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.
Department of Chemistry, University of Roorkee, India.
A
A
Panwar
S
S
Baniwal
C L
CL
Sharma
A K
AK
Singh
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