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Abstract: In general, chromium is existed in stable oxidation states, such as Cr(III) and Cr(VI) in the environment. While a certain amount of Cr(III) is required for human metabolism, Cr(VI) is known to have toxic and carcinogenic effects for all living species. Chromium compounds are widely used in different fields, such as electroplating, dyeing, photographic and textile industries. Owing to this reason, it and its compounds can easily interfere with the water resources. Because of differences in toxicity, it is important to develop a sensitive analytical method for the speciation, preconcentration and determination of chromium species in the water resources. In this work, speciation and preconcentration of Cr(III) and Cr(VI) were performed using Amberlite CG-120 resin before detection step by flame atomic absorption spectrometry. The experimental conditions for model solutions were optimized so that Cr(III) was adsorbed in a column while Cr(VI) was not. To perform this, some experimental parameters, such as pH, eluent’ type/concentration/flow rate, sample solution flow rate and adsorbent amount were optimized. Furthermore, Cr(VI) was reduced to Cr(III) to determine total chromium. Then, Cr(VI) was calculated by the differences between total chromium and Cr(III). The limit of detection (3 s) and preconcentration factor were found to be 0.3 μg L–1and 600, respectively. This proposed method was successfully applied for the determination of inorganic chromium species in the different spring waters supplied from Isparta province (Eyüpler Village), Burdur province (Ağlasun County), the commercial drinking water samples purchased from local market in Burdur province, and the waste water supplied from Isparta province (Suleyman Demirel Organized Industrial Region) at Turkey. The accuracy of the method was successfully checked by certified reference material (TMDA-70.2 Ontario Lake water) at 95% confidence level.

In this study, Amberlite CG-120 adsorbent was used for the separation/preconcentration of Ni(II) ions in commercial drinking, spring and lake water samples before detection by flame atomic absorption spectrometry. Various optimization parameters for Ni(II) determination, such as pH, eluent type and concentration, sample and eluent flow rates, amount of adsorbent, were investigated to obtain better sensitivity, accuracy, precision and quantitative recovery. Furthermore, the interference effects of some ions on the recovery efficiency of Ni(II) were also investigated. The optimum experimental parameters were obtained in the case of pH 1; 5 mL of 4 mol L−1HCl for eluent and 0.3 g for the adsorbent amount. The limit of detection was found to be 0.58 μg L−1and linearity ranged from 5 to 50 μg L−1. The accuracy of the method was tested by the certified reference material of TMDA-70.2 Ontario Lake Water at a 95% confidence level.

In this study, new luminescent coordination polymers containing cadmium ions, 1,10-phenanthroline and benzene-1,3,5-tricarboxylic acid ligands were synthesised under hydrothermal conditions. The structure of the synthesised Cd(II) CPs was investigated by X-ray diffraction, scanning electron microscope, matrix-assisted laser desorption ionisation mass spectrometry, elemental analysis, thermogravimetric analysis and Fourier transform infrared spectroscopy. In addition, the adsorption and sensing applications of Cd(II) CPs were investigated. The removal of diclofenac, an organic micropollutant, from aqueous systems was investigated for the adsorption application of Cd(II) CPs. The adsorption isotherms fitted the Langmuir model better than the Freundlich model. Adsorption equilibrium was reached after 240 min at pH 6.5 and 298 K, resulting in a maximum adsorption capacity of 1822 mg/g. In the other analytical application of Cd(II) CPs, the detection of Cu2+and Ni2+cations in aqueous medium was investigated based on their fluorescence properties. According to the results Cd(II) CPs have better sensitivity and selectivity. The fluorescence intensity of Cd(II) CPs decreased linearly due to the quenching mechanism. The KSVvalues were calculated to be 1.82 × 108M−1for Cu2+and 8.2 × 108M−1for Ni2+. The limits of detection Cu2+and Ni2+cations for Cd(II) CPs were calculated to be 2.78 × 10−8and 6.15 × 10−9M, respectively. The detection of Cu2+and Ni2+ions was performed with a fast response, a wide linear range and a very low detection limit and could be used on real water samples without any matrix interference.