Kinetic determination of morphine by means of Bray-Liebhafsky oscillatory reaction system using analyte pulse perturbation technique.

Faculty of Pharmacy, Department of Physical Chemistry, University of Belgrade, Vojvode Stepe 450, YU-11000 Belgrade, Serbia and Montenegro. <>
Analytica chimica acta (Impact Factor: 4.31). 02/2007; 582(2):367-74. DOI:10.1016/j.aca.2006.09.026
Source: PubMed

ABSTRACT A novel kinetic method for micro-quantitative determinations of morphine (MH) is proposed and validated. The method is based on the potentiometric monitoring of the concentration perturbations of the oscillatory reaction system being in a stable non-equilibrium stationary state close to the bifurcation point between stable and oscillatory state. The response of the Bray-Liebhafsky (BL) oscillatory reaction as a matrix system, to the perturbations by different concentrations of morphine, is followed by a Pt-electrode. The proposed method relies on the linear relationship between maximal potential shift, DeltaE(m), and the logarithm of the added morphine amounts in the range of 0.004-0.18 micromol. Under optimum conditions, the sensitivity of the proposed method (as the limit of detection) is 0.001 micromol and the method is featured by good precision (R.S.D.=1.6%) as well as the excellent sample throughput (45 samples h(-1)). In addition to standard solution analysis, this approach was successfully applied for quantitative determination of morphine in a typical pharmaceutical dosage form. Some aspects of the possible mechanism of morphine action on the BL oscillating chemical system are discussed in detail.

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