1、INTERNATIONAL STANDARD IS0 3620 Second edition 1994-1 2-1 5 Corrected and reprinted 1995-02-0 1 Photography - Processing chemicals - Specifications for aluminium potassium sulfate Photographie - Produits chimiques de traitement - Spcifications pour le sulfate double daluminium et de potassium Refere
2、nce number IS0 3620: 1994(E) 4853903 0594085 5Tb W IS0 3620:1994(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 technica
3、l 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 in the work. IS0 collaborates closely wit
4、h the International Electrotechnical Commission (IEC) 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 t
5、he member bodies casting a vote. International Standard IS0 3620 was prepared by Technical Committee ISOflC 42, Photography. This second edition cancels and replaces the first edition (IS0 3620:1976), which has been technically revised. Annex A of this International Standard is for information only.
6、 O IS0 1994 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standar
7、dization Case postale 56 CH-1 21 1 Genve 20 Switzerland Printed in Switzerland II o IS0 I 4853903 0594086 432 I IS0 3620:1994(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 m
8、ethods and procedures cited in this International Standard are compiled in parts 1 and 5 of IS0 10349. 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 o
9、therwise hazardous chemicals. Safe laboratory practice for the handling of chemicals requires the use of safety glasses or 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 ar
10、e to be exercised at all times but care has been taken to provide warnings for hazardous materials. Hazard warnings 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 regar
11、ding hazards, handling and use of these chemicals may be available from the manufacturer. 0.2 This International Standard provides chemical and physical require- ments for the suitability of a photographic-grade chemical. The tests correlate with undesirable photographic effects. Purity requirements
12、 are set as low as possible consistent with these photographic effects. These criteria are considered the 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
13、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. Inert impurities are limited to amounts whic
14、h 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 appropriate use test, the shorter, more economical test
15、 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 as a valuable complement to the identity test
16、. 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 for general information only and are not part o
17、f the requirements. . 111 = 4853903 05L1087 379 IS0 3620:1994(E) o IS0 0.3 Efforts have been made to employ tests 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 h
18、ave been specified 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
19、place of the tests described in this International Standard. Correlation of such alternative procedures with the 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“, ho
20、wever, alternative methods shall not be used. IV 4851903 0594088 205 9 99,5 % (m/m) min. 0,005 % (m/m) Max. 0,Ol % (m/m) max. Clear and free from insoluble matter except for a slight flocculence INTERNATIONAL STANDARD o IS0 IS0 3620: 1994( E) 7.1 7.2 7.3 7.4 Photography - Processing chemicals - Spec
21、ifications for aluminium potassium sulfate 1 Scope This International Standard establishes criteria for the purity of photographic-grade aluminium potassium sulfate dodecahydrate, AlK(SO4I2.1 2H20, and speci- fies the tests to be used to determine the purity. 2 Normative references The following sta
22、ndards 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 Standard are encouraged t
23、o 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 : 1992, Photography - Photographic- grade chemicals - Test methods - Part 7: General. IS0 10349-5: 1
24、992, Photography - Photographic- grade chemicals - Test methods - Part 5: Determi- nation of heavy metals and iron content. 3 General 3.2 Hazardous properties Aluminium potassium sulfate is not hazardous when handled with normal precautions. 3.3 Storage Aluminium potassium sulfate should be stored i
25、n a closed container at room temperature. 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 IS0 10349-1 unless otherwise noted. The hazard warning symbols used as a reminder i
26、n those steps detailing handling oper- ations are defined in IS0 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. 3.1 Physical properties Aluminium potassium sulfat
27、e dodecahydrate AlK(S04)2.1 2H20 exists in the form of colourless crystals or a white powder. It has a relative molecular mass of 474,39. 6 Sampling See IS0 10349-1 Table 1 - Summary of requirements Test Limit International Standard in II Subcause which test method is given Assay as AIK(S04)2.1 2H20
28、1 Heavy metals (as Pb) Iron (Fe) Appearance of solution IS0 3620 IS0 10349-5 IS0 10349-5 IS0 3620 I NOTE - m/m = mass/macs 1 IS0 3620:1994(E) o IS0 7 Test methods where 7.1 Assay 7.1.1 Specif cat ion c is the actual concentration, in moles per litre, of the lead nitrate (7.1.2.2); Content of AlK(S04
29、)2.12H20 shall be 99.5 % (m/m) V is the volume, in millilitres, of the lead min. nitrate used for the titration (7.1.4); 7.1.2 Reagents m is the mass, in grams, of the test portion; 7.1.2.1 EDTA solution, standard volumetric solution of 0,05 mol/l (16,8 g/l of the disodium salt, C1 237,2 is a conver
30、sion factor inclusive of the factors above (.e. 474,4) corrected by a factor of 2 to compensate for EDTA con- sumption by lead nitrate vs. that of aluminium potassium sulfate. 7.1.3 Apparatus 7.2 Heavy metals content 7.1.3.1 Burette, of 50 mI capacity. 7.2.1 Specification 7.1.3.2 Pipette, of 20 ml c
31、apacity. 7.1.4 Procedure Weigh, to the nearest 0,001 g, a test portion of about 2,25 g of the test sample. Dissolve it in water and dilute to 100 ml. Using the pipette (7.1.3.21, take 20 ml of this solution and add 40,O ml of the EDTA solution (7.1 2.1) followed by 100 mI of water. Heat on a water b
32、ath for 10 min then cool. Add 1 g of hexamine (7.1.2.4) and, using the burette (7.1.3.1) titrate with the lead nitrate (7.1.2.2) () using 0,4 ml of the xylenol orange indicator (7.1.2.3). The endpoint occurs when the solution goes from red to yellow in colour. Maximum content of heavy metals shall b
33、e 0,005 % (m/m). 7.2.2 Procedure NOTE 1 The standard for the iron test (7.3) is prepared in the same way as the heavy metals standard. Determine the percentage of heavy metals in accordance with IS0 10349-5. Use a test portion of 0,99 g to 1,Ol g prepared in accordance with IS0 10349-5:1992, 7.2. Us
34、e 5 ml of the heavy metals standard prepared in accordance with IS0 10349-5: 1992, 8.1.2. 7.1.5 Expression of results The assay, expressed as a percentage by mass, of 7.3 Iron content aluminium potassium sulfate dodecahydrate AIK(S04)2.1 2H201 is given by the formula 7.3.1 Specification (474,4 - 237
35、,2eV)/m Maximum content of iron shall be 0.01 % (m/m). 1) Commercially analytical reagent is recommended. A procedure for the preparation and standardization of EDTA solution is given in annex A. 2) Hazard warning codes are defined in IS0 10349-1 :I 992, clause 4. 3) Xyienoi orange solutions have be
36、en reported to be unstable. It is recommended that solutions be prepared on a daily basis. 4) Also known as: methenamine, hexamethylenamine, 1,3,5,7-tetraazaadamantane, aminoform, cystamin, cystogen, formin uritone and urotropin. 2 o IS0 4851903 0594090 963 IS0 3620:1994(E) 7.3.2 Procedure 7.4 Appea
37、rance of solution Determine the percentage of iron in accordance with 7.4.1 Specification IS0 10349-5. Use a test portion of 0.49 g to 0,51 g of the sample prepared in accordance with IS0 10349-5: 1992, 7.2. Use 5 ml of the iron standard prepared in accordance with IS0 10349-5:1992, 8.1.2. The solut
38、ion shall be clear and free from insoluble matter except for a slight flocculence. 7.4.2 Procedure Prepare a 50 g/I solution of the sample in water. Examine the solution for colour and clarity. 3 IS0 3620:1994(E) = 4853903 O594853 470 = o IS0 Annex A (informative) Preparation of EDTA solution: Stand
39、ard volumetric solution of 0,05 mol/l (16,8 g) A.l Reagents A.l.l Ethylenediaminetetraacetic acid (EDTA) dihydrate, disodium salt, C10H14N2Na2082H20. NOTE 2 The relative molecular mass for the dihydrate salt is 372.23, The relative molecular mass for the non-hydrated salt is 336,20. A.1.2 Calcium ca
40、rbonate, Caco3, chelometric standard grade material4). A.1.3 Hydrochloric acid, HCI, (1 + 313. A.1.4 Sodium hydroxide, NaOH, standard volu- metric solution of 1 mol/l (40,O g/Il6). A.1.5 Hydroxynaphthol blue indicator. A.2 Apparatus A.2.1 Burette, of 50 mI capacity. A.2.2 Pipette, of 2 mi capacity.
41、A.3 Procedure Dissolve 20 g of disodium EDTA dihydrate (A.l .I) in water and dilute to 1 litre. Weigh, to the nearest 0,000 1 g, about 0,200 g of the calcium carbonate (A.1.2). Transfer the calcium car- bonate to a 400 ml beaker and add 10 ml of water. Cover the beaker with a watch glass and add 2 m
42、l of hydrochloric acid (A.1.3) from a pipette (A.2.2) inserted between the watch glass and the lip of the beaker. Swirl the beaker to assist dissolution of the calcium carbonate. Wash down the sides of the beaker, the watch glass and the outside of the pipette and dilute the solution to about 100 ml
43、 with water. While stirring with a magnetic stirrer, add about 30 ml of the prepared EDTA solution using the burette (A.2.1), followed by 15 ml of sodium hydroxide (A.1.4) and 0,300 g of hydroxynaphthol blue indicator (A.1.5). Continue the titration with the EDTA solution to the endpoint when a blue
44、 colour appears. A.4 Expression of results The actual concentration of the EDTA solution, c, in moles per litre, is given by the formula c = m/(O,I O0 09.v) where m is the mass, in grams, of the calcium carbonate (A.1.2); V is the volume, in millilitres, of the prepared EDTA solution (A. 1 .I 1; 0,1
45、00 O9 is the relative molecular mass of calcium carbonate (.e. 100,09) x the conversion factor for millilitres to litres (.e. 0,001 1. Adjust the concentration of the EDTA solution to exactly 0,051 mol/l by diluting with water. The volume of water required, in millilitres, Vw, is given by the formul
46、a where c is the actual concentration of the prepared EDTA solution, in moles per litre; S is the volume, in millilitres, of the prepared EDTA solution to be diluted. 4) It is recommended that the calcium carbonate be dried to constant weight in a low-temperature oven and maintained in a desiccator
47、to prevent absorption of water. 5) This solution can be prepared from concentrated hydrochloric acid, p= 1,18 (DANGER: ) 6) This solution can be prepared from solid sodium hydroxide (DANGER: ). 4 4851903 0594852 307 IS0 3620:1994(E) o IS0 ICs 37.040.30 Descriptors: photography, photographic materials, chemical reagents, aluminium potassium sulphate, specifications, materials specifications, purity criteria, tests, chemical analysis. Price based on 4 Dacles
