISO tneClar Secteraairt accepts no lilibaity ni this .aera Aebod is a tedarmakr fo Aebod Stsyems Icntaropro.de teDails fo the sfotwera pcudorts sude to crtaee tihs PFD file can be fdnuo in the Glarene Info leratiev to the fil;e the Pc-FDaertion arapmte
11、res were tpoimizde for pirtning. Evyre cera sah neeb taken to enseru taht teh file is suitlbae fro sue by ISO memreb idob.se In teh lnuikley etnev ttah a plborem leratign to it is f,dnuo lpsaee ifnrom teh tneClar Sceterairat at the sserdda givne lebwo. ISO 0002 All rhgits rsevre.de elnUss towrehise
12、scepfidei, on trap of tihs cilbuptanoi mya eb cudorperde ro utzilide ni yna form ro yb yna snaem, eelctinorc ro mecinahcal, inclidugn tohpociypong dna micrfoilm, wittuoh repmissino in writing form eitreh ISO at teh erddass lebwo ro ISOs memreb ydob in the ctnuoyr of the rtseuqee.r ISO cirypothg fofi
13、ce saCe tsopale 65 1121-HC aveneG 20 leT. + 41 22 947 10 11 xaF + 14 22 947 90 74 E-mail cirypothgiso.ch eWb www.iso.ch Printed in Switzlredna ii ISO 0002 All irhgts seredevrISO 3629:2000(E) ISO 0002 All rights rsedevre iii Contents Page Foreword.iv Introduction.v 1 Scope 1 2 Normative references 1
14、3 General1 3.1 Physical properties1 3.2 Hazardous properties1 3.3 Storage1 4 Requirements.1 5 Reagents and glassware.2 6 Sampling.2 7 Test methods2 7.1 Assay 2 7.2 Mass fraction of heavy metals4 7.3 Mass fraction of iron .5 7.4 Reaction to ammoniacal silver nitrate.5 7.5 pH value5 7.6 Mass fraction
15、of thiosulfate (as S 2 O 3 2 ) 5 7.7 Appearance of solution.6ISO 3629:2000(E) iv ISO 0002 All rights rsedevre 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
16、 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 and non-governmental, in liaison with ISO, also take part
17、 in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the t
18、echnical 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. Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of pa
19、tent rights. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 3629 was prepared by Technical Committee ISO/TC 42, Photography. This third edition cancels and replaces the second edition (ISO 3629:1996), of which it constitutes a technical re
20、vision.ISO 3629:2000(E) ISO 0002 All rights rsedevre v Introduction 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 ISO
21、 10349-1. 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 require
22、s 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 safe performance of any chemical procedure must be exercised at all times, but specific details have been provided for hazardous materials. Haza
23、rd 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 ISO 10349-1. More detailed information regarding hazards, handling and use of these chemicals may be available from the manufacturer. This Inter
24、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 to
25、be the minimum requirements necessary to ensure 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 hav
26、e 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 that will not unduly reduce the assay. All tests are performed on samples “as received” to reflect the
27、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. Assay procedures have been
28、 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 another chemical or mixture
29、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. Efforts have been made to employ tests that are capable of being run in any nor
30、mally equipped laboratory and, wherever possible, to avoid tests that 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 impro
31、vements 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 u
32、ser. In the case of disagreement in results, the method called for in the specification should prevail. Where a requirement states “to pass test”, however, alternative methods should not be used.INTERNATIONAL STANDARD ISO 3629:2000(E) ISO 0002 All rights rsedevre 1 Photography Processing chemicals S
33、pecifications for potassium metabisulfite 1 Scope This International Standard establishes criteria for the purity of photographic-grade potassium metabisulfite and specifies the tests to be used to determine the purity. 2 Normative references The following normative documents contain provisions whic
34、h, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the poss
35、ibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 10349-1:1992, Photography Photo
36、graphic-grade chemicals Test methods Part 1: General. ISO 10349-5:1992, Photography Photographic-grade chemicals Test methods Part 5: Determination of heavy metals and iron content. ISO 10349-9:1992, Photography Photographic-grade chemicals Test methods Part 9: Reaction to ammoniacal silver nitrate.
37、 3 General 3.1 Physical properties Potassium metabisulfite (K 2 S 2 O 5 ) exists in the form of white, glassy crystals. It has a relative molecular mass of 222,33. 3.2 Hazardous properties Potassium metabisulfite is not hazardous when handled with normal precautions, but it is toxic if ingested. Avo
38、id contact with acids. 3.3 Storage Potassium metabisulfite shall be stored in a closed container at room temperature. 4 Requirements A summary of the requirements is shown in Table 1.ISO 3629:2000(E) 2 ISO 0002 All rights rsedevre Table 1 Summary of requirements Test Limit Subclause International St
39、andard in which test method is given Assay Minimum: 95,0 % 7.1 ISO 3629 Mass fraction of heavy metals (as Pb) Maximum: 0,005 % 7.2 ISO 10349-5 Mass fraction of iron (Fe) Maximum: 0,005 % 7.3 ISO 10349-5 Reaction to ammoniacal silver nitrate To pass test 7.4 ISO 10349-9 pH value 3,7 to 4,6 7.5 ISO 36
40、29 Mass fraction of thiosulfate (as S 2 O 3 2 ) Maximum: 0,04 % 7.6 ISO 3629 Appearance of solution Clear and free from insoluble matter except for a slight flocculence 7.7 ISO 3629 5 Reagents and glassware All reagents, materials and glassware shall conform to the requirements specified in ISO 1034
41、9-1 unless otherwise noted. 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
42、 from country to country. 6 Sampling See ISO 10349-1. 7 Test methods 7.1 Assay 7.1.1 Specification The minimum mass fraction of potassium metabisulfite shall be 95,0 %. 7.1.2 Reagents 7.1.2.1 Acetic acid, glacial,CH 3 COOH (DANGER: B C ) 1) . 7.1.2.2 Acetic acid, c(CH 3 COOH) 2mol /l . Dilute 120 g
43、of glacial acetic acid (7.1.2.1) (DANGER: B C ) to 1 litre. 7.1.2.3 Hydrochloric acid (HCl), 1,18 g/ml (DANGER: B C ). 7.1.2.4 Potassium iodide (KI). 1) Hazard warning codes are defined in ISO 10349-1.ISO 3629:2000(E) ISO 0002 All rights rsedevre 3 7.1.2.5 Iodine, c(I 2 ) = 0,05 mol/l (12,7 g/l) 2)
44、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 (7.1.2.4) and 100 ml of water. After solution is complete, add three drops of hydrochloric acid (7.1.2.3) (DANGER: B C ) and dilute to 1 litre at 20 C in a v
45、olumetric flask. From the mass of iodine, m, calculate the concentration, c, in moles per litre, from 254 m c 7.1.2.6 Salicylic acid, c(HOC 6 H 4 COOH)=1%(10g/l). 7.1.2.7 Starch indicator, 5 g/l solution. Stir 5 g of soluble starch into 100 ml of 1 % salicylic acid solution (7.1.2.6). Add 300 ml of
46、this solution to 400 ml of boiling water. Boil until the starch dissolves and dilute to 1 litre with water. 7.1.2.8 Sodium thiosulfate, c(Na 2 S 2 O 3 ) = 0,100 mol/l (15,8 g/l) 2) . 7.1.2.9 Sulfuric acid, c(H 2 SO 4 ) = 0,05 mol/l (4,9 g/l) 2) 4) . 7.1.2.10 Ethanol (C 2 H 5 OH), 95 % (denatured). 7
47、.1.2.11 Phenolphthalein indicator, 5 g/l solution. Dissolve 1 g of phenolphthalein in 100 ml of ethanol (7.1.2.10) and add 100 ml of water with constant stirring. Filter if necessary. 7.1.2.12 Neutral formaldehyde, c(HCHO) 37 % (360 g/l) (DANGER: B C S ). Adjust the pH of the formaldehyde solution s
48、o that it is neutral to phenolphthalein indicator (7.1.2.11). 7.1.3 Apparatus 7.1.3.1 Burette, of capacity 50 ml. 7.1.3.2 Pipette, of capacity 50 ml. 7.1.4 Procedure Using a pipette (7.1.3.2), transfer 50,00 ml of the iodine solution (7.1.2.5) to a flask. Weigh, to the nearest 0,000 1 g, a test port
49、ion of about 0,23 g and wash this into the flask. Add 5 ml of the acetic acid (7.1.2.2) and mix to ensure complete dissolution of the sample. Using a burette (7.1.3.1), titrate with the sodium thiosulfate solution (7.1.2.8), adding 2 ml of the starch indicator (7.1.2.7) just before the endpoint. Weigh, to the nearest 0,001 g, another test portion of about 5 g. Dissolve it in 50 ml of water and add 50 ml of the neutral formaldehyde (7.1.2.12). Add a few drops of the p
