This study examines zinc(II)–chitosan complexes as a bio-sorbent for phosphate removal from aqueous solutions. The bio-sorbent is prepared and is characterized via Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), and Point of Zero Charge (pHPZC)–drift method. The adsorption capacity of zinc(II)–chitosan bio-sorbent is compared with those of chitosan and ZnO–c...

meso -2,6-Dichlorophenyltripyrrinone (TPN-Cl 2 ), a probe molecule for zinc II ions, is dispersed in a polymer host. The red fl uorescence peak at 620 nm appears when the molecule forms a complex with zinc at its center. TPNCl 2 has a high selectivity for zinc II and tolerates many common metal ions present in the human body. The probe molecules are blended with a hydrogel polymer, poly(2-hydro...

To explore the displacement of Zn(2+) by Ni(2+) from within N-, S-, and O-chelate ligands, (N-(3-thiabutyl)-N'-(3-thiapentaneoate)-1,4-diazacycloheptane)zinc(II), Zn-1'-Ac, and 1,4-diazacycloheptane-1,4-diylbis(3-thiapentanoato) zinc(II), Zn-1'-Ac(2), were reacted with Ni(BF(4))(2) in a methanol solution and were found to yield, in both cases, the bright blue, hexa-coordinate Ni-1'-Ac(2) metal-...

Zinc ions form a yellow complex with di-2-pyridyl ketone salicyloylhydrazone (DPKSH). This complex showed maximum absorption at 376 nm, and it was used to develop spectrophotometric flow injection methods for Zn(II) determination in different samples. Two types of flow systems were proposed. In the first system, a linear analytical curve was obtained in a concentration range from 0.217 to 4.60 ...

A simple and rapid method has been developed for solvent extraction and spectrophotometric determination of copper (II) using o-methylphenyl thiourea (OMPT) as a sensitive reagent. The basis of proposed method is formation of copper (II)-OMPT complex. Copper (II) was extracted with 0.020 mol L-1 OMPT in chloroform from aqueous solution in 0.075 mol L-1 potassium iodate. The absorbance of comple...

Bacteria respond dynamically to the changes in zinc availability. Repression by the Bacillus subtilis transcription factor Zur requires Zn(II), which binds with negative cooperativity to two regulatory sites per dimer to form, sequentially, Zur2:Zn3 and Zur2:Zn4 forms of the repressor. Here we show that, as cells transition from zinc sufficiency to deficiency, operons regulated by Zur are derep...

The ZIP (Zrt/Irt-like protein) family of zinc transporters is found in all three domains of life. However, little is known about the phylogenetic relationship amongst ZIP transporters, their distribution, or their origin. Here we employed phylogenetic analysis to explore the evolution of ZIP transporters, with a focus on the major human fungal pathogen, Candida albicans. Pan-domain analysis of ...

Steffen Runge, M athias O. Senge* Institut für Organische Chemie (WE02), Fachbereich Chemie, Freie Universität Berlin, Takustraße 3, D-14195 Berlin, Germany Z. Naturforsch. 53b, 1021-1030 (1998); received June 15, 1998 Porphyrins, Quinones, Electron Transfer Compounds, Crystal Structure, Conformation A series of 5-(benzoquinone)-10,15,20-trialkylporphyrins was synthesized via cross conden­ sati...

Assessment of adsorption zinc (II) ions from aqueous solution using alginate-SBA-15 sorbent nanocomposite was investigated as a function of zinc concentration, solution pH, and contact time. For that purpose, the alginate-SBA-15 nanocomposite adsorbent was prepared through encapsulation method by immobilization mesoporous SBA-15 into a polymeric matrix. Identification of functional groups and s...

In this study, we focused on microfluidic electrochemical analysis of zinc complexes (Zn(phen)(his)Cl2, Zn(his)Cl2) and ZnS quantum dots (QDs) using printed electrodes. This method was chosen due to the simple (easy to use) instrumentation and variable setting of flows. Reduction signals of zinc under the strictly defined and controlled conditions (pH, temperature, flow rate, accumulation time ...