The Analysis and Fate of the Fungicide Fenpropimorph and Its Degradation Product Fenpropimorphic Acid in Soil by Liquid Chromatography Mass Spectrometry

Abstract

This article describes a method for extraction of soil samples and analysis with liquid chromatography and mass spectrometric detection after atmospheric pressure chemical ionisation (APCI) of the fungicide fenpropimorph and its degradation product fenpropimorphic acid. The method gives high recovery rates (about 80 %) and detection limits below 1 μg/kg soil for both compounds. The article elucidates the difference between the parent compound and the degradation product with respect to adsorption properties, where fenpropimorph with a K_d value about 161 kg/L in a sandy loam is expected to be immobile in soil while the K_d value for fenpropimorphic acid is determined to 1.3 kg/L which means a much higher mobility.

Two studies on the degradation of fenpropimorph and occurrence of the degradation product are mentioned. The first experiment is a batch experiment where fenpropimorph is mixed with the soil while the second experiment is a field study with pesticide application in normal dosage and ten times normal dosage. Both experiments demonstrate the occurrence of the degradation product in the soil during months after application.