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.

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.

Screening Method for Vitamins A and D in Fortified Skim Milk, Chocolate Milk, and Vitamin D Liquid Concentrates

1979 ◽  
Vol 62 (6) ◽  
pp. 1358-1360
Author(s):  
Susan K Henderson ◽  
Lucia A Mclean
Keyword(s):  
Vitamin D ◽  
High Pressure ◽  
Liquid Chromatography ◽  
Vitamin A ◽  
Mobile Phase ◽  
Screening Method ◽  
Skim Milk ◽  
Chocolate Milk ◽  
Reverse Phase ◽  
Milk Chocolate

Abstract Vitamin A was determined in fortified chocolate milk and skim milk; vitamin D was determined in fortified chocolate milk, skim milk, and vitamin D concentrates, using reverse phase high pressure liquid chromatography (HPLC). The sample is saponified, extracted with hexane, and chromatographed in an HPLC system on a 10 μm Vydac TP reverse phase C18 column, using acetonitrile-methanol (9+1) as the mobile phase. For 6 replicates, the recoveries of vitamins A and D, using this procedure, were 99 and 98%, respectively.

High-Pressure Liquid Chromatography of Benzo (a) pyrene and Benzo(ghi)perylene in Oil-Contaminated Shellfish

1976 ◽  
Vol 59 (5) ◽  
pp. 989-992 ◽  
Author(s):  
Humberto Guerrero ◽  
Edward R Biehl ◽  
Charles T Kenner
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Petroleum Ether ◽  
Silica Gel ◽  
High Pressure Liquid Chromatography ◽  
High Pressure Liquid Chromatographic ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic ◽  
Polynuclear Aromatics

Abstract A high-pressure liquid chromatographic procedure is described for the determination of benzo (a) pyrene and benzo(ghi)perylene. These polynuclear aromatics are extracted with acetonitrile and partitioned into petroleum ether, the petroleum ether is removed, and the residue is saponified. The compounds are purified and isolated by passing the residue through a silica gel column and a high-pressure liquid chromatographic column, and detected by their ultraviolet absorption. Recoveries of standards through the procedure averaged 104%.

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 Polythiazide in Pharmaceutical Dosage Forms by High-Pressure Liquid Chromatography

1975 ◽  
Vol 64 (8) ◽  
pp. 1406-1408 ◽  
Author(s):  
R.E. Moskalyk ◽  
R.A. Locock ◽  
L.G. Chatten ◽  
Monique F. Bielech ◽  
A.M. Veltman
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Dosage Forms ◽  
Pharmaceutical Dosage Forms

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.

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
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