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Solvent Exchange from Dichloromethane to n-Hexanes Using the DryVap® Concentrator System
Solvent Exchange from Dichloromethane to n-Hexanes Using the DryVap® Concentrator System
8 Oct 2015In this application note, to demonstrate the performance of the DryVap® system, three samples were spiked with a pesticides mixture and were then dried, concentrated, and exchange. The analysis of pesticides for environmental extracts typically requires a solvent exchange from dichloromethane (DCM) to an ECD-compatible solvent such as n-hexane. The prescribed method of solvent exchange and concentration is given in EPA Method 3510 and uses a Kuderna-Danish (K-D) apparatus achieve the results. However, the K-D method is very time consuming and can take up to 1.5 hr to complete and is very sensitive to human error.
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Environmental Monitoring and TestingEnvironmental monitoring and testing uses handheld portable analyzers, kits, spectrometers or chromatography systems for air, water, soil, food and other sample testing. Useful features of analyzers such as BOD and COD include portability, easy calibration, automation and sensitivity. Environmental test kits for pH, water, moisture, etc, should be accurate, sensitive, reliable, fast and easy to use.Evaporators and Freeze DryersCentrifugal evaporation is used for solvent removal from a sample. This is a useful technique for sample concentration or sample drying. Many centrifugal evaporators are modular with a central vacuum pump for generating low pressure. Useful features of evaporators or vacuum ovens include minimal solvent bumping, solvent resistance, computer control, temperature regulation and benchtop design.PesticidesPesticides are used to protect crops from diseases, pests and unwanted plants. They are classed as persistent organic pollutants (POPs) and can be harmful to humans. The Environmental Protection Agency (EPA) currently regulates the use of pesticides in the USA. Environmental ContaminationContaminants in the environment are harmful chemicals that are present in the air, land and water. These include pesticides, pharmaceuticals, persistent organic pollutants (POPs) and many more.Solvent Extraction