Background and Objectives: Dithiocarbamates are groups of fungicides used to control pests of agricultural products. Analysis of these pesticides with liquid and gas chromatography instruments is associated with various problems due to the presence of metal groups in the structure of these compounds. Therefore, one of the ways for analysis the pesticides is to check the level of decomposition metabolites of ethylene thiourea and propylene thiourea. The purpose of this study was to establish and validate a method for the analysis of ethylene thiourea and propylene thiourea in grains using liquid chromatography tandem mass spectrometry.
Materials and Methods: Preparation was based on the optimized QuPP-OP method with methanolic extraction in presence of ethylenediaminetetraacetic acid solution without purification steps. To overcome the matrix effect, calibration curve was drawn using analysis of spike samples.
Results: Results showed that the method was linear in the range of 10–400 ng/g and assessment results were accurate and precise. The average recovery proportions and CV% for repeatability were 96.42, 12.1, 97.40 and 13.86% for propylene thiourea and ethylenethiourea, respectively. The LOD and LOQ of the method for the two compounds were 3.3, and 10 ng/g, respectively.
Conclusion: Results showed that the presented assessment method included necessary validity of the analysis of ethylene thiourea and propylene thiourea in cereals.
