ISO 10349-7:1992

Photography - Photographic-grade chemicals - Test methods - Part 7: Determination of alkalinity or acidity

The method is based on weighing the test portion, dissolution in carbon-dioxide-free water, adding phenolphthalein indicator, and observing the colour of the test solution: if the test solution turns pink, determination of the alkalinity, if it remains colourless, determination of the acidity.

Photographie — Produits chimiques de qualité photographique — Méthodes d'essai — Partie 7: Détermination de l'alcalinité ou de l'acidité

General Information

• Status: Published
• Publication Date: 29-Dec-1992
• ICS: 37.040.30 - Photographic chemicals
• Technical Committee: ISO/TC 42 - Photography
• Drafting Committee: ISO/TC 42 - Photography
• Current Stage: 9093 - International Standard confirmed
• Start Date: 05-Jun-2023
• Completion Date: 13-Dec-2025

Overview

ISO 10349-7:1992 is an international standard established by the International Organization for Standardization (ISO) that specifies test methods for determining the alkalinity or acidity of photographic-grade chemicals. This method is essential for ensuring the quality and consistency of chemicals used in photographic processes. The procedure involves a straightforward titration technique based on the dissolution of a test sample in carbon-dioxide-free water, the addition of a phenolphthalein indicator, and subsequent observation of the color change to determine if the solution is alkaline or acidic.

Key Topics

• Test Methodology
  The standard describes a volumetric titration method where a weighed portion of a photographic chemical is dissolved in carbon-dioxide-free water. After adding phenolphthalein indicator:

  • A pink color indicates alkalinity; titration is carried out with hydrochloric acid.
  • A colorless solution indicates acidity; titration is performed with sodium hydroxide.

• Reagents
  The test requires:

  • Standard hydrochloric acid solution (0.01 mol/L)
  • Standard sodium hydroxide solution (carbonate-free, 0.01 mol/L)
  • Phenolphthalein indicator (prepared by dissolving phenolphthalein in methanol or ethanol)
  • Carbon-dioxide-free water (boiled and cooled to remove dissolved CO₂)

• Calculation of Results
  The alkalinity or acidity is calculated as a percentage by mass using the volume of titrant consumed, its concentration, and a defined factor related to the equivalent weight of the acid or base involved.

• Scope and Applicability
  This part of the ISO 10349 series applies specifically to photographic-grade chemicals and is designed to provide precise and reproducible assessment of chemical acidity or alkalinity, critical parameters affecting photographic material performance.

Applications

• Quality Control in Photographic Chemical Production
  Manufacturers of photographic-grade chemicals use ISO 10349-7 to monitor and control the acidity or alkalinity of their products to meet strict standards essential for consistent photographic processing.

• Research and Development in Photography
  Laboratories developing new photographic chemicals or formulations apply this standard to characterize chemical properties accurately.

• Compliance and Certification
  Ensuring conformity with international quality standards enhances market acceptance and regulatory compliance of photographic chemicals globally.

• Photographic Processing Facilities
  Facilities engaged in photo development and printing may use this test method to verify chemical quality, ensuring optimal processing conditions and final image quality.

Related Standards

ISO 10349 is a multi-part series covering test methods for photographic-grade chemicals, including:

• ISO 10349-1: General Requirements
• ISO 10349-2: Determination of Matter Insoluble in Water
• ISO 10349-3: Determination of Matter Insoluble in Ammonium Hydroxide Solution
• ISO 10349-4: Determination of Residue after Ignition
• ISO 10349-5: Determination of Heavy Metals and Iron Content
• ISO 10349-6: Determination of Halide Content
• ISO 10349-8: Determination of Volatile Matter
• ISO 10349-9: Reaction to Ammoniacal Silver Nitrate
• ISO 10349-10: Determination of Sulfide Content
• ISO 10349-11: Determination of Specific Gravity
• ISO 10349-12: Determination of Density

Together, these parts provide comprehensive test procedures for evaluating the quality and purity of photographic chemicals used throughout the imaging industry.

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Keywords: ISO 10349-7, photographic-grade chemicals, alkalinity determination, acidity test, titration method, phenolphthalein indicator, hydrochloric acid titration, sodium hydroxide titration, photographic chemical quality, ISO standards photography, chemical analysis photography

Standards Content (Sample)

INTERNATIONAL
IS0
STANDARD
10349-7
First edition
1992-l 2-l 5
Photography - Photographic-grade
chemicals - Test methods -
Part 7:
Determination of alkalinity or acidity
Photographie - Produits chimiques de qua/it& photographique -
M&hodes d’essai -
Partie 7: D&termination de l’aIcalinit6 ou de I’aciditk
Reference number
IS0 10349-7:1992(E)
IS0 10349=7:1992(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 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 10349-7 was prepared by Technical Committee
lSO/TC 42, Photography.
IS0 10349 consists of the following parts, under the general title Pho-
- Photographic-grade chemicals - Test methods:
tography
- Part I: General
- Part 2: Determination of matter insoluble in water
- Part 3: Determination of matter insoluble in ammonium hydroxide
solution
- Part 4: Determination of residue after ignition
- Part 5: Determination of heavy metals and iron content
- Part 6: Determination of halide content
- Part 7: Determination of alkalinity or acidity
- Part 8: Determination of volatile matter
- Part 9: Reaction to ammoniacal silver nitrate
- Part IO: Determination of sulfide con tent
0 IS0 1992
All rights reserved. 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 per-
mission in writing from the publisher.
International Organization for Standardization
Case Postale 56 0 CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii
IS0 10349=7:1992(E)
- Part 1 I: Determination of specific gravity
- Part 12: Determination of density

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INTERNATIONAL STANDARD
IS0 10349=7:1992(ET)
- Photographic-grade chemicals
Photography - Test
methods -
Part 7:
Determination of alkalinity or acidity
1 Scope 4 Reagents
This part of IS0 10349 specifies a general test See IS0 10349-I for general requirements.
method for the determination of either the alkalinity
or the acidity of photographic-grade chemicals.
4.1 Standard hydrochloric acid solution,
0,Ol mol/l (0,365 g/l).‘)
4.2 Standard sodium hydroxide solution, free of
2 Normative reference
carbonate, 0.01 mol/l (0,400 g/l)?
The following standard contains provisions which,
through reference in this text, constitute provisions
4.3 Phenolphthalein indicator
of this part of IS0 10349. At the time of publication,
Dissolve 0,l g of phenolphthalein in 50 ml of
the edition indicated was valid. All standards are sub-
methanol or ethanol
...