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Cilj istraživanja ovog rada je primena novih sorbenasa u disperzivnoj mikroekstrakciji čvrstom fazom (D-µ-SPE) kao tehnikom pripreme uzoraka vode za analizu 16 prioritetnih PAU gasnom hromatografijom sa masenom spektrometrijom (GC-MS). D-µ-SPE se pokazala kao efikasna i ekonomična tehnika pripreme uzoraka vode pri čemu se troši mala količina rastvarača za ekstrakciju i koristi jeftin pribor za pripremu uzoraka koja traje 7 minuta (uključujući pripreme standardnih rastvora i odmeravanje sorbenasa). Niske vrednosti granice detekcije i kvantifikacije, prihvatljive vrednosti tačnosti i preciznosti predloženu metodu analize 16 prioritetnih PAU kvalifikujuje za rutinsku analizu vode.

Metals, whether from natural and anthropogenic sources, can migrate between different parts of the environment and accumulate in flora and fauna, and in this way can finally reach people through the food chain. The possibility of contamination of plants by metals limits their use both in the pharmaceutical and food industry, because the increased concentration of some metals can have a negative impact on the health of humans and animals. The medicinal herbaceous species Seseli pallasii Besser is used in traditional medicine, but also as a spice in nutrition, so the assessment of the presence of metals is essential to ensure its safe application. For the estimation of the contents of the micro (Al, B, Ba, Co, Cu, Fe, Mn, V, Zn) and macroelenates (Ca, K, Mg and Na) in vegetative parts of plant species Seseli pallasii Besser (root, leaf, flower and fruit) from Southeast Serbia the method of induced coupled plasma with optical emission spectrometry (ISP-OES) was applied. The content of micro and macroelements in the studed medicinal plant species is below the recommended limits, which confirms that Seseli pallasii Besser can be safely used in traditional medicine and nutrition. Metali, bilo da su iz prirodnih i antropogenih izvora, mogu da migriraju između različitih delova životne sredine i akumuliraju se u floru i faunu, i na taj način konačno mogu dospeti do ljudi putem lanca ishrane. Mogućnost kontaminacije biljaka metalima ograničava njihovu upotrebu kako u farmaceutskoj tako i u prehrambenoj industriji, jer povećana koncentracija nekih metala može imati negativan uticaj na zdravlje ljudi i životinja. Lekovita biljna vrsta Seseli pallasii Besser koristi se u tradicionalnoj medicini, ali i kao začin u ishrani, pa je procena prisustva metala od suštinske važnosti kako bi se osigurala njena bezbedna primena. Za procenu sadržaja mikro (Al, B, Ba, Co, Cu, Fe, Mn, V, Zn) i makroelenenata (Ca, K, Mg i Na) u delovima biljke S. pallasii Besser (koren, list, cvet i plod) iz jugoistočne Srbije korišćena je metoda indukovano spregnute plazme sa optičkom emisionom spektrometrijom (ISP-OES). Sadržaj mikro i makroelemenata u proučavanoj lekovitoj biljnoj vrsti je ispod preporučenih granica, što potvrđuje da se S. pallasii Besser može sigurno koristiti u tradicionalnoj medicini i ishrani.

The aim of this paper is to determine the efficiency of D-µ-SPE with application of novel sorbents as a technique for sample preparation of water samples for the analysis of 16 priority PAHs by GC-MS. The sample preparation technique proved to be very fast, efficient and economical. The results of the proposed method demonstrate that this technique can be applied for routine analysis of PAHs in water. The advantages of this method are characterized by low values of limit of detection (from 0.147 ppb for benzo [a] anthracene to 0.784 ppb for naphthalene) and the limit of quantification (0.717 ppb for naphthalene to 9.459 ppb for benzo [k] fluorantene. Ciljevi istraživanja ovog rada su određivanje efikasnosti disperzivne mikroekstrakcije čvrstom fazom (D-µ-SPE) kao tehnike pripreme uzoraka vode za analizu 16 prioritetnih PAU gasnom hromatografijom sa masenom spektrometrijom, primenom novih sorbenasa. Tehnika pripreme uzoraka pokazala se kao veoma brza, efikasna i ekonomična. Rezultati predložene metode dokazuju da se ova tehnika može primeniti kao tehnika pripreme uzoraka za rutinsku analizu PAU u vodi. Prednosti ovakovog načina analize odlikuju se niskim vrednostima granice detekcije (od 0.147 ppb za benzo[a]antracen do 0.784 ppb za naftalen) i granice kvatifikacije (0.717 ppb za naftalen do 9.459 ppb za benzo[k]fluoranten).

The aim of this paper is application of novel sorbents in dispersive micro solid phase extraction (D-μ-SPE) as a technique for sample preparation of water, for the analysis of 16 PAHs by gass chromatography - mass spectrometry (GC-MS). D-μ-SPE proved to be an effective technique consuming a small amount of the solvent for the analysis. D-μ-SPE is characterized by its rapidity (7 minutes per sample including all preparation of standard solutions and measuring of sorbents) and cheapness as well. Low values of the detection limit and limit of quantification, acceptable accuracy and precision values propose this method for routine water analysis for the determination of PAHs. Cilj istraživanja ovog rada je primena novih sorbenasa u disperzivnoj mikroekstrakciji čvrstom fazom (D-µ-SPE) kao tehnikom pripreme uzoraka vode za analizu 16 prioritetnih PAU gasnom hromatografijom sa masenom spektrometrijom (GC-MS). D-µ-SPE se pokazala kao efikasna i ekonomična tehnika pripreme uzoraka vode pri čemu se troši mala količina rastvarača za ekstrakciju i koristi jeftin pribor za pripremu uzoraka koja traje 7 minuta (uključujući pripreme standardnih rastvora i odmeravanje sorbenasa). Niske vrednosti granice detekcije i kvantifikacije, prihvatljive vrednosti tačnosti i preciznosti predloženu metodu analize 16 prioritetnih PAU kvalifikujuje za rutinsku analizu vode.

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97 92 M30 M33 In this paper we present the development of an online course at the edX BAEKTEL platform named “Lexical Recognition in the Natural Language Processing (NLP)”. It is based on the course of the same name for PhD studies at the University of Belgrade, Faculty of Philology. There are not many courses in Computational Linguistics (CL) on OER platforms, and there is none in Serbian either for CL or NLP. We have developed this course in order to improve this situation as it can prove useful both for linguists working in corpus linguistics and computer scientists developing NLP applications. The participant will become familiar with the use of Unitex, the corpus processing system for which many valuable resources for Serbian were already developed. This course covers a broad range of topics such as pattern recognition using regular expressions, electronic dictionaries, Finite-state automata and transducers, etc. Within the course different didactic forms were used including text, video tutorials and some useful practical exercises that should facilitate the understanding of the course subject and enable the participants to easily acquire the necessary knowledge to use the existing resources for NLP for Serbian and to develop new ones.