Selective extraction of mercury by 4-phenyl-5-p-tolyl-1,3,4-thiadiazolium-2-thiolate (PTTDT)

The extraction of radio-mercury(II) by PTTDT was investigated as function of diluent, hydrochloric acid concentration, extractant concentration and certain foreign compounds in the aqueous phase. The extraction was found to be quantitative when chloroform was used as diluent and at low HCl or high PTTDT concentrations. Neither the presence of boric acid, nor several metal salts (NaF, CuSO₄, ZnSO₄ or Na₂SO₄) had any effect on the E%. The presence of chloride or bromide lowers the E% considerably. A radiochemical procedure was developed to pre-concentrate mercury from artifical sea water using an organic: aqueous phase ratio of 1∶100.     

Glucose

Ohne Zusammenfassung     

2-(8-quinolylazo)-7-phenylazochromotropic acid as an analytical reagent

2-(8-Quinolylazo)-7-phenylazochromotropic acid (QAPAC) has been synthesized by coupling diazotized 8-aminoquinoline with 2-phenylazochromotropic acid as well as by coupling diazotized aniline with 2-(8-quinolylazo)chromotropic acid. The properties of QAPAC and the spectrophotometric characteristics of some metal-QAPAC complexes are reported.     

Valence double ionization of O2 at photon energies below and above the molecular double ionization threshold

A recently developed time-of-flight photoelectron-photoelectron coincidence spectroscopy technique, which gives complete two-dimensional e(-)-e(-) spectra in single photon double ionization, is applied to molecular oxygen at photon energies below and above the adiabatic double ionization threshold of O(2). Analysis of the two-dimensional coincidence maps reveals specific indirect pathways for the double ionization process. Dissociative ionization paths with subsequent autoionization of atomic oxygen are found to be the dominant processes for all chosen photon energies. Spectra of the photoelectrons coincident with the autoionization electrons show that intermediate O(2)(+) states are involved which do not autoionize to molecular O(2)(2+). In particular, the ground state of O(2)(2+) is vibrationally resolved and shows a regular progression which can be well described by direct Franck-Condon transitions at an internuclear distance R(e)(X (1)Sigma(g)(+))=1.054 A. Quantum yields of double ionization for O(2), of a form discussed in this paper, are determined.     

Effect of ginseng saponins on the survival of cerebral cortex neurons in cell cultures

The effects of nerve growth factor (NGF) and saponins isolated from Panax ginseng C.A. Mayer on the survival of chick and rat embryonic cerebral cortex neurons were examined. Ginsenoside Rg1 (GRg1) exerted a survival-promoting effect on both chick and rat cerebral cortex neurons in cell cultures. Ginsenoside Rb1 (GRb1) also had an effect in the rat and displayed some influence in the chick. NGF alone exerted no effect on both neurons, although it did potentiate the GRb1 effect on chick embryonic cerebral cortex neurons, but did not alter the GRb1 effect on rat embryonic cerebral cortex neurons. NGF did not alter the survival-promoting effect of GRg1 on either chick or rat embryonic cerebral cortex neurons. The other saponins alone or with NGF exerted no effect on the survival of cerebral cortex neurons in either the chick or rat.