Atropine-selective membrane electrodes and relative selectivity concept.
TFPB was introduced as a charged ionophore for atropine selective electrodes. Typical Nernstian responses were found (57.78, 58.95 and 58.41 mV/decade) for PVC-membrane electrodes incorporating NPOE, DOS, and DDP as plasticizers. They exhibited practical linear ranges of 9.1 x 10(-3) - 10(-6), 9.1 x 10(-3) - 10(-6) and 9.1 x 10(-3) - 10(-7) M, respectively. It works in the sub-micro scale of atropine concentrations. The optimum pH-range was 3.18 - 8.97. The selectivity coefficient values were estimated for different organic and inorganic cations. They were interpreted by using the "Relative Selectivity Concept", which was introduced for the first time. The new concept was applied for comparing the selectivity properties of previously reported electrodes. The effect of the presence of ephedrine, caffeine, glucose, Na(+), Ca(2+), and Mg(2+) on the calibration graphs of the electrodes was studied.
Zareh
Mohsen M
MM
Department of Chemistry, Faculty of Science, Zagazig University, Zagazig, Egypt. mohsenzareh@hotmail.com
D016477:Artifacts; D001285:Atropine / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002138:Calibration; D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D007476:Ionophores; D008567:Membranes, Artificial; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000737:chemistry; D010968:Plasticizers / Q000737:chemistry*; D011143:Polyvinyl Chloride / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
D007476:Ionophores; D008567:Membranes, Artificial; D004364:Pharmaceutical Preparations; D010968:Plasticizers; D001285:Atropine; D011143:Polyvinyl Chloride