The development of industry, agriculture, transport and urbanization has resulted in excessive emissions of heavy metals into the environment, which due to their bioaccumulative properties express negative effects on the environment and living organisms as a whole. In this work the presence of heavy metals in the soil samples of the urban area of Lukavac and Kalesija municipality and their effect on the health of the population were studied. Soil samples were collected in October 2017 at five locations in the urban area of Lukavac municipality and two urban locations in Kalesija municipality. Concentrations of chromium (Cr) copper (Cu), cobalt (Co), nickel (Ni), cadmium (Cd), lead (Pb), manganese (Mn), iron (Fe) and zinc (Zn) in the soil samples were determined. The results indicated that in some locations the concentration of heavy metals exceeded the maximum permissible concentration (MPC). MPC value for chromium was exceeded at four locations in the urban area of Lukavac, whereas MPC value for nickel and cadmium was exceeded at all locations. In Kalesija, MPC value was exceeded for chromium and nickel at one location, while cadmium MPC was exceeded at both locations. The negative impact of heavy metals on the health of the population is the cause of many malignant diseases. Statistical analysis of the number of patients with malignant diseases in the area of the Lukavac and Kalesija revealed significantly higher prevalence of malignant diseases of the lungs, breast, skin and cervix in the Lukavac (p<0,05) in comparisson to Kalesija municipality.

Complex formation equilibria of aluminum(III), gadolinium(III), and yttrium(III) ions with the fluoroquinolone antibacterials moxifloxacin, ofloxacin, fleroxacin, lomefloxacin, levofloxacin, and ciprofloxacin were studied in aqueous solution by potentiometric and spectroscopic methods. The identity and stability of metal–fluoroquinolone complexes were determined by analyzing potentiometric titration curves (310 K, μ = 0.15 M NaCl, pH range = 2–11, CL/CM = 1 : 1 to 3 : 1, CM = 1.0 mM) with the aid of Hyperquad2006 program. The main species formed in the system may be formulated as MpHqLr (p = 1, q = −2 to 2, r = 1–3, L = fluoroquinolone anion, logarithm of overall stability constant, log βp,q,r = in the range ca. −10 to 45). The stability of complexes is mostly influenced by metal ion properties (ionization potential, ionic radius) indicating partial ionic character of the coordination bond. The complexes were also characterized by spectroscopic measurements: spectrofluorimetry, 1H-NMR, and ESI-MS. Fluorimetric data were evaluated with the aid of HypSpec2014 and indicated the formation of MLr (r = 1–3) complexes with cumulative conditional stability constants significantly lower than the thermodynamic ones. NMR and MS data corroborate potentiometrically determined speciation. Calculated plasma mobilizing capacity of the ligands generally follows the order levofloxacin > moxifloxacin > ciprofloxacin at concentration levels of the ligands higher or equal to ca. 10−4 M.

The speciation of Al3+, Gd3+ and Y3+ ions in human plasma has been studied by computer simulation using the program HySS2009. A literature computer model of blood plasma was updated and comprised 9 metals, 43 ligands and over 6100 complexes. To this model critically evaluated data of Al3+, Gd3+ and Y3+ constants with blood plasma ligands have been added. Low molecular mass (LMM) speciation of Al3+ ion strongly depends upon the chosen equilibrium model of the metal - phosphate and metal - citrate systems. The obtained computer simulation of LMM speciation data of Al3+ ion were: AlPO4Cit (40.7%), AlPO4CitOH (22.9%), AlCitOH (19.2%) and AlPO4(OH) (12.7%) (% of total LMM Al species pool); for Gd3+ ion: GdAspCit (30%) and GdCit(OH)2 (20%) (% of total [Gd]) and for Y3+ ion: YCit (48%), Y(CO3)2 (32%) and Y(CO3) (11%) (% of total [Y]). Citrate appears as the important binding and mobilizing ligand for all examined ions, while the dominating species are the ternary ones.

Solutions of AlCl3 were analyzed at concentrations from 0.03 to 5.0 mmol dm-3 and pH from 3.5 to 6.0 using an electrospray ionization quadrupole mass spectrometer (ESI-Q-MS). Mass spectral data were compared with those obtained by 27Al nuclear magnetic resonance (NMR) spectroscopy and potentiometry. Hydrolytic aluminum species were present in solution mainly as +1 positively charged complexes with n coordinated water molecules (n = 1-3). Analysis revealed that polymeric complexes of +2 and +3 charges (at higher Al concentrations and pH > 4) contained coordinated chloride ions. The general appearance of the mass spectra is dependent on instrumental parameters such as solvent flow rate, ionization source temperature and cone and capillary voltages. Thus, fine tuning of the instrument with respect to these parameters was performed. Sample cone voltages not exceeding 50 V led to the best agreement between potentiometric, 27Al NMR and mass spectral data.

The complex formation equilibria between gadolinium(III) ion and moxifloxacin (MOXI) were studied in aqueous solutions. The investigations were performed by glass electrode potentiometric (ionic medium: 0.1mol dm-3 LiCl, 298 K) and UV spectrophotometric measurements. In the concentration range 0.5≤ [Gd3+] ≤ 1.0; 1.0 ≤ [MOXI] £ 2.0 mmol dm-3 ([MOXI]/[Gd] = 1: 1to 5: 1) and pH between 2.5and 9.0, gadolinium(III) and moxifloxacin form the complexes of the composition: Gd(HMOXI)3+, Gd(HMOXI)23+, Gd(HMOXI)33+, Gd(HMOXI)2MOXI2+, Gd(HMOXI)(MOXI)2+, Gd(MOXI)3. The stability constants of the complexes were calculated with the aid of Hyperquad2006 suite of programs, taking into account the hydrolysis of Gd3+ ion and protonation of moxifloxacin anion. The possible structure of the complexes, in solution, and their formation mechanism is suggested. The effect of moxifloxacin, and for comparison purpose, DTPA on gadolinium(III) plasma speciation was evaluated by computer simulation.

The protonation and complex formation equilibria in aluminium(III) + ofloxacin (Hoflo) solutions in the presence of either cetyltrimethylammonium bromide (CTAB, 5.0 mmol L−1), cetylpyridinium chloride (CPCL, 2.0 mmol L−1) or polyethylene glycol tert-octylphenyl ether (triton X-100, 1.0 mmol L−1) have been studied by glass-electrode potentiometric measurements in a 0.1 mol L−1 LiCl ionic medium at 298 K. In the concentration range 0.4 ≤ CAl ≤ 1.0 mmol L−1, with a ligand to metal ratio of 1 : 1 to 5 : 1, and 3.5 ≤ −log h ≤ 7.0, a non-linear least squares treatment of the data indicate that in all studied systems the complex Al(oflo)2+ forms as the dominating one. Its overall stability constant (log β) is in the range 10.37–11.90 (depending on the type of surfactant), which is about 1 log unit higher than in the absence of surfactants. The formation of bis(ofloxacinato) and mixed protonated or hydrolytic complexes is largely suppressed in the presence of surfactants. The adsorption of ofloxacin on aluminium ...

The protonation, hydrolytic and complexation equilibria in aluminum(III) + ofloxacin (Hoflo) solutions in the presence of sodium dodecylsulphate (SDS) have been studied by glass electrode Potentiometrie measurements in 0.1 mol/dm LiCl ionic medium, at 298 K. The results obtained indicate that in the presence of SDS the beginning of hydrolysis of Al ion shifts toward lower pH for approximately 1 pH unit in comparison with that in the absence of SDS. The obtained experimental data were consistent with the formation of only AI-(OH)4 complex with considerably higher stability constant (log ß3 .4 = 11.39 ± 0.05) than that in the absence of surfactant (log ß3 .4 = 13.73 ± 0.04). Protonation constants of ofloxacin anion (ofloxacinate, oflo) are significantly higher in the presence of SDS. In Al + oflo + SDS solutions, in the concentration ranges 0.6 < [Al] < 2.5 mmol/dm'; 0.6 < [oflo] < 7.5 mmol/dm and 3.0 < pH < 5.0 the formation of the following complexes, with their respective stability constants (logßp q r), was observed: Al(oflo) (10.28 ± 0.08); Al(OH)oflo (3.04 ± 0.10) and Al2(OH),oflo (4.56 ± 0.06) Introduction Ofloxacin (9-f luoro-3-methyl-10-(4-methyll -p iperazinyl) -7-oxo-2,3-dihydro-7H-pyr ido-( l ,2 ,3-de) l ,4benzoxazine-6-carboxylic acid), H(oflo), belongs to the class of fluorinated 4-quinolone antibiotics which finds use in the treatment of urinary and respiratory infections. It exhibits strong activity against Gram-negative and some Gram-positive bacteria, though many anaerobic strains are resistant. The mechanism of its action is based on inhibition of bacterial DNA gyrase thus, interfering with normal cell replication [1,2],