a sensitive, selective and effective ionic liquid-based single drop microextraction technique was developed by using ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate, c6mimpf6, coupled with electrothermal atomic absorption spectrometry (etaas) for the determination of copper and silver in environmental samples. dithizone was used as chelating agent. several factors that influence t...

Human and rabbit ocular tissues contain high concentrations of zinc. In descending order in human globes, the metal concentration appears to be: retina-choroid, ciliary body, iris, optic nerve, sclera, cornea, and lens. Diamox does not alter the concentration of ocular zinc. In preliminary studies dithizone, a known zinc chelator, does not appear to alter ocular zinc concentration as well. The ...

in this work, a procedure for preconcentration of silver using dispersive liquid–liquid microextraction with the reagent dithizone as complexing reagent was developed. at ph 2, silver ions are complexed with dithizone and extracted into the fine droplets formed when mixing carbon tetrachloride (extraction solvent), ethanol (disperser solvent) and the sample solution. after extraction, the phase...

A bead-injection system is proposed for total mercury determination in river-water samples. The procedure is based on the introduction of a defined quantity of a resin suspension in the flow system. The selected beads are packed inside of a flow cell and the formed resin mini-column constitutes the optical path. The sample volume is then selected, and its passage by the mini-column allows reten...

Endogenous metals such as zinc may contribute to beta-amyloid (Abeta) aggregation and hence the plaque formation. In the present study, we examined brains of four Swedish mutant amyloid precursor protein (APP) transgenic mice at 12 months of age for histochemically reactive zinc in the plaques. Here, we report that all the Congo red (+) mature plaques contained chelatable zinc, as demonstrated ...

Auxotrophic marker genes such as URA3, LEU2, and HIS3 in Saccharomyces cerevisiae have long been used to select cells that have been successfully transformed with recombinant DNA. A longstanding challenge in working with these genes is that counterselection procedures are often lacking. This paper describes the unexpected discovery of a simple plate assay that imparts a bright red stain to cell...

C OLORIMETRIC ANALYSIS has been employed extensively in determination of copper and zinc in human serum and other biologic materials. Greenleaf (1) and Callan and Henderson (2) determined copper colorimetrically using dithizone and diethyldithiocarbamate, respectivelv. Zinc was determined colorinietricallv by Fischer and Leopoldi (4) and by Wolf (5), using dithizone. These procedures were evalu...

The study of zinc metabolism in experimental animals and humans is dependent upon a reliable analytical method. Numerous methods, gravimetric, turbidimetric, and calorimetric (l), have been tried and found wanting. Fischer (2) first introduced diphenylthiocarbazone (dithizone) for the analysis of metals with relation to industrial processes. This organic dye combines with a number of the heavy ...