ISO 23646:2022

Soil quality — Determination of organochlorine pesticides by gas chromatography with mass selective detection (GC-MS) and gas chromatography with electron-capture detection (GC-ECD)

Scope

This document specifies a method for quantitative determination of organochlorine pesticides (OCPs) and semi-volatile chlorobenzenes in soil and sediment, using GC-MS and GC-ECD.
The limit of detection and the limit of application depends on the determinants, the sample intake, the equipment used, the quality of chemicals used for the extraction of the sample and the clean-up of the extract.
Under the conditions specified in this document, lower limits of application from 1 μg/kg (expressed as dry matter) for soils to 10 μg/kg (expressed as dry matter) for sediments can be achieved. The necessity to achieve these lower limits of application depends on the analyses order and the current limit values.
Soils and sediments can differ in properties as well as in the expected contamination levels of OCPs and the presence of interfering substances. These differences make it impossible to describe one general procedure. Based on the properties of the samples, this document contains decision tables regarding drying-, extraction- and clean-up procedures. This method is performance based. The method can be modified if all performance criteria given in this method are met.
The method can be applied to the analysis of other chlorinated compounds not specified in the scope in cases where suitability has been proven by proper in-house validation experiments.
NOTE       The validation data are shown in Annex A. This document is validated only for α-HCH, β-HCH, γ-HCH, δ-HCH, o,p′-DDE, p,p′-DDE, o,p′-DDD, p,p′-DDD, o,p′-DDT and p,p′-DDT. For sediments, data are displayed measured using an ECD detection. The comparability of ECD and MS data in terms of the approach of this document was demonstrated on additional matrices.