Temporal-spatial analysis of cyromazine in cowpea using liquid chromatography-mass spectrometry coupled with mass spectrometry imaging

Abstract

Cowpea (Vigna unguiculata L. Walp.) is an economically important crop. It is nutritious and popular with consumers. However, it has been listed as one of the agricultural products of critical concern about safety in China and cyromazine is the major risk factor. This study analyzed the dissipation and permeation kinetics of cyromazine residue in cowpea, to offer a scientific basis for the rational use of pesticide and ensuring the safety of agricultural products. Investigated the dissipation and residue level of the systemic insecticide cyromazine on cowpea under field and stored conditions. Subsequently, studied the spatial distribution of cyromazine using MSI to visualize the dynamic processes of permeation and migration in the tissues post pesticide application. The dissipation processing of cyromazine in cowpea was shown to follow the first-order kinetics and half-life was 7.76 days in the field. In cowpea, the permeation and migration rate of cyromazine was quite faster than that in the kidney beans and accumulation mainly in the pulp. It is not safe to apply cyromazine to cowpeas with reference to the application method on kidney beans. These findings present vital data for the determination of risks linked with cowpea consumption and pesticide intake.