Photolytic degradation of nitrofurantoine

Abstract

Farmaceutici prisutni u okolišu mogu se razgraditi na različite načine. Za farmaceutike koji nisu podložni biorazgradnji i hidrolizi, direktna i indirektna fotoliza djelovanjem Sunčeve svjetlosti najznačajniji je put abiotičke razgradnje u površinskim vodama. Cilj ovoga rada bio je proučiti direktnu i indirektnu fotolitičku razgradnju farmaceutika nitrofurantoina. Otopine nitrofurantoina pripremljene su u MilliQ vodi s pH-vrijednostima 4, 6, 8 i 10, izvorskoj vodi, sintetskoj otpadnoj vodi te otopinama klorida, sulfata, nitrata, fosfata i huminskih kiselina. Pripremljene otopine izlagane su umjetnom Sunčevom zračenju te je tijek fotolitičke razgradnje praćen tekućinskom kromatografijom visoke djelotvornosti vezanoj detektorom s nizom dioda (HPLC-DAD). Rezultati istraživanja pokazali su da fotolitička razgradnja nitrofurantoina ovisi o pH-vrijednosti, povećanjem pH-vrijednosti vode, brzina se smanjuje. Također, rezultati pokazuju da sastav matice uzorka vode utječe na brzinu fotolitičke razgradnje NFT-a te je ispitan utjecaj pojedinih sastojaka matice (Cl-, huminske kiseline, NO3-, SO42-, PO43-). Najznačajniji utjecaj u vidu smanjenja brzine razgradnje uočen je u prisutnosti huminskih kiselina i fosfata. Dobiveni rezultati u ovome radu pridonijet će boljem razumijevanju ponašanja antibiotika nitrofurantoina u vodama u okolišu te mogućem utjecaju na ljudsko zdravlje i okoliš.The pharmaceuticals present int he environment may be degraded in difrent ways. For pharmaceuticals that are not subject to biodegradation and hydrolysis, direct and indirect photolysis by sunlight is the most important mechanism of degradation in surface waters. The aim of this work was to study the direct and indirect photolytic degradation of the anibiotic nitrofurantoin. Nitrofurantoin solutions prepared in MilliQ water with a pH value of 4,6,8 and 10; spring water, synthetic waste water and solutions of chloride, sulfate, nitrate, phosphate and humanic acid were prepared and exposed to artifical solar radiation. The rate of photolytic degradation was monitored by high performance liquid chromatography with diode array detection (HPLC-DAD). The results showed that the photolytic degradation of nitrofurantoin depends on pH; the degradation is slower in the solutions with higher pH values. Also, degradation rate depends on matrix composition and therefore degradation the impact of individual ions (Cl-, humic acid, NO3-, SO42-, PO43-) were investigates. The most significat reduction in degradation rate was observed int he presence of humic acids and phosphate. The results of this study will contribute to a better understanding of the fate of nitrofurantoin in the environment and the possible impact on human health and the environment