ISO 11466-1995 PDF

Full title and description

ISO 11466:1995 — Soil quality — Extraction of trace elements soluble in aqua regia. Specifies a laboratory extraction procedure using aqua regia to solubilize a portion of trace elements from soils and similar materials for subsequent determination by atomic spectrometric techniques.

Abstract

This International Standard defines a method for extracting trace elements from soils (and similar matrices) by treatment with aqua regia. It is intended for materials containing less than about 20 % (m/m) organic carbon (materials with higher organic carbon require additional nitric acid). The extract is suitable for analysis by appropriate atomic spectrometric methods; the standard notes that aqua regia does not completely dissolve all soil matrices and that extraction efficiencies vary by element and matrix.

General information

• Status: Withdrawn (withdrawal proposed in 2021; withdrawal recorded by commercial distributors in 2022).
• Publication date: March 1995 (Edition 1, 1995-03).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 13.080.10 — Chemical characteristics of soils.
• Edition / version: Edition 1 (1995).
• Number of pages: 6 pages.

Scope

Specifies a laboratory extraction procedure using aqua regia for determination of the fraction of trace elements soluble in aqua regia from soils and similar materials prepared according to relevant sample‑preparation standards. The method is intended for soils with approximately less than 20 % organic carbon; for matrices with higher organic carbon content additional treatment (for example with nitric acid) is indicated. The standard also cautions that aqua regia extraction does not produce a true “total” digestion for many materials and that extraction efficiency depends on element and matrix.

Key topics and requirements

• Definition of reagents and preparation of aqua regia for the extraction procedure.
• Sample pretreatment and recommended sample sizes (references to sample‑preparation standards such as ISO 11464 are implied).
• Extraction procedure steps (digestion with aqua regia, heating/standing conditions) and handling of the resulting solution for instrumental analysis.
• Limitations and applicability: suitable for soils with < ~20 % organic carbon; not a total digestion — extraction efficiency varies by element and matrix; potential spectral interferences at high solute concentrations.
• Intended analytical follow‑up: compatibility with atomic spectrometric techniques (AAS, ICP‑AES/ICP‑MS) and recommendation to verify method suitability using reference materials and quality controls.

Typical use and users

Used by environmental and agricultural testing laboratories, contaminated‑land consultants, regulatory agencies, research institutions, and quality‑assurance teams performing routine screening or monitoring of soils and related materials. Typical applications include environmental monitoring, contaminant screening, baseline surveys, and preparatory extraction for instrumental determination of metals and metalloids.

Related standards

Closely related to ISO sample preparation and analysis standards: ISO 11464 (sample pretreatment of soils), ISO 10694 (determination of organic carbon in soils), ISO 11047 and ISO 22036 (methods for determination of metals in aqua regia extracts by AAS/ICP techniques), and other soil/trace‑element methods. ISO 11466 has been withdrawn in the context of later, broader aqua‑regia digestion standards — the digestion methods in ISO 54321:2020 (and corresponding regional/adopted versions published in 2021) provide updated, more comprehensive aqua regia digestion procedures for soil, sludge, treated biowaste and waste.

Keywords

ISO 11466, soil quality, aqua regia, extraction, digestion, trace elements, metals, soil analysis, AAS, ICP, environmental monitoring, sample preparation.

FAQ

Q: What is this standard?

A: ISO 11466:1995 is an International Standard that specified a laboratory procedure for extraction of the fraction of trace elements soluble in aqua regia from soils and similar materials for subsequent instrumental analysis.

Q: What does it cover?

A: It covers preparation of reagents, the aqua regia extraction procedure (including applicability limits such as organic carbon guidance), handling of the extract and notes on analytical follow‑up by atomic spectrometric techniques; it also highlights method limitations (not a total digestion, matrix/element dependence).

Q: Who typically uses it?

A: Environmental testing laboratories, regulatory and governmental bodies, consultants assessing contaminated sites, academic researchers, and anyone performing routine or screening analyses of trace metals in soils. Laboratories should combine this extraction with appropriate analytical methods (AAS, ICP) and quality controls.

Q: Is it current or superseded?

A: ISO 11466:1995 has been withdrawn (withdrawal activity recorded in ISO lifecycle information and commercial catalogs; distributors list a withdrawal date in 2022). Updated and more comprehensive aqua‑regia digestion guidance is available in ISO 54321:2020 (published 2020) and its regional/adopted versions (EN/ DIN/BS adaptations published 2021), which cover aqua regia digestion methods for soils, treated biowaste, sludge and waste. Users are advised to apply the current ISO 54321 text or relevant regional adoption for new work.

Q: Is it part of a series?

A: Yes — ISO 11466 sits within the ISO soil‑quality and environmental chemistry family of standards and is cross‑referenced with other ISO methods for sample‑preparation (ISO 11464), organic carbon determination (ISO 10694) and analytical methods for metal determination in aqua‑regia extracts (for example ISO 11047, ISO 22036). Subsequent consolidation and updating of aqua regia digestion practice is reflected in ISO 54321:2020.

Q: What are the key keywords?

A: Aqua regia, extraction, soil quality, trace elements, digestion, metals, AAS, ICP, sample preparation, environmental analysis.