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Flow‐Through Assay of Quinine Using Solid Contact Potentiometric Sensors Based on Molecularly Imprinted Polymers
Author(s) -
Kamel Ayman H.,
Sayour Hossam E. M.
Publication year - 2009
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200904699
Subject(s) - repeatability , molecularly imprinted polymer , potentiometric titration , methacrylic acid , reproducibility , chromatography , potentiometric sensor , polymer , methacrylate , chemistry , selectivity , materials science , monomer , electrode , organic chemistry , catalysis
Miniaturized potentiometric membrane sensors for quinine incorporated with molecular imprinted polymer (MIP) were synthesized and implemented. Planar PVC based polymeric membrane sensors containing quinine‐methacrylic and/or acrylic acid‐ethylene glycol methacrylate were dispensed into anisotropically etched wells on polyimide wafers. The determination of quinine was carried out in acidic solution at pH 6, where positively charged species predominated prevalently. The suggested miniaturized planner sensors exhibited marked selectivity, sensitivity, long‐term stability and reproducibility. At their optimum conditions, the sensors displayed wide concentration ranges of 4.0×10 −6 –1.0×10 −2 mol L −1 and 1.0×10 −5 –1.0×10 −2 mol L −1 with slopes of about 61.3–55.7 mV decade −1 ; respectively. Sensors exhibit detection limits of 1.2×10 −6 and 8.2×10 −6 mol L −1 upon the use of methacrylic and acrylic acid monomers in the imprinted polymer, respectively. Validation of the assay method according to the quality assurance standards (range, within‐day repeatability, between‐day variability, standard deviation, accuracy, and good performance characteristics) which could assure good reliable novel sensors for quinine estimation was justified. Application of the proposed flow‐through assay method for routine determination of quinine in soft drinks was assayed and the results compared favorably with data obtained by the standard fluorimetric method.