Lipophilic β-cyclodextrin-based ion-selective electrodes
Polymer and Materials Science
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
2,3,6-Trioctyl and 2,6-didodecyl-β-cyclodextrins have been incorporated in ion-selective electrodes as neutral ionophores for the detection of the local anesthetics procaine, prilocaine, lidocaine and bupivacaine hydrochlorides. Nernstian response and excellent limits of detection were observed (-log [C]≥5.0). Interference from ‘serum’ levels of sodium, potassium and calcium (150.0 mmol dm-3 Na+, 1.26 mmol dm-3 Ca2+ 4.30 mmol dm-3 K+ ), was negligible (-log Kijpot,) (overall)≥4.0). The major organic interferents were molecules of similar size and structure which caused reduced slope and drift in baseline potentials at 10 mmol dm-3 levels of concentrations. However, the interferences were substantially reduced when the interferent concentration was reduced by a factor of 10. Nernstian response was maintained in the presence of bovine serum albumin (BSA), serum (HS) and aI acid glycoprotein (AAG). A polyurethane, (Tecoflex SG80) membrane matrix was more biocompatible when compared to PVC as evidenced by lower E0 (internal) shifts with the former.
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