Identification of dithiocarbamate fungicides by hydrophilic interaction liquid chromatography-mass spectrometry.

Abstract

PURPOSE: Many dithiocarbamate (DTC) fungicides are complexes between organic anions and metal cations. They are difficult to be analyzed, and no simple methods have been established to directly determine their components. In this study, we developed a simple method to detect organic anions and metal cations simultaneously without derivatization. METHODS: DTC compounds were dissolved in alkaline ethylenediaminetetraacetic acid (EDTA) solution to generate organic anions and metal-EDTA complexes. They were analyzed simultaneously by hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-MS). In addition to commercially available DTC formulations, soil samples stained with the formulations were analyzed by simulating illegal dumping cases onto the ground. RESULTS: All DTC standards and formulations were dissolved in alkaline EDTA solution, and the corresponding organic anions and metal-EDTA complexes were detected. DTC components were also detected in the soil samples without significant interference from the soil, and the DTC formulations were also detectable. CONCLUSIONS: Conventional detection methods require derivatization and only provide the classification of organic anions; however, our method enables complete discrimination of DTCs, including the metal cations, without any derivatization. Our method enables the forensic analysis of DTCs in not only poisoning cases, but also illegal dumping cases.