Development of Ion-selective Electrodes for Tropane, Atropine, and Scopolamine - a Concept for the Analysis of Tropane Alkaloids

We present the development of novel ion-selective electrodes for tropane, atropine, and scopolamine, as a general model for tropane alkaloids and drugs such as e. g. cocaine. These potentiometric sensors rely either on a metallocarborane or tetraphenylborate complex as recognition element and led to systems with a near-Nernstian behaviour in the range of 10(-5)-10(-2) mol/L and detection limits around 2 . 10(-5) mol/L. Selectivity studies with commonly used drug additives (caffeine, phenacetin) and closely related tropane derivatives show very low influence of the additives and a structure dependent interference for the derivatives. Beside this, a hydrogel-based concept with a similar performance was developed, which could be used for on-site measurement of solid samples. The developed sensors therefore demonstrated their suitability and might be used to enable the development of portable sensor arrays for the quantification of a wide range of tropane alkaloids.