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D C Fenimore

Publications and source records attributed to D C Fenimore.

17 recordsLinked to original sources
PubMed1983

Determination of fluphenazine in plasma by high-performance thin-layer chromatography.

Determination of fluphenazine in blood plasma by in situ fluorescent detection after separation by high-performance thin-layer chromatography is described. Enhancement of fluorescent emission of the drug is accomplished by exposure to UV light in the presence of paraffin oil which permits a limit of detectability of approximately 0.1 ng/ml in blood plasma. Thirty samples or more can be processed in a 7-h period with excellent precision (less than 3% relative standard deviation at 2.5 ng/ml). Investigation of extraction procedures, chromatographic conditions, photodevelopment, and fluorescent detection are described.

Chromatography, High Pressure Liquid↗
PubMed1981

Rapid microanalysis of anticonvulsants by high-performance thin-layer chromatography.

A rapid microanalytical method is described for phenobarbital, phenytoin, primidone and carbamazepine utilizing high-performance thin-layer chromatography (HPTLC). This procedure incorporates a single extraction of a 50-microliter plasma sample. One tenth of the extract is concentrated and applied to the HPTLC plate by a Contact Spotter, chromatographically separated and quantitated by in situ ultraviolet reflectance densitometry. The coefficient of variation is less than 4% (n = 8), the extraction efficiency is approximately 95% and the minimum detectable amount of pure drug standards applied to and developed on the HPTLC plate is 5 ng or less for all four anticonvulsants.

Anticonvulsants↗
PubMed1978

Determination of drugs in plasma by high-performance thin-layer chromatography.

High-performance thin-layer chromatography was used to determine chlorpromazine, amitriptyline, nortriptyline, imipramine, desipramine, phenobarbital, and phenytoin in plasma, to demonstrate the utility of this technique for routine analysis. We quantitated the separated components by use of ultraviolet reflectance spectrometry with detection limits as low as 1 microgram/liter. Regressions of psychoactive agents extracted from plasma were linear over the range of 0 to 300 microgram/liter. The anti-convulsant drugs, phenobarbital and phenytoin, were determined over a range of 0 to 50 mg/liter. Analyses were rapid, reproducible, and well-suited to large-scale programs. Separated components also can be identified in situ by ultraviolet spectrophotometry.

Amitriptyline↗
PubMed1978

The placental transfer and materno-fetal disposition of methadone in monkeys.

A method is described for the quantitation of levo-methadone[3H] in biological samples which involves sample extraction and thin-layer chromatographic separation. Four pregnant Macaca mulata monkeys, two in early gestation and two in late gestation, were given single i.m. injections of levo-methadone[3H]. Twenty-nine fetal and maternal tissues and fluids were assayed to provide quantities of unchanged methadone and methadone plus metabolites. Little placental transfer of methadone or its metabolites occurred during early gestation, but equivalent concentrations of unchanged methadone were found in maternal and fetal tissues during late gestation (maternal brain, 172 ng/g; fetal brain, 123 ng/g). With few exceptions, tissues or fluids from the late gestation mothers showed higher levels of unchanged methadone than those from early gestation mothers at both 1 hour (P less than .001) and 6 hours (P less than .010) after administration. The late gestation mother had a 40.2% greater concentration of unchanged methadone at 6 hours and a 50.1% greater concentration at 1 hour than the early gestation mothers. These data suggest a slowing of metabolism during advanced pregnancy. At 6 hours after administration the eyes of both early and late gestation mothers and late gestation fetuses showed the highest concentrations of unchanged methadone of any maternal or fetal tissue. This localization of methadone appears to be associated with pigmented epithelium.

Animals↗
PubMed1977

High-performance thin-layer chromatographic determination of psychopharmacologic agents in blood serum.

High-performance thin-layer chromatography affords a rapid, sensitive method for determination of psychopharmacologic agents in blood serum samples. Quantitation of the representative drugs chlorpromazine, amitriptyline, nortriptyline, imipramine, and desipramine at levels as low as 5 ng/ml is demonstrated by scanning the developed thin-layer plates with a chromatographic spectrophotometer in the ultraviolet absorption mode. Neither derivatization prior to, nor color development after chromatographic separation is required to achieve sensitivity and reproducibility of determinations.

Amitriptyline↗
PubMed1977

Nickel gas chromatographic columns: an alternative to glass for biological samples.

Nickel tubing may be substituted for glass in the fabrication of gas chromatographic columns for use with samples of biological interest. Comparisons of separations of mixtures of steroids, narcotic alkaloids, phenothiazines, and amphetamines on stainless stell, glass, and nickel packed columns showed little or no observable sample decomposition on glass or nickel as contrasted to complete loss of certain compounds on stainless steel. The nickel columns are easily prepared, durable, economical, and not subject to breakage.

Alkaloids↗
PubMed1977

Improved gas chromatographic analysis of chlorpromazine in blood serum.

Reliable determinations of chlorpromazine levels in blood serum samples obtained from patients were accomplished by electron capture gas chromatography. By using modifications of the procedure to insure stability of the sample, minimal losses during sample preparation and gas chromatography, and by selecting appropriate operating parameters of the electron capture detector, excellent agreement was obtained in replicate analyses with a limit of sensitivity of 1 ng/ml in 1 ml of plasma.

Chlorpromazine↗