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"The potential to determine the gastric bioaccessibility (BA) of Tl, As, Pb(II), Cu(II), Zn(II) and Cd(II) using a simple extraction method was evaluated in selected samples from soils contaminated by mining and metallurgical wastes. The SBRC (Solubility and Bioavailability Research Consortium) test was used as a gastric BA comparative method versus a simple extraction method using HCl solution at pH 1.5. High cor- relations (r ≥ 0.98, p ˂ 0.01) were obtained between the two extraction methods for Cd(II), Cu(II), Tl and Zn(II), in all samples investigated. Bioaccessible As, however, only showed a high correlation in the metallurgical area (r = 0.99, p ˂ 0.01), but not in the mining area (r = 0.88, p ˂ 0.01). Conversely, Pb(II) showed a better correlation in samples from the mining area (r = 0.99, p ˂ 0.01) than in those of the metallurgical area (r = 0.92, p ˂ 0.01). Three experimental conditions of the extraction procedures ensured the high correlations observed: (1) Maintaining a strict pH control of 1.5 (± 0.1), (2) a stirring time of 1 h (± 1 min), and (3) filtration of the extraction mixture through a membrane of small pore size (0.05 µm). Bioaccessible Tl was detected in all samples, a fact that has not been reported before in these environments, and alerts to potential health risks not previously identified."

The bis-chelates of zinc (7–11) and cadmium (12–17) with general formula [M{R2P(X)NC(Y)NR′-η2-X,Y}2] were obtained from ligands 1–6 (iPr2P(X)NHC(Y)NC4H8: 1: X = S, Y = S; 2: X = S, Y = O; 3: X = O, Y = S; 4: X = S, Y = Se, 5: X = Se, Y = S; Ph2P(X)NC(Y)NC5H10: 6: X = S, Y = S). 4 and cadmium complex 15 are the first examples of this ligand system with carbon-bonded selenium as a donor atom. All the compounds were characterized by FTIR and multi-nuclear NMR spectroscopies, and microanalysis. The molecular structures of complexes 1, 7, 8, 11, and 15 were elucidated by single crystal X-ray diffraction. Thermal gravimetric analysis (TGA) and thermolysis experiments were carried out for the metal complexes. Selected pyrolysis residues were analyzed by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and X-ray powder diffraction (XRPD). Remarkably, cadmium complex 13 gave a few crystals of CdS encrusted on the surface of CdO. Preliminary studies using the O,S-mixed cadmium complexes (13 and 14) as single source precursors (SSPs) were carried out for the deposition of thin films via AA-CVD. The results show that CdS films are obtained from both complexes, and in the case of 14 (the complex containing a PO fragment), persistent high carbon content was detected.