Improving Pesticide Analysis... 

An application report is available from Genevac (UK) that discusses a novel environmental sample preparation protocol and evaluates a centrifugal evaporation system that together increase recovery of volatile compounds enabling improved analysis of pesticides.

During preparation of environmental samples, containing semi-volatile pesticides, evaporation becomes a critical step because of the need to avoid compound loss during the concentration process. Analyte loss is detrimental to accurate analysis, and official directives must be satisfied with regard to minimum analyte recovery.

The report, compiled by the Environmental Protection Agency of Tuscany, Italy (ARPAT), evaluates a new evaporator (the Genevac EZ2-ENVI) to determine the optimal concentration process and then describes tests carried out on real matrices spiked with pesticides to validate the new sample preparation protocol. The new processes and methods were then compared to the original method used by the ARPAT laboratories.

The report concludes that the new sample preparation protocol using the EZ2-ENVI evaporator delivers satisfactory recovery and reproducibility for the analysis of volatile pesticide compounds extracted from organic matrices. In addition reducing the number of sample transfers between different containers, and eliminating the filtration step by addition of anhydrous sodium sulphate directly to the samples significantly improve the sample preparation protocol. The evaporators’ ability to provide hands-free automated concentration of a number of samples at the same time and to provide protection from cross contamination and bumping was noted to deliver significant productivity benefits compared to using a rotary evaporator.