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.

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.

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.

Determination of acetaminophen concentrations in serum by high-pressure liquid chromatography.

1977 ◽  
Vol 23 (9) ◽  
pp. 1596-1598 ◽  
Author(s):  
R A Horvitz ◽  
P I Jatlow
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Diethyl Ether ◽  
High Pressure Liquid Chromatography ◽  
Internal Standard ◽  
Reversed Phase ◽  
Single Extraction ◽  
Toxic Concentrations

Abstract We describe a method for determination of serum acetaminophen concentrations in serum by reversed phase high-pressure liquid chromatography. The homolog N-propionyl-p-aminophenol was used as an internal standard. The procedure, which requires only a single extraction with diethyl ether, can be optimized to be linear over the ranges of 10 to 100 or 1 to 20 mg/liter. Within-run CV was 1.2%; between-run CV was 4.4% and 4.9% at two different concentrations. Many commonly used drugs were tested and found not to interfere. The procedure is simple and rapid enough for use on an emergency basis in cases of overdosage, and can be optimized for measurement of either therapeutic or toxic concentrations.

Quantitative Distribution of Lichen Products in Australian Scyphose Cladonia Species

1981 ◽  
Vol 13 (3) ◽  
pp. 259-263 ◽  
Author(s):  
A. W. Archer
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Capillary Flow ◽  
Internal Standard ◽  
Reverse Phase ◽  
Quantitative Distribution ◽  
Saturated Solutions

AbstractThe quantitative distribution of five lichen acids, including fumarprotocetraric acid, in seven specimens of Australian scyphose Cladonia species was determined by reverse phase high pressure liquid chromatography, using butylated hydroxy-toluene as internal standard. The highest concentrations of lichen acids were found in the scyphi and it is suggested that this localized distribution of lichen acids is due to repeated upward capillary flow, of saturated solutions of the acids, in the podetia followed by evaporation in the upper parts of the podetia.

High-Pressure Liquid Chromatography of Caffeine in Coffee

1976 ◽  
Vol 59 (6) ◽  
pp. 1258-1261
Author(s):  
Bryan L Madison ◽  
William J Kozarek ◽  
Cecilia P Damo
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Mobile Phase ◽  
Methylene Chloride ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Ultraviolet Detector ◽  
Decaffeinated Coffee

Abstract A new method is described for the determination of caffeine in coffee, based on high-pressure liquid chromatography. The caffeine is extracted from the sample with water and/or methylene chloride, and then separated from interfering materials by passing an aliquot of the extract through a high-pressure column containing sulfonated cation exchange resin, using 0.01M nitric acid as the mobile phase. An ultraviolet detector measures the absorption of the solution directly. The method is rapid and eliminates the lengthy separations common to other methods. The procedure was applied successfully to decaffeinated and non-decaffeinated green, roasted, and instant coffees. This method gives a more accurate measure of the caffeine content in decaffeinated coffee samples than the micro Bailey-Andrew and modified Levine methods, with equal or better precision. This method gives results equal to those obtained by the official methods for non-decaffeinated samples.

scholarly journals Determination of Ceftriaxone in Cerebrospinal Fluid by Ion-Pair Liquid Chromatography

2005 ◽  
Vol 88 (2) ◽  
pp. 436-439 ◽  
Author(s):  
Marta de Diego Glaría ◽  
Gloria Godoy Moscciati ◽  
Ricardo Godoy Ramos
Keyword(s):  
Cerebrospinal Fluid ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
Tetrabutylammonium Bromide ◽  
Internal Standard ◽  
Ion Pair ◽  
Deionized Water ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic

Abstract An ion-pair liquid chromatographic assay was developed and validated for the determination of ceftriaxone in cerebrospinal fluid. Chromatographic separation was achieved on a C18 column (125 × 4 mm, 5 μm) with detection at 270 nm, a 1 mL/min flow rate and a 50 μL loop. The mobile phase consisted of 300 mL acetonitrile, 50 mL 0.1M phosphate buffer (pH 7.4), 3.2 g tetrabutylammonium bromide as the ion-pairing agent, and dilution with distilled deionized water to 1 L. Cephradine was used as the internal standard. The assay was linear for ceftriaxone concentrations of 0.5–50 μg/mL. The coefficients of variation for precision were <4.61%. The accuracy ranged from 96.07 to 102.42%. The detection and quantitation limits were 0.019 and 0.065 μg/mL, respectively. This method was used to quantify ceftriaxone in the cerebrospinal fluid of children with meningitis. The results showed that the method described here is useful for the determination of ceftriaxone in cerebrospinal fluid.

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

Improved sample preparation in determination of urinary metanephrines by liquid chromatography with electrochemical detection

1990 ◽  
Vol 36 (3) ◽  
pp. 538-540 ◽  
Author(s):  
R N Gupta
Keyword(s):  
Liquid Chromatography ◽  
Sample Preparation ◽  
Mobile Phase ◽  
Sodium Acetate ◽  
Simple Procedure ◽  
Internal Standard ◽  
Boiling Water Bath ◽  
Reduced Pressure ◽  
Urinary Metanephrines

Abstract In this relatively simple procedure for extracting metanephrines from urine, after an internal standard (4-hydroxy-3-methoxybenzylamine in 1 mmol/L HCl) is added, the sample is hydrolyzed in a boiling water bath, then treated with ammonia and alumina. Excess ammonia is removed under reduced pressure and the sample is applied to a 1-mL Bond Elut SCX column, which is washed, and metanephrines and internal standard are eluted with 0.5 mmol/L sodium acetate/acetonitrile (3/1 by vol). Of this elute, 5 microL is injected into a 15 cm x 4.6 mm (i.d.) column packed with 5-microns octadecylsilyl silica particles, which is eluted with a mobile phase containing tetramethylammonium perchlorate. Peaks are detected coulometrically at +0.28 V. In the resulting chromatogram, metanephrines give sharp peaks, well resolved from peaks for solvent and internal standard. There are no extraneous peaks for catechols or mono-oxygenated phenylethylamines. Results correlated well (r = 0.999, n = 13) with those by earlier described liquid-chromatography.

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