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Organometallic Compounds in the Aquatic Environment
Published in B. K. Afghan, Alfred S. Y. Chau, Analysis of Trace Organics in the Aquatic Environment, 2017
Dithizone reacts with a number of metals and has also been used extensively in spectrophotometric determination of organolead. Cremer57 used dithizone to determine triethyllead compounds in tissues and blood. Making use of the dithizone reactions, Moss and Browett58 determined tetraalkyllead by converting them to their corresponding dialkyllead with iondine monochloride, which was determined as dithizonates spectrophotometrically. Similarly, Hancock and Slater59 extracted the coverted dialkyllead with dithizone from solution in the presence of EDTA which complexed any inorganic lead present. The lead is determined by AAS after decomposition of the dialkyllead complexes with acids. An alternate reagent, 4-(2-pyridylazo)-resorcinol (PAR) was used by Pilloni and Plazzogna60 to determine the dialkyllead species specifically. The dithizone reactions with organolead were further expanded in a method to determine simultaneously triethyllead, diethyllead, and inorganic lead in solutions by measuring the absorbance at three different wavelengths based on their characteristic absorption spectra of their dithizonates.61
Mercury in Water
Published in Béla G. Lipták, Analytical Instrumentation, 2018
Dithizone is widely used in the colorimetric analysis of mercury, where the absorption of visible light is detected as a measure of mercury concentration. When an aqueous solution of mercury with a wide pH range (0 to 13) is shaken with a solution of dithizone in chloroform, carbon tetrachloride, or benzene, a mercury complex is formed which dissolves in the organic layer. Dithizone is designated as H2Dz, the mercuric (Hg2+) dithizonate is represented as Hg (HDz)2, and the mercurous (Hg1+) dithizonate as Hg (HDz).
Microwave assisted synthesis of poly (N-vinylimidazole) grafted chitosan as an effective adsorbent for mercury (II) removal from aqueous solution: Equilibrium, kinetic, thermodynamics and regeneration studies
Published in Journal of Dispersion Science and Technology, 2020
Abdelkader Labidi, Asier M. Salaberria, Susana C. M. Fernandes, Jalel Labidi, Manef Abderrabba
After each adsorption experiment, the concentration of the mercury (II) ions remaining in each solution was determined by UV-visible spectrophotometry at λmax = 492 nm that corresponds to the maximum absorbance of mercury (kinetic study). The pH of the solution (pH 6.0) was adjusted with using 0.5 M HCl and 0.5 M NaOH solutions. The solutions were prepared as follow: (i) 0.1354 g of HgCl2 should be diluted in 100 mL of deionized water to prepare a standard solution that corresponds to 1000 mgL−1 of mercury (II). From this solution, six solutions were prepared with different concentrations: 50, 100, 150, 200, 250 and 300 mgL−1; (ii) a 10 mgL−1 dithizone solution was also prepared by dissolving 0.01 g of dithizone in 100 mL of acetone. Dithizone is a chelating reagent widely used for separation and trace metal preconcentration because of the formation of a colored solution in the presence of mercury (II) ions.[28]
Progress on electrochemical sensors for the determination of heavy metal ions from contaminated water
Published in Journal of the Chinese Advanced Materials Society, 2018
Xiangzi Dai, Shuping Wu, Songjun Li
Meanwhile, Jing et al. have developed IIPs using cadmium ions as the template which were directly grafted on the surface of low-cost print paper based on the reversible addition–fragmentation chain transfer polymerization.[82] It can be applied as a recognition element to selectively capture the target ions in the complex samples owning to the selective recognition, formation of dithizone-cadmium complexes and light transmission ability. IIPs-paper has response to Cd(II) in the linear range from 1 to 100 nM and the limit of detection was 0.4 nM. Rezvani Ivari et al. also prepared a novel IIP based potentiometric sensor for the trace determination of Cd(II).[83] The Cd(II)-IIP electrode was fabricated by dispersing cadmium (II) IIP particles in 2-nitrophenyloctyl ether as a plasticizer and then embedding them in a polyvinylchloride polymeric matrix. The obtained IIP sensor showed a Nernstian response for Cd(II) over the concentration range of 2.0 × 10−7–1.0 × 10−2 M and the detect limit of 1.0 × 10−7 M. The proposed electrode was successfully applied in the analysis of spiked water samples. Lai et al. synthesized an Pb(II) imprinted polymer (Pb-IIP) using methacrylic acid as a monomer, Pb(II) as template ions, ethylene glycol dimethacrylate (EGDMA) as a crosslinker, 8-hydoxyquinoline as a ligand and azobisisobutyronitrile as initiator.[84] The polymer was applied to voltammetric sensor for Pb(II) adsorption and trace detection. Compared to other heavy metal ions, such as Hg(II), Cd(II) and Cu(II), the polymer has shown a delightful selectivity for Pb(II) and used to detect trace levels of Pb(II) in food and water samples with linear range of 0.05–60 mμ M of Pb(II) concentrations and a limit of detection at 0.01 mμ M.