Electrochemical behavior and underpotential deposition of Sm on reactive electrodes (Al, Ni, Cu and Zn) in a LiCl-KCl melt

A significant flux of heavy metals, among other toxins, reaches the lungs through smoking. This study reports Cd, Pb, Cu and Zn contents in tobacco of 11 brands of cigarette commonly sold in Ethiopia. The heavy metals were determined by atomic absorption spectrophotometry after wet digestion of cigarette tobacco using HNO3 and H2O2. The concentration of trace metals in the cigarettes ranged (mean) (μg/g), Cd: 1.3−7.6 (2.48±0.32), Pb: 0.50−12.50 (6.24±2.2), Cu: 2.89−25.35 (13.70±4.12) and Zn: 24.40−62.55 (36.22±7.50) while Ni was not detected in all the eleven brands of cigarettes. Comparable levels of trace metals were obtained in the tobacco of both imported and Ethiopian cigarettes. The average trace metal contents of cigarettes available in Ethiopia were Cd 1.82±0.39, Pb 4.23±0.97, Cu 10.2±3.1 and Zn 28.2±7.8 μg/cigarette and a person who smokes 20 cigarettes per day is estimated to increase his/her daily Cd, Pb, Cu and Zn retention by approximately 0.036, 0.085, 0.204, 0.564 mg/day, respectively. The results indicate that smoking and exposure to cigarette smoke is a serious problem to be taken into account when carrying out epidemiological studies on human exposure to trace metals.

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HEAVY METALS IN WATER, SEDIMENTS AND MARINE FISHES FROM BULGARIAN BLACK SEA

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

10.31519/conferencearticle_5b1b93d4d78bb6.88545986 ◽

2017 ◽

Author(s):

Katya Peycheva ◽

Mona Stancheva ◽

Stanislava Georgieva ◽

...

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Black Sea ◽

Fish Species ◽

Distribution Patterns ◽

Marine Fishes ◽

Marine Water ◽

Mean Values ◽

Sprattus Sprattus ◽

Cu And Zn

In this study, the ecosystem marine water-sediment-biota was investigated and the pollution was assessed. The concentrations of eight elements were determined in marine water, sediments and four fish species collected from Black Sea (Varna), Bulgaria during 2013. Marine water recorded the highest concentrations of Zn (15-22 μg/L), As (1.1–1.2 μg/L) and Pb (0.7-0.8 μg/L) while Zn (31-52 μg/g), Pb (21-29 μg/g) and Cu (20-34 μg/g) and show the highest concentrations in sediments. Water and sediments showed similar spatial distribution patterns for the highest mean values of the different metals. In the analysed fish species, the highest concentration of the metals Cu and Zn were found in Trachurus Mediterrneus (0.42 mg/kg w.w) and in Sprattus Sprattus (12.7 mg/kg w.w), respectively while the heavy metals As and Hg were found with maximum values in Pseta Maxima (3.99 mg/kg w.w and 0.08 mg/kg w.w respectively). The results from this study were compared with our data for a previous period (2004-2006) and they show decrease in the levels of heavy metal.

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ELECTROCHEMICAL BEHAVIOR OF B30 Cu-Ni ALLOY WITH SUPER-HYDROPHOBIC SURFACE IN 3.5%NaCl SOLUTION

ACTA METALLURGICA SINICA ◽

10.3724/sp.j.1037.2011.00470 ◽

2012 ◽

Vol 48 (1) ◽

pp. 94

Author(s):

Qunjie XU ◽

Xianqin DENG ◽

Hongtao PAN ◽

Hong YUN

Keyword(s):

Electrochemical Behavior ◽

Hydrophobic Surface ◽

Nacl Solution ◽

Ni Alloy

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Study of Electrochemical Behavior of Some Dental Alloys

Revista de Chimie ◽

10.37358/rc.18.6.6377 ◽

2018 ◽

Vol 69 (6) ◽

pp. 1598-1602

Author(s):

Alice Arina Ciocan Pendefunda ◽

Constanta Mocanu ◽

Doriana Agop Forna ◽

Cristina Iordache ◽

Elena Luca ◽

...

Keyword(s):

Oral Cavity ◽

Electrochemical Behavior ◽

Base Alloy ◽

Artificial Saliva ◽

Surface Condition ◽

Continuous Process ◽

Metal Alloys ◽

Alloy Surface ◽

Dental Alloys ◽

Dental Restorations

The purpose of the study is to investigate the electrochemical behavior of two dental alloys: palladium alloy (Palidor) and Ni-Cr alloy (Verasoft) in three types of artificial saliva. Determination of corrosion potential and recording of linear and cyclic polarization curves were performed with PGP201 potentiostat (VoltaLab 21- Radelkis Copenhagen. In order to study the modifications produced on the surface of the electrodes, a complex optical microscope MC 1 research type (IOR, Romania) was used, adapted to a digital camera, which was connected to a computer for the digital acquisition of images . Two metal alloys based on Ag-Pd and Ni-Cr were used for the experiments. The materials used came from different types of dental restorations removed from the oral cavity of the patients after a 5-15 years period. As corrosion environments, three artificial saliva were used: Fusayama, Afnor and Rondelli. The Pd-Ag dental alloy exhibits a very good corrosion resistance and the treatment in the Afnor saliva does not affect the surface of the alloy. Electrochemical behavior in Fusayama-Meyer�s saliva of the alloy surface results in a series of spots representing deposits of insoluble salts resulting from the oxidation process, while in the Rondelli saliva there is a series of small corrosion points on the alloy surface. The behavior of the Verasoft alloy in the Afnor and Rondelli saliva is similar; In both solutions, the potential breakthroughs are very close, but in Fusayama-Meyer�s saliva, the potential for initiation of corrosion points is very low (206 mV), a potential that can be encountered in the oral cavity. All metals and metal alloys, even the noble and semi-precious ones, are susceptible to corrosion, forming compounds with properties different from those of the metal or base alloy, which change their surface condition. Metallic dental restorations are permanently affected by the factors of the oral environment (physical-mechanical, chemical and biological), being subjected to a continuous process of degradation.

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