| Abstract: | An immunoassay (ELISA) for analysis of metsulfuron‐methyl was evaluated as a method for quantifying residues in soil. Soil samples were extracted with phosphate buffered saline (PBS), PBS + acetone (80 + 20 by volume) or ammonium carbonate and were analyzed with both ELISA and LC‐MS. A tendency for the ELISA to overstimate the metsulfuron‐methyl content was noted and matrix effects were pronounced, particularly in PBS + acetone or ammonium carbonate extracts. Dilution of extracts before analysis improved the situation but reduced the sensitivity of the assay. Using light standard concentrations it was shown that the extracts in PBS on dilutions exhibited a curve parallel with the standard curve, indicating no significant interference due to matrix effects. A working range of 10–250 ng litre?1 was found for ELISA on this type of extracts. © 2000 Society of Chemical Industry |
