Reaffirmed 2024

NATIONAL FOREWORD

This Indian Standard which is identical with ISO 7579 : 2009 ‘Dyestuffs — Determination of solubility in organic solvents — Gravimetric and photometric methods’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on recommendation of the Raw Materials for Paints, Varnishes and Related Product Sectional Committee and approval of the Chemical Division Council.

Many dyestuffs are soluble in a solvent to an extent which is independent of the amount of dyestuff present in the solvent, as long as excess dyestuff does not dissolve in solution. This concentration is defined as the saturation concentration and represents the solubility of the dyestuff in the solvent. In some cases, however, there is no fixed saturation concentration and the amount of dyestuff which dissolves increases with the amount of dyestuff added. A gravimetric and photometric procedure to assess the solubility of dyestuffs are described in this standard.

Considering the importance of test method for determination of solubility of dyestuffs in organic solvents and to follow the uniform practices globally, the Committee felt that it would be more convenient to prepare this standard method by adoption of ISO 7579 on dual number basis.

The text of ISO Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain terminologies and conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:

a) Wherever the words ‘International Standard/Document’ appear referring to this standard, they should be read as ‘Indian Standard’.

b) Comma (,) has been used as a decimal marker, while in Indian Standards, the current practice is to use a point (.) as the decimal marker.