2000 Volume 16 Issue 12 Pages 1285-1289
Inspired by the success of using monometalloporphyrin complexes as ionic carriers for salicylate-sensitive electrodes, several μ-oxo-bismetalloporphyrin complexes were synthesized by the reaction of monometalloporphyrins with NaOH. A mu-oxo-bis[5-(p-hydroxylphenyl)-10,15,20-triphenyl-porphinatomanganese(III)] [[Mn(5-HP)TPP]2O]-based sensor responds to salicylate ion over the concentration range 6.3 × 10-7 - 1.0 × 10-1 mol L-1 with a Nernstian slope and a response time of 50 s, which is faster than that of monometalloporphyrin counterparts. The electrode exhibits anti-Hofmeister selectivity toward salicylate with respect to common co-existing anions and shows a stable response for more than six months. The effect of the compositions of the electrode membrane has been studied and the experimental conditions optimized. The interaction mode of [Mn(5-HP)TPP]2O with Sal- has also been investigated. The electrode was preliminarily applied to the determination of salicylate in urine.