Analysis of Regulated Pesticides in Drinking Water Using Accela and Equan

Pesticides are used throughout the world to control pests that are harmful to crops, animals, or people. Because of the danger of pesticides to human health and the environment, regulatory agencies control their use and set pesticide residue tolerance levels. The limits of detection (LODs) for many of these substances are at the parts-per-trillion (ppt) level. To achieve this level of detection, off-line sample pre-concentration is often performed. However, these sample preparation procedures can be time consuming, adding as much as one to two days to the total analysis time. Therefore, a method for on-line sample pre-concentration that bypasses the off-line sample pre-concentration provides a significant time savings over conventional methods.

We describe a method for on-line sample clean-up and analysis using the EQuan system. This method couples a fast-HPLC system with two Hypersil GOLD LC columns (Thermo Scientific, Bellefonte, Pennsylvania, USA) — one for pre-concentration of the sample (1 mL), the second for the analytical separation — and an LC–MS–MS instrument. Using this configuration, run times of six minutes are achieved for the analysis of a mixture of pesticides.

View Full Article