The analysis and fate of the fungicide fenpropimorph and its degradation product fenpropimorphic acid in soil by liquid chromatography mass spectrometry

This article describes a method for extraction of soil samples and analysis with liquid chromatography and mass spectrometric detection after atmosphe ric pressure chemical ionisation (APCI) of the fungicide fenpropimorph and its degradation product fenpropimorphic acid. The method gives high recover y rates (about 80 %) and detection limits below 1 mug/kg soil for both comp ounds. The article elucidates the difference between the parent compound an d the degradation product with respect to adsorption properties, where fenp ropimorph 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 determine d to 1.3 kg/L which means a much higher mobility. Two studies on the degradation of fenpropimorph and occurrence of the degra dation product are mentioned. The first experiment is a batch experiment wh ere fenpropimorph is mixed with the soil while the second experiment is a f ield study with pesticide application in normal dosage and ten times normal dosage. Both experiments demonstrate the occurrence of the degradation pro duct in the soil during months after application.