Continuing our series on using Accelerated Solvent Extraction (ASE) which was developed to meet recent and anticipated changes in environmental regulations will cause severe restrictions on the amount of solvent usage in laboratories worldwide in the preparation of solid waste samples.
Here, we present the ASE technique significantly improving Organochlorine Pesticide (OCP) sample extraction methodology! OCPs are manmade chemicals that have been widely used around the world to protect crops, livestock, and homes from damage due to insects. These compounds are also known as Persistent Organic Pollutants (POPs) due to their tendency to resist breakdown in the environment and also are highly stable and insoluble in water and can therefore be absorbed by soils and sediments. Plants in turn can absorb the compounds from the soil, and animals that eat the plants can absorb them―still relatively unchanged. This process is known as bioaccumulation—and it’s happening all the time. And we’re not immune from this process—the very nature of bioaccumulation is that it concentrates as you move up the food chain.
While many of these compounds have been banned from use in the United States, many are still manufactured here for use in other countries. The pesticide DDT is perhaps the best known example of an OCP. Banned from use in the 1970’s, DDT and its metabolites are still found in soils and in biological tissue samples of persons who were born well after the ban. Other OCPs include aldrin, dieldrin, and methoxychlor.
Extraction of Chlorinated Pesticides Using Accelerated Solvent Extraction
Application Note 320, Extraction of Chlorinated Pesticides Using Accelerated Solvent Extraction (ASE), (downloadable PDF) describes a simple, fast method for the extraction of chlorinated pesticides from agricultural samples. This method meets the requirements of U.S. EPA Method 3545, which is a high temperature and pressure procedure for extracting water insoluble or slightly water soluble semivolatile organic compounds from soils, clays, sediments, sludges, and waste solids. The EPA Method was developed and validated on an automated extraction system.
The method described in the application note is applicable to the extraction of chlorinated pesticides from soils, clays, wastes, and sediments containing from 5 to 250 μg/kg of the target compounds.
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Also, here is a 3.49 min video on the ASE technique and instrument.
Interested in how ASE workflows can improve your productivity for environmental contaminants and help you save time and solvent? We invite you to write us in the Comments box below.