National foreword

This Section of BS 7755 has been prepared by Subcommittee EH/4/3 and is identical with ISO 11466:1995 Soil quality — Extraction of trace elements soluble in aqua regia, published by the International Organization for Standardization (ISO).

ISO 11466 was prepared by Subcommittee 3, Chemical methods, of Technical Committee ISO/TC 190, Soil quality, with the active participation and approval of the UK.

BS 7755 is being published in a series of Parts subdivided into Sections and Subsections that will generally correspond to particular international standards. Other Parts of BS 7755 are, or will be, as follows.

Part 1: Terminology and classification;
Part 2: Sampling;
Part 3: Chemical methods;
Part 4: Biological methods;
Part 5: Physical methods.

Cross-references

A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application.

Compliance with a British Standard does not of itself confer immunity from legal obligations.

WARNING — Digestions with hydrochloric and nitric acid are potentially hazardous and safety glasses or goggles must be used.

The digestion should be carried out in a well-ventilated fume cupboard with the reflux digestion on a temperature-controlled heating apparatus. It is essential to add antibumping granules (or roughened glass beads) both to the blank and the samples to prevent bumping and loss of solution. It is important to maintain gentle reflux, both of the blank and the test samples, to avoid temperature fluctuations which could cause local superheating.

Committees responsible for this British Standard

The preparation of this British Standard was entrusted by Technical Committee EH/4, Soil quality, to Subcommittee EH/4/3, Chemical methods, upon which the following bodies were represented:

Association of Consulting Scientists
Association of Public Analysts
British Ceramic Research Ltd.
British Gas plc
British Society of Soil Science
Department of the Environment (Drinking Water Inspectorate)
Department of Trade and Industry (Laboratory of the Government Chemist)
National Rivers Authority
Royal Society of Chemistry
Society of Chemical Industry
Soft Survey and Land Research Centre
Water Research Centre
Water Services Association of England and Wales

This British Standard, having been prepared under the direction of the Health and Environment Sector Board, was published under the authority of the Standards Board and comes into effect on 15 October 1995

The following BSI references relate to the work on this standard:

Committee reference EH/4/3
Draft for comment 92/59281 DC

1 Scope

This International Standard specifies a method for the extraction, with aqua regia, of trace elements from soils and similar materials, prepared according to ISO 11464, and containing less than about 20 % (m/m) organic carbon according to ISO 10694. Materials containing more than about 20 % (m/m) organic carbon will require treatment with additional nitric acid (see note 8). The resulting solution is suitable for the determination of trace elements using appropriate atomic spectrometric techniques. With high solute concentrations in extract solutions, spectral interferences and background enhancement should be expected.

NOTE 1 Aqua regia will not totally dissolve most soils and similar materials, and the efficiency of extraction for particular elements differs from element to element. Such efficiency might also differ for the same element in different matrices. Users of this International Standard should carry out a programme of analysis using reference materials to assure themselves that the method given here is appropriate for their needs. Elements extractable in aqua regia cannot, therefore, be decribed as “totals”; conversely they cannot be regarded as the “bio-available” fraction, as the extraction procedure is too vigorous to represent any biological process.

2 Normative references

3 Principle

4 Reagents

4.1 General

4.2 Water

4.3

4.4

4.5

5 Apparatus

5.1

5.2

5.3

5.4

5.5

5.6

5.7

5.8

5.9

5.10

5.11

6 Preparation of laboratory sample

7 Procedure

8 Test report

List of references

BS 7755-3.9:1995

Soil quality. Chemical methods - Extraction of trace elements soluble in aqua regia

Current

Published:

15 Oct 1995