ISO 6849:1996

IS0
INTERNATIONAL
6849
STANDARD
First edition
1996-l l-01
Photography - Processing wastes -
Determination of boron
Photographie - Effluents de traitement - D&termination du bore
Reference number
IS0 6849:1996(E)

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IS0 6849: 1996(E)
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 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 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 IS0 6849 was prepared by Technical Committee
ISO/TC 42, Photography.
Annex A of this International Standard is for information only.
0 IS0 lb96
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 Standardization
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland

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@ IS0
Introduction
This International Standard is one of a series devoted to the analysis of
photographic wastes; it encompasses the field of analysis of boron in
photographic effluents.
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 clause 4. More detailed information
regarding hazards, handling and use of these chemicals may be available
from the manufacturer.
In the case of effluents, the photographic laboratory can best establish its
conformity to regulations by appropriate chemical analysis. In some cases,
in-house analyses will be possible; often the use of an outside laboratory
will be required.

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IS0 6849:1996(E)
INTERNATIONAL STANDARD @ IS0
Determination of
Photography - Processing wastes -
boron
1 Scope
This International Standard specifies two methods for the determination of boron in photographic processing
wastes. The first method is the estimation of borates by titration of the boric acid-mannitol complex, which is a
stronger acid than the boric acid from which it is formed. It is suitable for boron concentrations of 0,l mg/l and
higher. In the range 0,l mg/l to 5 mg/l, phosphate is removed by precipitation by lead acetate. In the range 1 mg/l
to 100 mg/l, the sample is diluted 25 times; this eliminates phosphorous interference if the phosphorous
concentration is below 500 mg/l.
The second and alternative method is a spectrophotometric technique using methylene blue and is useful in the
boron range of 0,l ml/l to I,0 mg/l, this being the concentration likely to be encountered in photographic processing
wastes.
2 Normative references
The following International 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 Standard 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.
Part 1: Guidance on the design of sampling programmes.
IS0 5667-l :I 980, Water quality - Sampling -
Part 2: Guidance on sampling techniques.
IS0 5667-2:1991, Water quality - Sampling -
IS0 5667-3: 1994, Water quality - Sampling - Part 3: Guidance on the preservation and handling of samples.
IS0 6353-l :I 982, Reagents for chemical analysis - Part 1: General test methods.
IS0 6353-2: 1983, Reagents for chemical analysis - Part 2: Specifications - First series.
IS0 6353-3: 1987, Reagents for chemical analysis - Part 3: Specifications - Second series.
IS0 10349-I : 1992, Photography - Photographic-grade chemicals - Test methods - Part 1: General.
3 Principle
In the method using boric acid-mannitol complex, sodium acetate is added to stabilize the pH. The sample is then
acidified with sulfuric acid and boiled to expel carbon dioxide. Upon cooling, the pH is adjusted to 7 with sodium
1

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@ IS0
IS0 6849: 1996(E)
hydroxide. Mannitol is added to form a complex acid with any boric acid present. The mixture is then titrated back
to pH 7 with 0,02 mol/l sodium hydroxide. Interference by atmospheric carbon dioxide is minimized by titrating both
the sample and a blank in a specified time. This method should not be used in the presence of ammonia gas, acetic
acid vapours, or hydrochloric acid fumes since these may be absorbed into the sample and change the pH.
In the spectrophotometric method using methylene blue, sulfuric acid and hydrofluoric acid are added to form
the tetrafluoroborate ion (BF4-). Methylene blue is then added and the complex formed is extracted with
1,2-dichloroethane. The absorbance of the extract is measured at a wavelength near 660 nm.
4 Safety and operational precautions
4.1 Hazard warnings
Some of the chemicals specified in the test procedures are caustic, toxic or otherwise hazardous. Specific danger
notices are given in the text and footnotes, but normal precautions are required during the performance of any
chemical procedure at all times. The first time that a hazardous material is handled in a procedure, the hazard will
be indicated by the word “DANGER” followed by a symbol consisting of angle brackets “( )” containing a letter
which designates the specific hazard and a statement of the hazard. A double bracket “(( ))” will be used for
particularly perilous situations. In subsequent statements involving handling of these hazardous materials, only the
hazard symbol consisting of the brackets and letter(s) will be displayed. Furthermore, for a given material, the
hazard symbols will be used only once in a single paragraph. Hazard symbols will not be used for common organic
solvents when used in quantities of less than 1 litre unless they are particularly hazardous.
Detailed warnings for handling chemicals and their diluted solutions are beyond the scope of this International
Standard.
shall provide training and health and safety information in conformance with legal
Employers
requiremen ts.
.
is in
The hazard sy mbol system use d rn this I nternational Standa rd ten ded to provide information to the users and is
.
not meant for compliance with legal requirements for la be llrng as these vary from country to country.
any
It is strongly recommended that anyone us Iing these them icals obtain from the manufacturer pertinent
information a Ibout the hazards, handling, u se and dispo Isal of these chemi cals.
42 . Hazard information code system
(B) Harmful if inhaled. Avoid breathing dust, vapour, mist or gas. Use only with adequate ventilation.
(C) Harmful if contact occurs. Avoid contact with eyes, skin or clothing. Wash thoroughly after handling.
(S) Harmful if swallowed. Wash thoroughly after handling. If swallowed, obtain medical attention immediately.
((S)) May be fatal if swallowed. If swallowed, obtain medical attention immediately.
(F) Will burn. Keep away from heat, sparks and open flame. Use with adequate ventilation.
(0) Oxidizer. Contact with other material may cause fire. Do not store near combustible materials.
4.3 Safety precautions
All pipette operations shall be performed with a pipette bulb or plunger pipette. This is a critical safety
warning!
Safety glasses shall be worn for all laboratory work.
2

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IS0 6849: 1996(E)
5 Materials and reagents
5.1 General
5.1 .I Handling and labelling
Reagents shall be handled in conformity with health and safety precautions as shown on containers or as given in
other sources of such information. Proper labelling of prepared reagents includes chemical name, date of
preparation, expiration date, restandardization date, name of preparer, and adequate health and safety precautions.
The discharge of reagents shall comply with applicable environmental regulations.
5.12 Purity
Reagents used in the test procedures shall be certified reagent-grade chemicals and shall meet appropriate
standards or be chemicals of a purity acceptable for the analysis. For details see IS0 6353-1, IS0 6353-Z and
IS0 6353-3.
5.1.3 Water
Whenever water is specified without other qualifiers in the test procedures, only distilled water or water of equal
purity shall be used.
5.1.4 Strength of solutions
5.1.4.1 Acids and ammonium hydroxide are full strength unless otherwise specified.
5.1.4.2 When a standardized solution is required, its concentration is expressed in moles per litre (mol/l). The
number of significant figures to which the molarity (mol/l) is known shall be sufficient to ensure that the reagent
does not limit the reliability of the test method.
5.1.4.3 When a standardized solution is not required, its concentration is expressed in grams per litre (g/l) to the
appropriate number of significant figures.
5.1.4.4 When a solution is to be diluted, its solution is indicated by (X + Y), meaning that X volumes of reagent, or
concentrated solution, are to be diluted with Y volumes of distilled or deionized water.
52 . Reagents for method using boric acid-mannitol complex
5.2.1 Lead acetate solution, c[Pb(CzHsO& . 3H20] = 0,5 mol/l.
Add approximately 750 ml of water to a 1 litre volumetric flask. Add and dissolve 190 g + 1 g of lead acetate
trihydrate (DANGER: ((S))) and dilute to volume with water. If the solution is not clear, filter it through a filter
paper 1) (prefolded; medium flow - 100 ml prefiltered water in 55 s; medium porosity - 8 pm particle retention).
5.2.2 Mannitol (CeH1406).
5.2.3 Sodium acetate solution, c(NaC2H302) = 0,l mol/l.
Add approximately 750 ml of water to a litre volu met ric flask. Add and dissolve 8,2 g & 0,l g of sodium acetate
(anhydrous), dilute to volume with water, st opper an dm ix well.
Whatman 2V is an example of a suitable filter paper available commercially. This i nformation is given for the convenience
1)
of this prod uct.
of users of this In terna tional Standard and do es no t constitute an endorsement by IS0

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5.2.4 Sodium hydroxide, standard volumetric solution, c(NaOH) = 0,020 0 mol/l.
Pipette 100,O ml of standard sodium hydroxide solution (0,100 0 mol/l) into a 500 ml volumetric flask. Dilute to
volume with boiled distilled water which has been cooled to room temperature. Avoid unnecessary exposure to air.
This solution is stable for about one week.
5.2.5 Sodium hydroxide, saturated solution.
Slowly dissolve 60 g of sodium hydroxide (DANGER: (C)) in 50 ml of freshly boiled, distilled water in a polyethylene
or polypropylene bottle. Allow this solution to stand for 48 h before using it. When using this solution, care should
be taken not to disturb it. Decant the amount needed to avoid contamination from sodium carbonate which has
settled to the bottom of the container.
DANGER - If the water has not cooled before adding the sodium hydroxide, the heat of solution may
cause the mixture to boil and erupt.
5.2.6 Sodium hydroxide, approximately 0,5 mol/l solution (carbonate free).
I Add from a graduated cylinder, 3 ml of the decanted saturated sodium hydroxide (DANGER: (C)) (5.25) to a 150 ml
beaker. Dilute to approximately 100 ml with freshly boiled distilled water and store in a polyethylene or
polypropylene bottle. Avoid prolonged and unnecessary exposure to air. The solution is stable for two days only.
5.2.7 Sodium sulfate solution, c(NazS04) = 0,5 mol/l.
volumetric fla
Add approxi mately 750 ml of water to a 1 litre sk. Add and dissolve 71 g + 1 g of sodium sulfate
(anhydrous), dilute to volume with water, stopper and mix well.
5.2.8 Sulfuric acid solution, c(HzS04) = 0,05 mol/l.
5.2.9 Thymol blue solution, 0,04 % in water.
5.3 Reagents for methylene blue method
5.3.1 Boron standard solution, boron = 0,l g/l.
Dissolve 0,572 g + 0,001 g of orthoboric acid in water, transfer to a 1 litre volumetr ic flask, add water up to the
mark, stopper and mix well. This solution can be kept for 6 mont hs after preparation.
5.3.2 Boron standard solution, boron = 0,001 g/l.
Pipette 10 ml of boron standard solution (0,l g/l) (5.3.1) into a 1 litre volumetric flask, add water up to the mark,
stopper and mix well. This solution should be used within 10 days after preparation.
...