A new polyvinyl choloride (PVC) membrane sensor for cerium (III) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) as an ionophore. The sensor exhibites a linear concentration range of 1.0×10-6 to 1.0×10-1 M, with a Nernstian slope of 18.0±1.0 mV/decade, and a detection limit of 9.7×10-7 M. It has a fast response time (5 s) and can be used for two m...

Dielectric constant and loss in liquid-ammonia solutions of alkali halides have been measured in the frequency range 0.7 — 70 GHz. At least one relaxation process exists in this frequency range in addition to the relaxation of the solvent molecules. The additional relaxation is ascribed to the orientational polarisation of ion pairs. The concentration of the ion pairs, calculated with a special...

A new polyvinyl choloride (PVC) membrane sensor for cerium (III) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) as an ionophore. The sensor exhibites a linear concentration range of 1.0×10-6to 1.0×10-1M, with a Nernstian slope of 18.0±1.0 mV/decade, and a detection limit of 9.7×10-7M. It has a fast response time (5 s) and can be used for two mont...

An overview is presented of classic and more recent applications of liquid chromatography for the analysis of metal species. The different approaches involving ion-exchange, ion-pair, and chelation separation mechanisms are discussed as well as the new philosophy of simply removing interferents before specific detections of metal ions (alkali and alakaline earths, rare earths, heavy and transit...

A new polyvinyl choloride (PVC) membrane sensor for cerium (III) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) as an ionophore. The sensor exhibites a linear concentration range of 1.0×10-6 to 1.0×10-1 M, with a Nernstian slope of 18.0±1.0 mV/decade, and a detection limit of 9.7×10-7 M. It has a fast response tim...

Contact ionization (doped) sources used in current Heavy Ion Fusion (HIF) experiments consist of a porous tungsten substrate doped with an alkali carbonate. During the early stages of the heating cycle (T ~ 600 °C), the carbonate breaks down and releases the alkali atoms that then diffuse through the substrate. At the emitter surface there is a balance between the fast desorption rate of the al...

In this paper we present the aggregational motifs of the widely used alkali-metal cyclopentadienides (CpLi, CpNa, CpK, CpRb, CpCs) in THF-d8 solution estimated by ECC-DOSY NMR spectroscopy. They form monomeric contact ion pairs (CIPs) in THF-d8 solution, whereas in NH3 solvent-separated ion pairs (SSIPs) are observed. The applicability of ECC-DOSY is further advanced by introducing ECC-MW estim...

The essential nature of K+ for growth of lactic acid bacteria has previously been established (1). The amount required for maximum growth seemed unusually high. Further investigation showed that the quantitative requirement for potassium was markedly influenced by the amounts of sodium and ammonium ions in the medium. These findings prompted an extension of the investigation to other alkali met...

Porphyrins are a group of tetrapyrrole pigments. Physical and chemical properties of porphyrins are often related to their compositions and structures. We conducted 1H solution NMR and UV-visible spectral analysis to characterize the structural feature of a water-soluble, synthetic porphyrin i.e. tetrakis (p-sulfonatophenyl) porphyrin, TPPS4, and its interaction with different metal ions in aqu...