<p>U okviru doktorske disertacije su razvijeni i optimizovani postupci pripreme uzoraka hrane (žitarica, sirovina, poluproizvoda i prehrambenih proizvoda na bazi žitarica, voća i povrća) i stočne hrane, kao i simultano određivanje tropanskih i glikoalkaloida primenom gasne i tečne hromatografije uz maseno-spektrometrijsku detekciju. Razdvajanje alkaloida primenom gasne hromatografije je izvedeno na kapilarnoj koloni (HP-5MS UI), uz detekciju sa kvadrupolnom masenom spektrometrijom SIM tehnikom, u intervalu m/z 50–550 a.m.u. Pri optimizovanim uslovima postignuto je razdvajanje homatropina, atropina i skopolamina u vremenu od 12.75 min, pri čemu<br />tropin i anisodamin nisu mogli biti detektovani. Glikoalkaloidi nisu direktno mogli biti određivani gasnom hromatografijom usled njihove visoke molekulske mase i male isparljivosti. Za simultano određivanje tropanskih alkaloida (tropin, l-hiosciamin, atropin, skopolamin, homatropin i anisodamin) i glikoalkaloida (α-solanin i α-kakonin) validirana je brza i osetljiva multirezidualna LC–MS/MS metoda. Korišćena je disperzivna čvrsto-fazna ekstrakcija sa 0.5% mravlje kiseline u acotonitrilu/vodi (75:25, v/v), solima magnezijum sulfat, natrijum hlorid i natrijum citrat kao i C<sub>18</sub> sorbent. Analiti su razdvojeni na Chirobiotic V koloni, sa mobilnom fazom sastavljenom od 10 mM amonijum formata u voda/acetonitril (90:10, v/v) i metanol/acetonitril (50:50, v/v), mešanim u odnosu 20:80 (v/v). Detekcija komponenti je izvedena u pozitivnom elektrosprej modu (ESI+), korišćenjem reakcionog višestrukog monitoring akvizacionog moda (MRM). Optimizovana tečno hromatografska metoda je podrazumevala brz i jednostavan proces ekstrakcije, sa prinosom od 61-111% za pojedine alkaloide, dobru linearnost u širokom opsegu (5-80 μg/kg, r<sup>2</sup>=0.998), dobru selektivnost, robusnost i preciznost (CV < 5%). Granica detekcije (LOD) za sve alkaloide je bila u opsegu od 0.74 do 0.79 ng/g dok se granica kvantifikacije (LOQ) kretala od 2.17 do 2.46 ng/g u svim žitaricama, izuzev za tropin u soji i lanenom semenu (LOD = 1.55 i LOQ = 4.91 ng/g). Pri analizi uzoraka sa tržišta alkaloidi nisu detektovani u analiziranim uzorcima hrane, kao što su: pšenica, raž, kukuruz, brašno od mešanih žitarica, kukuruzno brašno, biskvit i krekeri. Stočna hrana namenjena ishrani svinja i peradi je sadržala atropin, skopolamin, α-solanin i α-kakonin u koncentracionom opsegu od 3.6 do 21.7 ng/g. Atropin i skopolamin su detektovani u koncentracionom opsegu od 2.8 do 9.8 ng/g u hrani namenjenoj ishrani krava i zečeva, dok u hrani nemenjenoj ishrani konja i divljih životinja alkaloidi nisu detektovani. U analiziranim uzorcima voća i povrća (jabuka, kruška, avokado, mrkva, krastvac i paprika) po prvi put u ovom radu su detektovani glikoalkaloidi, α-solanin i α-kakonin. Koncentracija oba glikoalkaloida se kretala u opsegu od 0.3 do 15 ng/g. Sadržaj glikoalkaloida u krompiru i čipsu (8708.9-18794.7 ng/g) se nalazio u okviru preporučenog ukupnog sadržaja glikoalkaloida od 200 mg/kg (sirova odvaga) (FAO/WHO, 1999). Apsorpcija i translokacija alkaloida od strane pšenice u koren, listove i stabljiku je ustanovljena upotrebom atropina <sup>14</sup>C. Utvrđeno je da biljka nakon 15 dana apsorbuje 4.30% i 2.28% atropina <sup>14</sup>C za niži (13676 dpm/g soil) i viši (37203 dpm/g soil) sadržaj standarda sa kojim je zemljište spajkovano, redom. Količina apsorbovanog atropina se smanjivala tokom rasta biljke. Biljka starosti 90 dana je apsorbovala 0.38% i 0.21% atropina <sup>14</sup>C za niži i viši sadržaj standarda, redom. Povećanje koncentracije supstance u zemljištu nije uticalo na dalje povećanje apsorpcije. Do nagomilavanja supstance je došlo u listovima (83%) dok su niže koncentracije zabilježene u korenu (8.6%), stabljici (4.2%) i semenu (4.1%). U analiziranim uzorcima vode, koja je poticala od ispiranja zemljišta obogaćenog atropinom <sup>14</sup>C, nakon 30 dana supstanca je detektovana u koncentraciji od 0.5%. Tokom vremena je ustanovljeno smanjenje ispiranja ove supstance (0.01% nakon 90 dana). Analiza uzoraka zemljišta nakon 30 i 60 dana je pokazala značajne adsorpcione osobine atropina, tako da je količina čvrsto adsorbovanog (neekstrahovanog) atropina iznosila 60% i 70%, redom. Zaostali atropin je bio stabilan i nakon 90 dana.</p> / <p>The methods of sample preparation have been developed and optimized for food (grains, raw materials, food products based on grains and fruits and vegetables) and feed analyses for the purpose of simultaneous determination of tropane and glycoalkaloids by gas and liquid chromatography hyphenated to mass spectrometry. Separation of alkaloids by gas chromatography was achieved by using capillary column HP-5MS UI. The alkaloids have been detected by using a quadrupole mass spectrometer inSIM mode for the range of m/z 50–550 a.m.u. Under optimised conditions, good separation of homatropine, atropine and scopolamine was achieved after 12.75 min, while tropine and anisodamine couldn`t be detected. Glycoalkaloids could not be analysed directly by gas chromatography due to their high molecular weight and low volatility. For simultaneous determination of tropane alkaloids (tropine, atropine, scopolamine, homatropine, anisodamine) and glycoalkaloids (α-solanine, α-chaconine) fast and sensitive multiresidue LC–MS/MS method was validated. In sample preparation dispersive solid phase extraction (DSPE) was performed with 0.5% formic acid in acetonitrile/water (75:25, v/v) and a mixture of magnesium sulphate, sodium chloride, sodium citrate and C18 sorbent. The analytes were separated by isocratic HPLC on a Chirobiotic V column with the mobile phase that consisted of 10 mM ammonium formate in water/acetonitrile (90:10, v/v) and methanol/acetonitrile (50:50, v/v), mixed in the ratio of 20:80 (v/v).<br />Compounds were detected in positive electrospray ionization mode (ESI+), using multi reaction monitoring (MRM). Optimised liquid-chromatographic method exhibited good linearity in the range 5-80 ng/g (r<sup>2</sup>=0.998). The method has shown to be specific, selective, accurate (recoveries from 61- 111%), precise (CV < 5%) and rugged. Calculated limits of detection (LOD) for all alkaloids were in the range 0.74-0.79 ng/g, while the limits of quantitation (LOQ) were in the range 2.2-4.9 ng/g in all grains, except for tropine in soybean and linseed (LOD = 1.55 and LOQ = 4.91 ng/g). The proposed method was applied in the analyses of samples obtained from local supermarkets. The alkaloids were not detected in following food samples:<br />wheat, rye, maize, mixed grain flour, corn flour, biscuits and crackers. The feeds for pigs and chicken were the most contaminated with atropine, scopolamine, α-solanine and α-chaconine with the contents of alkaloids in the range of 3.6 to 21.7 ng/g. Atropine and scopolamine were detected in cattle and rabbit feed in concentrations ranging from 2.8 to 9.8 ng/g, while in feed for horses and wild animals none of the target alkaloids were detected. Conducted research reports for the first time the presence of glycoalkaloids, α-solanine and α-chaconine in fruit and vegetable samples (apple, pear, avocado, carrot, cucumber and paprika). The concentrations of these alkaloids were in the range of 0.3 to 15 ng/g. The content of glycoalkaloids in potato and chips complied with the recommended content of total glycoalkaloids concentration of 200 mg/kg (raw weight) (FAO/WHO, 1999). Absorption and translocation of alkaloids in wheat (roots, leaves, stem) was determined by using atropine <sup>14</sup>C. It was found that young wheat after 15 days absorbed approximately 4.30% and 2.28% of atropine <sup>14</sup>C for low (13676 dpm/g soil) and high (37203 dpm/g soil) spiked levels in soil, respectively. Increase in the spiked concentration in the soil did not affect higher absorption of atropine <sup>14</sup>C in wheat. The highest accumulation of atropine <sup>14</sup>C was observed in the leaves (83%) while lower<br />concentrations were detected in the roots (8.6%), stems (4.2%) and seeds (4.1%). In collected water samples during the soil leaching, atropine <sup>14</sup>C was detected in the concentration of 0.5%. Leaching decreased with the time (0.01% after 90 days). Analyses of soil samples after 30 and 60 days showed strong adsorption of atropine to the soil and quantity of adsorbed atropine was 60% and 70%, respectively. Adsorbed atropine in the soil was stable after 90 days.</p>
| Identifer | oai:union.ndltd.org:uns.ac.rs/oai:CRISUNS:(BISIS)76985 |
| Date | 30 September 2011 |
| Creators | Jandrić Zora |
| Contributors | Švarc-Gajić Jaroslava, Lončar Eva, Mikov Momir, Malbaša Radomir |
| 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 |
| Format | application/pdf |
Page generated in 0.0125 seconds