Selective recognition of Cd(II) using 5, 11, 17, 23-Tetra-tert-butyl-25,27bis(7’-methoxycoumarin-3’-methyloxy)-26, 28-dihydroxycalix[4]arene

The work in this study is based on the selective determination of Cd(II) using 5, 11, 17, 23-Tetra-tert-butyl-25, 27bis(7’-methoxycoumarin-3’-methyloxy)-26, 28-dihydroxycalix[4]arene as neutral ionophore. The anion excluder KTpClPB and various plasticizers, viz., o-NPOE, DBP, DBBP, TEP, DOP, CN and OA have been used to improve the performance of sensor. The best performance was obtained with o-NPOE as plasticizer with composition PVC (33%): o-NOPE (54%): Ionophore (5%): NaTPB (8%). This sensor exhibits Nernstian response with slope 23.0 ± 0.3 mV/decade of activity in the concentration range 1.0×10⁻⁹to 1.0×10⁻¹M of Cd(II), performs satisfactorily over wide pH range of (2.0–8.6) with a fast response time (10s). The proposed sensor can be used over a period of 10 months without significance drift in potential. It has been used successfully for direct determination of Cd(II) in different real samples.