|Marek, Leetta - MN DEPT. AGRICULTURE|
Submitted to: Spectroscopy Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 4, 1996
Publication Date: N/A
Technical Abstract: Analysis of some of the newer pesticides presents greater challenges to the analyst than older chemicals. They are applied at much lower rates than the older pesticides, they are often thermally labile, and either the parent chemical or its metabolites are polar and nonvolatile. Analysis by traditional methods such as HPLC or GC-MS is often not satisfactory. Analysis methods are needed for these chemicals at the desired level of sensitivity and that can be used for confirmation. For example, imidacloprid is a new chemistry of insecticide. Soil application rates are less than 0.3 mg kg-1; therefore, an analytical method capable of determining imidacloprid in soil at levels less than 0.03 mg kg-1 will be needed. Methods to determine smaller amounts of imidacloprid in soil solution are also needed. At present, HPLC is being used for analysis because imidacloprid is thermally labile under normal GC conditions and most common derivatives could not be formed or were not sufficiently stabl under GC conditions. We have used an electrospray LC-MS system as part of a rapid and sensitive method for the determination of imidacloprid in soil and water samples. The electrospray LC-MS method enables the analysis at the desired levels of sensitivity for environmental fate and to characterize sorption in soil. Also, the fragmentation patterns allows the confirmation necessary in conjunction with the quantitation in the environmental analysis.