<p>U okviru doktorske disertacije razvijena je brza i selektivna metoda za<br />određivanje i praćenje ostataka herbicida na bazi sulfonilurea (nikosulfuron,<br />oksasulfuron, tribenuron metil, tritosulfuron, triasulfuron, rimsulfuron i<br />prosulfuron) u zemljištu primenom visoko pritisne tečne hromatografije sa<br />UV detektor sa nizom fotoosetljivih dioda (HPLC-UV-DAD). Razdvajanje<br />sulfonilurea je izvedeno uz primenu Zorbax Eclipse XDB-C18 kolone. U cilju<br />definisanja odgovarajućih uslova analize, ispitan je i definisan uticaj<br />najznačajnijih eksperimentalnih faktora. Usvojeni su sledeći optimalni uslovi<br />gradijentne elucije: mobilna faza acetonitril (A) i 0,1% sirćetna kiselina (B) t<br />= 0 min, 52% A; t = 2-2,5 min, 47% A; t = 2,5-5 min, 52% A, pri konstatnom<br />protoku od 1 mL min-1 i temperaturi kolone od 250C. Na osnovu odziva<br />analitičkog signala, njegove reproduktivnosti i linearnosti, talasna dužina od<br />240 nm je usvojena kao odgovarajuća. Utvrđeno je da je uticaj matriksa bio<br />izražen te je stoga za kvantitativno određivanje sadržaja SU u uzorcima<br />zemljišta primenom HPLC-UV-DAD metode korišćena MMC kalibraciona<br />kriva. Pri analizi ekstrakata nekontaminiranog zemljišta ostvarena je granica<br />kvantitativnog određivanja za nikosulfuron, oksasulfuron, tribenuron metil,<br />tritosulfuron, triasulfuron, rimsulfuron i prosulfuron od 3,16 μg kg-1, 3,40 μg<br />kg-1, 3,76 μg kg-1, 4,13 μg kg-1, 3,60 μg kg-1, 3,04 μg kg-1 i 2,97 μg kg-1,<br />redom. Za potrebe osetljivijih, selektivnijih i tačnijih određivanja SU u<br />zemljištu, definisana je metoda uz primenu tečne hromatografije sa<br />tandemskom masenom spektrometrijom (HPLC-MS-MS). HPLC-MS-MS je<br />korišćena kao referntna tehnika za proveru rezultata koji su dobijeni<br />primenom HPLC uz UV-DAD detektor. Definisan je efikasan postupak za<br />pripremu uzoraka zemljišta u cilju hromatografskog određivanja SU.<br />Najefikasnija ekstrakcija ostvarena je primenom smeše dihlormetanacetonitril<br />(2:1, v/v), zakišeljene sirćetnom kiselinom (0,8%, v/v), uz dodatak<br />uree (0,3 g/ 10g zemljišta). Postupak mikrotalasne estrakcije u zatvorenom<br />sistemu omogućio je najbolje uslove za ekstrakciju SU. U cilju izdvajanja SU,<br />iz matriksa ekstrakata zemljišta, primenjena je ekstrakcija na čvrstoj fazi (SPE) sa silika gelom kao adsorbensom. Definisana metoda za određivanje<br />ispitivanih SU, kao i razvijeni postupak pripreme uzoraka, uspešno je<br />primenjen u analizi realnih uzoraka zemljišta. Veoma dobre vrednosti testa<br />povrata ostvarene pri analizi primenom HPLC-UV-DAD metode, potvrdile su<br />pre svega ispravnost postupka pripreme uzoraka, a delom i kompletne<br />metode. Tačnost razvijene metode za određivanje SU u zemljištu potvrđena je<br />paralelnim analizama uzoraka zemljišta korišćenjem HPLC-MS-MS.<br />Primenom Studentovog t-testa (upareni), utvrđeno je da se rezultati paralelnih<br />analiza statistički značajno ne razlikuju (P=95%). Istraživanja u okviru<br />disertacije obuhvatila su i praćenje disipacije nikosulfurona, rimsulfurona,<br />oksasulfurona i prosufurona u različitim komercijalnim dozama primene<br />tokom 50 dana u polju na tri različite dubine (0-15 cm, 15-30 cm i 30-45 cm),<br />kao i laboratorijskim uslovima na dve temperature (250C i 300C). Vreme<br />polurazgradnje (DT50) ispitivanih SU (nikosulfuron, oksasulfuron i<br />prosulfuron) definisano Mitttag-Lefler-ovom funkcijom u ogledima u<br />laboratorijskim uslovima na 250C iznosilo je 0,65 dana (50 g ha-1 a.k.), 0,64<br />dana (160 g ha-1 a.k.) i 0,66 dana (30 g ha-1 a.k.), redom, a na 300C za<br />nikosulfuron 0,20 dana (50 g ha-1 a.k.) i prosulfuron 0,49 dana (50 g ha-1 a.k.).<br />DT50 za ispitivane SU u polju, takođe definisano Mitttag-Lefler-ovom<br />funkcijom, iznosilo je 72 minuta (0,05 dana), 0,23 dana, 0,12 dana i 0,15<br />dana, za nikosulfuron, rimsulfuron, oksasulfuron i prosulfuron, redom.<br />Značajno veća disipacija koja je utvrđena istraživanjima u okviru ove<br />disertacije najverovatnije je uzrokovana uticajem abiotičkih i biotičkih<br />procesa, kao i faktora spoljašnje sredine.</p> / <p>In this thesis a fast and selective method for determination and monitoring<br />of residues sulfonylurea herbicides (SU) (nicosulfuron, oxasulfuron,<br />tribenuron methyl, tritosulfuron, triasulfuron, rimsulfuron and prosulfuron)<br />in soil, by applying high-performance liquid chromatography with UV<br />detector with diode array diodes (HPLC-UV-DAD) was developed. The<br />separation of the sulfonylurea was performed by use of a Zorbax Eclipse<br />XDB-C18 column. In order to define appropriate conditions of analysis,<br />the influence of the most significant the experimental factors was<br />investigated and defined. The following optimal conditions for gradient<br />elution: mobile phase acetonitrile (A) and 0.1% acetic acid (B) t = 0 min,<br />52% A; t = 2-2.5 min, 47% A; t = 2.5-5 min, 52% A were adopted at a<br />constant flow rate of 1 mL min-1 and column temperature of 250C. On<br />basis of the response of the analytical signal, its reproducibility and<br />linearity, the wavelength of 240 nm was adopted as an appropriate. The<br />influence of the matrix was expressed and therefore for the quantitative<br />determination of investigated SU in soil samples application of HPLCUV-<br />DAD methods was used MMC calibration curve. In the analysis of<br />extracts of nocontaminated soil limits of quantitation for nicosulfuron,<br />oxasulfuron, tribenuron methyl, tritosulfuron, triasulfuron, rimsulfuron and<br />prosulfuron was achieved 3.16 μg kg-1, 3.40 μg kg-1, 3.76 μg kg-1, 4.13 μg<br />kg-1, 3.60 μg kg-1, 3.04 μg kg-1 and 2.97 μg kg-1, respectively. The method<br />by using liquid chromatography-tandem mass spectrometry (HPLC-MSMS)<br />was defined in order to find more sensitive, more selective and more<br />accurate way to determine concentration SU in soil. HPLC-MS-MS was<br />used as the reference technique for checking results that have been<br />obtained by HPLC with UV-DAD detector. An efficient procedure<br />preparation of soil samples for the purpose chromatographic determination<br />of SU was defined. Using a mixture of dichloromethane-acetonitrile (2: 1,<br />v / v), acidified with acetic acid (0.8%, v / v), with the addition of urea (0.3<br />g / 10 g soil) was applied as the most effective way for extraction SU.<br />Microwave extraction process in a closed system allowed the best<br />conditions for the extraction of SU. In order to extract SU from matrix<br />exctracts soil the solid phase the extraction (SPE) with silica gel as an<br />adsorbent was used. The defined method for determination of investigated SU, as well as the developed procedure of sample preparation, was<br />successfully applied in the analysis of real samples of soil. The correctness<br />of procedure of sample preparation was confirmed with very good values<br />of recovery test which was applied in the analysis by using HPLC-UVDAD.<br />The accuracy of the developed method for determination of SU was<br />confirmed by coupled analysis soil samples using HPLC-MS-MS. The<br />results of parallel analysis does not differ significantly at 95% confidence<br />level. It was obtained using Student t-test (paired). The method developed<br />in this thesis was used for monitoring the dissipation of nicosulfuron,<br />rimsulfuron, oxasulfuron prosufuron, in different commercial doses of<br />application during 50 days in field at three different depths (0-15 cm, 15-<br />30 cm and 30-45 cm) and for laboratory conditions at two temperatures<br />(25ºC and 30ºC). The half-life time (DT50) of investigated SU were<br />calculated by use of Mitttag-Lefler function in experiments under<br />laboratory conditions at 25ºC. The values of DT50 for nicosulfuron,<br />prosufuron and oxasulfuron read: 0.65 days (50 g ha-1 a.k.), 0.64 days (160<br />g ha-1 a.k.) and 0.66 days (30 g ha-1 a.k.), respectively. In the same type of<br />experiments at 30ºC we get DT50 for nicosulfuron equals 0.20 days (50 g<br />ha-1 a.k.) and for prosulfuron equals 0.49 days (50 g ha-1 a.k.). The values<br />of DT50 on experiments in field were obtain also by use of Mitttag-Lefler's<br />function, and half-life times for nicosulfuron, rimsulfuron, oxasulfuron and<br />prosufuron from the commercially recommended doses, equal 72 minutes<br />(0.05 days), 0.23 days, 0.12 days and 0.15 days, respectively. Significantly<br />greater dissipation which was determined in this thesis was probably<br />caused by the influence of abiotic and biotic processes as well as<br />environmental factors.</p>
| Identifer | oai:union.ndltd.org:uns.ac.rs/oai:CRISUNS:(BISIS)102385 |
| Date | 26 December 2016 |
| Creators | Grahovac Nada |
| Contributors | Suturović Zvonimir, Kravić Snežana, Kondić-Špika Ankica |
| Publisher | Univerzitet u Novom Sadu, Tehnološki fakultet Novi Sad, University of Novi Sad, Faculty of Technology at Novi Sad |
| Source Sets | University of Novi Sad |
| Language | Serbian |
| Detected Language | English |
| Type | PhD thesis |
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