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At least 37 records · Page 2Linked to original sources
PubMed1975

Determination of coumaphos and its oxygen analog in eggs by in situ fluorometry.

A method is reported for the simultaneous determination of coumaphos (o,o-diethyl o(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl)phosphorothioate) and its oxygen analog, Coroxon, in eggs in the ppb range. The residues are extracted with acetone and chloroform. The extract is purified by liquid-liquid partition followed by column chromatography and then by 2-dimensional thin layer chromatography. The fluorescence is measured directly on the chromatogram.

Animals↗
PubMed1976

Determination of quinomethionate (6-methylquinoline-2,3-diyldithiocarbonate) residues in crops by in situ fluorometry.

A simple method is described for the quantitative determination of quinomethionate (6-methylquinoline- 2,3 - diyldithiocarbonate) in crops. The pesticide residue is extracted with acetonitrile and partitioned in petroleum ether. After separation from the co-extractives by thin layer chromatography (TLC), the fluorescence is measured directly on a silica gel TLC plate. An average of 89% recovery is obtained at the 0.05 ppm level in apples, peaches, pears, and tomatoes.

Chromatography, Thin Layer↗
PubMed1976

Fluorometry of plasma amino nitrogen, with use of fluorescamine.

We describe a fluorometric procedure, with use of fluorescamine, for determining plasma amino nitrogen in a 10-mul sample of deproteinized plasma. Values for apparently healthy human subjects agree well with those obtained by spectrophotometry. The simplicity and speed of the assay recommends it as a screening procedure for detecting aminoacidopathies.

Adult↗
PubMed1977

Histotoxic properties of carbon monoxide in the living organ I. Fluorometry of oxidation-reduction state of the rabbit kidney in situ.

Effect of carbon monoxide on the redox state and blood flow in the renal cortex of the rabbit was examined by the fluorometric method. By a short-period (1-3 min) inhalation of CO in concentrations over 1%, the following were revealed: (1) Reduced pyridine nucleotide was increased, (2) oscillatory change of the reduced pyridine nucleotide, which is characteristic for the histotoxic reaction, developed, and (3) extent of the fluorescence changes tended to be in proportion to the concentration of CO, but no change was caused by inhalation of CO in lower concentrations (0.1%, 0.5%) even if the inhalation was continued for 30 min. As to the blood flow, CO in concentrations over 0.5% decreased it, whereas anoxia due to nitrogen increased it. Some implications were discussed from toxicological points of view on the results obtained.

Animals↗
PubMed1978

Determination of 8-methoxypsoralen in plasma by scanning fluorometry after thin-layer chromatography.

A rapid and sensitive method is described for determining 8-methoxypsoralen in plasma. Plasma samples are acidified with 6 mol/liter and heated in a boiling water bath to release the plasma-bound drug nondestructively. It then is extracted into a solvent mixture consisting of benzene/ethyl acetate (9/1 by vol). The solvent phase is separated, evaporated, and an aliquot of the dissolved residue is thin-layer chromatographed, with benzene/ethyl acetete (9/1) as developing solvent. The plate is dried and the spots, made visible under ultraviolet light (320-400 nm), are scanned. The smallest amount detectable is 20 ng; the overall analytical recovery from plasma is 84%. We used the method to determine the drug in the plasma of rabbits after intravenous and oral administration of 10 mg, and in one patient after an oral dose of 30 mg.

Animals↗
PubMed1978

[Cell cycle phases: determination of G1, S e G2 by fluorometry (author's transl)].

The G1, S and G2 phases of the cell cycle in Allium cepa root tips were determined in Acriflavin--Feulgen--stained material. Pigeon erythrocyte nuclei were employed as standard for DNA dry mass determinations. Micro-interferometric and fluorometric measurements gave the average of 77,1. 10(-12) g for the G1 nuclei from the root tips.

Cell Cycle↗
PubMed1977

Simultaneous determination of captan and captafol in apples and potatoes by thin layer chromatography and in situ fluorometry.

A simple method is described for the simultaneous quantitative determination of captan [N-(trichloromethylthio)-3a,4,7,7a-tetrahydrophthalimide] and captafol [N-(1,1,2,2-tetrachloroethylthio) -3a,4,7,7a - tetrahydrophthalimide] in apples and potatoes. The fungicide residues are extracted with acetonitrile, partitioned into a solution of methylene chloride in petroleum ether, separated from each other and the co-extractives on a thin layer chromatographic plate impregnated with aluminum chloride, sprayed with sodium chlorate, and heated. The fluorescence is then measured directly from the chromatogram. Recoveries were greater than 90% in the test crops at the 0.2 ppm level.

Captan↗
PubMed1977

DNA-fluorometry of mammalian sperm.

The Dna-content of sperm and testicular cells was measured by pulse-cytophotometry with high resolution. From flat sperm symmetric and narrow fluorescene distributions were obtained. Enzymatic treatment with papain or pronase and staining with an ethidiumbromide-mithramycin dye solution generate stoichiometric DNA-staining including that of mature sperm with a coefficient of variation below 2%.

Animals↗