PVC-based 2,2,2-cryptand sensor for zinc ions

A PVC-based membrane of 2,2,2-cryptand exhibits a very good response for Zn2+ in a wide concentration range (from 2.06 ppm to 6.54 x 10(3) ppm) with a slope of 22.0 mV/decade of Zn2+ concentration. The response time of the sensor is <10 s, and the membrane can be used for more than 3 months without any observed divergence in potentials. The proposed sensor exhibits very good selectivity for Zn2+ over other cations and can be used in a wide pH range (2.8-7.0). It has also been possible to use this assembly as an indicator electrode in potentiometric titrations involving zinc ions.