Plasticized poly(vinyl chloride) membranes that incorporate a highly lipophilic sodium-selective neutral ionophore (ETH 4120) and novel H(+)-selective chromo-ionophores, lipophilic isologs of Nile Blue, are used in the competitive binding of Na+ and H+ for a reversible, optical determination of sodium activities in buffered solutions at different selected pH values. These optode membranes are u...

'Ghosts' of bovine chromaffin granules, in which the complex mixture of proteins and solutes normally found in the granule matrix is replaced by buffered sucrose are osmotically sensitive. They shrink when the osmotic pressure of the suspension medium is increased, and swell if solute entry is facilitated by the addition of ionophores. Swelling in the presence of ionophores has been used to inv...

Three organic ionophores (2-4) based on the p-tert-butylthiacalix[4]arene backbone, blocked in the 1,3-alternate conformation, bearing two pyridyl coordinating moieties (ortho for 2, meta for 3 and para for 4), have been synthesized and characterized in the solid state. The solvent extraction experiments with the metal ions showed that the ability of these derivatives to complex with Ag(+) appe...

A class of squaramide-based tripodal molecules was employed as new ionophores for highly sensitive and selective sulfate-selective sensors. Compared with the reported tripodal ionophore with urea, squaramide groups as superior hydrogen bonding donor were introduced into the tripodal structure to obtain new ionophores leading to better electrode performance. Three derivatives with unsubstituted ...

Veratridine, an activator of action potential Na(+) ionophores, stimulated passive Na(+) uptake by electrically excitable neuroblastoma and muscle cells but had no effect on clonal cell lines defective in Na(+)-ionophore activity. Veratridine-dependent Na(+) uptake was completely inhibited by tetrodotoxin, a specific inhibitor of the action potential Na(+) ionophore. Half-maximal inhibition was...

A series of ionophores based on diaza 18-crown-6 units possessing amide and sulfonamide functions were prepared. Their complexing properties were investigated in solvent polymeric membrane electrodes. The influence of the structure of ligands, prepared on the selectivity of complexation, was examined with special respect to lead ions. Substantial changes were observed, when methyl substituent i...

International conferences• L. Lvova, G. Verrelli, R. Paolesse, C. Di Natale, A. D′Amico; An appli-cation of porphyrin-based Electronic Tongue system for ’Verdicchio’ wineanalysis; Eurosensors XVIII; Rome, 12-15 September 2004• L.Lvova, G. Verrelli, R. Paolesse, C. Di Natale, A. D′Amico, S. Makarychev-Mikhailov; Pt(II)TPP and Pt(IV)TPPCl2 as ionophores for polymericmembra...

Surveys were distributed to the beef producers in Ontario, in the fall of 1999, to establish use patterns and perceptions about antibiotics. Most of the 587 respondents thought that antibiotic use needed to be reduced, but as many as half of the respondents may not have known the difference between antibiotics and other injectable products. The results indicate that any guidelines should explai...

A thiocyanate poly(vinyl chloride) (PVC) membrane electrode based on [1,2-bis(diphenylphosphino)ethane]dihalopalladium(II), [(dppe)PdX2, X = Cl (L), X = I (L)] as active sensor has been developed. The diiodopalladium complex, [(dppe)PdI2](L) displays an anti-Hofmeister selectivity sequence: SCN‒ > I‒ > ClO4‒ > Sal‒ > Br‒ > NO2‒ > HPO4‒ > AcO‒ > NO3‒ > H2PO4‒ > CO32‒. The electrode exhibits a Ne...

A liquid chromatography-mass spectrometric method was developed and validated to determine six polyether ionophores (lasalocid sodium, monensin sodium, salinomycin sodium, narasin, maduramicin ammonium alpha, and semduramicin sodium) in feed samples. The method developed was very straightforward, involving extraction with 84% acetonitrile of the coccidiostats from the feed samples and filtratio...