Flow-injection analysis of dopamine in injections with a periodate-selective electrode

• Type: Article in International Scientific Journal
• Date: 2000

Authors

Montenegro, MCBSM (Author) FFUP; Sales, MGF (Author) Other

Journal

Title: Journal of Pharmaceutical Sciences

Vol. 89

Pages: 876-884

ISSN: 0022-3549

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 21 Citations

Scopus - 23 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-000-ZN9

DOI: 10.1002/1520-6017(200007)89:7<876::aid-jps4>3.3.co;2-i

Abstract (EN): Dopamine determination in pharmaceutical preparations based on its oxidation with periodate (IO4-) using a new IO4--selective electrode under flow conditions is presented. An electrode with a tubular configuration, no internal reference solution, and a PVC (31.2%) membrane, with metaperiodate bis(triphenylphosphoranylidene)ammonium (1.3%) as ion exchanger and 2-nitrophenyloctylether (67.5%) as mediator solvent, was used. Optimization procedures were directed at potentials versus dopamine readings instead of potential versus the remaining IO4-. This approach was achieved by selecting a 50-cm reactor and an overall flow of 7 mL/min, and injecting 70 mu L of dopamine standards in a 3.0 x 10(-4) M IO4- solution. Under these conditions, a linearity range of 8.0 x 10(-3) to 2.7 x 10(-1) g/L, with a slope of 310.1 +/- 7.4 mV L g(-1) and a reproducibility of +/-0.4 mV, were recorded (n = 8). Interference from common excipients was negligible. Under these conditions, analysis of dopamine injections (n = 12) presenting 200 mg/injection gave average and standard deviation values of 201.0 and 3.3 mg/injection, respectively. A simple and inexpensive flow-injection analysis (FIA) manifold, with a good potentiometric detector, enabled the analysis of 200 samples/h without requiring pretreatment procedures. Comparison with the dopamine injection analysis in the United States Pharmacopoeia monograph showed good accuracy, with a relative deviation of -0.2%. (C) 2000 Wiley-Liss, Inc. and the American Pharmaceutical Association.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9