Direktna i indirektna fotoliza fumonizina u vodenoj sredini kao i procena njihove toksičnosti

Abstract

Fumonizini B serije (B1, B2 i B3) se najčešće nalaze u žitaricama ihrani od žitarica, ali je potvrđeno njihovo prisustvo i u različitimvrstama voda. Fumonizini mogu negativno uticati na zdravlje ljudi iživotinja te se teži iznalaženju efikasne metode za njihovo uklanjanje.U tom cilju, ispitana je efikasnost razgradnje fumonizina u vodenojsredini primenom direktne i indirektne fotolize. Na primerudirektne fotolize fumonizina B1 (FB1) ispitani su optimalni usloviu pogledu početne pH-vrednosti primenom UV i simuliranog sunčevogzračenja (SSZ). Pri indirektnoj fotolizi primenjena su dva tretmana, uprisustvu H2O2, odnosno . I u ovom slučaju tretmani suoptimizovani u pogledu početne pH-vrednosti, kao i koncentracijeH2O2, odnosno takođe primenom UV i SSZ. Nadalje, ispitana jeefikasnost direktne i indirektne (H2O2) fotolize fumonizina B2(FB2) primenom UV i SSZ, na dve pH-vrednosti. Jedna pH-vrednost jeodabrana pri kojoj je razgranja najekonomičnija (pH 8), a druga prikojoj je razgradnja najefikasnija (pH 4). Ispitan je i sinergističkiuticaj između FB1 i FB2 tokom direktne i indirektne (UV/H2O2,odnosno UV/ ) fotolize. Najefikasnija metoda fotolize (UV/H2O2)je primenjena i za ispitivanje efikasnosti razgradnje fumonizina B3(FB3). Takođe je ispitana i efikasnost fotokatalitičke razgradnjeprimenom TiO2 Degussa P25, TiO2 Wackherr i ZnO kao fotokatalizatorai UV zračenja. Nađeno je da je fotokatalitička razgradnja FB1 i FB3primenom TiO2 Wackherr kao fotokatalizatora pri prirodnom pH (oko8) najefikasniji tretman za njihovo uklanjanje iz vodene sredine.Međutim, u slučaju FB2 fotokataliza se nije pokazala pogodna za njegovufotorazgradnju, jer primenom sva tri fotokatalizatora dolazi donjegove potpune adsorpcije.Nadalje, ispitan je uticaj tipova voda (matriksa) na brzinu razgradnjeFB1 primenom UV, UV/H2O2 i UV/ tretmana. Isto tako, da bi seispitao uticaj pojedinih jona čija je koncentracija u odabranimtipovima voda bila najviša, kao i huminske kiseline ispitan je injihov uticaj dodavanjem u reakcionu smešu količine koja odgovaraispitivanim vodama. Uticaj jona i huminske kiseline na efikasnostrazgradnje FB1 je ispitan primenom UV i UV/H2O2 tretmana.Citotoksična aktivnost standardnih rastvora različitihkoncentracija sva tri fumonizina ispitana je na četiri ćelijskelinije: Neuro-2a, MRC-5, H-4-II-E i BHK. Ispitan je i citotoksičniuticaj nastalih intermedijera nakon primene različitih tretmana zauklanjanje FB1, FB2 i FB3 na rast sve četiri ćelijske linije.

Fumonisins of the B series (B1, B2 and B3) are most often found in cereals andcereal foods, but their presence has also been confirmed in various types ofwater. Fumonisins can adversely affect human and animal health, and effortsare being made to find an effective method to eliminate them. To this end, theefficiency of fumonisin degradation in the aqueous medium was investigatedusing direct and indirect photolysis. On the example of direct photolysis offumonisin B1 (FB1), the optimal conditions in terms of initial pH value wereexamined using UV and simulated solar radiation (SSR). In indirectphotolysis, two treatments were applied, in the presence of H2O2, respectively.In this case, the treatments were also optimized in terms of the initial pHvalue, as well as the concentration of H2O2, i.e. by using UV and SS radiation.Furthermore, the efficiency of direct and indirect (H2O2) photolysis offumonisin B2 (FB2) was examined under UV and SS radiation, at two pHvalues. One pH value was chosen at which degradation is the most economical(pH 8), and the other at which degradation is the most efficient (pH 4). Thesynergistic effect between FB1 and FB2 during direct and indirect (UV/H2O2and UV/ ) photolysis was also investigated. The most efficient methodof photolysis (UV/H2O2) was further used to test the degradation efficiency offumonisin B3 (FB3). In addition, the efficiency of photocatalytic degradationwas investigated using TiO2 Degussa P25, TiO2 Wackherr and ZnO asphotocatalysts under UV radiation. Photocatalytic degradation of FB1 and FB3using TiO2 Wackherr as photocatalysts at natural pH (about 8) was found tobe the most effective treatment for their removal from the aquaticenvironment. However, in the case of FB2, photocatalysis did not prove to besuitable for its photodegradation, because the use of all three photocatalystsleads to its complete adsorption.Furthermore, the influence of water types (matrix) on the rate of FB1degradation using UV, UV/H2O2, and UV/ treatments was investigated.Also, in order to examine the influence of individual ions whose concentrationin the selected types of water was the highest, as well as humic acids, theirinfluence was examined by adding to the reaction mixture an amountcorresponding to the tested waters. The effect of ions and humic acid on thedegradation efficiency of FB1 was investigated using UV and UV/H2O2treatments.The cytotoxic activity of the standard solutions of different concentrations ofall three fumonisins was examined on four cell lines: Neuro-2a, MRC-5, H-4-II-E and BHK. The cytotoxic effect of the resulting intermediates afterapplication of different treatments to remove FB1, FB2 and FB3 on the growthof all four cell lines was also examined..