Large Volume Injection for Increased Sensitivity of Pesticide Analysis:

Pesticides are frequently determined in various food and beverage types and in environmental samples. A common sample preparation method used is known as QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe). The method involves salting-out liquid-liquid extraction with acetonitrile and subsequent clean-up of the extract using dispersive solid-phase extraction. Usually, 1 – 2 μL of the extract is then injected into the analytical instrument for analysis. To further improve the sensitivity, automated evaporative concentration of the extract using the GERSTEL mVAP can be combined with Large Volume Injection in the GERSTEL CIS 4 inlet and GC-MS analysis. In this work, various parameters of automated evaporation and concentration using mVAP and Large Volume Injection with CIS 4 were studied and optimized on pesticides-spiked acetonitrile in a univariate approach.