Thesis - University Access Only
Master of Science (MS)
Department / School
An analytical method using capillary gas chromatography and mass spectrometry (GC/MS) with selected ion monitoring (SIM) to determine thirteen common herbicide residues( clopyralid, dicamba, MCPA, bromoxynil, 2,4-D, triclopyr, bentazon, DCPA, fluazifop, picloram, acifluorfen, diclofop, fenoxaprop) has been developed. The method involves an alkaline hydrolysis for extracting herbicides from the plant tissue, solvent partitioning into methylene chloride, followed by methylation of the extracted acidic herbicides with diazomethane. Florisil column cleanup was used for the removal of interfering coextractants. Separation and quantification of the herbicides was carried out by capillary GC/MS with SIM. The objective of this research was the development of a simple and efficient method for quantitative multiclass and multiresidue herbicide analysis in plants. An improved Florisil cleanup procedure was developed for removal of many interferences from 13 herbicides that have different structural and polarity properties. The recoveries of residues at the 1 ppm level were 80%-- 95% and at the 0.1 ppm level were 75% --85%. Detection limits were on the range of 0.2 to 0.02 ng depending on the herbicide. This corresponds to about 0.1 ppm to 0.01 ppm in the sample.
Library of Congress Subject Headings
South Dakota State University
Wen, Yongkang, "The Simultaneous Determination of Thirteen Herbicides in Plants by Gas Chromatography/Mass Spectrometry" (1994). Electronic Theses and Dissertations. 27.