ISO 16720:2005

Overview

ISO 16720:2005 is an international standard that specifies the pretreatment of soil samples by freeze-drying to prepare them for subsequent analytical testing. Developed by the International Organization for Standardization (ISO), this standard provides a reliable and efficient method to remove moisture from soils, sludges, and sediments while preserving non-volatile elements and organic compounds for accurate laboratory analysis.

This method is particularly designed for samples that contain high water content and is also applicable as a first step in determining dry matter or water content. Freeze-drying, also known as lyophilization, helps maintain sample integrity by sublimating water under controlled low temperature and vacuum conditions, preventing alteration of the compounds of interest.

Key Topics

• Scope and Applicability The standard applies primarily to soil samples but can also be extended to sludges and sediments. It targets the preservation of elements and organic compounds that remain stable during freeze-drying.

• Freeze-Drying Principle Freeze-drying involves:

  • Pre-cooling samples below their eutectic point (usually