The Determination of Urinary Oxypurines as Markers of Gastrointestinal Tumors

1987 ◽  
Vol 73 (3) ◽  
pp. 289-294 ◽  
Author(s):  
Marco Lorenzi ◽  
Daniela Vannoni ◽  
Roberto Leoncini ◽  
Ranieri Caldarone ◽  
Enrico Marinello
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Urinary Excretion ◽  
Tumor Marker ◽  
Cancer Patients ◽  
Plasma Levels ◽  
Colorectal Tumor ◽  
Reverse Phase ◽  
Tumor Bearing

Plasma levels and urinary excretion of oxypurines – hypoxanthine and xanthine – were evaluated by reverse-phase high-pressure liquid chromatography in 13 patients affected by gastric tumors and in 19 colorectal tumor-bearing patients. Preliminary results indicate higher values of urinary xanthine and an increase in the xanthine/hypoxanthine ratio in cancer patients. The increase was not generalized to all subjects, and did not appear related either to the stage of the disease or to CEA values. The limits within which the determination of urinary oxypurines can be employed as a tumor marker are discussed.

Determination of Zearalenone in Corn by High Pressure Liquid Chromatography and Fluorescence Detection

1978 ◽  
Vol 61 (5) ◽  
pp. 1058-1062
Author(s):  
George M Ware ◽  
Charles W Thorpe
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Fluorescence Detection ◽  
Hplc Analysis ◽  
Fluorescence Detector ◽  
Reverse Phase

Abstract A method is reported for determining zearalenone in corn at levels as low as 10 ng/g. Samples are extracted with chloroform-water and cleaned up by liquid-liquid chromatography, and the zearalenone is detected by a fluorescence detector after separation by reverse phase high pressure liquid chromatography (HPLC). Recoveries of zearalenone added to corn at levels from 10 to 200 ng/g averaged greater than 89%. In addition, a confirmation procedure is described which involves sequential HPLC analysis of the sample and a zearalenone standard, using 4 different excitation wavelengths and comparing fluorescence responses obtained. This method was successfully applied to the analysis of 11 samples of cornmeal; zearalenone was detected in 9 of the samples at levels from 11 to 69 ng/g.

A Simple Procedure for the Determination of Carbamazepine in Plasma by High Pressure-Liquid Chromatography

1979 ◽  
Vol 16 (1-6) ◽  
pp. 213-216 ◽  
Author(s):  
C. K. Johnston ◽  
G. H. Lester
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Mobile Phase ◽  
Simple Procedure ◽  
Internal Standard ◽  
Reverse Phase ◽  
Coefficients Of Variation ◽  
Initial Results

We describe a simple, rapid procedure for the estimation of carbamazepine in plasma. Protein is precipitated, and extraction is achieved by the addition of acetonitrile containing the internal standard N-acetyltryptophan ethyl ester. Separation is by reverse-phase high-pressure liquid chromatography with an acetonitrile: water mobile phase, and detection is by UV absorption at 280 nm. Total retention time is less than 7 minutes. Initial results gave within-batch and between-batch coefficients of variation of less than 2 %, and mean recovery of 97 %. The method is free from interference by other common anticonvulsant drugs.

High Pressure Liquid Chromatographic Determination of Antihistamine-Adrenergic Combination Products

1980 ◽  
Vol 63 (1) ◽  
pp. 91-94 ◽  
Author(s):  
William J Bachman
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Chromatographic Determination ◽  
Step Response ◽  
Chlorpheniramine Maleate ◽  
Reverse Phase ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Reverse phase high pressure liquid chromatography (HPLC) with ion-pairing is used for the determination of pseudoephedrine hydrochloride in combination with triprolidine hydrochloride or chlorpheniramine maleate in sirups and tablets. Sirups require a preliminary column chromatography cleanup step. Response is linear for pseudoephedrine hydrochloride (range of 0–20 μg), chlorpheniramine maleate (range of 0–1.3 μg), and triprolidine hydrochloride (range of 0–1.0 μg). Recoveries from synthetic formulations were 98.8–101.3% for pseudoephedrine hydrochloride, 100.0–101.2% for chlorpheniramine maleate, and 97.7–99.8% for triprolidine hydrochloride. The coefficient of variation for the method is less than 1%.

Determination of quinidine and metabolites in urine by reverse-phase high-pressure liquid chromatography

1979 ◽  
Vol 91 (3) ◽  
pp. 277-284 ◽  
Author(s):  
Mario R. Bonora ◽  
Theodor W. Guentert ◽  
Robert A. Upton ◽  
Sidney Riegelman
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Reverse Phase

Rapid HPLC Determination of Hydroxymethylfurfural in Tomato Paste

1980 ◽  
Vol 63 (5) ◽  
pp. 1074-1076
Author(s):  
Bradford H Allen ◽  
Henry B Chin
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Rapid Determination ◽  
Hplc Determination ◽  
Isocratic Elution ◽  
Reverse Phase ◽  
Ultraviolet Detector ◽  
Tomato Paste

Abstract A procedure is presented for the rapid determination of hydroxymethylfurfural in tomato paste. The clear serum obtained from the ultracentrifugation of tomato paste is analyzed by high pressure liquid chromatography using a reverse phase LiChrosorb C8 column, an ultraviolet detector operated at 284 nm, and isocratic elution with water.

Simultaneous Determination of Vitamins A and D in Dosage Forms by High Pressure Liquid Chromatography

1982 ◽  
Vol 65 (3) ◽  
pp. 619-623
Author(s):  
Maria Ines ◽  
R M Santoro ◽  
João F Magalhães ◽  
Erika R M Hackmann
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Vitamin A ◽  
Petroleum Ether ◽  
High Pressure Liquid Chromatography ◽  
Mobile Phase ◽  
Dosage Forms ◽  
Reverse Phase ◽  
Solvent Residues

Abstract Vitamins A and D were determined simultaneously in oily solutions, ointments, and elixirs, but only vitamin A could be determined in capsules. Samples were saponified with KOH in isopropanol-water, using hydroquinone as antioxidant, and extracted with ether-petroleum ether (1 + 1). After evaporation of solvent, residues were dissolved in isopropanol. Vitamins in these solutions were determined by reverse phase high pressure liquid chromatography, using methanol-water as mobile phase and detection at 254 nm. The reproducibility, using external standards, was 1.6-2.5% and 1.2-3.8% for vitamins A and D, respectively.

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