The aim of this work was to develop a selective cloud point extraction method for the separation and preconcentration of copper (II) prior to spectrophotometric determination. For this purpose Dithizone was used as a complexing agent and the experimental solution was acidified with sulfuric acid. Triton X-114 was used as a surfactant and after phase separation, based on the cloud point of the mixture, the rich phase was diduted with tetrahydrofuran (THF) and the enriched analyte determined by spectrophotometric analysis. The chemical and thermodynamic variables affecting the complexation and phase separation were optimized. Calibration plot of absorbance vs. concentration was linear within the range of 15-250 ng ml -1 Cu( II ) the limit of detection being 4.6 ng ml -1. The proposed procedure was successfully applied to the determination of copper in liver samples.

In this work, the SBA-15-supported Dithizone-copper(I) [SBA-15-dtz– Cu(I)] complex as a new heterogeneous catalyst is prepared for the first time. The catalyst prepared is characterized by the FT-IR spectroscopy, SEM, and ICP techniques. This reusable heterogeneous catalyst can be used in the click reactions for the green and facile synthesis of 1, 4-disubstituted 1, 2, 3-triazoles via a one-pot three-component reaction of benzyl chloride derivatives, terminal alkynes, and sodium azide in the water at 60 ° C. A synthetic technique offering numerous advantages including environmentally friendly, high-to-excellent reaction yields, operational simplicity, short reaction times, reusability of the catalyst, and lack of an organic solvent was developed.

This article presents a new approach to measure the concentrations of lead and cadmium in soil marine samples. The technique involves a two-step process: first, the samples are pre-concentrated using liquid-liquid extraction, and then atomic fluorescence spectrometry is used for analysis. In this process, Dithizone is used as the chelating agent. During the procedure, a complex is formed between lead and cadmium with Dithizone. The researchers also investigated important factors that may affect the efficiency of the extraction, such as pH of the sample and shaking duration.The results demonstrated that the extraction process yielded optimal results within a pH range of 7 to 9, and the ideal duration of shaking was between 10 to 30 minutes. Through stoichiometry analysis, it was determined that the most probable structure of the extracted ion pair complex consisted of one metal ion bonded to two ligand molecules (1M+2:2HDZ-). The influence of organic solvents on the extraction process showed that the distribution ratio (D) for extraction increased with a decrease in dielectric constant. Particularly, carbon tetrachloride demonstrated a higher distribution ratio (D), possibly due to its lower dielectric constant, which aids in the disruption of hydration shell around metal cations (Cd and Pb), allowing for enhanced coordination between the ligand molecules and metal cations. A previously described method for analyzing Cd and Pb in marine soil was adapted for this study.

A simultaneous preconcentration procedure for the determination of Cd (II), Ni (II), Co (II) and Cu (II) by atomic absorption spectrometry is described. The method is based on solid phase extraction of the metal ions on Dithizone loaded on naphthalene in a mini-column, elution with nitric acid and determination by flame atomic absorption spectrometry. The sorption conditions including NaOH concentration, sample volume and the amount of Dithizone were optimized in order to attain the highest sensitivity. The calibration graph was linear in the range of 0.5-75.0 ng ml-1 for Cd (II), 1.0-150.0 ng ml-1 for Ni (II), 1.0-150.0 ng ml-1 for Co (II) and 1.0-125.0 ng ml-1 for Cu (II) in the initial solution. The limit of detection based on 3Sb was 0.13, 0.32, 0.33 and 0.43 ng ml-1 for Cd (II), Ni (II), Co (II) and Cu (II), respectively. The relative standard deviations (R. S. D) for ten replicate measurements of 20 ng ml-1of Cd (II), 100 ng ml-1 of Ni (II), Co (II) and 75 ng ml-1 of Cu (II) were 3.46, 2.43, 2.45 and 3.26%, respectively. The method was applied to the determination of Cd (II), Ni (II), Co (II) and Cu (II) in black tea, tap and river water samples.

The aim of this work was to develop a new and simple coacervative extraction method for the preconcentration and spectrophotometric determination of Cu(II) in water samples. Dithizone was used as the chelating agent while an anionic surfactant, namely sodium dodecyl sulfate (SDS), was used as extracting agent at room temperature. Central composite design (CCD) based on response surface methodology (RSM) was employed to optimize main experimental parameters such as pH values of solutions, concentration of the surfactant and volume of the saturated salt. Analytical characteristics of the method such as limit of detection, linear range, relative standard deviation (R. S. D. ) and relative standard error (R. S. E. ) were calculated under the optimum conditions. The calibration graph was linear in the range of 10-100 ng ml-1 with the detection limit of 3. 8 ng ml-1. The interference effects of some anions and cations were also studied. The method was successfully applied for the determination of Cu(II) in water samples.