Application of thermal analysis in the selection of polymer components used as a binder for metal injection moulding of Co–Cr–Mo alloy powder

Studies on the separation of calcium and neodymium ions by using ethylenediaminetetraacetic acid (H₄EDTA) as a complexing agent were performed. This research was undertaken due to the possibility of H₄EDTA applying to isolate rare earth elements from the solution after acidic leaching of phosphogypsum, and because of the similarity of coordination properties of calcium and lanthanides ions. The experiment was carried out in model systems containing Ca²⁺ and Nd³⁺ ions in hydrochloric or sulphuric acid. The content of calcium and neodymium metals, phase composition and thermal behaviour of the obtained products were determined by ICP-OES, FTIR, XRD and TG/DTA techniques. During the separation process, the precipitates of a light pink colour were obtained. The obtained results show that the neodymium ethylenediaminetetraacetate has been successfully formed and that the isolation of neodymium ions was more efficient in chloride medium. The precipitate included 72.2 and 3.9% of the starting amount of neodymium and calcium used in the experiment, respectively. However, in sulphates medium, these amounts were equal to 73.8 and 53.5%, respectively. Moreover, the obtained powder was polluted with sulphates. The addition of the EDTA in an excess (15%) contributed only to an increase in calcium content in the complex.

     

Analytical methods for determination of benzodiazepines. A short review

Benzodiazepines (BDZs) are generally commonly used as anxiolytic and/or hypnotic drugs as a ligand of the GABA_A-benzodiazepine receptor. Moreover, some of benzodiazepines are widely used as an anti-depressive and sedative drugs, and also as anti-epileptic drugs and in some cases can be useful as an adjunct treatment in refractory epilepsies or anti-alcoholic therapy. High-performance liquid chromatography (HPLC) methods, thin-layer chromatography (TLC) methods, gas chromatography (GC) methods, capillary electrophoresis (CE) methods and some of spectrophotometric and spectrofluorometric methods were developed and have been extensively applied to the analysis of number of benzodiazepine derivative drugs (BDZs) providing reliable and accurate results. The available chemical methods for the determination of BDZs in biological materials and pharmaceutical formulations are reviewed in this work.      

New electrode material GCE/AgNPs-D3 as an electrochemical sensor used for the detection of thallium ions

Optimal working parameters for the innovative electrode GCE/AgNPs-D3 were determined and the selectivity was assessed. The stripping anodic peak current of thallium characterized in linearity over range from 4.9 ⋅ 10⁻⁸ to 4.9 ⋅ 10⁻⁷ mol ⋅ dm⁻³, with LOD = 7.16 ppb (3.5 ⋅ 10⁻⁸ mol ⋅ dm⁻³). Furthermore, the new electrode showed more than sevenfold improvement in the thallium current signal compared to the unmodified electrode GCE. High selectivity was achieved using EDTA disodium salt as a complexing agent for other metals.