A PVC-BASED CRYPTAND C2(B)22 MEMBRANE POTENTIOMETRIC SENSOR FOR ZINC(II)

A PVC membrane electrode for zinc ions based on cryptand C2(B)22 as me mbrane carrier was prepared. The electrode exhibits a linear stable re sponse over a wide concentration range (5.0 x 10(-2) - 5.0 x 10(-5) mo l/L) with a slope of 24 mV/decade and a limit of detection of 3.98 x 1 0(-5) mol/L (2.6 mu g/g). It has a fast response time of about 30 s an d can be used for at least 4 months without any divergence in potentia l. The proposed sensor revealed good selectivities for Zn2+ over a wid e variety of other metal ions and could be used in a pH range of 4-7. It was used as an indicator electrode in potentiometric titration of z inc ion.