1、INTERNATIONAL STANDARD ISO 3619 Second edition 1994-12-15 Photography - Processing chemicals - Specifications for ammonium thiosulfate solution Photographie - Produits chimiques de traitemen t - Spkifica tions relatives au thiosulfa te d ammonium en Solution Reference number ISO 3619:1994(E) ISO 361
2、9:1994(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
3、 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 in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on a
4、ll matters 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 IS
5、O 3619 was prepared by Technical Committee ISOflC 42, Photography. This second edition cancels and replaces the first edition (ISO 3619:1976), which has been technically revised. 0 ISO 1994 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized In
6、any form or by any means, electronie or mechanical. rncluding photocopying and microfilm, without Permission In writing from the publisher. International Organization for Standardization Case postale 56 l CH-l 211 Geneve 20 l Swrtzerland Printed in Switzerland ii 0 ISO ISO 3619:1994(E) Introduction
7、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, 3, 4, 5, IO, 11 and 12 of ISO 10349. This International St
8、andard 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 use of safety glasses or
9、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 for hazardous materials. Hazard warnings designa
10、ted 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 the manufacturer. 0.2 This International Standard p
11、rovides 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. These criteria are considered the minimum requireme
12、nts 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 set to take advan
13、tage 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 condition of materials
14、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 included in all cases
15、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. ldentity tests have been included whenever a possibility exists that another Chemical or mixture of chemicals could pass
16、the other tests. All requirements listed in clause 4 are mandatory. The physicai appearance sf the material and any footnotes are for general Information only and are not part of the requirements. ISO 3619:1994(E) 0 ISO 0.3 Efforts have been made to employ tests which are capable of being run in any
17、 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 satisfactory method is available. Over the past few years, great
18、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 alternative procedures with the given method is the responsibility of
19、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 3619:1994(E) Photography - Processing chemicals - Specifications for amm
20、onium thiosulfate solution 1 Scope This International Standard establishes criteria for the purity of photographit-grade ammonium thiosulfate Solution and specifies the tests to be used to determine the purity. 2 Normative references The following Standards contain provisions which, through referenc
21、e 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 encouraged to investigate the possibility of applying the mos
22、t 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 10349-3: 1992, Photography - Photographic- grade chemicals -
23、Test methods - Part 3: Deter- mination of matter insoluble in ammonium h ydroxide Solution. ISO 10349-4: 1992, Photography - Photographic- grade chemicals - Test methods - Part 4: Deter- mination of residue after ignition. ISO 10349-5: 1992, Photography - Photographic- grade chemicals - Test methods
24、 - Part 5: Deter- mination of heavy metals and iron content. ISO 10349-10: 1992, Photography - Photographic- grade chemicals - Test methods - Part 70: Determi- nation of sulfide con ten t. ISO 10349-11 :1992, Photography - Photographic- grade chemicals - Test methods - Part 11: Determi- nation of sp
25、ecific gravity. ISO 10349-12: 1992, Photography - Photographic- grade chemicak - Test methods - Part 72: Determi- nation of density. 3 General 3.1 Physical properties Ammonium thiosulfate, (NH4 crystallization may occur at reduced temperatures (cold weather). lt has a relative molecular mass of 148,
26、20. 3.2 Hazardous properties Ammonium thiosulfate Solution is not hazardous when handled with normal precautions. Ammonium thiosulfate should not be mixed with large volumes of strong acids or alkalis. 3.3 Storage Ammonium thiosulfate solution shall be stored in a closed Container at room temperatur
27、e. 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 10349-1 unless otherwise noted. The hazard warning Symbols used as a reminder in those Steps detailing handling oper-
28、 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 from country to country. 6 Sampling See ISO 10349-1. 1 ISO 3619:1994(E) Table 1 - Summary of requirements 0 ISO
29、Test Limit Subclause International Standard in which test method is given Essay las (NH,)2S2031 53,0 % (WZ/UZ) min. 7.1 ISO 3619 61,0 % (m/m) max. Alkalinity (as NH,OH) 0,3 % (m/m) min. 7.1 ISO 3619 1,5 % (m/m) max. Sulfites as (NH,pO,l 1 % (m/m) max. 7.1 ISO 3619 Insoluble matter (as precipitate of
30、 0,2 % (m/m) max. 7.2 ISO 10349-3 Calcium and magnesium in ammonium hydroxide) Residue after ignition 0,2 % (m/m) max. 7.3 ISO 10349-4 Heavy metals (as Pb) 0,001 % (m/m) max. 7.4 ISO 10349-5 Iron (Fe) 0,001 % (m/m) max. 7.5 ISO 10349-5 Sulfides (as S*-) 0,000 25 % (m/m) max. 7.6 ISO 10349-10 Specifi
31、c gravity (at 20 “C) 1,290 min. 7.7.1 ISO 10349-11 or 1,346 max. density (at 20 “C) 1,284 g/ml min. 7.7.2 ISO 10349-12 1,340 g/ml max. NOTE - m/m = mass/mass 7 Test methods 7.1 Assay as (NH4) is the volume, in millilitres, of the iodine Solution used to resch the endpoint of the second titration (7.
32、1.4); is the actual concentration, expressed in moles per litre, of the sodium hydroxide solution (7.1.2.3); is the volume, in millilitres, of the sodium hydroxide used to resch the endpoint of the third titration (7.1.4); is the conversion factor obtained from the molar mass of ammonium thiosulfate
33、 (i.e. 148,2) x 2 moles of thiosulfate per mole of iodine (i.e. 2) x the Sample ratio (i.e. IO) x the conversion factor for millilitres to litres (i.e. 0,001) x 100 (for percentage); 0,333 is a correction factor for the ratio of acid generated by the iodine used in the Oxidation of the sulfite three
34、 equivalents of acid are formed (see note l), two of which are due to the consumption of iodine; m is the mass, in grams, of the test Portion. 7.1.5.2 The alkalinity, expressed as a percentage by mass of ammonium hydroxide (NH,OH), is given by 3,5q l V,/m Cl is the actual concentration, expressed in
35、 moles per litre, of the hydrochloric acid (7.1.2.2); Vl is the volume, in millilitres, of the hydro- chloric acid used to resch the endpoint of the first titration (7.1.4); 35 I is the conversion factor obtained from the mass of ammonium hydroxide equivalent to 1 mole of hydrochloric acid (i.e. 35)
36、 x the conversion factor for millilitres to litres (i.e. 0,001) x 100 (for percentage); m is the mass, in grams, of the test Portion. 7.1.5.3 The sulfite content, expressed as a per- centage by mass of ammonium sulfite (NH4)2S03, is given by where is the actual concentration, expressed in moles of s
37、odium hydroxide per litre, of the sodium hydroxide Solution (7.1.2.3); v3 is the volume, in millilitres, of the sodium hydroxide used to resch the endpoint of the third titration (7.1.4); 38,7 is the conversion factor obtained from the mass of ammonium sulfite equivalent to one-third mole of sodium
38、hydroxide (see note 1) (i.e. 0,333 3 x 116) x the Sample ratio (i.e. IO) x the conversion factor for millilitres to litre (i.e. 0,001) x 100 (for percentage); m is the mass, in grams, of the test Portion. NOTE 1 The pertinent Chemical reactions for this analysis are the following. 3 ISO 3619:1994(E)
39、 0 ISO Oxidation of ammonium thiosulfate: 7.5 Iron content 2s*o3*- + 1, *- s/JoE*- + 21- 7.5.1 Specification Oxidation of sulfite species: Maximum content of iron shall be 0,001 % (m/m). HS03- + 1, + H20 r- HSO,-+ 21-+2H+ HSO,- ,- H+ + SO,*- 7.5.2 Procedure Determine the percentage of iron in accord
40、ance with ISO 10349-5. Use a test Portion of the residue from the ignition test (7.3.2) corresponding to 2 g of the Sample prepared in accordance with ISO 10349-5: 1992, 7.1 (i.e. 5 ml of the 25 ml residue Solution). Use 2 ml of the iron Standard prepared in accordance with ISO 10349-5:1992, 8.1 .l
41、. Three equivalents of acid are formed in the Oxidation of sulfite by iodine, two by the Oxidation and the third is due to the increased acidity of biosulfate vs. bisulfite. Thus a factor of 0,333 is used to correct for the acid due to the acidity differente. 7.2 In soluble matter Calcium and ma gne
42、sium content (as a precipitate of nium hydroxide) in ammo 7.6 Sulfide content (as S*-) 7.2.1 Specification 7.6.1 Specification Maximum content of insoluble matter shall be 0,2 % (m/m). Maximum content of sulfide shall be 0,000 25 % (m/m). 7.2.2. Procedure 7.6.2 Procedure Determine the percentage of
43、insoluble matter in accordance with ISO 10349-3. Determine the percentage of sulfide in accordance with ISO 10349-10. Use a test Portion, weighed to the nearest 0,05 g, of 2,O g of the Sample and mix with 40 ml of water. Use a 5 ml Portion of the sulfide Standard. 7.3 Residue after ignition 7.3.1 Sp
44、ecification Maximum residue after ignition shall be 0,2 % (m/m). 7.7 Specific gravity or density 7.3.2 Procedure Either th e specific gravity or density test will be sufficient to satisfy conformity to the spe cif ica tion. Determine the residue after ignition in accordance with ISO 10349-4. Weigh,
45、to the nearest 0,Ol g, a test Portion of about IO g of the test Sample. Evaporate to dryness on a steam bath and then continue the procedure in accordance with ISO 10349-4. Incinerate at 600 “C i: 50 OC, for 4 h. Cool in a desiccator and then weigh to the nearest 0,001 g. Retain this residue for the
46、 heavy metals (7.4) and iron (7.5) tests. 7.7.1 Specific gravity 7.7.1 .l Specification The specific gravity shall be between 1,290 and 1,346 at 20 “C. 7.4 Heavy metals content (as Pb) 7.7.1.2 Procedure 7.4.1 Specification Determine the specific gravity in accordance with ISO 10349-11, using a hydro
47、meter which includes the range 1,25 to 1,35. Maximum content of heavy metals shall be 0,001 % (mlm). 7.4.2 Procedure 7.7.2 Density NOTE 2 The Standard for the iron test (7.5) is prepared in the Same way as the heavy metals Standard. 7.7.2.1 Specification The density shall be between 1,288 g/ml and 1
48、,343 g/ml at 20 “C. Determine the percentage of heavy metals in accord- ante with ISO 10349-5. Use a test Portion of the residue from the ignition test (7.3.2) corresponding to 2 g of the Sample prepared in accordance with ISO 10349-5:1992, 7.1 (i.e. 5 ml of the 25 ml residue Solution). Use 2 ml of the heavy metals Standard prepared in accordance with ISO 10349-5:1992, 8.1 .l. 7.7.2.2 Procedure Betermine the density in accordance with ISO 10349-12. 4
