Determination of triazines and their metabolites in environmental samples using molecularly imprinted polymer extraction, pressurized liquid extraction and LC–tandem mass spectrometry

Abstract

Summary The present work describes the development of a selective and sensitive method for the simultaneous determination of triazines and triazine metabolites in waters and soils, and its further application to natural samples. The method is based on sample extraction and pre-concentration with commercial molecularly imprinted polymer cartridges (MIP4SPE Triazine 10) followed by liquid chromatography–tandem mass spectrometric (LC–MS/MS) analysis operating in the selected reaction monitoring (SRM) mode. Method detection limits achieved were as low as 0.015 ng L −1 (ground water) and 0.2 ng kg −1 (soil and sludge). Method recovery rates were found to be analyte dependent, ranging from 55% to 123%. The intra-day and inter-day precision was given by RSD values between 2% and 4% and between 6% and 10%, respectively for the latter for most compounds. The suitability of the method for the environmental trace analysis of triazine pesticides and their metabolites in aqueous samples was demonstrated through the analysis of several ground water and sludge-amended soil samples. The outcomes of this study revealed that simazine was the most frequently found analyte in ground water, with values up to 105.11 ng L −1 . Results also evidenced that all the pesticides investigated were present in the solid matrices, being sebuthylazine that at the highest concentrations, with values ranging from 0.46 to 2.26 ng g −1 . Pesticide concentrations in the sludge applied as fertilized were generally low, which indicated that their contribution to the total amount of pesticides in the soil was not quantitatively relevant in comparison with that of pesticides coming from direct spreading to agricultural lands.