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Spectrophotometric determination of iron in a pharmaceutical : bachelor thesis
No full textŽeljezo je metal poznat i koristan čovjeku, kako u tehničkom smislu tako i u nutritivnom. Jedan je od važnih bioelemenata našeg organizma. Zaslužan je za opskrbu kisikom i normalno funkcioniranje organizma. Njegov nedostatak uzrokuje slabokrvnost ili anemiju, koja se može liječiti prehranom ili lijekovima. U ovom eksperimentalnom radu je opisano spektrofotometrijsko određivanje željeza u lijeku Tardyferon namijenjenom za liječenje anemije, koji je prethodno raščinjen u mikrovalnoj pećnici. UV/VIS spektroskopija je metoda koja se primjenjuje za određivanje nepoznate koncentracije uzorka pomoću Beerovog zakona. Mjerenje se vršilo u vidljivom području pri valnoj duljini 506 nm i kiseloj sredini pH=1.Iron is metal well known and useful for human, as in technical way and in nutritional way. It is one of important bioelement of our system. It is responsible for the oxygen supply and for the normal functioning of the organism. Its lack in organism causes anemia which can be treated with food or pharmaceutical. Spectrophotometric determination of iron in pharmaceutical Tardyferon which is intended to treat anemia, is described in this experimental work. Preparation is previously dissolved in microwave oven. UV/VIS spectroscopy is method which is used to determine an unknow sample concentration using Beer law. The measurement was performed in the visible range at the wavelength of 506 nm and acidic enviroment at pH=1
Use of GC-MS in research of cancer : bachelor thesis
No full textRak je novotvorina za koju je karakteristična nekontrolirana dioba stanica. Može biti zloćudni ili dobroćudni. Zbog brzog širenja jako je teško na vrijeme otkriti i liječiti ljude oboljele od ove bolesti. Tijekom povijesti su razvijene različite kliničke metode za istraživanje i detektiranje tumorskih bolesti, no ni jedna od razvijenih metoda se ne može iskoristiti za dugoročno liječenje i zaustavljanje bolesti. U svrhu ranijeg otkrivanja i sprječavanja bolest razvija se istraživanje biomarkera. Biomarkeri ili tumorski biljezi su biološke molekule koje ukazuju na normalne ili abnormalne procese u ljudskom tijelu, ili na prisustvo neke bolesti, kao što je rak. Zbog toga je u istraživanju raka sve više u uporabi GC-MS tehnika. Ova metoda koristi različita tkiva i tekućine iz ljudskog organizma u svrhu otkrivanja biomarkera. GC- MS tehnika sastoji se od uređaja za plinsku kromatografiju, koji služi za razdvajanja komponenti iz uzorka, i masenog spektrometra, koji služi kao detektor za identifikaciju odvojenih komponenti. Uporabom ove tehnike otkriven je velik broj molekula koje mogu poslužiti kao biomarkeri, tj. Koje se mogu iskoristiti za pravovremeno otkrivanje raka i kvalitetno praćenje razvijanja bolesti.Cancer is a neoplasm which is classified by abnormal cell growth. Cancer can be malign or benign. Because it spreads very fast, it is very difficult to discover this disease and curing people who have cancer. Throughout history variosu clinical methods were developed for the research and detection of tumor diseases, but none of the methods can be used for long term treatment and for stopping the disease. In purpose of early detection and prevention of the disease, the research of biomarkers is developing. Biomarkers or tumor markers are biomolecules which indicate normal and abnormal processes in the human body, or a disease, such as cancer. Because of that the GC-MS tehnique is nowadays more used. This tehnique uses differnt types of tissues and liquids from the human body for the detection of biomarkers. The GC-MS tehnique is composed of the device for gas cromatography, which is used for separation of components from the sample, and the device for mass spectrometry, which is used for the identification of the separated components. By the use of this tehnique a great amont of molecules have been discovered, which can be used as biomarkers, in other words, which can be used in the early detection of cancer and quality tracking of the developing of the disease
A review of methods in cell genetics : bachelor thesis
No full textGenetika je mlada znanost koja se bavi proučavanjem zakonitosti nasljeđivanja, sličnosti i različitosti živih organizama. Genetika proučava strukturu i funkciju gena, nasljeđivanje gena, promjene koje se događaju u organizmima i mnoge uzročnike bolesti. Citogenetika je grana genetike koja proučava stanične strukture koje su odgovorne za nasljeđivanje. Tako ona istražuje građu i broj kromosoma, smještaj gena i mutacije. Cilj ovog rada bio je opisati metode u staničnoj genetici, citogenetici. U radu su detaljno opisane metode protočne citometrije i metoda fluorescnetne in situ hibridizacije (FISH). Protočna citometrija je metoda koja omogućava brzu, osjetljivu i točnu analizu velikog broja staničnih komponenti. Ona se koristi za izolaciju specifičnih stanica ili staničnih jezgri iz smjese stanica na osnovu različitog raspršivanja svjetlosti, odnosno fluorescencije. Upravo fluorescencija razdvaja stanice koje su obilježene različitim fluorescentnim reagensima. Fluorescentna in situ hibridizacija je tehnika koja uz pomoć nukleinske sonde, odnosno probe, uočava određenu sekvencu u kromosomu. Sonda predstavlja fluorescentno označenu molekulu DNA koja je komplementarna sekvenci genoma kojeg treba otkriti. Tako je ovom tehnikom moguće čitave kromosome predstaviti u bojama. Metoda FISH upotrebljava se za identificiranje gena, dijelova gena, kromosoma i za otkrivanje pojedinih promjena u kromosomima.Genetics is a young science that deals with the study of the laws of inheritance, similarities and differences of living organisms. Genetics studies the structure and function of genes, gene inheritance, changes that occur in organisms, and many pathogens. Cytogenetics is a branch of genetics that studies cellular structures responsible for inheritance. Thus, she investigates the structure and number of chromosomes, gene placement and mutations. The aim of this work was to describe methods in cellular genetics, cytogenetics. This work describes the flow cytometry method and the fluorescent in situ hybridization (FISH) method. Flow cytometry is a technique that allows fast, sensitive and accurate analysis of a large number of cellular components. It is used to isolate specific cells or cell nuclei from a mixture of cells based on different light scattering or fluorescence. Fluorescent in situ hybridization is a technique that uses a nucleic to detect a specific sequence in a chromosome. The probe is a fluorescently labeled DNA molecule that is complementary to the sequence of the genome to be detected. Thus, with this technique, it is possible to present entire chromosomes in colors. The FISH method is used to identify genes, parts of genes, chromosomes and to detect individual changes in chromosomes
Thermal properties of poly(lactic acid)/modified olive stone flour composites : diploma thesis
No full textModifikacija svojstava polilaktidne kiseline (PLA) provedena je dodatkom modificiranih mljevenih koštica masline (mMKM) s ciljem priprave biorazgradljivog kompozita. Uspješno su pripravljeni polimerni kompoziti svih sastava pomoći na ekstruderu s rotirajućim cilindrom. Diferencijalna pretražna kalorimetrija (DSC) je primijenjena u istraživanju utjecaja različitih udjela mMKM na toplinska svojstva i kristalnost PLA. Toplinska svojstva i kristalnost PLA u kompozitima PLA/mMKM ukazuju na slabe interakcije izmeĎu punila i kompozita. Punilo mMKM u kompozitima PLA/mMKM ima samo ulogu zamjene dijela skupljeg materijala s jeftinijim. Toplinska postojanost kompozita istraživana je primjenom neizotermne termogravimetrije (TG). Kompoziti PLA/mMKM se razgraĎuju do tri stupnja razgradnje. mMKM pogoršava toplinsku postojanost polimernih kompozita. Buduća istraživanja treba usmjeriti k promijeni modifikatora ili postupka modifikacije površine MKM kako bi se uspostavile jače interakcije izmeĎu punila i polimerne matrice čime bi se dobila bolja svojstva polimernog materijala.The modification of the properties of poly(lactid acid) (PLA) was performed by adding modified olive stone flour (mMKM) with the aim of preparing a biodegradable composite. Polymer composites of all compositions have been successfully prepared using a rotary cylinder extruder. Influence of different proportions of mMKM on the thermal properties and crystallinity was investigated using differential screening calorimetry (DSC). The thermal properties and crystallinity of PLA in PLA/mMKM composites indicate weak interactions between fillers and composites. The mMKM filler in PLA/mMKM composites has just the role of replacing a part of the more expensive material with a cheaper one. The thermal stability of the composite was investigated using non-isothermal thermogravimetry (TG). PLA/mMKM composites are degraded in three degradation stages. mMKM degrades the thermal stability of polymer composites. Future research should focus on changing the MKM surface modifier or surface modification process to establish stronger interactions between the filler and the polymer matrix to obtain better properties of the polymeric materia
Electrochemical behavior of quercetin on carbon nanomaterials: a contribution to the optimization of electroanalitical methods for determination of natural reducers : diploma thesis
No full textU ovom radu su predstavljeni rezultati istraživanja ponašanja kvercetina na različito modificiranim elektrodama od staklastog ugljika. Elektrokemijska ispitivanja su vršena u tri različita pufera (acetetnom, otopini model vina, Britton-Robinson puferu) te pri različitim pH vrijednostima (2,6-6,6 u Britton-Robinson puferu). Uočena je znatna ovisnost elektrokemijskog ponašanja kvercetina na modificiranim elektrodama o mjernom puferu. Kao najpogodniji pufer pokazao se Britton-Robinson pufer, dok su značajna kinetička ograničenja zabilježena u acetatnom puferu. Kinetička ograničenja vezana za prijenos elektrona kroz heterogenu granicu faza ispitivana su u širokom području brzina posmika. Utvrđen je kompleksni kontrolni mehanizam elektrokemijskog ponašanja kvercetina na pripravljenim elektrodama vođen kaskadnim (slijednim redoks reakcijama). Utjecaj pH na elektrokemijsko ponašanje kvercetina je ispitavan u području ph od 3,6 do 6,6. Povišenjem pH vrijednosti dolazi do promijene potencijala strujnih pikova, ali i do smanjenja osjetljivosti. Ove pojave objašnjene su u kontekstu predloženih mehanizama oksidacije/redukcije kvercetina. Uočen je i značajan utjecaja prisilne konvekcije na elektrokemijski odziv kao i vremena mjerenja te vrste pufera koji kontroliraju kemijsku stabilnost kvercetina. Ova ispitivanja su ukazala da je ponašanje kvercetina na elektrodama modificiranim s ugljikovim nanomaterijalima kompleksnog karaktera i nije kontrolirano jednim parametrom, već da je kombinacija kako difuzije tako i adsorpcije. Kao najoptimalniji sustav za određivanje kvercetina, na osnovu analize, isprofilirale su se elektrode modificirane s ugljikovim nanocijevčicama u Britton-Robinson puferu, pri pH 3,6, ali i elektrode modificirane s elektrokemijskim reduciranim grafenom u otopinama modela vina i Britton-Robinson puferu s nešto manjom osjetljivošću, te većom stabilnošću odziva. Rezultati ovog diplomskog rada, zajedno s dobivenim rezultatima drugim polifenolima na istim elektrodama mogu pomoći ka prevladavanju interferencija, povećanju osjetljivosti i uspostavi nove metode za određivanje polifenola u realnim uzorcima.This graduate thesis presents the results of research on the behavior of caffeic acid on variously modified glassy carbon electrodes. Electrochemical tests were performed in three different buffer solutions (acetate, wine model solution, Britton-Robinson buffer) at different pH values (2,6-6,6 in Britton-Robinson buffer). A significant dependence of the electrochemical behavior of caffeic acid on the modified electrodes was observed depending on the buffer in which the measurements were performed. Britton-Robinson buffer proved to be the most suitable buffer, while significant kinetic limitations were noted in acetate buffer. The kinetic constraints related to electron transfer across the heterogeneous phase boundary were investigated over a wide range of scan rates. A complex control mechanism of the electrochemical behavior of quercetin on the prepared electrodes guided by cascade (sequential redox reactions) was determined. The effect of pH on the electrochemical behavior of quercetin was examined in the pH range of 3.6 to 6.6. . Increasing the pH value shifts the potential of current peaks, but also reduces the sensitivity. These phenomena are explained in the context of the proposed mechanisms of oxidation/reduction of quercetin. Significant effects of forced convection on the electrochemical response as well as measurement times and types of buffers that control the chemical stability of quercetin were observed. These studies indicated that the behavior of quercetin on electrodes modified with carbon nanomaterials is of a complex character and is not controlled by a single parameter, but by a combination of both diffusion and adsorption. As the most optimal system for determining quercetine, based on the analysis, electrodes modified with carbon nanotubes in Britton-Robinson buffer, at pH 3.6, but also electrodes modified with electrochemically reduced graphene in solutions of wine models and Britton-Robinson buffer with less sensitive and more stable in response. The results of this thesis, together with the results obtained with other polyphenols on the same electrodes can help to overcome interference, increase sensitivity and develop new methods for the determination of polyphenols in real samples
Determination of pesticide residues in flour : bachelor thesis
No full textUpotreba pesticida seţe još do davnih dana kada su korišteni razni jednostavni anorganski spojevi, spojevi sadrţani u biljkama i pripravljeni biljni preparati u svrhu zaštite usjeva od štetnika. Do preokreta dolazi otkrićem insekticidnog djelovanja diklordinitrofeniltrikloretana (DDT). Primjenom pesticida dolazi do otpornosti štetnika na te pojedine pesticide, što dovodi do pojaĉane proizvodnje novih. Zbog njihove široke primjene i njihovih negativnih uĉinaka (toksiĉnost, zagaĊenje vode i okoliša) doneseni su strogi zakoni i provode se detaljna istraţivanja ostataka pesticida u hrani. U radu je opisana podjela pesticida i njihovi glavni predstavnici s naglaskom na insekticide, fungicide,herbicide i rodenticide kao i metode njihovog odreĊivanja u brašnu.The use of pesticides dates back to ancient times when various simple inorganic compounds, compounds contained in plants and prepared herbal preparations were used for the purpose of protecting crops from pests. The reversal occurs with the discovery of the insecticidal action of dichlorodinitrophenyltrichloroethane (DDT). The application of pesticides leads to the resistance of pests to these individual pesticides, which leads to increased production of new ones. Due to their wide application and their negative effects (toxicity, water and environmental pollution) strict laws have been passed and detailed research of pesticide residues in food is being carried out. The paper describes the division of pesticides and their main representatives with emphasis on insecticides, fungicides, herbicides and rodenticides as well as methods of their determination in flour
Influence of Mn on the corrosion behavior of CuAlMn alloy in NaCl solution : diploma thesis
No full textKorozijsko ponašanje različitih CuAlMn legura s prisjetljivosti oblika (Cu-12%Al-4%Mn, Cu-12.3%Al-5.2%- Mn i Cu-12%Al-6%Mn) u 0.9 % NaCl otopini (pri pH = 7.4 i T = 37 °C) ispitano je praćenjem vremenske promjene potencijala otvorenog strujnog kruga te primjenom polarizacijskih metoda i elektrokemijske impedancijske spektroskopije. Ustanovljeno je da na potencijalu otvorenog strujnog kruga korozijska otpornost ispitivanih uzoraka raste s porastom sadržaja Mn u leguri, tj. redom: Cu-12%Al-4%Mn 0.1 V), brzina korozije raste sa sadržajem Mn u leguri. Ispitivanjem uzoraka svjetlosnim mikroskopom uočena su oštećenja na površini Cu-12.3%Al-5.2%-Mn i Cu-12%Al-6%Mn legura, dok je površina Cu-12%Al-4%Mn legure gotovo neoštećena korozijom, što je potvrđeno i SEM/EDS analizom površine uzoraka.The corrosion behavior of different CuAlMn shape memory alloys (Cu-12%Al-4%Mn, Cu-12.3%Al-5.2%-Mn and Cu-12%Al-6%Mn) in 0.9 % NaCl solution at pH = 7.4 and T = 37 °C was investigated using open circuit potential measurements, polarization and electrochemical impedance spectroscopy methods. It has been found that the corrosion resistance of the tested samples at open circuit potential increases with increasing Mn content in the alloy, i.e. growing in the order of: Cu-12%Al-4% Mn 0.1 V), the corrosion rate increases with Mn content in the alloy, and light microscopy investigations reveal pits on the surface of Cu-12.3%Al-5.2%-Mn and Cu-12%Al-6%Mn alloys, while Cu- 12%Al-4%Mn surface is almost clear of any corrosion damage, which was also confirmed by SEM/EDS analysis of the samples surface
Characterization of PEO/POSS composite : bachelor thesis
No full textU ovom radu istraživan je utjecaj poli(etilen-glikol) poliedarskog oligomernog silseskvioksana (PEG POSS) i aminopropil hepta izobutil poliedarskog oligomernog silseskvioksana (APHIB POSS) na temperature faznih prijalaza, udio kristalne faze i toplinsku stabilnost poli(etilen-oksida). U tu svrhu pripravljene su pastile PEO-a modificirane dodatkom 5 % i 10 % PEG POSS-a, odnosno APHIB POSS-a metodom taljenja u statičkim uvjetima. Nađeno je da se dodatkom modifikatora taljenje i kristalizacija odvijaju u nešto užem temperaturnom području, a udio kristalne faze smanjuje se za 2 – 5 %. Dinamičkom termogravimetrijom utvrđeno je da se PEO i PEO/PEG POSS razgrađuju u jednom razgradnom stupnju u temperaturnom području od 330 do 450 °C. PEO/APHIB POSS razgrađuju se u dva razgradnja stupnja. Prvi razgradni stupanj odgovara razgradnji nanopunila dok se drugi pripisuje razgradnji PEO-a. Dodatak POSS-a ne utječe na temperaturu početka razgradnje PEO-a.In this work, the effect of poly(ethylene glycol) polyhedral oligomeric silsesquioxane (PEG POSS) and aminopropyl hepta isobutil polyhedral oligomeric silsesquioxane (APHIB POSS) on phase transition temperatures, crystallinity and thermal stability of poly(ethylene-oxide) was investigated. Samples of PEO modified by addition of 5 % and 10 % of PEG POSS and APHIB POSS respectively, were prepared by melting method in static conditions. It was found that addition of POSS narrows melting and crystallization region and decreases crystallinity of PEO for 2-5%. By dynamic thermogravimetry was found that PEO and PEO/PEG POSS decompose in one decomposition step in temperature region from 330 to 450 °C. PEO/APHIB POSS decompose in two decomposition steps. First step corresponds to nanoparticles degradation while the second step corresponds to PEO degradation. Addition of POSS does not affect on the onset degradation temperature of PEO
Volatile compounds of withe and yellow muscat wines : bachelor thesis
No full textMuškatna vina karakteriziraju tipične cvjetne i voćne arome, koje uglavnom potječu iz grožđa. Muškat je jedino grožđe od kojeg se dobiva vino koje zapravo ima okus poput samog grožđa. Dvije sorte muškata, muškat bijeli i muškat žuti, berbe 2019, proizvedeni su u Vinskoj kući Kirić u Ludbreškim Vinogradima. Za izolaciju hlapljivih aromatičnih spojeva, korištene su dvije metode, ekstrakcija tekuće-tekuće sa smjesom otapala pentan:dietil-eter, (2:1 v/v) i tehnika vršnih para na krutoj fazi (HS-SPME). Dobiveni uzorci analizirani su pomoću vezanog sustava plinska kromatografija-spektrometrija masa, GC-MS. Vršne pare oba muškatna vina sadržavaju veće koncentracije spojeva arome fermentacije poput estera masnih kiselina i acetatnih estera (etil-oktanoat, etil-dekanoat i izoamil acetat), masnih kiselina (oktanska, dekanska i oktadec-9-enska kiselina) i višeg alkohola izoamilnog alkohola. Uzorci dobiveni ekstrakcijom tekuće-tekuće sadržavaju veće koncentracije spojeva koji su formirani tijekom alkoholne fermentacije, poput 2-feniletanola i dietil-sukcinata u bijelom muškatu, kao i spojeve nastale tijekom zrenja i odležavanja vina, kao što su derivati furana u žutom muškatu. Spojevi primarne arome, posebno dva monoterpenska alkohola linalol i α-terpinol, identificirani su u vrlo malim količinama samo u uzorcima izoliranim HS- SPME metodom.Muscat wines are characterized by typical floral and fruity aromas, which are mostly of grape origin. Muscat is the only wine grape that produces wine that actually tastes like the grape itself. Two varieties of Muscat wines, Muscat white and Muscat yellow, harvest 2019, were produced in Vinska kuća Kirić in the Ludbreg vineyards. For the isolation of volatile aroma compounds, two isolation methods were used, the liquid-liquid extraction with solvent mixture pentane:diethyl ether, (2:1 v/v) and headspace solid-phase microextraction (HS-SPME). The obtained samples were analyzed by gas chromatography-mass spectroscopy, GC-MS. The headspaces of both Muscat wines contained higher concentrations of fermentation aroma compounds such as fatty acid esters and acetate esters (ethyl octanoate, ethyl decanoate and isoamyl acetate), fatty acids (octanoic, decanoic and octadec-9-enoic acid), and higher alcohol isoamyl alcohol. Samples obtained by liquid-liquid extraction were characterized by higher concentration of compounds formed during alcoholic fermentation, such as 2-phenylethanol and diethyl succinate in Muscat white, as well as compounds formed during wine ripening and ageing, such as furane derivatives in Muscat yellow. Primary aroma compounds, namely two monoterpene alcohols linalool and α-terpineol, were identified in very small amounts only in samples obtained by HS-SPME method
Volumetric properties of solutions of 1-ethyl-3-methylimidazolium chloride in butan-2-ol at different temperatures : bachelor thesis
No full textMjerene su gustoće umjereno razrijeđenih otopina 1-etil-3-metilimidazolijevog klorida (EMImCl) u butan-2-olu pri različitim temperaturama, = 15, 20, 25 i 30 °C. Iz dobivenih gustoća, određena su volumetrijska svojstva (prividni i parcijalni molarni volumeni) EMImCl u butan-2-olu. Korištenjem Massonove jednadžbe izračunati su prividni granični molarni volumen i interakcijski koeficijent. Iz prividnog graničnog molarnog volumena, određenog pri različitim temperaturama, također je izračunata prividna granična molarna ekspanzibilnost za EMImCl u butan-2-olu pri svim radnim temperaturama – ti su podaci dali uvid u svojstva EMImCl u butan-2-olu.The densities of moderately dilute solutions of the 1-ethyl-3-methylimidazolium chloride (EMImCl) in butan-2-ol were measured (using Anton-Paar DMA 4500M densimeter) at diferent temperatures, = 15, 20, 25 and 30 °C. From the obtained density data, volumetric properties (apparent molar volumes and partial molar volumes) have been evaluated. The volumetric data have been analyzed using Masson's equation. The limiting apparent molar volume or partial molar volume at infinite dilution, and the slope of Masson's equation at different temperatures for EMImCl in butan-2-ol have been interpreted in terms of ionion and ion-solvent interactions, respectively. In addition, negative values in the whole temperature range for the limiting apparent molar expansibility indicates structure breaking properties of EMImCl in butan-2-ol