A polystyrene based membrane electrode for cadmium(II) ions.
A polystyrene based membrane of 3,4:12,13-dibenzo-2,5,11,14-tetraoxo- 1,6,10,15-tetraazacyclooctade-cane shows a Nernstian response to Cd(II) ions over a wide concentration range (3.16 x 10(-6) - 1.00 x 10(-1) mol L(-1) with a Nernstian slope of 29.8 mV/decade of concentration, between pH 2.0 and 6.0. This electrode has been found to be chemically inert and of adequate stability with a response time of 20s. The electrode gives reproducible results with a lifetime of 130 days. The membrane works satisfactorily in a partially non-aqueous medium up to a maximum 35% (v/v) content of methanol and ethanol. The practical utility of the proposed chemical sensor has been observed by using it as end-point indicator in the titration of Cd(II) ions with EDTA. The potentiometric selectivity coefficient values indicate that the membrane sensor is highly selective for Cd(II) ions over a number of cations. Small amounts of surfactants do not disturb the functioning of the sensor. This electrode has also been used to estimate cadmium ions in real samples.
Panwar
A
A
Department of Chemistry, University of Roorkee, India.
Baniwal
S
S
Sharma
C L
CL
Singh
A K
AK
D002104:Cadmium / Q000737:chemistry*; D004566:Electrodes; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007700:Kinetics; D008567:Membranes, Artificial; D011137:Polystyrenes / Q000737:chemistry*; D011199:Potentiometry; D012997:Solvents
C423509:3,4-12,13-dibenzo-2,5,11,14-tetraoxo-1,6,10,15-tetraazacyclooctadecane; D006575:Heterocyclic Compounds, 3-Ring; D007202:Indicators and Reagents; D008567:Membranes, Artificial; D011137:Polystyrenes; D012997:Solvents; D002104:Cadmium