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Title:Določevanje kroma(VI) v mikrofluidnem sistemu z optotermično mikroskopsko detekcijo : /
Authors:Malovrh, Sara (Author)
Franko, Mladen (Mentor) More about this mentor... New window
Files:.pdf Sara_Malovrh.pdf (1,62 MB)
 
Language:Slovenian
Work type:Bachelor thesis/paper (mb11)
Tipology:2.11 - Undergraduate Thesis
Organization:FZO - Faculty of Environmental Sciences
Abstract:Krom (Cr) spada med kovinske onesnaževalce, katerega učinek na okolje je močno odvisen od oksidacijskega stanja. Za ljudi je problematična njegova šestvalentna oblika Cr(VI), ki je rakotvorna, zato je potreba po hitri detekciji Cr(VI) velika. V diplomski nalogi smo preverjali točnost detekcije Cr(VI) ob prisotnosti različnih presežkov motečih elementov kot so šestvalentni molibden (Mo(VI)), petvalentni vanadij (V(V)), trivalentno železo (Fe(III)) in dvovalentno živo srebro (Hg(II)). Po kolorimetrični reakciji čistega standarda Cr(VI) in raztopin motečih elementov z difenilkarbazidom (DPC) smo za meritev uporabili spektrofotometrijsko metodo (SPEC) in mikroskopijo s toplotnimi lečami v mikrofluidnem sistemu za pretočno injekcijsko analizo (µFIA - TLM). Rezultati so pokazali, da največjo napako pri meritvah povzroči prisotnost V(V). Izvedli smo tudi študijo razpada preiskovanih kompleksov Cr-DPCO, Mo-DPCO, V-DPCO, Fe-DPCO in Hg-DPCO v odvisnosti od moči vzbujevalnega laserja v mikrofluidnem TLS sistemu (TLM). Dokazali smo, da je železov kompleks stabilnejši od ostalih preiskovanih ionskih kompleksov, ki so znani kot fotolabilni. Z izračunom spodnje meje določevanja (LOD) za SPEC in TLM metodo smo pokazali, da je TLM, zaradi nižje LOD vrednosti primernejša metoda za detekcijo nizkih koncentracij Cr(VI) v vzorcu. Analiza vzorcev iz Soče in Ljubljanice je prikazala sliko realnega stanja v, potencialno s Cr(VI), onesnaženi reki.
Keywords:spektrofotometrija, TLS, TLM, fotolabilnost, moteči elementi
Year of publishing:2015
Source:Nova Gorica
COBISS_ID:4046075 Link is opened in a new window
URN:URN:SI:UNG:REP:FAPXVP6L
Views:3329
Downloads:181
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Secondary language

Language:English
Title:DETERMINATION OF CROMIUM(VI) IN A MICROFLUID SYSTEM WITH OPTOTHERMAL MICROSCOPIC DETECTION : /
Abstract:Chromium is one of metal pollutants, whose effect on the environment strongly depends on its oxidation state. Its most harmfull state for people is hexavalent state Cr(VI) which is carcinogenic. In our study we were checking its determination at presence of different concentration of interfering ions V(V), Mo(VI), Fe(III) and Hg(II). After colorimetric reaction of standard Cr(VI) and other interference elements with diphenylcarbazide (DPC) we measured samples with spectrophotometric method (SPEC) and thermal lens microscopy in microfluidic flow-injection system (μFIA - TLM). The highest influences on detection of Cr(VI) were measured in presence of V(V). We also studied degradation of Cr-DPCO, Mo-DPCO, V-DPCO, Fe-DPCO and Hg-DPCO in dependence of input laser power in TLM system. We proved that Fe-DPCO complex is more stable than other reasurched ion complexes, all known as fotolable. The calculated limit of detection (LOD) for SPEC and microfluid TLS (TLM) shows, that TLM is more appropriate method for detection of lower Cr(VI) concentration in samples. Analysis of real water samples from Soča and Ljubljanica rivers show the real state of rivers, which potentially could be polluted by Cr(VI).
Keywords:spectrophotometry, TLS, TLM, photolable, interference elements


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