Synthesis of dimethyl derivatives of imidazolinone herbicides: their use in efficient gas chromatographic methods for the determination of these herbicides.

The dimethyl derivatives of imazaquin, imazapyr, imazmethapyr, imazethapyr, 2-[4,5 dihydro-1, 4-dimethyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-methoxymethyl- 3-pyridine carboxylic acid, 2-[4,5-dihydro-1,4 -dimethyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-4-methyl benzoic acid, and 2-[4,5-dihydro-1,4-dimethyl-4-(1-methyl ethyl)-5-oxo-1H-imidazol-2-yl]-5-methyl benzoic acid were prepared and fully characterized. The availability of these derivatives has led to the development of efficient and multiresidue gas chromatographic methods for trace level analysis of imidazolinone herbicides in matrixes such as water, soybean, and soil.

The Missouri Medical Informatics Thesaurus.

The Missouri Medical Informatics Thesaurus, containing approximately 2,000 sorted terms, arranged within a hierarchical structure, covers the multi-disciplinary medical informatics field more accurately than anything else available. Researchers at the University of Missouri-Columbia developed this thesaurus using the four primary methods of thesaurus construction to assure both literary and user warrant in the final terminology. The thesaurus can also be quickly revised to include the rapidly evolving terminology of the discipline.

Construction of a medical informatics thesaurus.

Medical Informatics needs a specific terminology that reflects the multi-disciplinary nature of the field and can rapidly change as the discipline evolves. Using the four primary methods of thesaurus construction, a group at the University of Missouri-Columbia is developing a thesaurus that meets these criteria and includes both user and literary warrant. The steps in construction include using existing thesauri, medical informatics literature, and the terminology of experts to produce a thesaurus arranged within a hierarchical structure.