A new flow-injection analytical procedure is proposed for the determination of the total amount of polyphenols in wines; the method is based on the formation of a colored complex between 4-aminoantipyrine and phenols, in the presence of an oxidizing reagent. The oxidizing agents hexacyanoferrate(III), peroxodisulfate, and tetroxoiodate(VII) were tested. Batch trials were first performed to sele...

Toxicity screening of compounds provides a means to identify compounds harmful for human health and the environment. Here, we further develop the technique of genomic phenotyping to improve throughput while maintaining specificity. We exposed cells to eight different compounds that rely on different modes of action: four genotoxic alkylating (methyl methanesulfonate (MMS), N-Methyl-N-nitrosoure...

In Nature, certain organisms can perform microbial corrosion on base metals by oxidation of neutral metallic atoms (H. L. Ehrlich, Appl. Microbiol. Biotechnol., 1997). Herein we describe the first discovery of biological nucleic acids able to catalyze and mediate gold oxidation from neutral Au(0) to trivalent Au(III) under certain oxidative environments provided by mild oxidizing reagent N-brom...

Evidence from gel filtration and sedimentation studies of crystalline bovine liver rhodanese indicated that the enzyme molecule of 37,000 molecular weight is a dimer. In the native state, this form is in rapid, pa-dependent equilibrium with the monomeric species. A stable dimer is formed under mild oxidizing conditions. Analysis of the protein by peptide mapping indicated that the monomers are ...

H [PV Mo O ] catalyzed oxidation of thiols to related disulfides under microwave irradiation(MW). 5 2 10 40 Hydrogen Peroxide as an oxidizing reagent under mild conditions carried out this reaction. This system provides an efficient convenient and practical method for the syntheses of symmetrical disulfides. In this work, the comparisons among the Keggin and Dawson type polyoxometalates are add...

The publications on Kjeldahl’s method for determining nitrogen that have appeared since Kjeldahl’s (1) original paper in 1883 perhaps outnumber those on any other analytical method in the same period of time.1 The diversity of papers is attributable to the immense usefulness of the method, to its need for modifications for applications to various types of organic and inorganic compounds, and to...