1、I NT E R NAT 1 O NA L STANDARD IS0 3622 Second edition 1996-1 0-1 5 Photography - Processing chemicals - Specifications for ammonium thiocyanate Photographie - Produits chimiques de traitement - Spcifications relatives au thiocyanate dammonium Reference number IS0 3622:1996(E) W 4853903 0684359 346
2、IS0 3622:1996(E) Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical committees. Each member body interested in a subj
3、ect 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 in the work. IS0 collaborates closely with the International Electrotechnical Commission (IE
4、C) on all 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 Stan
5、dard IS0 3622 was prepared by Technical Committee ISOflC 42, Photography. This second edition cancels and replaces the first edition (IS0 3622:1976), which has been technically revised. 8 IS0 1996 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utili
6、zed in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case Postale 56 CH-1 21 1 Genve 20 Switzerland Printed in Switzerland II - 4851903 0684160 Ob8 = 9 IS0 IS0
7、 3622:1996(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 1,4, 5 and 6 of IS0 10349. This In
8、ternational 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 use of safe
9、ty 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. Hazard warn
10、ings designated by a letter enclosed in angle brackets “( “ are used as a reminder in those steps detailing handling operations and are defined in IS0 10349-1. More detailed information regarding hazards, handling and use of these chemicals may be available from the manufacturer. 0.2 This Internatio
11、nal 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 minim
12、um 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 set t
13、o 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 condition o
14、f 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 included i
15、n 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 chemicals
16、 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. . 111 IS0 3622:1996(E) 4853703 Ob84LbL TT4 Q IS0 0.3 Efforts have been made to employ tests
17、 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 satisfactory method is avai
18、lable. 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 alternative procedures with the
19、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. iv = q851903 Ob84Lb2 930 INTERNATIONAL STANDARD (8 IS0 IS0 3622:199
20、6(El Photography - Processing chemicals - Specifications for a rn mo n i u rn t h i ocy a na t e 1 Scope This International Standard establishes criteria for the purity of photographic-grade ammonium thiocyanate and specifies the test methods to be used to determine the purity. 2 Normative reference
21、s 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 standards are subject to revision, and parties to agreements based on this International Standa
22、rd are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards. IS0 10349-1 :I 992, Photography - Photographic-grade chemicals - Test methods - Part 1: Genera
23、l. IS0 1 0349-4: 1992, Photography - Photographic-grade chemicals - Test methods - Part 4: Determination of residue after ignition. IS0 10349-5:1992, Photography - Photographic-grade chemicals - Test methods - Part 5: Determination of heavy metals and iron content. IS0 1034!3-6:1992, Photography - P
24、hotographic-grade chemicals - Test methods - Part 6: Determination of halide content. 3 General 3.1 Physical properties Ammonium thiocyanate (NH4CNS) exists as colourless, deliquescent crystals. It has a relative molecular mass of 76,12. 3.2 Hazardous properties Ammonium thiocyanate presents no spec
25、ial hazardous problems under normal handling I IS0 3622:1996(E) D 4853903 Ob84Lb3 877 0 IS0 3.3 Storage Store in a cool dry place. Care shall be taken to avoid conditions of high heat and/or humidity which can cause decomposition and emission of toxic fumes. 4 Requirements A summary of the requireme
26、nts is shown in table 1 5 Reagents and glassware All reagents, materials and glassware shall conform to the requirements specified in IS0 103491 unless otherwise noted. The hazard warning symbols used as a reminder in those steps detailing handling operations are defined in IS0 10349-1. These symbol
27、s 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 IS0 10349-1 7 Test procedures 7.1 Assay 7.1.1 Specification Content of NH c2 is the actual concentration, in moles per l
28、itre, of the ammonium thiocyanate (7.1.2.4); m is the mass, in grams, of the test portion; 50 is the volume, in millilitres, of silver nitrate added (7.1.4); 7,612 is the conversion factor obtained from the mass of ammonium thiocyanate equivalent to 1 mole of silver nitrate (.e. 76.1 2) x the conver
29、sion factor for millilitres to litres (.e. 0,001 1 x 1 O0 (for percentage), 7.2 Residue after ignition 7.2.1 Specification Maximum content of residue after ignition shall be 0,lO YO (m/m). 1) This solution may be prepared from concentrated nitric acid, 69 % (mim) (approx.) (DANGER: (C)(B)(O). (Hazar
30、d warning codes are defined in IS0 10349-1 .) 2) Commercially available analysed reagent solutions are recommended. Procedures for the preparations of these materials are available in any quantitative analysis text. 3) This solution may be prepared from solid silver nitrate (DANGER: (C). 3 m 4853903
31、 0684165 b4T m IS0 3622:1996(E) IS0 7.2.2 Procedure Determine the percentage residue after ignition in accordance with IS0 103494. Weigh about 5,O g of sample and ignite it in a platinum crucible (600 OC f 50 OC, 4 h, 0,001 9). Cool in a desiccator and then weigh to the nearest 0,001 g. 7.3 Heavy me
32、tals content 7.3.1 Specification Maximum content of heavy metals shall be 0,002 % (m/m). 7.3.2 Procedure NOTE - The standard for the iron test (7.4) is prepared in the same way as the heavy metals standard. Determine the percentage of heavy metals in accordance with IS0 103495. Use a test portion of
33、 1.90 g to 2,lO g, prepared in accordance with IS0 103495:1992. 7.2. Use 4 ml of the heavy metals standard prepared in accordance with IS0 10349-5:1992, 8.1.1. 7.4 Iron content 7.4.1 Specification Maximum content of iron shall be 0,000 5 YO (m/m). 7.4.2 Procedure Determine the percentage of iron in
34、accordance with IS0 10349-5. Use a test portion of 1,90 g to 2.10 g, prepared in accordance with IS0 103495:1992, 7.2. Use 1 ml of the iron standard prepared in accordance with IS0 10349-5:1992, 8.1.1. 7.5 Halide content (as CI-) 7.5.1 Specification Maximum content of halide shall be 0,06 % (m/m) O,
35、l YO (m/m) as “&Il. 7.5.2 Reagents 7.5.2.1 Sodium hydroxide (NaOH), solid (DANGER: (C). 7.5.2.2 Hydrogen peroxide (HzOz), 67 g/i (approx.) solution. Dilute 1 volume of 30 % hydrogen peroxide (DANGER: (C)(O) with 4 volumes of water. 7.5.3 Procedure Weigh, to the nearest 0,l g, a test portion of about
36、 1 g and dissolve it in 30 ml of the hydrogen peroxide (7.5.2.2). Add 1 g of sodium hydroxide (7.5.2.1) (DANGER: (C) and swirl until the vigorous reaction ceases. Add another 30 ml of hydrogen peroxide (7.5.2.2) and boil for 2 min. Cool and dilute to 1 O0 ml with water. Use a 1 O ml aliquot of this
37、test solution. Continue the procedure in accordance with IS0 103496:1992, clause 4, using 6 ml of the halide standard solution A. 4 Q IS0 W 4851903 0684366 586 9 IS0 3622:1996(E) 7.6 pH value 7.6.1 Specification The pH of the solution shall be between 4,5 and 6,O. 7.6.2 Apparatus 7.6.2.1 Electronic
38、pH-meter, equipped with a glass electrode and standard reference electrode. 7.6.3 Procedure Weigh, to the nearest 0.1 g, a test portion of about 5 g and dissolve it in about 80 ml of boiled water. Dilute to 100 ml. Measure the pH of the solution at 20 OC, using the pH-meter (7.6.2.1) in accordance w
39、ith the manufacturers instructions. 7.7 Sulfur compounds For use in non-developer solutions (e.g. fixers), the less-sensitive iodine consumption test is adequate, whereas for use in developers the more-sensitive ammoniacal silver nitrate test is required. 7.7.1 Amount precipitated by ammoniacal silv
40、er nitrate 4) 7.7.1 .I Specification Maximum content of sulfur shall be 0,005 YO (m/m). 7.7.1.2 Reagents 7.7.1.2.1 Sulfide standard solution (1 mI = 0,010 mg S2-1. Dissolve 1,5 g of sodium sulfide nonahydrate (Na2S9H20) (DANGER: (B)(S) in 100 ml of water in a 200 ml volumetric flask. Dilute to volum
41、e with water and mix well. Pipette 1 ml of this solution into a 100 ml volumetric flask, dilute to volume with water and mix well. Label this solution “sulfide standard“. 7.7.1.2.2 Ammonium hydroxide NH40H). p 031 g/ml (DANGER: (C)(B). 7.7.1.2.3 Silver nitrate (AgN03), 1 O0 g/l solution 3). 7.7.1.2.
42、4 Silver nitrate, standard volumetric solution of 0,001 mol/l (0,170 g/I) 2) 3). 7.7.1.3 Apparatus 7.7.1.3.1 Two matched Nessler colour-comparison cylinders, of 50 ml capacity. 7.7.1.4 Procedure Weigh, to the nearest 0.01 g, a test portion of about 1 g and dissolve it in 25 ml of water. Add this sol
43、ution to a mixture of 20 ml of ammonium hydroxide (7.7.1.2.2) (DANGER: (C)(B) and 2 ml of the silver nitrate (7.7.1.2.3). Also prepare a control by adding 5 ml of sulfide standard (7.7.1.2.1) to a mixture of 20 ml of water, 20 ml of ammonium hydroxide (7.7.1.2.2) and 3 ml of 0,001 mol/ silver nitrat
44、e (7.7.1.2.4). Heat both solutions in a boiling water bath for 15 min. Cool, transfer to the Nessler colour-comparison cylinders (7.7.1.3.1) and dilute to 50 MI. 4) The test method given here for sulfur compounds is not the same as the ammoniacal silver nitrate test given in IS0 10349-9:1992, Photog
45、raphy - Photographicgrade chemicals - Test methods - Part 9: Reaction to ammoniacal silver nitrate. 5 4851903 0684167 412 = IS0 3622:1996(E) IS0 Compare the colours produced in the two Nessler colour-comparison cylinders. Any colour produced in the sample shall not exceed that produced in the sulfid
46、e standard control. CAUTION - Dispose of all test solutions and rinse all used apparatus immediately. Explosive compounds may be formed on standing. 7.7.2 Iodine consumption 7.7.2.1 Specification To pass test. 7.7.2.2 Reagents 7.7.2.2.1 Iodine (Iz), standard volumetric solution of 0,l O0 mol/l2). 7.
47、7.2.2.2 Sulfuric acid (H2SO4). 1 O % solution 5). 7.7.2.2.3 Salicylic acid (iiC&i4C2ii), 1 % (1 O 9/11 solution. Prepare a solution of 1 g of salicylic acid in 1 O0 ml of water. 7.7.2.2.4 Starch indicator, 5 gil solution. Stir 5 g of soluble starch with 100 ml of 1 % salicylic acid (7.7.2.2.3). Then
48、 add 300 ml to 400 ml of boiting water and boil until the starch dissolves. Finally dilute to 1 O00 ml with water. 7.7.2.3 Procedure Dissolve 4,95 g to 5,05 g of the sample in 50 ml of water. Add 1,7 ml of the sulfuric acid (7.7.2.2.2), 1 g of potassium iodide (KI) and 1 ml of starch indicator (7.7.
49、2.2.4). Titrate with the iodine solution (7.7.2.2.1). Not more than 1 ,O mI of the iodine solution shall be required. 7.8 Sulfate content (as S042-) 7.8.1 Specification Maximum content of sulfate shall be 0,04 % (m/m) 0,06 % (mim) as (NH4)2S04. 7.8.2 Reagents 7.8.2.1 Hydrochloric acid (HCI), (1 + 9) solution 6). 7.8.2.2 Barium chloride Dissolve 100 g of barium chloride dihydrate (BaC12-2H20) (DANGER: (S) in 1 O00 ml of water. 7.8.2.3 Sulfate standard solution (1 mI = 0.1 O mg SO$). Dissolve a soluble sulfate salt in water e.g. 181 mg of potassium sulfate (K2
