Quantitation of Heterogeneous Formulations of Morpholine-Type Fungicides and Surfactants in Polluted Soils

Abstract

The paper reports ultraviolet matrix-assisted laser desorption/ionization mass spectroscopy (UVMALDI-MS) protocol for determination of complex heterogeneous emulsion or suspension formulations. The active agents and surfactants are morpholine fungicide fenpropimorph (1), amorolfine (2), tridemorph (mixture of 2,6-dimethyl-4-alkylmorpholins 3–6), 2,6-dimethyl-4-[2-methyl-3-(6-methyl-decahydro-naphthalen-2-yl)-propyl]-morpholine (7), dodemorph (8), main metabolite of 1 fenpropimorph acid (9), sodium dodecyl sulfate (10), and stearate (11). The full method and techniques validation as well as method performance parameters are discussed in terms of their maximal representativeness toward real environmental and foodstuff assay problems. These are additionally complicated by heterogeneous laterally, vertically, and time distribution of pesticide contaminants and their major metabolites in environmental samples. The real environmental heterogeneous distribution is elucidated, studying sterilized soil fractions with particle size 2.0 μm, clay content 11.5 %, silt 23.0 %, sand 8.1 %, and pH ∈ 6.0–8.1. A statistical sampling cluster approach is used. The method performance parameters are concentration LODs of 0.026 mg kg−1 (res. LOQs 0.08666 mg kg−1). Concentration linear dynamic ranges are ∈ 0.025–7.3 mg kg−1 (r2 = 0.99822 and 0.99421) and ∈ 2.3–7.4 mg kg−1 (level of confidence of 99.331 %) for complex spiked heterogeneous soil samples. The data illustrates the great capability of method and its promising application for environmental contamination monitoring and controlling programs for assessment.