Automated High-Pressure Liquid Chromatographic Assay for Antiepileptic Drugs and Their Major Metabolites by Direct Injection of Serum Samples

1984 ◽  
Vol 6 (4) ◽  
pp. 478-483 ◽  
Author(s):  
Wilhelm Kuhnz ◽  
Heinz Nau
Keyword(s):  
High Pressure ◽  
Antiepileptic Drugs ◽  
Direct Injection ◽  
Serum Samples ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic

High Pressure Liquid Chromatographic Determination of Vitamins A and E in Cereal Products

1979 ◽  
Vol 62 (3) ◽  
pp. 637-641
Author(s):  
Warren A Widicus ◽  
James R Kirk
Keyword(s):  
High Pressure ◽  
Direct Injection ◽  
Chromatographic Determination ◽  
Retinyl Palmitate ◽  
Tocopheryl Acetate ◽  
High Pressure Liquid Chromatographic ◽  
Cereal Products ◽  
Average Recovery ◽  
Liquid Chromatographic

Abstract A rapid method for the simultaneous determination of vitamins A and E in fortified cereal products has been developed. Saponification of retinyl or tocopheryl esters is not required, permitting direct injection of the extracted lipids onto the high pressure liquid chromatographic column without sample cleanup. Elution times of 2.46 and 3.40 min were determined for retinyl palmitate and tocopheryl acetate, respectively, using a μPorasil column and an isocratic mobile phase of hexane-chloroform (85+15) with a flow rate of 1.5 mL/min. The average recovery of retinyl palmitate was 99.2% (std dev. 4.28), and the average recovery of tocopheryl acetate was 94.9% (std dev. 4.10) in 2 cereals containing corn, oat, rice, and wheat. No significant amounts of naturally occurring tocopherols were found in the cereals.

Assay of Formulations Containing 2,4-D and/or Picloram by Direct Injection High Pressure Liquid Chromatography

1979 ◽  
Vol 62 (2) ◽  
pp. 297-303
Author(s):  
Timothy S Stevens
Keyword(s):  
High Pressure ◽  
Chromatographic Method ◽  
Direct Injection ◽  
Hplc Method ◽  
Dichlorophenoxyacetic Acid ◽  
Reverse Phase ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Method ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Liquid Chromatographic

Abstract A rapid and precise fully automated, direct injection high pressure liquid chromatographic method is described for assaying liquid formulations of 2,4-dichlorophenoxyacetic acid (2,4-D) and/or picloram (4-amino-3,5,6-trichloropicolinic acid). The method is specific for the 2,4-D and picloram isomers. No sample preparation is needed, triplicate assays can be performed in 1 hr, and precision is about 1% relative at the 95% confidence level. Compounds are separated on a 9 mm id reverse phase microparticulate column with an eluant of ace* tonitrile-water (1+4) , buffered at pH 2.95. No bias was observed between this method and the official final action HPLC method for picloram and 2,4-D in picloram-2,4-D mixtures, 6.B09-6.B12.

Simultaneous high-pressure liquid-chromatographic determination of some anticonvulsants in serum.

1976 ◽  
Vol 22 (1) ◽  
pp. 25-31 ◽  
Author(s):  
R F Adams ◽  
F L Vandemark
Keyword(s):  
High Pressure ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Serum Samples ◽  
Reverse Phase ◽  
High Pressure Liquid Chromatographic ◽  
Peak Areas ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We describe procedures for simultaneously determining some anticonvulsants (phenobarbital, diphenylhydantoin, primidone, ethosuximide, methsuximide, carbamazepine) in serum by high-pressure liquid chromatography. The drugs, together with an internal standard, phenacetin, are adsorbed from serum onto charcoal and eluted from it with organic solvent. The eluate is analyzed isocratically on a reverse-phase column with a mobile phase consisting of acetonitrile/water (17/83 by volume). The eluted drugs are detected by their absorption at 195 nm, and quantities estimated from their peak areas as compared with those of extracted standards. Results are reproducible to about 6%. Sensitivities, for 0.5-ml serum samples, of 0.1 mg/liter for all the drugs analyzed except ethosuximide (0.5 mg/liter) are attained routinely. Correlation of results with gas chromatography was 0.912 for phenobarbital, 0.982 for diphenylhydantoin, 0.886 for primidone, and 0.966 for ethosuximide. Amobarbital and secobarbital interfere with the analysis; chlordiazepoxide, methaqualone, salicylate, diazepam, and oxazepam do not. Including extraction, analysis time for a single sample is 20 min.

High-pressure liquid-chromatographic separation of lactate dehydrogenase isoenzymes.

1976 ◽  
Vol 22 (4) ◽  
pp. 471-474 ◽  
Author(s):  
P J Kudirka ◽  
R R Schroeder ◽  
T E Hewitt ◽  
E C Toren
Keyword(s):  
High Pressure ◽  
Lactate Dehydrogenase ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Serum Samples ◽  
High Pressure Liquid Chromatographic ◽  
Tissue Extracts ◽  
Liquid Chromatographic Separation ◽  
Liquid Chromatographic ◽  
Lactate Dehydrogenase Isoenzymes

Abstract The isoenzymes of lactate dehydrogenase (EC 1.1.1.27) were separated with excellent resolution in less than 1 h by high-pressure anion-exchange chromatography. These isoenzymes were determined in some tissue extracts and high-activity serum samples by this technique.

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