7 research outputs found
Ispitivanje kvaliteta podzemnih, izvorskih i rečnih voda sa područja jugoistočne Srbije
The study deals with mineral characterisation 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 (ICPAES) technique. The study area was in the Southern Serbia, and included slopes of Rtanj, Ozren, Bukovik, Vrdenik and Čemernik 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 168.3, 8.10 and 14.9 μg 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.Ovaj rad predstavlja analizu kvaliteta prirodnih voda iz jugoistočne Srbije. Sadržaj arsena, aluminijuma, kalcijuma, kadmijuma, kobalta, hroma, bakra, gvožđa, kalijuma, magnezijuma, mangana, natrijuma, nikla, olova i cinka je određivan u izvorskim i podzemnim vodama, kao i u rečnoj vodi. Analiza navedenih elemenata je izvedena ICP-AES tehnikom. Analizirani su uzorci voda iz oblasti jugoistočne Srbije, uključujući područja planine Rtnja, Ozrena, Bukovika, Vrdenika i Čemernika, kao i područje doline reke Južne Morave. Određeni sadržaji analiziranih elemenata su poređeni sa važećim pravilnicima Republike Srbije i preporukama Svetske zdravstvene organizacije (SZO). Visoki sadržaj makro-elemenata, odnosno kalcijuma, magnezijuma i kalijuma uočeni su u izvorskim i nekoliko uzoraka podzemnih voda, što može biti posledica direktnog uticaja magmatskih stena. Pojedini uzorci voda su sadržali nešto više sadržaje gvožđa, mangana i bakra u koncentraciji do 168,3, 8,10 i 14,9 μg dm-3, redom, ali u granicama propisanim Pravilnikom i u skladu da preporukama SZO. Ostali teški metali nisu detektovani u ispitivanim uzorcima. Na osnovu dobijenih rezultata se može zaključiti da testirani uzorci podzemnih i izvorskih voda imaju značajan potencijal u smislu proizvodnje flaširane vode, uz neophodna dodatna istraživanja. Dodatna istraživanja bi trebalo usmeriti na kompletnu hemijsku analizu i ispitivanje fizičkih i mikrobioloških karakteristika uzoraka voda. Pored toga, neophodno je sprovesti sistematsko hidrogeološko ispitivanje izdašnosti podzemnih i izvorskih voda tokom svih godišnjih doba. U međuvremenu treba preduzeti mere predostrožnosti kako bi se ovi vodeni resursi zaštitili i očuvali
Chronopotentiometric stripping analysis of selenium using mercury film electrode
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 1.15μg/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
Determination of As(III) and As(V) in waters by chronopotentiometric stripping analysis
Arsenic is a naturally occurring toxic and carcinogenic element. The degree of the toxicity depends on its chemical form and the concentration. Application of a sensitive, selective, simple and rapid method for detection and monitoring of different oxidation states of arsenic in waters is of great importance because main route of population exposure is through drinking water. In this work chronopotentiometric stripping analysis (CSA) was used for the determination of As(III) and As(V) in tap, well, river and rain waters from Vojvodina (Serbia). Gold film electrode on the glassy carbon support was used as the working electrode. The experimental parameters of the technique were investigated and optimized. Detection limit of the method for the electrolysis time of 600 s was 2 μg/dm3 of As(III)
Determination of sensitivity limit in quantative analysis of polycyclic aromatic hydrocarbons by Gc-ms
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
Chemometric analysis of metal contents in different types of chocolates
The relationships between the contents of various metals (Cu, Ni, Pb and Al)
in 38 different milk chocolate samples were studied using a chemometric
approach. The chemometric expressions were generated using a training set of
25 chocolate samples and the predictive ability of the resulting models was
evaluated against a test set of 13 chocolate samples. The chemometric
analysis was based on the application of multiple linear regression analysis
(MLR). MLR was performed in order to select the significant models for
predicting the metal contents. The MLR equations that represent the content
of one metal as a function of the contents of other metals were established.
High agreement between experimental and predicted values, obtained in the
validation procedure, indicated the good quality of the models. It enables
the researchers to establish reliable relationships between the contents of
various metals which can be used for their prediction in different types of
chocolate prior to their analysis. This can reduce the trial-and-error
element and experimental costs in the production.[Projekat Ministarstva nauke
Republike Srbije, br. 31055, br. 172012 i br. 172014
Determination of polycyclic aromatic hydrocarbons in soil by gas chromatography-mass spectrometry
Polycyclic aromatic hydrocarbons (PAHs) were determined in soil samples from forty different locations in Vojvodina. The samples were Soxhlet extracted cleaned-up and analyzed using gas chromatography-mass spectrometry (GC-MS) in the selected ion monitoring mode (SIM). Each PAH was separately quantified using an eight-point calibration of mixed standard solutions in the range between 0.25 and 10 μg/cm3. The sum of the 16 US Environmental Protection Agency PAHs analyzed in the soil samples varied from 0.043 to 1.362 mg/kg of dry soil