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Biomedical subjects

G R Gotelli

Publications and source records attributed to G R Gotelli.

10 recordsLinked to original sources
PubMed1981

Fluorometric liquid-chromatographic determination of serum cortisol.

We describe a sensitive and specific liquid-chromatographic assay for serum cortisol, exploiting acid-induced fluorescence. Each analysis requires only 50 microL of serum, and chromatography is complete in 7 min. Analytical recovery of cortisol added to serum ranged from 90 to 105% and between-run precision (CV) from 6 to 8%. The lower limit of detection for cortisol is 10 micrograms/L, and linearity extends to 1600 micrograms/L. Numerous steroids and drugs tested did not interfere.

Chromatography, Liquid↗
PubMed1980

Simultaneous liquid-chromatographic determination of zinc protoporphyrin IX, protoporphyrin IX, and coproporphyrin in whole blood.

We describe a method for simultaneously measuring concentrations of coproporphyrin, zinc protoporphyrin IX, and protoporphyrin IX in whole blood by liquid chromatography, with use of reversed-phase ion-pair system, fluorometric detection, and internal standardization. Each analysis requires 10 microL of whole blood and 15 min total analysis time. Analytical recovery ranged from 84 to 92%, day-to-day precision (CV) from 5 to 12%. Uroporphyrin, though not studied in detail, can also be detected by this method.

Chromatography, Liquid↗
PubMed1978

Improved liquid chromatographic determination of placental estriol in urine.

Placental estriol in urine can be determined, after enzymatic hydrolysis, by liquid chromatography. A single-step extraction technique results in rapid processing with minimal sample manipulation. Analytical recovery of estriol added to urine was 96 to 106%. Day-to-day precision (CV), established by 10 replicate analyses at a mean concentration of 15.9 mg of estriol per liter, was 3.7%.

Chromatography, High Pressure Liquid↗
PubMed1978

Simultaneous determination of phosphatidylglycerol and the lecithin/sphingomyelin ratio in amniotic fluid.

We describe a single-dimension thin-layer chromatographic method by which one can simultaneously determine the lecithin/sphingomyelin ratio and the proportion of phosphatidylglycerol in amniotic fluid. The phospholipids are conveniently detected by an improved molybdenum-blue spray reagent, which immediately produces blue spots on a white background. The stained phospholipids are stable for at least 90 min after spraying, and densitometry results in symmetrical peaks that are easily quantitated.

Amniotic Fluid↗
PubMed1977

Determination of placental estriol in urine by gas-liquid chromatography, with equilenin as internal standard.

Placental estriol in urine can be determined by rapid enzymatic hydrolysis, extraction with neutral XAD-2 resin, and quantitation by gas-liquid chromatography, with equilenin as the internal standard. Glucose, methenamine mandelate, hydrochlorothiazide, phenolphthalein, or salicylate do not interfere. Analytical recovery of estriol added to urine was 92-108%. Day-to-day precison (CV), established by 15 repilicate analyses at a mean concentration of 21.3 mg/liter, was 6.6%.

17-Ketosteroids↗
PubMed1977

Determination of acetaminophen and phenacetin in plasma by high-pressure liquid chromatography.

We describe a sensitive and precise high-pressure liquid chromatographic method in which acetoacetanilide is used as the internal standard to simultaneously determine acetaminophen and phenacetin in plasma. Therapeutic as well as toxic concentrations can be determined on as little as 0.1 ml of plasma. Sample preparation is rapid and chromatography is complete in 5 min. Quantitation is accurate at 0.5 mg/liter concentration for both drugs. Day-to-day precision within 5% is attainable. Of 36 other drugs tested, only theophylline interfered, with the determination of acetaminophen.

Acetaminophen↗