Solvent Exchange from Dichloromethane to n-Hexanes Using the DryVap® Concentrator System

In 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.