Polymeric membrane sensors based on Cd(II) Schiff base complexes for selective iodide determination in environmental and medicinal samples.
The two cadmium chelates of schiff bases, N,N'-bis(salicylidene)-1,4-diaminobutane, (Cd-S(1)) and N,N'-bis(salicylidene)-3,4-diaminotoluene (Cd-S(2)), have been synthesized and explored as ionophores for preparing PVC-based membrane sensors selective to iodide(I) ion. Potentiometric investigations indicate high affinity of these receptors for iodide ion. Polyvinyl chloride (PVC)-based membranes of Cd-S(1) and Cd-S(2) using as hexadecyltrimethylammonium bromide (HTAB) cation discriminator and o-nitrophenyloctyl ether (o-NPOE), dibutylphthalate (DBP), acetophenone (AP) and tributylphosphate (TBP) as plasticizing solvent mediators were prepared and investigated as iodide-selective sensors. The best performance was shown by the membrane of composition (w/w) of (Cd-S(1)) (7%):PVC (31%):DBP (60%):HTAB (2%). The sensor works well over a wide concentration range 5.3x10(-7) to 1.0x10(-2)M with Nernstian compliance (59.2mVdecade(-1) of activity) within pH range 2.5-9.0 with a response time of 11s and showed good selectivity for iodide ion over a number of anions. The sensor exhibits adequate life (3 months) with good reproducibility (S.D.+/-0.24mV) and could be used successfully for the determination of iodide content in environmental water samples and mouth wash samples.
Singh
Ashok Kumar
AK
Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India. akscyfcy@iitr.ernet.in
Mehtab
Sameena
S
D002104:Cadmium / Q000737:chemistry*; D002138:Calibration; D004785:Environmental Pollutants / Q000032:analysis*; D007454:Iodides / Q000032:analysis*; D008567:Membranes, Artificial; D009067:Mouthwashes / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D015203:Reproducibility of Results; D012545:Schiff Bases / Q000737:chemistry*; D012680:Sensitivity and Specificity
D004785:Environmental Pollutants; D007454:Iodides; D008567:Membranes, Artificial; D009067:Mouthwashes; D011108:Polymers; D012545:Schiff Bases; D002104:Cadmium