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Comparison of extraction methods for lutein from laying hens food
No full textLutein je jedan od najzastupljenijih karotenoida u prirodi i prehrani čovjeka. Budući da ga ne sintetizira čovjek, mora se unositi u organizam putem hrane zbog njegovog antioksidativnog djelovanja i prevencije poremećaja vida. Lutein se u velikim koncentracijama nalazi u jajima nesilica čija se kvaliteta zbog masovne proizvodnje danas znatno smanjila. Zbog toga se provode brojna istraživanja u kojima se povećanjem koncentracije luteina u krmnim smjesama za hranidbu nesilica nastoji dobiti funkcionalna namirnica s pozitivnim učinkom na zdravlje čovjeka. U radu je određivana koncentracija luteina u hrani za nesilice tekućinskom kromatografijom visoke djelotvornosti s UV detekcijom. Uzorci su za analizu pripremljeni pomoću dvije metode. Usporedbom rezultata dobivenih tim metodama, u odnosu na literaturne podatke bolji rezultati postignuti su metodom 2.Lutein is one of the most widespread carotenoids in the nature and in the daily nutrition. Due to the inability of humans to synthetize lutein, it must be ingested via foods. It has antioxidative activity and is important in the prevention of macular degeneration. Lutein is found in high concentrations in laying hen eggs, the quality of which has significantly decreased today due to mass production. Therefore, numerous studies are conducted in which, by increasing the concentration of lutein in feed mixtures for laying hens, an attempt is made to obtain a functional food with a positive effect on human health. The concentration of lutein in laying hens was determined by high-performance liquid chromatography with UV detection. Samples were prepared for analysis using two methods. By comparing the results obtained with these methods and with the literature data, better results were achieved with method 2
Study of metal complexes with dipicolinic acid hydrazide derivatives with voltammetric techniques
No full textCilj ovog završnog rada je elektrokemijski karakterizirati dva novosintetizirana kompleksna spoja s hidrazidnim derivatima dipikolinske kiseline, i ZnL-MOF u dva različita inertna elektrolita (KCl i ) koristeći cikličku i diferencijalnu pulsnu voltametriju. Sva mjerenja su provedena u Faradayevom kavezu pomoću PalmSens potenciostata/galvanostata uz računalni program PSTrace koristeći troelektrodni sustav koji se sastojao od radne elektrode od staklastog ugljika, referentne Ag/AgCl elektrode i protuelektrode platinske žice. Sustav je propuhivan argonom visoke čistoće kako bi se izbjegla kontaminacija kisikom tijekom mjerenja, radna elektroda je polirana te su sve elektrode ispirane ultračistom vodom prije svakog mjerenja. Rezultati cikličke voltametrije oba kompleksna spoja pokazuju po jedan oksidacijski i jedan redukcijski strujni vrh u oba inertna elektrolita. U oba inertna elektrolita dolazi do adsorpcije oksidacijskog produkta kompleksa na površinu elektrode od staklastog ugljika, što nije utvrđeno kod kompleksa ZnL-MOF.The aim of this final work is to electrochemically characterize two newly synthesized complex compounds with hydrazide derivatives of dipyliconic acid, and ZnL-MOF in two different inert electrolytes (KCl and ) by using cyclic and differential pulse voltammetry. All measurements were carried out in Faraday's cage by using PalmSens potentiostat/galvanostat with the PSTrace computer program using a three-electrode system which consisted of a working glassy carbon electrode, reference Ag/AgCl electrode and a counter electrode platinum wire. The system was purged with high purity argon to avoid oxygen contamination before each measurement, working electrode was polished and all electrodes were washed with ultra pure water before each measurement. The results of the cyclic voltammetry of both complex compounds show one oxidation and one reduction peak in both inert electrolytes. In both inert electrolytes, adsorption of the oxidative product of the complex occurred on the surface of the glassy carbon electrode, which was not determined for the ZnL-MOF complex
Primary and secondary pollutants in the boundary layer of the atmosphere at Kopački rit Nature Park
No full textAtmosferski polutanti imaju utjecaj na samog čovjeka, ali i okoliš. Podijeljeni su na primarne polutante (direktnom emisijom dolaze u atmosferu) i na sekundarne polutante (nastaju nizom kemijskih reakcija u atmosferi). U ovom završnom radu analizirane su mjerene vrijednosti benzena kao primarnog polutanta te ozona kao sekundarnog polutanta. Za razliku od stratosferskog ozona koji štiti život na Zemlji od ultraljubičastog zračenja tako što ga apsorbira, prizemni/troposferski ozon je zapravo štetan i nastaje fotokemijskim reakcijama iz primarnih polutanata; dušikovih oksida i hlapljivih ugljikovodika. U radu je prikazan dnevni hod benzena i ozona u 2018. i 2019. godini, pomoću grafova. Podaci su prikupljeni u mjernoj postaji koja se nalazi u Tikvešu, Parku prirode Kopački rit.Atmospheric pollutants have an impact on human, but also on environment. They are divided into primary pollutants (they come into the atmosphere by direct emission) and secondary pollutants (formed by a series of chemical reactions in the atmosphere). In this paper, the measured values of benzene as the primary pollutant and ozone as the secondary pollutant are analyzed. Unlike stratospheric ozone, which protects life on Earth from ultraviolet radiation by absorbing it, ground level/tropospheric ozone is actually harmful and is formed by photochemical reactions from primary pollutants; nitrogen oxides and volatile hydrocarbons. The paper presents the daily course of benzene and ozone in 2018. and 2019., using graphs. The data were collected at a measuring station located in Tikveš, at Kopački rit Nature park
Heavy metals in organism
No full textTeški metali su elementi s velikom gustoćom, koja iznosi više od 5 g/cm3. Nalaze se u vodi, tlu, zraku, biljnom i životinjskom svijetu te ljudskom organizmu. Teški metali predstavljaju problem za okoliš. Dijele se na one koji su neophodni za normalno funkcioniranje metabolizma - bakar, cink, mangan, željezo i one koji su toksični - olovo, živa, kadmij, arsen, aluminij, kositar, kobalt, paladij, platina. Izloženost teškim metalima iz okoliša ima različite utjecaje na ljudski organizam. Sve ovisi o njihovoj koncentraciji, odnosno mogu biti i lijek i otrov. Ukoliko dođe do prevelike izloženosti može doći do ozbiljnog pogoršanja zdravlja.Heavy metals are defined as elements with a density greater than 5 g/cm3. They can be found in water, soil, air, flora and fauna and the human body. Heavy metals are an environmental problem. They are divided into those that are necessary for the normal functioning of metabolism - copper, zinc, manganese and iron and those that are toxic - lead, mercury, cadmium, arsenic, aluminium, tin, cobalt, palladium, platinum. Exposure to heavy metals from the environment has various effects on the human body. It all depends on their concentration, that is, they can be both a drug and a poison. Excessive exposure can lead to serious deterioration in health
Galvanic and Electrolytic cells
No full textOvaj završni rad temelji se na empirijskom istraživanju ključnih odrednica galvanskog članka i elektrolize. U nastavku rada nastojat će se prikazati osnovni sadržajni elementi elektrolize, galvanskog članka, elektrodnog potencijala, primarnog i sekundarnog galvanskog članka kao i vrste elektroda. Također, u teorijskom su dijelu obrađene karakteristike galvanskog članka ili galvanskog elementa, koji je ujedno primarni električni članak i neobnovljivi izvor električne struje u kojem se primjerice za razliku od sekundarnog članka (akumulatora), kemijska energija nepovratno pretvara u električnu. Uz samo definiranje i određivanje galvanskog članka vezuju se i neka od utjecajnijih imena koja su imala snažan utjecaj na konstrukciju galvanskog članka, a to su Luigi Galvani, Alessandro Volt, John Frederica Daniell i Georges Leclanché koja će biti spomenuta i obrađena u ovom završnom radu. Ovim završnim radom se jasno želi ukazati na važnost elektrolize i galvanskog članka te na njihov utjecaj na razvoj daljnjih procesa usko vezanih za elektrokemijske reakcije.This final work is based on an empirical research of key determinants of galvanic cell and electrolysis. In the continuation of this work, the main elements of electrolysis, galvanic cell, electrode potential, primary and secondary galvanic cell and electrodes will be presented. Also in the theoretical part are described the characteristics of a galvanic cell or a galvanic element, which is also a primary electrical cell and non renewable source of electric current, in which, for example, unlike the secondary cell (battery), the chemical energy turns irretrievably into electrical. Apart from the definition and designation of a galvanic cell, some of the most influential names that have had a strong influence on the construction of the galvanic cell, like Luigi Galvani, Alessandro Volt, John Frederic Daniell and Georges Leclanché, will be mentioned and discussed in this final work. This final work clearly seeks to highlight the importance of electrolysis and galvanic cell and their influence on the development of further processes closely related to electrochemical reactions
Validation of the HPLC method for the determination of patulin in food products in the Slavonia area
No full textKvalitetno analitičko mjerenje osigurava pouzdane analitičke rezultate. Kako bismo dobili pouzdan i točan analitički rezultat, potrebno je validirati metodu. Provjera valjanosti analitičke metode ili validacija dokumentirani je postupak kojim se dokazuje namjena i svrha analitičke metode. Cilj je diplomskog rada provesti djelomičnu validaciju metode za određivanje patulina u soku od jabuke i u kašicama od jabuke na način da se analiziraju samo neki parametri (linearnost, preciznost, točnost, granica detekcije i kvantifikacije). Patulin je prirodni mikotoksin, sekundarni proizvod u metabolizmu plijesni. Plijesni su glavni uzročnici kvarenja voća i kao takvi predstavljaju rizik za zdravlje ljudi. U radu su se odredile i koncentracije patulina u ekološkim i ne ekološkim uzorcima soka od jabuke i u kašicama.Quality analytical measurment gives reliable analytical results. It is nessesary to validate method, if we want to get reliable and acurrate analytical result. Validation or checking of validity of analytical method is documented procedure which proves the purpouse of analytical method. The aim of this thesis is to do partial validation (analysis of linearity, precision, accuarcy, limits of detection and quantification) of method for determination of patuline in apple juice and in apple porridge. Patuline is natural mycotoxine and secondary byproduct in mold metabolism. Molds are main factor for fruit spoilage and they represent big risk for human health. Concentrations of patuline in eco- and non-eco apple juice and apple porridge samples are determended in this thesis
Optimization of synthesis of superparamagnetic nanoparticales CoFe2O4 with ultra thin gold layer
No full textU ovom diplomskom radu nanočestice kobalt ferita sintetizirane su koprecipitacijskom metodom u vodenoj otopini soli željezova klorida heksahidrata ( × ) i kobaltova klorida heksahidrata ( × ) u prisutnosti natrijeva hidroksida (NaOH). Istražen je utjecaj temperature i vremena reakcije na veličinu i oblik nanočestica. Sintezom pri temperaturi od 60 ℃ su nastale nanočestice promjera oko 30 nm, dok su produženim stajanjem u reakcijskoj smjesi nastali nanokristali kubične strukture. Prilikom sinteze uz nanočestice nastaje znatna količina hidroksidnih međuprodukata. Magnetskom dekantacijom su produkti pročišćeni prilikom čega je promjer nanočestica očuvan kao i njihova svojstva. Površina sintetiziranih nanočestica je modificirana redukcijom tetrakloroaurične kiseline s askorbinskom kiselinom pri čemu dolazi do formacije sloja zlata na površini nanočestica. Nanočestice su okarakterizirane dinamičkim raspršenjem svjetlosti (DLS), transmisijskim elektronskim mikroskopom (TEM), infracrvenom spektroskopijom s Fourierovom transformacijom (FT-IR), rentgenskom difrakcijom (PXRD), termogravimetrijskom analizom (TGA), diferencijalno pretražnom kalorimetrijom (DSC) i UV/VIS spektroskopijom.This master thesis deals with the synthesis of cobalt ferrite nanoparticles by co-precipitation method from aqueous solution containing iron chloride hexahydrate ( × ) and cobalt chloride hexahydrate ( × ) with sodium hydroxide (NaOH). The effect of temperature and reaction time on nanoparticles size and shape were studied. Synthesis at a temperature of 60 ℃ resulted in nanoparticles with a diameter of 30 nm, while prolonged reaction time resulted in cubic nanoparticles of cobalt ferrite. During synthesis a considerable amount of hydroxide intermediates were formed. The products were purified by magnetic decantation, while the size of the nanoparticles and their characteristic were preserved. The surface of synthesised nanoparticles was modified by the reduction of tetrachloroauric acid with ascorbic acid whereby a layer of gold was formed on the surface of the nanoparticles. Nanoparticles are characterised by dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and UV/VIS spectroscopy
Preparation of aromatic diamines salts
No full textU ovom su radu pripremljene soli aromatskih diamina. Sve soli pripremljene su otapanjem o-fenilendiamina, p-fenilendiamina i m-fenilendiamina u tri različite kiseline: klorovodičnoj, sumpornoj i dušičnoj kiselini. Sve dobivene soli analizirane su na FT-IR spektrofotometru te su im određena tališta.In this study aromatic diamines salts were prepared. All salts were prepared by dissolving o-phenyldiamine, p-phenyldiamine, m-phenyldiamine in three different acids: hydrochloric acid, sulfuric acid and nitric acid. All formed salts have been analysed using FT-IR spectrophotometer and their melting points have been measured
Vitamine B complex based coenzymes
No full textKoenzimi su male složene organske molekule koje uglavnom potječu od vitamina i drugih esencijalnih hranjivih tvari. Sveprisutni su u prirodi te sudjeluju u enzimski kataliziranim reakcijama. Koenzimi vitamina B skupine pripadaju najvažnijim koenzimima u ljudskom metabolizmu te imaju različite uloge koje omogućavaju normalno funkcioniranje stanica u svakodnevnom životu. Sudjeluju u poboljšanju metabolizma, imunološkog i živčanog sustava, čuvaju kožu i mišiće, potiču rast i podjelu stanica te imaju mnoge druge pozitivne učinke na zdravlje organizma. Nedostatak jednog ili više njih djeluje negativno na metabolizam, a naposljetku i na zdravlje. Koenzimi vitamina B skupine su: tiamin-pirofosfat ( TPP ), flavin-mononukleotid ( FMN ), flavin-adenin-dinukleotid ( FAD ), nikotinamid-adenin- dinukleotid ( NAD+ ), nikotinamid- adenin-dinukeotid fosfat (NADP+), koenzim A ( CoA ), piridoksal-5′-fosfat ( PLP ), biocitin, tetrahidrofolat ( THF ) i koenzim . Zajedničko evolucijsko podrijetlo ovih koenzima učinilo ih je neophodnim za in vivo stanične metaboličke procese. Cilj ovoga rada je opisati koenzime vitamina B skupine i njihove funkcije u biosintezi. Koenzimi, kao što su nikotinamid i oksidi flavina u oksidoreduktazama prvi su razmatrani koenzimi u prirodi, dok su varijacije tih organskih molekula nedavno otkrivene.Coenzymes are small complex organic molecules that mostly originate from vitamins and other essential nutrients. They are common in nature and they participate in enzymatically catalysed reactions. Vitamin B coenzymes are some of the most important coenzymes in the human metabolism and they are responsible for various functions that enable normal functioning of the cells in everyday life. Their function plays a part in the improvement of metabolism, the immune system, and the nervous system, as well as preserving the skin and the muscles, aiding in the growth and division of cells, and many other positive effects for the health of the organism. A deficiency of one or more of those coenzymes has a negative effect on the metabolism, and ultimately on the human health. Coenzymes from the vitamin B complex are: thiamine-pyrophosphate ( TPP ), flavin-mononucleotide (FMN), flavin-adenine-dinucleotide (FAD), nicotinamide-adenine-dinucleotide (NAD+ ), nicotinamide-adenine-dinucleotide-phosphate (NADP+), coenzyme A ( CoA ), pyridoxal-5'-phosphate (PLP), biocytin, tetrahydrofolate (THF), and coenzyme . The common evolutional origin of these coenzymes has made them essential for in vivo cellular metabolic processes. The aim of this paper is to describe the coenzymes of the vitamin B complex and their functions in biosynthesis. Coenzymes like nicotinamide and flavin oxides in oxidoreductases are the first considered coenzymes in nature, while variants of those organic molecules have been discovered only recently
Total Antioxidant Capacity Analysis in Biological Samples
No full textAntioksidansi su tvari koje štite stanice od oksidacijskog djelovanja slobodnih radikala i sprječavaju nastajanje oksidacijskog stresa koji je posljedica prekomjernog stvaranja reaktivnih spojeva kisika zbog poremećene ravnoteže oksidacijsko - redukcijskih procesa u biološkim organizmima. Analiza redukcijskog kapaciteta na bazi cerija (IV) predloženog naziva CERAC razvijena je za mjerenje ukupnog antioksidativnog kapaciteta (eng.Total antioxidant capacity, TAC). Maksimum apsorbancije od 320 nm Ce (IV) otopina tipičan je za nehidrolizirani i nereducirani ion. Pri određivanju TAC-a kao antioksidansi korišteni su askorbinska kiselina, galna kiselina i kvercetin te su konstruirane kalibracijske krivulje u rasponu koncentracije askorbinske kiseline od 2× do 8× mol/L, kvercetina od 2× do 8×10-6 mol/L i galne kiseline od 2× do 8× mol/L. Realni sustav bile su tablete pripravljene od brašna sjemenki crnog grožđa. Izmjereni podaci za uzorak uspoređeni su s kalibracijski krivuljama antioksidansa. Dobiveni rezultati iznosili su 1,52 mg kvercetina ekvivalenta u 1g tableta i 2,17 mg ekvivalenta galne kiseline u 1g tableta te se tako pokazalo dobro podudaranje s rezultatima TAC-a određenog Folin-Ciocalteu-ovim reagensom kao prihvaćenom metodom za određivanje TAC-a polifenolnih uzoraka.Antioxidans are substances that protect cells from oxidative impact of free radicals and they prevent oxidative stress which is result of excessively formation of reactiv oxygen species because of the disrupted balance of oxidation-reduction processes in biological organisms. Analysis of reduction capacity on the base of cerium (IV) proposed name CERAC has been developed to measure total antioxidant capacity. Maximume absorbance of 320 nm Ce (IV) solutions is typical for nonhydrolized and nonreductive ion. In determining of TAC as a antioxidans ascorbic acid, gallic acid and quercetin were used and then calibration curves were constructed, and in a range of concentration of ascorbic acid from 2× to 8× mol/L, quercetin from 2× to 8× mol/L and gallic acid from 2× to 8× mol/L. Real system were pills made of flour of black grape seeds. Mesured data for sample were compared to calibration curves of antioxidans. Recived results were 1,52 mg of quercetin equivalent in 1 g pill and 2,17 mg of equivalent gallic acid in 1 g pill so it is showed good matching to results of TAC that is determined by Folin-Ciocalteu reagens as a accepted method for TAC polyphenol samples determination