1、ApprovedAmerican NationalStandardANSI/I3A IT4.156-2002for Photography Processing Chemicals Specifications for Anhydrous Sodium Formaldehyde BisulfiteANSI/I3AIT4.156-2002ANSI/I3A IT4.156-2002(Revision and redesignation ofANSI/NAPM IT4.156-1986 (R1995)American National Standardfor Photography Processi
2、ng Chemicals Specifications for AnhydrousSodium Formaldehyde BisulfiteSecretariatInternational Imaging Industry Association, Inc. (I3A)Approved September 5, 2002 American National Standards Institute, Inc.Approval of an American National Standard requires review by ANSI that therequirements for due
3、process, consensus, and other criteria for approval havebeen met by the standards developer.Consensus is established when, in the judgement of the ANSI Board ofStandards Review, substantial agreement has been reached by directly andmaterially affected interests. Substantial agreement means much more
4、 thana simple majority, but not necessarily unanimity. Consensus requires that allviews and objections be considered, and that a concerted effort be madetowards their resolution.The use of American National Standards is completely voluntary; theirexistence does not in any respect preclude anyone, wh
5、ether he has approvedthe standards or not, from manufacturing, marketing, purchasing, or usingproducts, processes, or procedures not conforming to the standards.The American National Standards Institute does not develop standards andwill in no circumstances give an interpretation of any American Nat
6、ionalStandard. Moreover, no person shall have the right or authority to issue aninterpretation of an American National Standard in the name of the AmericanNational Standards Institute. Requests for interpretations should beaddressed to the secretariat or sponsor whose name appears on the titlepage o
7、f this standard.CAUTION NOTICE: This American National Standard may be revised orwithdrawn at any time. The procedures of the American National StandardsInstitute require that action be taken periodically to reaffirm, revise, orwithdraw this standard. Purchasers of American National Standards mayrec
8、eive current information on all standards by calling or writing the AmericanNational Standards Institute.American National StandardPublished byAmerican National Standards Institute, Inc.25 West 43rd Street, New York, NY 10036Copyright 2002 by American National Standards Institute, Inc.All rights res
9、erved.No part of this publication may be reproduced in anyform, in an electronic retrieval system or otherwise,without prior written permission of the publisher.Printed in the United States of AmericaiContentsPageForeword ii0 Introduction. iii1 Scope . 12 Normative references . 13 General. 14 Requir
10、ements . 15 Reagents and glassware 26 Sampling. 27 Test methods 2Table1 Summary of requirements 2AnnexA Preparation and standardization of standard iodine solutions 7B Preparation and standardization of standard sodium thiosulfate solutions 9iiForeword (This foreword is not part of American National
11、 Standard ANSI/I3A IT4.156-2002.)This standard is one of a series of standards establishing criteria of purity for chemi-cals used in processing photographic materials. In the current review process, thisseries of standards is being updated and revised in format. Many of the standards inthis series,
12、 but not all, also exist as standards of the International Organization forStandardization (ISO). The current updates and revisions are in accord with thatdone for the ISO standards. In an effort to promote the concept of international stan-dardization, references to ISO standards have been left in
13、place.Suggestions for the improvement of this standard will be welcome. They should besent to the International Imaging Industry Association, Inc. (I3A), 550 MamaroneckAvenue, Suite 307, Harrison, NY 10528-1615; e-mail: i3astdsi3a.org.This standard was processed and approved for submittal to ANSI by
14、 I3A TechnicalCommittee IT4 on Photographic Processing. Committee approval of the standarddoes not necessarily imply that all committee members voted for its approval. At thetime it approved this edition of the standard, the IT4 Committee had the followingmembers:Joseph M. Rao, ChairmanJohn Gignac,
15、SecretaryOrganization Represented Name of RepresentativeInternational Imaging Industry Association, Inc. (I3A) . Jan CarlockLinda CrosbyKunihiro FujiwaraRonald A. KleinLaszlo PapaiAnthony JarkowskiGeneral Chemical Corporation. Mark DulikPhotographic Society of America, Inc. . Grant HaistPhoto Market
16、ing Association International Herb SteinIndividual ExpertsPeter KrauseNorman NewmanJoseph M. RaoSubcommittee IT4-1 on Specifications for Photographic Chemicals, which was re-sponsible for this edition, had the following members:Joseph M. Rao, Chairman-protem Jan CarlockLinda CrosbyMark DulikKunihiro
17、 FujiwaraNorman NewmanLaszlo PapaiJoseph M. RaoHerb Steiniii0 Introduction0.1 This standard is one of a series that establishes criteria of purity for chemicalsused in processing photographic materials. General test methods and procedurescited in this standard are compiled in Parts 1, 3, 5, and 8 of
18、 ISO 10349.This standard is intended for use by individuals with a working knowledge of analyti-cal techniques, which may not always be the case. Some of the procedures utilizecaustic, toxic, or otherwise hazardous chemicals. Safe laboratory practice for thehandling of chemicals requires the use of
19、safety glasses or goggles and other protec-tive apparel such as rubber gloves, face masks, or aprons where appropriate.Normal precautions required in the performance of any chemical procedure shall beexercised at all times, but care has been taken in this standard to provide warningsfor hazardous ma
20、terials. Hazard warnings designated by a letter enclosed in anglebrackets, , are used as a reminder in those steps detailing handling operationsand are defined in ISO 10349-1. More detailed information regarding hazards, han-dling, and use of these chemicals may be available from the manufacturer.0.
21、2 This standard provides chemicals and physical requirements for the suitability ofa photographic-grade chemical. The tests correlate with undesirable photographiceffects. Purity requirements are set as low as possible consistent with these photo-graphic effects. These criteria are considered the mi
22、nimum requirements necessaryto assure sufficient purity for use in photographic processing solutions, except that ifthe purity of a commonly available grade of chemical exceeds photographic process-ing requirements and if there is no economic penalty in its use, the purity require-ments have been se
23、t to take advantage of the availability of the higher qualitymaterial.Every effort has been made to keep the number of requirements to a minimum. Inertimpurities are limited to amounts that will not unduly reduce the assay. All tests areperformed on samples “as received“ to reflect the condition of
24、materials furnished foruse. Although the ultimate criterion for suitability of such a chemical is its successfulperformance in an appropriate use test, the shorter, more economical test methodsdescribed in this standard are generally adequate.Assay procedures have been included in all cases where a
25、satisfactory method isavailable. An effective assay requirement serves not only as a safeguard of chemicalpurity, but also as a valuable complement to the identity test. Identity tests havebeen included whenever a possibility exists that another chemical or mixture ofchemicals could pass the other t
26、ests.All requirements listed in clause 4 are mandatory. The physical appearance of thematerial and any footnotes are for general information only and are not part of the re-quirements.0.3 Efforts have been made to employ tests that are capable of being run in any nor-mally equipped laboratory and, w
27、herever possible, to avoid tests that require highlyspecialized equipment or techniques. Instrumental methods have been specifiedonly as alternative methods or alone in those cases where no other satisfactorymethod is available.Over the past few years, great improvements have been made in instrument
28、ation forvarious analyses. Where such techniques have equivalent or greater precision, theymay be used in place of the tests described in this standard. Correlation of such al-ternative procedures with the given method is the responsibility of the user. In caseof disagreement in results, the method
29、called for in the specification shall prevail.Where a requirement states “to pass test“, however, alterative methods shall not beused.AMERICAN NATIONAL STANDARD ANSI/I3A IT4.156-20021 American National Standard for Photography Processing Chemicals Specifications for Anhydrous Sodium Formaldehyde Bis
30、ulfite 1 Scope This standard establishes criteria for the purity of photographic-grade anhydrous sodium formal-dehyde bisulfite and specifies the tests to be used to determine the purity. 2 Normative references The following standards contain provisions which, through reference in this text, constit
31、ute provi-sions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to in-vestigate the possibility of applying the most recent editions of the standards indicated belo
32、w. Members of IEC and ISO maintain registers of currently valid standards. ISO 10349-1:1992, Photography Photographic-grade chemicals Test methods Part 1: Gen-eral. ISO 10349-3:1992 (R1999), Photography Photographic-grade chemicals Test methods Part 3: Determination of matter insoluble in ammonium h
33、ydroxide solution. ISO 10349-5:1992 (R1999), Photography Photographic-grade chemicals Test methods Part 5: Determination of heavy metals and iron content. ISO 10349-8:1992, Photography Photographic-grade chemicals Test methods Part 8: De-termination of volatile matter. 3 General 3.1 Physical propert
34、ies Anhydrous sodium formaldehyde bisulfite, (NaHSO3HCHO), exists as fine white crystals or a crystalline powder. It has a relative molecular mass of 134.09. 3.2 Hazardous properties Anhydrous sodium formaldehyde bisulfite liberates formaldehyde when treated with strong alkali or when heated. It may
35、 also liberate sulfur dioxide and hydrogen sulfide on exposure to strong acids or high temperatures. 3.3 Storage Anhydrous sodium formaldehyde bisulfite shall be stored in a closed container at room tempera-ture. 4 Requirements A summary of the requirements is shown in Table 1. ANSI/I3A IT4.156-2002
36、2 Table 1 Summary of requirements Test Limit Subclause Standard in which test method is given Assay (as NaHSO3HCHO) Minimum: 99.0% 7.1 ANSI/I3A IT4.156 Free formaldehyde (HCHO) None 7.2 ANSI/I3A IT4.156 Mass fraction of free bi-sulfite (HSO3-) Maximum: 0.4% 7.3 ANSI/I3A IT4.156 Mass fraction of inso
37、lu-ble matter (as precipitate of calcium and magne-sium in ammonium hy-droxide) Maximum: 0.2% 7.4 ISO 10349-3 Mass fraction of volatile matter Maximum 0.2% 7.5 ISO 10349-8 Mass fraction of heavy metals (as Pb) Maximum: 0.002% 7.6 ISO 10349-5 Mass fraction of iron (Fe) Maximum: 0.002% 7.7 ISO 10349-5
38、 Appearance of solution To pass test 7.8 ANSI/I3A IT4.156 5 Reagents and glassware All reagents, materials, and glassware shall conform with the requirements specified in ISO 10349-1 unless otherwise noted. The hazard warning symbols, used as a reminder in those steps detailing handling operations,
39、are defined in ISO 10349-1. These symbols are used to pro-vide information to the user and are not meant to provide conformance with hazardous labeling requirements, as these vary from country to country. 6 Sampling See ISO 10349-1. 7 Test methods 7.1 Assay 7.1.1 Specification The minimum mass fract
40、ion of anhydrous sodium formaldehyde bisulfite (NaHSO3HCHO) shall be 99.0%. ANSI/I3A IT4.156-20023 7.1.2 Reagents 7.1.2.1 Iodine l2, standard volumetric solution of 0.1 mol/l (12.69 g/l).1),2)7.1.2.2 Sodium hydroxide solution, NaOH, 10 mol/l (400 g/l) (DANGER ).3)In a 1500-ml beaker containing 800 m
41、l of water, slowly add 400 g of sodium hydroxide (DANGER ). Stir continuously until dissolved, cool to room temperature, and dilute to 1 liter with wa-ter. 7.1.2.3 Hydrochloric acid, HCl, 1.18 g/ml (DANGER: , ). 7.1.2.4 Sodium thiosulfate, Na2S2O3, standard volumetric solution of 0.1 mol/l (15.81 g/
42、l).1) ,4) 7.1.2.5 Salicylic acid solution, C6H4(OH)COOH, 1% (10 g/l) Add 10 g of salicylic acid (DANGER: ) to 500 ml of water. Stir until dissolved. Dilute to 1 liter with water. 7.1.2.6 Starch indicator solution Stir 5 g of soluble starch with 100 ml of salicylic acid solution (7.1.2.5). Add 300 ml
43、 to 400 ml of boiling water and boil until the starch dissolves. Dilute to 1 liter with water. 7.1.3 Procedure Weigh about 1.0 g of a test portion of the sample to the nearest 0.001 g in a tared 100 ml glass beaker. Dissolve the sample in water and quantitatively transfer it to a 500-ml volumetric f
44、lask. Dilute to the mark with water and mix well. Pipet a 25-ml aliquot of the diluted sample into a 125-ml glass stoppered Erlenmeyer flask. Pipet 25 ml of 0.1 mol/l standard iodine solution (7.1.2.1) into the flask. Slowly add sodium hydroxide solution (7.1.2.2) () until the solution turns light-y
45、ellow, insert the stopper, and let stand for 30 minutes. Add 1 ml of hydrochloric acid solution (7.1.2.3) (, ) and titrate the ex-cess iodine with 0.1 mol/l sodium thiosulfate solution (7.1.2.4) to a light straw color. Add 1 ml of starch indicator solution (7.1.2.6) and continue titrating to a clear
46、 endpoint. 7.1.4 Expression of results The assay, expressed as a percentage by mass, of anhydrous sodium formaldehyde bisulfite, NaHSO3HCHO, is given by 6.70 (c1V1 c2V2) / m where c1is the actual concentration, expressed in moles per liter, of the iodine solution (7.1.2.1); c2is the actual concentra
47、tion, expressed in moles per liter, of the sodium thiosulfate solution (7.1.2.4); V1is the volume, expressed in milliliters, of the iodine solution (7.1.2.1) used to reach the titration endpoint; _ 1)Commercially available analyzed reagent solutions are recommended. If solutions are to be prepared,
48、see any quantitative chemistry text. 2)See Annex A for preparation of standard iodine solutions. 3)Hazard warning codes are defined in ISO 10349-1, clause 4. 4)See Annex B for preparation of standard sodium thiosulfate solutions. ANSI/I3A IT4.156-20024 V2is the volume, expressed in milliliters, of t
49、he sodium thiosulfate solution (7.1.2.4) used to reach the titration endpoint; m is the mass, expressed in grams, of the test portion; 6.70 is the conversion factor obtained from the mass of sodium formaldehyde bisulfite equivalent to 1 mole of iodine (i.e., 67.04) x the conversion for milliliters to liters (i.e., 0.001) x 100 (for percentage). 7.2 Free formaldehyde 7.2.1 Specification There shall be no free formaldehyde present by the test. 7.2.2 Reagents 7.2.2.1 Hydrochloric acid solution, HCI, dilute. Carefully pour 8 ml of hydrochloric a
