What is ISO 23646 - Determination of OCPs about? 
Organochlorine pesticides (OCPs) are organic synthetic substances that are globally used. ISO 23646 specifies a method for the quantitative determination of OCPs and semi-volatile chlorobenzenes in soil and sediment, using GC-MS and GC-ECD.
Based on the properties of the samples, ISO 23646 contains decision tables regarding drying-, extraction- and clean-up procedures. The method described in ISO 23646 is performance-based. It can be modified if all performance criteria given in this method are met. ISO 23646 applies 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. ISO 23646 applies only to 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 and measured using an ECD detection. The comparability of ECD and MS data in terms of the approach of ISO 23646 was demonstrated on additional matrices.
Who is ISO 23646 - Determination of OCPs for? 
ISO 23646 on the determination of OCPs is useful for: 
- Entities responsible for testing the quality of soil
- Environmentalists
- Researchers and scientists
- Quality control personnel
- Regulatory authorities
Why should you use ISO 23646 - Determination of OCPs?
The vast majority of OCPs have been released directly into the environment as agricultural insecticides but they have been also used as by-products for different applications, e.g. as a wood preserver. OCPs are persistent, bioaccumulating and prone to long-range atmospheric transport and deposition. They are ubiquitous in the environment (water, soil, sediment and waste) and their presence is regularly monitored and controlled.
ISO 23646 discusses terms, definitions, principles, and interferences that depict a user-friendly idea of the OCP determination process. ISO 23646 also provides users with a test procedure that assesses the chemical characteristics of soil samples ensuring their usability.
The guidelines in ISO 23646 help you with the determination of OCPs in soil samples that enables you to evaluate the quality of soil.
What’s changed since the last update?
BS ISO 23646:2022 supersedes ISO 10382:2002. BS ISO 23646:2022 includes some technical changes with respect to ISO 10382:2002. These include: 
- Polychlorinated biphenyls have been deleted from the Scope
- Modern extraction techniques and commonly used methods with optimized extraction time, proven clean-up methods and state of the art quantification methods have been added
