Assessment of the distribution of pesticides on soil particle fractions in simulated irrigation run-off using centrifugal SPLITT fractionation and ELISA Original Research Article

This study was designed to measure the distribution of pesticides within the mobile phase of simulated irrigation run-off water, using centrifugal split-flow thin-channel (SPLITT) fractionation, a novel technique providing a gentle separation of natural sediment and suspended particles. Particular attention is paid to the extraction of pesticide residues for enzyme-linked immunosorbent assay (ELISA) analysis; ELISA was used because of the limited sample size. Centrifugal SPLITT fractionation combined laminar flow hydrodynamics and centrifugal sedimentation to obtain a continuous binary separation of suspended particles. The non-destructive technique allowed an accurate separation of particles into fractions with divisions at 0.5, 2 and 10 μm, with those above 25 μm being performed by wet sieving. ELISA was used to analyse the concentration of endosulfan and diuron for each fraction generated by the SPLITT technique. This data can be used to determine the role that particulate fines and colloidal fractions play in the transport of bound organic pollutants within the environment and to examine prospects for remediation on farms. Article Outline