Werner E. Morf

Reduction of the Anion Interference in Neutral Carrier Liquid-Membrane Electrodes Responsive to Cations

Abstract Based on A theoretical treatment of neutral carrier liquid-membrane electrodes, propositions are derived to reduce the interference of the cation response by lipid-soluble anions in the sample solution. The performance of such electrodes is shown to be improved by incorporating lipophilic anions, such as tetraphenylborate, into the membrane. There is A quantitative agreement between the theoretical predictions and the results thus obtained for carrier based calcium- and potassium-selective electrodes.

The Origin of Transient Response Phenomena of Ion-Selective Electrodes

Abstract The emf vs. time behavior of ion-selective membrane electrodes in the presence of primary and interfering ions has been investigated theoretically. A simple model is evolved to treat inhomogeneities of the membrane phase. The results permit an explicit description and straightforward explanation of observable effects such as sluggish response or transient response of glass- and other membrane electrodes.

Neutral carrier based silicone rubber membranes for H3O+, K+, NH4+ and Ca2+ selective electrodes

SummarySilicone rubber is a universal membrane matrix for neutral carrier based ion-selective electrodes. Carrier antibiotics as well as synthetic ionophores yield sensors with selectivities that are comparable or even higher than those of corresponding poly(vinyl chloride) (PVC) membrane systems. The permeability of silicone rubber membranes for gas molecules is about ten times higher than the permeability of PVC membranes. In contrast, the electrical conductivity is by a factor of 10–100 lower.ZusammenfassungIn ionenselektiven Elektroden auf der Basis von neutralen Carriern läßt sich Silikongummi als universelle Membranmatrix einsetzen. Entsprechende Sensoren sind sowohl mit ionenselektiven Antibiotika als auch mit synthetischen Carriern realisiert worden. Ihre Selektivitäten übertreffen teilweise jene von entsprechenden PVC-Membranen. Die Permeabilität der Silikongummimembranen für Gasmolekel ist ungefähr zehnmal höher als jene von PVC-Membranen. Andererseits ist die elektrische Leitfähigkeit um einen Faktor 10–100 niedriger.

Optimization of a bicarbonate-selective liquid membrane electrode

SummaryBased on a theoretical analysis, the response characteristics of a gas permeable/hydrogen ion carrier membrane exhibiting selectivity for bicarbonate have been improved. Novel minielectrodes show a linear response to HCO3− in the range 10−3M to 10−1M (slope:-54 mV) and a 95%-response time of 94 s (10−1M solution).ZusammenfassungAuf der Grundlage einer theoretischen Analyse wurden die Elektrodeneigenschaften eines Bicarbonatsensors, beruhend auf einer gasdurchlässigen und gleichzeitig Wasserstoffionencarrier enthaltenden Membran, optimiert. Neuartige Minielektroden weisen eine lineare Elektrodenfunktion im Bereich 10−3M bis 10−1M HCC3− auf (Steilheit:-54 mV); die 95%-Ansprechzeit in 0,1M Lösungen beträgt 94 s.