D. Ammann

Lipophilic salts as membrane additives and their influence on the properties of macro- and micro-electrodes based on neutral carriers

Abstract The influence of salts containing lipophilic cations and anions on the electrical resistance of the membranes of calcium ion-selective macro- and micro-electrodes based on a neutral carrier is described. The resistance of macroelectrodes was decreased by a factor of about 50 or of about 3 compared to membranes without and with potassium tetrakis- (p-chlorophenyl)borate, respectively. No significant reduction of the membrane resistance was achieved for microelectrodes. The lower detection limit and the Ca2+/K+ selectivity factor were improved for both types of electrode.

A hydrogen ion-selective liquid-membrane electrode based on tri-n-dodecylamine as neutral carrier

Abstract An electrically neutral hydrogen ion-selective carrier, tri-n-dodecylamine, is used as the active component for liquid-membrane electrodes. The observed ion selectivities are superior to those of previously described pH-sensitive liquid-membrane electrodes. The electrode characteristics permit the study of intracellular as well as extracellular hydrogen ion activities.

Aquocyanocobalt(III)-hepta(2-phenylethyl)-cobyrinate as a cationic carrier for nitrite-selective liquid-membrane electrodes

The synthesis of aquocyanocobalt(III)-hepta(2-phenylethyl)-cobyrinate is described. It is a more lipophilic substitute for a previously reported nitrite-carrier. Membranes based on this more readily accessible cobyrinate exhibit selectivity coefficients for nitrite (Kpot) over nitrate and chloride of 10−4.2 and 10–4.6, respectively. Near-theoretical slopes were found for 10−4.5−10−1.0 M nitrite. After contact of the sensor with flowing tap water for 35 days, no deterioration of the electrode characteristics was observed.

Anion-selective liquid membrane electrodes based on lipophilic quaternary ammonium compounds

SummaryA series of 15 anion-selective membranes, based on quaternary ammonium compounds of different constitution and on a variety of plasticizers in different compositions of the solvent polymeric membranes, lead throughout to the selectivity sequence

Valinomycin-based K+ selective microelectrodes with low electrical membrane resistance

ClO_4 - > SCN - > I - > NO_3 - > Br - > Cl - > HCO_3 - \sim OAc - \sim SO_4 ^2 - \sim HPO_4 ^2 - .

Ion‐Selective Electrodes and Their Clinical Application in the Continuous Ion Monitoringa

. A detailed analysis demonstrates that the selectivity pattern of such systems may be drastically modified only ifa)a mobile, positively charged site with a sufficiently strong and specific interaction with anions is chosen and/orb)an electrically neutral anion-selective membrane component is used.ZusammenfassungEine Reihe von 15 anionenselektiven Membranen, beruhend auf unterschiedlichen quaternären Ammoniumionen und auf verschiedenen Weichmachern, führt auch bei voneinander abweichenden Membranzusammensetzungen durchwegs zur Selektivitätssequenz:

Modeling and optimizing the costs of electronic systems

ClO_4 - > SCN - > I - > NO_3 - > Br - > Cl - > HCO_3 - \sim OAc - \sim SO_4 ^2 - \sim HPO_4 ^2 - .