The study deals with mineral characterization of natural waters from South-East Serbia. The contents of aluminium, arsenic, calcium, cadmium, cobalt, chromium, cooper, iron, potassium, magnesium, manganese, sodium, nickel, lead and zinc were analysed in spring, ground and river waters by inductively coupled plasma-atomic emission spectrometry (ICP-AES) technique. The study area was in the Southern Serbia, and included slopes of Rtanj, Ozren, Bukovik, Vrdenik and Cemernik mountains, and the valley of South Morava. Obtained contents were compared with Serbian regulations on the quality of water for human use, and directive of World Health Organization (WHO) for maximum allowed concentrations of chemical substances. High contents of macro-elements, namely calcium, magnesium and potassium, were detected in several spring and ground water samples which are believed to be due to direct influence of rock minerals. Some water samples contained iron, manganese and copper in concentration up to 84.2 ?g dm-3, 8.10 ?g dm-3 and 14.9 ?g dm-3, respectively, but within the permissible limits. Other heavy metals were not detected in analysed samples. Based on the derived results, tested ground and spring water samples have significant potential to be used as sources for the production of bottled water, but further investigations are necessary. Additional investigations have to be focused on complete physical, chemical and microbiological assessments of water resources. Systematic hydrogeological assessment also should be performed in all seasons. In the meantime, precautionary measures should be immediately taken to protect and preserve these water resources. [Projekat Ministarstva nauke Republike Srbije, br. TR 31014]

The limit of detection (LOD) and the limit of quantitation (LOQ) for 16 individual PAHs from the Environmental Protection Agency (EPA) list (naphthalene, acenaphthylene, acenaphtene, fluorene, phenanthrene antrachene, fluoranthene, pyrene, benzo(a)anthracene, chrysene benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h) anthracene, benzo(g,h,i)perylene and indeno(1,2,3-cd)pyrene) were determined by Gas Chromatography – Mass Spectrometry (GC-MS). Determination was performed by SCAN (digital linear scanning) and SIM (selected ion monitoring) techniques preceded by the optimization of the experimental factors. The limit of detection obtained by the SCAN technique was in the range of 0.179 – 15.236 ng, and the quantitation limit in the range of 1.017 – 50.788 ng. SIM technique enabled LOD and LOQ in the range of 0.036 – 13.886 pg and 0.119 – 46.287 pg respectively

The influence of the most important experimental factors in chronopotentiometric stripping analysis (CSA) of selenium( IV) using mercury film working electrode was examined. Interferences of copper, iron and lead were investigated as well. The possibility of avoiding prolonged deaeration of the solution was examined by applying medium exchange modification of the technique, where the dissolution of the deposit was performed in calcium-chloride solution. Detection limits obtained for the modification of the CSA with prior deaeration and medium exchange modification were 0.4 μg/dmJ and 1.15μg/dmJ, respectively. Accuracy of the defined techniques has been confirmed by analysing reference material (RM 8436) -wheat durum flour. The results obtained by applying both modifications of the technique showed a very good agreement of total selenium content with declareted value