University of North Florida
Browse the Citations
-OR-

Contact Info

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

View Stuart Chalk's profile on LinkedIn

Benzodiazepine, derivatives

@ ChemSpider@ NIST@ PubChem

Citations 4

"Chemiluminescence Detection Of The Benzodiazepine Loprazolam"
Anal. Chim. Acta 1989 Volume 227, Issue 1 Pages 65-71
Anthony R. J. Andrews and Alan Townshend

Abstract: Of seven such compounds tested only loprazolam gave any significant emission after oxidation, e.g., by KMnO4. The optimum conditions used in a 0.5 mm i.d. PTFE tubing dual-flow injection system were: 0.2 mM KMnO4, with 0.94 M formic acid (at pH 0.9) as the carrier stream at 1.3 mL min-1 in both lines. The response was rectilinear between 10 µM and 5 mM for a 50 µL injection, and the limit of detection was 7 µM. Iron(II) and Mn(II) interfered. The method was applied in analysis of tablets, but results were rather higher than expected.
Pharmaceutical Chemiluminescence Optimization pH Interferences Redox

"Chemiluminescence Detection Of A Benzodiazepine"
Anal. Proc. 1989 Volume 26, Issue 11 Pages 368-369
Anthony R. J. Andrews, Alan Townshend

Abstract: Seven benzodiazepines (concentration. 1 mM) were examined for chemiluminescence in a flow injection system with various oxidizing and reducing reagents and water as carrier. Only loprazolam (I), with acidic KMnO4 as reagent, gave a measurable response. Optimum conditions for the determination of I were; water as solvent, 0.94 M formic acid, adjusted to pH 0.9 with HCl, as carrier, 0.2 mM KMnO4 as reagent, and a flow rate of 1.3 mL min-1 in the sample and reagent lines. The calibration graph was rectilinear from 0.01 to 5 mM I, and the detection limit was 7 µM. Of 12 metal ions examined, only Fe(II) and Mn(II) interfered. The method could be used to determine I in tablets; excipients did not interfere.
Pharmaceutical Chemiluminescence Optimization pH Calibration Interferences Detection limit Redox

"Determination Of 1,4-benzodiazepines By Flow Injection Analysis With Spectrophotometric Detection"
Quim. Anal. 1988 Volume 7, Issue 3 Pages 323-329
Prada, D.;Vicnete, J.;Lorenzo Abad, E.;Hernandez Blanco, M.;Hernandez, L.

Abstract: Optimum parameters for the determination of oxazepam, prazepam and clotiazepam comprise an injection volume of 250 µL, a reactor length and i.d. of 50 cm and 0.5 mm, respectively, a flow rate of 5 mL min-1 and a carrier stream of 0.1 M acetic acid - acetate buffer of pH 4.5. Detection is at 230 nm, and the sampling rate is 120 h-1. The method has been used to determine the drugs in formulations, by extraction with methanol and dilution of the extract with the carrier solution, and also in urine, by extraction at pH 7.0 (phosphate buffer) with ethyl ether.
Pharmaceutical Urine Clinical analysis Spectrophotometry Optimization

"Voltammetric On-line Analysis Of Molecules Of Biological Importance"
J. Electroanal. Chem. 1981 Volume 128, Issue 1 Pages 459-467
W. Franklin Smyth, A. Ivaska, J.S. Burmicz, I.E. Davidson and Y. Vaneesorn

Abstract: The on-line voltammetric behavior of several groups of biologically important molecules, (a) 1,4-benzodiazepines, (b) 2-thiobarbituric acids and (c) thioamides, is investigated. A flow through voltammetric cell based on the wall jet principle is described and the DC and pulse working modes are studied in on-line situations. Direct oxidation at the glassy carbon electrode, direct oxidation at a mercury coated glassy carbon electrode and cathodic stripping on this mercury coated glassy carbon electrode have been evaluated with respect to analytical optimization, i.e., in terms of linear range, limit of detection etc.
Voltammetry Electrode Detector Flowcell