University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Valproic acid

  • IUPAC Name: 2-propylpentanoic acid
  • Molecular Formula: C8H16O2
  • CAS Registry Number: 99-66-1
  • InChI: InChI=1S/C8H16O2/c1-3-5-7(6-4-2)8(9)10/h7H,3-6H2,1-2H3,(H,9,10)
  • InChI Key: NIJJYAXOARWZEE-UHFFFAOYSA-N

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Citations 3

"Correcting Measurement Errors Using Reference Materials In Method Validation"
Microchim. Acta 1996 Volume 123, Issue 1-4 Pages 231-240
Jytte Molin Christensen

Abstract: The correction of measurement errors in method evaluation studies is discussed. In the first example, reference materials were used in a method evaluation study of Pb in blood using two different AAS instruments (Perkin-Elmer Models 4100 and 5100) with Zeeman background correction. The number of method evaluation function (MEF) samples was insufficient for the MEF slopes to be used for correction of systematic errors. Secondly, a method evaluation study on valproate in plasma using an EMIT assay (SYVA) on a COBAS MIRA S is described; systematic error above 300 mM valproate was corrected for using the slope of the MEF. Thirdly, correction during evaluation of a FIA AAS method to determine As compounds and their metabolites in urine is described. The use of reference materials to determine performance characteristics during method development is discussed.
Urine Spectrophotometry Reference material

"Automated Fluoriimmunoassay Of Theophylline And Valproic Acid By Flow Injection Analysis With Use Of HPLC Instruments"
Clin. Chem. 1989 Volume 35, Issue 3 Pages 469-470
P Allain, A Turcant and A Premel-Cabic

Abstract: The equipment comprised an HPLC pump, a robotic unit and a fluorimeter. In the robotic unit (Gilson) the serum was twice diluted, then mixed with the reagents (β-galactosyl umbelliferone - drug conjugate and β-galactosidase-labelled antiserum) and with buffer solution All reagents were as supplied for the Ames therapeutic drug assay (Ames Div., Miles Labs., Elkhart, IN). The mixture was heated at 30°C for 16 min, and then injected into the carrier reagent. Fluorescence was measured at 450 nm (excitation at 405 nm). For theophylline, results correlated well (r = 0.98) with those obtained by HPLC on Spherisorb C6 after extraction. For valproic acid, results correlated well (r = 0.96) with those obtained by GC on a 5% FFAP column, after extraction with CCl4. The automated method required only one eighth of the reagent volume used in the manual method. Within- and between-run coefficient of variation were 4.5 and 6.4%, respectively, for 13.8 mg L-1 of theophylline and 3.7 and 6.6%, respectively, for 55 mg L-1 of valproic acid. Detection limits were 1 mg l-1.
Blood Serum Immunoassay Fluorescence Clinical analysis Method comparison Instrumentation Buffer Robot

"Flow Injection Analysis Of Carboxylic Acid Drugs Using Cationic Dyes And Online Ion-pair Extraction"
J. Liq. Chromatogr. Relat. Technol. 1988 Volume 11, Issue 16 Pages 3353-3373
James T. Stewart; James R. Lang; Irwin L. Honigberg

Abstract: Six dyes were tested as ion-pair reagents to determine salicylic acid(I), valproic acid(II) and ibuprofen(III); optimum results were achieved with gentian violet (C. I. Basic Violet 3) for spectrophotometric detection at 588 nm and acridine orange (C. I. Basic Orange 14) for fluorescence detection at >470 nm (excitation at 297 nm). The analytical system comprised a HPLC pump, a 30-turn glass mixing coil, a glass phase separator and a silica flow-through cell. The mobile phase was 10 mM phosphate buffer (pH 7) - methanol (9:1) at 1 mL min-1, which was mixed with a 19.5 µM solution of the dye in CHCl3 at 1.25 mL min-1. For test operation in the separation mode, a column (10 cm x 4.6 mm) of ODS silica (10 µm) was inserted between the injector and the mixing coil. Calibration graphs for I, II and III were rectilinear for 0.5 to 10, 5 to 50 and 1 to 10 µg mL-1 (spectrophotometry) and for 0.13 to 5, 2.5 to 50 and 0.5 to 20 µg mL-1 (fluorimetry), respectively. Prostaglandin F2α could also be determined spectrophotometrically in the range 16 to 500 µg mL-1.
Pharmaceutical HPLC Fluorescence Spectrophotometry Sample preparation Extraction Optimization Phase separator Ion pair extraction