Analytical method development and validation for the quantification of metaldehyde in soil

Previously published methods for the analysis of metaldehyde were adapted for its reliable quantification in soil extracts. Varied methanol-water extraction solvents were trialed, but the use of pure methanol proved to be the most reliable approach for the scaled down methodology. Analysis of metaldehyde was done using LC MS. Initially the method had problems with matrix suppression of the signal. The method was therefore further developed to overcome this challenge to avoid the costs and time demands of laborious clean-up protocols. This modification to the method involved use of the BEH Phenyl column instead of the C-18 column initially used, and optimization of the gradient flow of the mobile phase. The optimized LC-MS method was validated and used for further research applications. In brief, We investigated the recovery of metaldehyde from spiked soil samples. The optimized LC-MS method achieved acceptable metaldehyde recoveries (100-132%, 109% on average) for a range of soil types. The optimized method was suitable for high through-put analyzes. (C) 2021 The Authors. Published by Elsevier B.V.