Nives Vladislavić

Cadmium and Lead Distribution in Marine Soil Sediments, Terrestrial Soil, Terrestrial Rock, and Atmospheric Particulate Matter around Split, Croatia

The distributions of cadmium and lead in marine sediments, surrounding soil, stones, and atmospheric particulate matter were determined at different locations in Split, Croatia. The determination of cadmium and lead was performed by flame atomic absorption spectrometry whereas atmospheric particulate matter samples were analyzed by inductively coupled plasma–optical emission spectrometry. Cadmium concentrations in the stones and soil were between 0.2 to 0.6 µg g−1 and 0.2 to 0.9 µg g−1. The concentration in the atmospheric particulate matter were <0.2 µg m−2 d−1(detection limit) to 1.4 µg m−2 d−1. Lead concentrations in marine sediments, stones, soil, and atmospheric particulate matter ranged from 31.2 to 144.4 µg g−1, 9.3 to 29.4 µg g−1, 11.3 to 66.1 µg g−1, and 0.5 to 241.4 µg m−2 d−1, respectively. The relationship between determined parameters was established using principal component analysis and the results are in agreement with the assumption that anthropogenic sources play important roles for lead and cadmium distribution.

Real-time monitoring of “self-oxidation” of cysteine in presence of Cu2+ : Novel findings in the oxidation mechanism

A novel approach for investigation of a mechanism and rate of “self-oxidation” of cysteine in the presence of Cu2+ is presented. Continuous monitoring was performed using simple, low-cost, and widely available commercial ion-selective electrode for Cu2+. Presented procedure provides a complete real-time picture of overall oxidation process and has revealed a sequentially organized process, with the domination of certain reactions in each stage. A plausible mechanism, in the light of the previously reported explanation, has been proposed to account for the experimental results together with an adequate scheme of the overall process. The dependence of both the pH (measurements were performed at pH 5, 7, 8) and the concentration of the initially present Cu2+ is presented and discussed. Additionally, information into the process was collected by experiments performed in oxygen-free atmosphere and changes in the mechanism of oxidation, at weakly alkaline pH values, were observed. Information presented in this study can be utilized in advanced biochemical monitoring systems, when considering the importance of the position of cysteine and cysteine containing peptides in metabolic processes.Graphical abstract

Electroanalytical Methods for Determination of Sunset Yellow— a Review

The review highlights the electroanalytical methods used for the determination of the artificial dye Sunset Yellow, one of the most frequently used azo–dyes, with a very wide field of the application during the last two decades. As azo–dyes may have detrimental effects on living organisms, their content in food must be strictly controlled. Despite other analytical methods for determination of azo– dyes, the electroanalytical methods, especially voltammetric methods, offer many other advantages besides high sensitivity, selectivity, and reproducibility – e.g., less time for sample preparation and determination, low investment and running cost, electrode miniaturization and modifications, as well as use of eco–friendly materials. This critical review focuses on the electrode materials and their modifications since they are the deciding factor for a successful voltammetric determination of Sunset Yellow. In addition to this, the reaction mechanisms for determination and analytical performance are also presented in the paper.