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Biomedical subjects

J R Fleeker

Publications and source records attributed to J R Fleeker.

11 recordsLinked to original sources
PubMed1982

Steam distillation and gas-liquid chromatographic determination of triallate and diallate in milk and plant tissue.

A procedure based on steam distillation is described for the determination of residues of the thiocarbamate herbicides diallate and triallate. The herbicides are steam-distilled directly from aqueous suspensions of milk and plant samples and trapped in hexane. After column cleanup on either activated Florisil or silica cartridges, samples are quantitated by gas-liquid chromatography. Recoveries of diallate and triallate from milk, lettuce, peas, corn, canarygrass seed and straw, and flax straw ranged from 77 to 96%.

Animals↗
PubMed1979

Thiocyanate utilization by an Arthrobacter.

An Arthrobacter species, which utilized thiocyanate (SCN-) as a nitrogen source, was isolated from soil by the enrichment culture method. The organism tolerated SCN- concentrations up to 0.1 M. On addition of nitrate or ammonium ion to cultures of the isolate growing in the presence of SCN-, the organism continued to degrade SCN-. Degradation could be followed by release of 14CO2 from SCN-(14C). The SCN- -degrading activity diminished to low levels as the stationary phase of growth was appraoched.

Arthrobacter↗
PubMedDate not supplied

Enzyme immunoassay for screening sulfamethazine residues in swine blood.

An enzyme immunoassay (EIA) was developed to screen for residues of sulfamethazine (SMT) and its metabolites in swine blood. Swine blood was treated with perchloric acid and centrifuged. The supernatant solution was neutralized with K2HPO4, centrifuged, and applied to a reverse phase C8 cartridge. The analytes were eluted with methanol-water (2 + 3), and the eluate was diluted and assayed. Average recoveries, using 14C-labeled compounds, were 73, 72, 61, and 62% for SMT, N4-glucosylSMT, N4-acetylSMT, and N4-desaminoSMT, respectively. Tubes coated with antibody were incubated with the eluate and an SMT-beta-galactosidase conjugate. Bound enzyme was detected with fluorogenic substrate. When blood was fortified with 0.1 ppm SMT or a molar equivalent of metabolite, the average relative response of the EIA was 100%, control blood; 61%, SMT; 66%, glucosylSMT; 60%, acetylSMT; and 77% desaminoSMT.

Animals↗