Kinetic determination of morphine by means of Bray-Liebhafsky oscillatory reaction system using analyte pulse perturbation technique.
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.
Pejić
Natasa D
ND
Faculty of Pharmacy, Department of Physical Chemistry, University of Belgrade, Vojvode Stepe 450, YU-11000 Belgrade, Serbia and Montenegro. bimesel@EUnet.yu <bimesel@EUnet.yu>
Blagojević
Slavica M
SM
Anić
Slobodan R
SR
Vukojević
Vladana B
VB
Mijatović
Miroslav D
MD
Cirić
Jasna S
JS
Marković
Zoran S
ZS
Marković
Svetlana D
SD
Kolar-Anić
Ljiljana Z
LZ
D002384:Catalysis; D004566:Electrodes; D007700:Kinetics; D009020:Morphine / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D009020:Morphine