POTENTIOMETRIC PHOSPHATE SELECTIVE ELECTRODE BASED ON A MULTIDENDATE TIN(IV) CARRIER

The incorporation of tris(3-chlorodimethylstannyl-propyl) chlorostannane (carrier 1), a novel tin(IV) based carrier, into a liquid polymeric membrane and its potentiometric properties are examined. Membranes doped with 2 wt% of this carrier are shown to display the highest selectivity for phosphate over many anions reported so far, including that of perchlorate. Its response time is in the order of seconds, while its detection limit is 1 x 10(-5) M. The ability for a multidentate coordination between the carrier and the phosphate anion is postulated to be the reason for the response, while the observed high selectivity is proposed to be due to the higher tendency for bond formation between the phosphate oxygens and the tin(IV) metal centers. On the other hand the lifetime of the electrode is short, due probably to the hydrolysis of the carrier in the membrane phase.