ISO 6439:1990 水質 — フェノール指数の測定 — 蒸留後の4-アミノアンチピリン分光法 | ページ 2

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. 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. 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 6439 was prepared by Technical Committee ISO/TC 147, Water quality.

This second edition cancels and replaces the first edition (ISO 6439: 1984), of which it constitutes a minor revision.

Annex A forms an integral part of this International Standard.

Introduction

The term"phenol index" as used in this International Standard only includes phenols which react with 4-aminoantipyrine under the conditions specified to give coloured compounds.

In a water containing phenol itself, there will usually be associated with it other phenolic compounds whose sensitivity to the reagents used in the following methods may not necessarily be the same.

The percentage composition of the various phenolic compounds (3.1) present in a given test sample is unpredictable. It is obvious, therefore, that a standard containing a mixture of phenolic compounds cannot be made applicable to all test samples. For this reason, phenol (C₆H₅OH) has been selected as a standard, and any colour produced by the reaction of other phenolic compounds is measured as phenol and reported as the phenol index (3.2).

It is not possible to use the procedures specified in this International Standard to differentiate between different kinds of phenols. Some phenolic compounds with substituents such as alkyl, aryl and nitro in the para position do not produce colour with 4-aminoantipyrine. Phenolic compounds containing para substituents such as a carboxyl, halogen, hydroxyl, methoxyl or sulfonic acid, do produce colour with 4-aminoantipyrine. Hence the phenol index includes only those phenolic compounds which can be determined under specified conditions.

1 Scope

This International Standard specifies methods for determining the phenol index (3.2) in drinking waters, surface waters and waste waters.

After a preliminary distillation, the test samples are analysed according to specific application as follows:

• method A (direct colorimetric method) : this method is capable of measuring the phenol index in test samples that contain more than 0,10 mg/l in the aqueous phase (without chloroform extraction), using phenol as a standard;
• method B (chloroform extraction method) : this method is capable of measuring the phenol index without dilution from about 0,002 mg/l to about 0,10 mg/l when the coloured end-product is extracted and concentrated in chloroform phase, using phenol as a standard.

2 Normative references

The following 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 ISO maintain registers of currently valid International Standards.

3 Definitions

For the purpose of this International Standard, the following definitions apply: