Preparation of a gabapentin potentiometric sensor and its application to pharmaceutical analysis

A novel gabapentin ion-selective electrode is prepared, characterized and used in pharmaceutical analysis. The gabapentin complex with phosphomolybdic acid (MO) was obtained in situ by soaking the PVC-membrane in a 1.0 × 10−3 M gabapentin solution. Among three different solvent mediators tested, dioctyl phthalate (DOP) exhibited a proper behavior including Nernstian slope of 59.8 ± 2 mV decade−1 for gabapentin in the concentration range 1.0 × 10−5 to 5.0 × 10−2 M with a limit of detection of 1.0 × 10−5 M. The electrode displays a good selectivity for gabapentin with respect to a number of pharmaceuticals that may be taken with gabapentin simultaneously. The sensor can be used in a pH range of 1.8–3.2. The membrane sensor was successfully applied to the determination of gabapentin in its tablets as well as its recovery from blood serum samples.