ISO 422:1994

INTERNATIONAL
ISO
STANDARD
422
Second edition
1994-1 O-l 5
Photography - Processing chemicals -
Specifications for p-methylaminophenol
sulfate
Produits chimiques de traitement - Spbifications pour Ie
Photographie -
sulfa te de p-m&h ylaminoph&ol
Reference number
ISO 422:1994(E)

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ISO 422:1994(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 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 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 Standard ISO 422 was prepared by Technical Committee
lSO/TC 42, Photography.
This second edition cancels and replaces the first edition (ISO 4221976)
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 any form or by any means, electronie or mechanica18 including photocopying and
microfilm, without permission in writing from the publisher.
International Organi zation for Standardization
CH-l 211 Geneve 20
Case postale 56 l l Switzerland
Printed in Switzerland

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0 ISO ISO 422: 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 methods and procedures cited in this International Standard are
compiled in Parts 1, 4, 5 and 8 of ISO 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 otherwise 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
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 warnings designated 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 provides Chemical and physical re-
quirements 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 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 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 which 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 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. 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 of the requirements.
. . .
Ill

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ISO 422:1994(E) 0 ISO
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. Instru-
mental 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 improvements have been made in instru-
mentation 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 User. In case of disagreement in
results, the method called for in the specification shall prevail. Where a
requirement states Yo pass test ”, however, alternative methods shall not
be used.

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INTERNATIONAL STANDARD o Iso ISO 422: 1994(E)
Processing chemicals - Specifications for
Photography -
p-methylaminophenol sulfate
3 General
1 Scope
3.1 Physical properties
This International Standard establishes criteria for the
purity of photographit-grade pmethylaminophenol
pMethylaminophenoI sulfate, tiOC6H4M-iCH3~
sulfate and specifies the test methods to be used to
‘!H2SO4, exists in the form of a white crystalline
determine the purity.
powder. lt has a relative molecular mass of 172,ZO.
3.2 Hazardous properties
2 Normative references
PMethylaminophenol sulfate is not hazardous when
The following International Standards contain pro-
handled with normal precautions.
visions which, through reference in this text, consti-
tute provisions of this International Standard. At the
time of publication, the editions indicated were valid.
3.3 Handling and storage
All Standards are subject to revision, and Parties to
agreements based on this International Standard are
PMethylaminophenoI sulfate shall be stored in a
encouraged to investigate the possibility of applying
closed Container at room temperature.
the most recent editions of the Standards indicated
below. Members of IEC and ISO maintain registers of
currently valid International Standards
4 Requirements
A summary of the requirements is shown in table 1.
ISO 565:1983, Test sieves - Woven metal wie cloth,
perforated plate and electroformed sheet - Nominal
sizes of openings.
5 Reagents and glassware
ISO 10349-1: 1992, Photography - Photographic-
All reagents, materials and glassware shall conform to
grade chemicals - Test methods - Part 7: General.
the requirements specified in ISO 10349-1 unless
otherwise noted. The hazard warning Symbols used
ISO 10349-4: 1992, Photography - Photographic-
as a reminder in those Steps detailing handling
grade chemicals - Test methods - Part 4: Determi-
operations are defined in ISO 10349-1. These Symbols
nation of residue after ignition.
are used to provide information to the user and are
not meant to provide conformance with hazardous
ISO 10349-5: 1992, Photography - Photographic-
labelling requirements, as these vary from country to
grade chemicals - Test methods - Part 5: Determi-
country.
na tion of heavy me tals and iron content.
ISO 10349-8: 1992, Photography - Photographic- 6 Sampling
grade chemicak - Test methods - Part 8: Determi-
See ISO 10349-1.
na tion of voia tile matter.

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ISO 422: 1994(E) 0 ISO
Table 1 - Summary of requirements
International
Standard in
Test Limit Subclause
which test
method is given
Assay
cerate titration
99,0 % (m/m) min. 7.1 ISO 422
102,O % (m/m) max.
Ot-
alkali titration 97,5 % (m/m) min. 7.2 ISO 422
Identity
ISO 422
melting Point of 7.3.1
nitroso derivative
mixed melting Point Not less than Sample 7.3.1 ISO 422
of nitroso derivative or Standard
infrared spectrum Equivalent to figure 1 7.3.2 ISO 422
(optional)
Residue after ignition 0,lO % (m/m) max. 7.4 ISO 10349-4
Heavy metals (as Pb)
0,002 % (m/m) max. 7.5 ISO 10349-5
Iron (Fe) 0,005 % (m/m) max. 7.6 ISO 10349-5
Volatile matter 7.7 ISO 10349-8
0,3 % (m/m) max.
PAminophenol 2,5 % (m/m) max. 7.8 ISO 422
p-Amino-N,N- 7.9 ISO 422
To pass test
dimethylaniline sulfate
Solubility in diethyl ether 7.10 ISO 422
0,2 % (m/m) max.
Appearance of Solution Clear and not more 7.1 1 ISO 422
than slightly yellow
NOTE - m/m = mass/mass
7.1.2.3 Ferroin indicator
7 Test methods
[tris(l ,IO-phenanthroline) iron(ll) ion].
7.1 Assay - Cerate titration
Dissolve 1,48 g of 1 ,IO-phenanthroline in 100 ml of
the iron(ll) sulfate Solution (7.1.2.2).
7.1.1. Specification
7.124 Sulfuric acid, H2S04, 0,050 mol/1
Content of HOC&i4NHCH+!&l2S04 shall be between
(4,9 g/l)l) 3, 4, .
99,0 % (I&PZ) min. and 102,O % (m/m) max.
7.1.3 Apparatus
7.12 Reagents
7.1.3.1 Watch glass.
7.121 Ammonium cerium(lV) hexanitrate,
Standard volumetric Solution of
(NH4)2Ce(No&,
7.1.3.2 Burette, of 50 ml capacity.
0,100 mol/1 (54,82 g/l)l ) 2).
sulfate Solution,
7.1.2.2 Iron(ll) 0,025 mol/1
7.1.4 Procedure
(580 g/l).
Weigh, to the nearest 0,000 1 g, a test Portion of
about 0,25 g on to a watch glass (7.1.3.1). Transfer
Dissolve 4,25 g of FeSOd.HzO in 1 litre of water.
the watch glass and test Portion to a 250 ml wide-
(Alternatively 5,60 g of FeS04.4H20, 6,05 g of
FeS04.5H20 or 6,95 g FeS04.7H20 may be used.) mouth conical flask containing 100 ml of water and
1) Commercially available analysed reagent solutions are recomrnended. If solutions are to be prepared, see any quantitative
analytical chemistry text.
2) A procedure for the preparation and standardization o-f this Solution is given in annex A.
3) This may be prepared from sulfuric acid, p = %,84 g/l (DANGER:<>).
4) Hazard wart-ring Codes are defined in ISO 10349-1 I
2

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ISO 422:1994(E)
0 ISO
10 ml of the sulfuric acid (7.1 J.4). Dissolve the 7.2.5 Expression of results
Sample add 3 drops of the ferroin indicator (7.123)
The assay, expressed as a percentage by mass, for p
and titrate with the ammonium Solution
methylaminophenol sulfate (HOCGH,NHCH3+?HzS04),
(7.121) to a light green colour which persists for
is given by
15 s.
17,22c ’V ’Jm
7.1.5 Expression of results
where
mass, for p
The assay, expressed as a percentage
bY
c’ is the actual concentration, expressed in
HCH3?!H2SOJ),
methylaminophenol sulfate (HOCGH4N
moles per litre, of the sodium hydroxide
is given by
(7.2.2.2);
8,61 cV/m
V’ is the volume, in millilitres, of the sodium
hydroxide (7.2.2.2) used to resch the
where
titration endpoint;
c is the actual concentration, expressed in
m’ is the mass, in grams, of the test Portion;
moles per litre, of the ammonium cerate
Solution, (NH,),Ce(NO& (7.121);
17,22 is the conversion factor obtained from the
V is the volume, in millilitres, of the ammonium
sulfate
mass of pmethylaminophenol
cerate Solution (7.121) used to resch the
equivalent to 1 mole of sodium hydroxide
titration endpoint;
(i.e. 172,2) x the conversion factor for
millilitres to litres (i.e. 0,001) x 100 (for
m is the mass, in grams, of the test Portion;
percentage).
8,6l is the conversion factor obtained from the
mass of pmethylaminophenol sulfate equiv-
7.3 Identity tests
alent to 1 mole of ammonium cerate (i.e.
86,l) x the conversion factor for millilitres to
7.3.1 Melting Point of nitroso derivative
litres (i.e. 0,001) x 100 (for percentage).
7.3.1.1 Specifications
7.2 Assay - Alkali titration
The melting Point shall be from 130 “C to 135 “C.
72.1 Specification
A mixed melting Point shall be from 130 “C to 135 “C
and shall not be less than either the Sample nitroso
Content of HOC,H,NHCH3-1/2H,SO, shall be
derivative or the Standard nitroso derivative.
97,5 % (m/m) min.
7.3.1.2 Reagents
7.22 Reagents
722.1 Acetone, (CH&CO. Sulfuric acid, H2S04, p = 1,84 g/l
7.3.1.2.1
(DANGERx>)~).
7.2.2.2 Sodium hydroxide, NaOH, Standard volu-
metric Solution of 0,100 mol/1 (4,00 g/l)l).
7.3.1.2.2 Sodium nitrite Solution, NaNO*, 100 g/l.
7.2.3 Apparatus
Dissolve 10 g of sodium nitrite in 100 ml of water.
7.2.3.1 Burette, of 50 ml capacity.
7.3.1.3 Apparatus
7.2.3.2 Electronie pH-meter, equipped with a glass
7.3.1.3.1 Capillary-tube melting Point apparatus,
electrode and Standard reference electrode.
complete with thermometer for the range 100 “C to
2OOOC.
7.2.4 Pro
...