Razvoj i primena metode analize odabranih sterola i steroidnih hormona u prirodnim i otpadnim vodama tečnom hromatografijom sa tandem masenom spektrometrijom
Prisustvo steroidnih jedinjenja u prirodnim i otpadnim vodama i njihov štetan uticaj na vodeniekosistem su prepoznati u naučnoj zajednici nekoliko decenija. Istraživanje ekotoksičnosti ovihemergentnih zagađujućih materija pokazalo je da njihovi tragovi u vodenoj sredini mogu izazvatirazličite štetne efekte po vodene organizme. Steroli i steroidni hormoni su opsežno istraženi urazličitim matricama životne sredine, te je dokazano da neki od njih čine prirodne konstituenteispitivanih matrica, ali u životnu sredinu u velikim količinama dospevaju iz netretiranih otpadnihvoda iz domaćinstava, industrije i poljoprivrede. Metode procene zagađenja životne sredinekomunalnim otpadnim vodama pri rutinskom monitoringu podrazumevaju upotrebu bakterijskihindikatora, međutim, ovi tradicionalni fekalni markeri mogu biti nepouzdani i mogu potcenitizdravstveni rizik, čak i kada ispunjavaju regulatorne standarde. Hemijski markeri, poput sterola,široko se koriste za praćenje fekalne kontaminacije životne sredine, podržavajući i dopunjujućikonvencionalne indikatore zagađenja. Pored koncentracije koprostanola, upotrebom odnosa sterolamoguće je odrediti nivo fekalne kontaminacije i razlikovati zagađenje poreklom od čoveka odbiogenog unosa poreklom od viših biljaka ili životinja.U ovom radu opisan je razvoj i optimizacija analitičke metode za istovremenu ekstrakciju,određivanje i pouzdanu potvrdu dvadeset steroida različitih klasa (humani/životinjski i biljni steroli,prirodni i sintetski steroidni hormoni) u rečnim i otpadnim vodama, kao i u suspendovanom materijaluvodenih uzoraka. Uzorci vode su pripremljeni ekstrakcijom na čvrstoj fazi, a suspendovani materijalultrazvučnoj ekstrakcijom. Dobijeni ekstrakti su analizirani metodom tečne hromatografije sa tandemmasenom spektrometrijom, uz korišćenje linearnog jonskog trapa kao masenog analizatora.Razvijena je instrumentalna metoda za potpuno hromatografsko razdvajanje svih analita, a posebnoonih sa identičnim reakcijama fragmentacije, zasnovana na upotrebi C8 kolone i acetonitrila kaoorganskog rastvarača u mobilnoj fazi. Optimizovana metoda je obezbedila visoke prinose analita sarelativnim standardnim devijacijama generalno manjim od 20%. Postignute su niske granice detekcijei kvantifikacije. Metoda je pokazala dobru linearnost u opsegu ispitivanih koncentracija.Rasprostranjenost steroidnih jedinjenja u životnoj sredini i nivo fekalnog zagađenjaprocenjeni su u oblasti ušća reka Dunava i Save u Beogradu, u kome se sirova komunalna otpadnavoda ispušta u vodotokove bez tretmana. Posebna pažnja je posvećena raspodeli steroida izmeđurastvorne i suspendovane faze uzoraka rečnih i otpadnih voda, s obzirom na afinitet sterola da sevezuju za suspendovane čestice. Takođe je procenjena efikasnost uklanjanja steroidnih jedinjenja udva postrojenja za prečišćavanje otpadnih voda u Srbiji. Humani/životinjski steroli koprostanol iholesterol, kao i fitosterol β-sitosterol bili su dominantna jedinjenja u svim uzorcima vode.Zastupljenost sterola i raspodela između faza u rečnoj vodi bili su drugačiji od onih u sirovoj otpadnojvodi, što ukazuje na izraženiji biogeni unos poreklom od viših biljaka, kao i veći uticaj otpadnih vodana sastav suspendovane faze. Utvrđena je izražena kontaminacija istraživanog područja, pri čemu jeDunav više zagađen ispuštanjem netretiranih otpadnih voda od Save zbog različitih hidrodinamičkihuslova koji dovode do značajno viših nivoa sterola u suspendovanim česticama. Takođe je pokazanoda se svi detektovani humani/životinjski steroli i fitosteroli dominantno vezuju za česticesuspendovanog materijala uzoraka rečne i otpadne vode, u poređenju sa rastvornom fazom.Naglašena je potreba da se u praćenju zagađenja životne sredine steroidnim jedinjenjima uzmu uobzir i analiziraju i rastvorna i suspendovana faza kako bi se dobila realna slika o kontaminacijisteroidima i njihovoj sudbini u vodenoj sredini. Konačno, utvrđena je visoka stopa uklanjanja sterolau postojenjima za tretman otpadnih voda (> 98% za koprostanol i holesterol), kao i da je odizračunatih odnosa sterola samo koprostanol/(koprostanol + holestanol) dovoljno osetljiv da na njegautiče poboljšanje kvaliteta prečišćene otpadne vode.
Hemijske nauke - Analitička hemija i Hemija životne sredine / Chemical sciences - Analytical Chemistry and Environmental Chemistry Datum odbrane: 29.09.2023.
The presence of steroid compounds in natural waters and wastewater and their harmful effectson the aquatic ecosystem have been recognized by the scientific community for several decades.Ecotoxicity research of these emerging contaminants has shown that trace amounts in the aquaticenvironment can cause various adverse effects on aquatic organisms. Sterols and steroid hormoneshave been extensively investigated in various environmental matrices, and it has been shown thatsome of them are natural constituents of the investigated matrices, but they enter the environment inlarge quantities via untreated wastewater from households, industry and agriculture. Methods forassessing environmental pollution with municipal wastewater in routine monitoring involve the useof bacterial indicators, however, these traditional fecal markers can be unreliable and mayunderestimate the health risk, even when they meet regulatory standards. Chemical markers, such assterols, are widely used to monitor fecal contamination of the environment, supporting andcomplementing conventional pollution indicators. In addition to the concentration of coprostanol, byusing the sterol ratios it is possible to determine the level of fecal contamination and to distinguishbetween anthropogenic pollution and biogenic input from higher plants or animals.This paper describes the development and optimization of an analytical method for thesimultaneous extraction, determination and reliable confirmation of twenty steroids of differentclasses (human/animal and plant sterols, natural and synthetic steroid hormones) in river water andwastewater, as well as in suspended material of water samples. Water samples were prepared by solid-phase extraction, and suspended material by ultrasonic extraction. The obtained extracts wereanalyzed by liquid chromatography with tandem mass spectrometry, using a linear ion trap as a massanalyzer. An instrumental method was developed for the complete chromatographic separation of allanalytes, especially those with identical fragmentation reactions, based on the use of a C8 columnand acetonitrile as an organic solvent in the mobile phase. The optimized method provided highanalyte recoveries with relative standard deviations generally lower than 20%. Low limits of detectionand quantification were achieved. The method showed good linearity in the range of testedconcentrations.The distribution of steroid compounds in the environment and the level of fecal pollution wereassessed in the confluence area of the Danube and the Sava rivers in Belgrade, where raw municipalwastewater is discharged into waterways without treatment. Special attention was paid to thedistribution of steroids between the dissolved and suspended phases of river and wastewater samples,considering the affinity of sterols to bind to suspended particles. The efficiency of steroid removal intwo wastewater treatment plants in Serbia was also evaluated. The human/animal sterols coprostanoland cholesterol as well as the phytosterol β-sitosterol were the dominant compounds in all watersamples. The pattern of sterols and the distribution between phases in river water were different fromthose in raw wastewater, which indicates a more pronounced biogenic input originating from higherplants, as well as a greater influence of wastewater on the composition of the suspended phase.Extensive contamination of the investigated area was determined, whereby the Danube is morepolluted by the discharge of untreated wastewater than the Sava due to different hydrodynamicconditions that lead to significantly higher levels of sterols in suspended particles. It was also shownthat all detected human/animal sterols and phytosterols bind dominantly to suspended particles ofriver and wastewater samples, compared to the dissolved phase. The need to consider and analyzeboth the dissolved and suspended phases in the monitoring of environmental pollution with steroidcompounds was emphasized in order to obtain a realistic picture of steroid contamination and theirfate in the aquatic environment. Finally, a high removal rate of sterols in wastewater treatment wasdetermined (> 98% for coprostanol and cholesterol), as well as that of the calculated sterol ratios,only coprostanol/(coprostanol + cholestanol) is sensitive enough to be affected by the improvementof the quality of treated wastewater.
srpski
2023
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