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TESTING MEMBRANE RESPONSE BASED ON Ag 2 S:AgCl:PTFE = 1:1:2 WITH THE ADDITION OF DIFFERENT HEMATITE RATIO : diploma thesis
No full textZadnjih par godina ion–selektivne elektrode postale su predmet brojnih znanstvenih istraživanja. U ovom radu testirane su membrane sastava:
• RC2 → Ag 2 S:AgCl:PTFE = 1:1:2
• HC1 → Ag 2 S:AgCl:PTFE = 1:1:2 uz dodatak 1% nanočestica α–Fe 2 O 3
• HC2 → Ag 2 S:AgCl:PTFE = 1:1:2 uz dodatak 0,5% nanočestica α–Fe 2 O 3
• HC3 → Ag 2 S:AgCl:PTFE = 1:1:2 uz dodatak 0,25% nanočestica α–Fe 2 O 3
Metodom slijednog razrjeđivanja ispitivan je odziv srebrovih i kloridnih iona u otopinama srebrovog nitrata i natrijevog klorida pri različitim pH vrijednostima. Razrjeđivanje se vršilo dok razlika između mjerenja nije bila manja od 1 mV. Svaka membrana je testirana minimalno tri puta. Dobiveni rezultati grafički su prikazani. Za ovakva ispitivanja najučinkovitija je potenciometrija zbog jednostavnosti, praktičnosti te niske cijene.Last few years ion-selective electrodes have become the subject of many scientific research. In this thesis tested membranes are based on:
• RC2 → Ag 2 S:AgCl:PTFE = 1:1:2
• HC1 → Ag 2 S:AgCl:PTFE = 1:1:2 with 1% α–Fe 2 O 3 nanoparticles
• HC2 → Ag 2 S:AgCl:PTFE = 1:1:2 with 0,5% α–Fe 2 O 3 nanoparticles
• HC3 → Ag 2 S:AgCl:PTFE = 1:1:2 with 0,25% α–Fe 2 O 3 nanoparticles
The response of silver and chloride ions in silver nitrate and sodium chloride solutions with different pH values was tested using serial dilution method. Dilution was made until difference between two potential measurements was smaller than 1 mV. Each membrane was tested minimum three times. The results are presented graphically. The potentiometric method is most suitable for this test due to its simplicity, practicality, and acceptable prices
Development of a method for qualitative determination of glutathione using a HPLC-DAD system : bachelor thesis
No full textGlutation (GSH) je intracelularni antioksidans. Tripeptid je glutamata, cisteina i glicina. Poznat je pod kemijskim nazivom kao γ-glutamilcisteinilglicin. (2S)-2-amino-4-[[(1R)-[(karboksimetil) karbamoil]- 2-sulfaniletil] karbamoil] butanoična kiselina. Glutation ima razne fiziološke funkcije među kojima je najistaknutija njegova antioksidacijska uloga štićenja stanica od slobodnih radikala i reaktivnih kisikovih vrsta, zbog čega je prisutan u skoro svim stanicama. Ovaj rad opisuje razvoj metode za kvantitativno određivanje glutationa pomoću tekućinske kromatografije visoke djelotvornosti spregnute s nizom dioda kao detektorom.Glutathione(GSH) is a intracellular thiole, tripeptide of glutamate, cisteine, and gycine. Chemically known as (2S)-2-amino-4-[[(1R)-[(carboxymethyl) carbamoyl]-2-sulfanylethyl] carbamoyl] butanoic acid. Glutathione has diverse physiological functions, the most prominent one being his antioxidant role in protection against reactive oxygen species, because of which he is present within almost every cell. This paper describes the development of a method for quantitative determination of glutathione via high performance liquid chromatography coupled with a diode array detector
AMYLOGRAPHIC DETERMINATION OF THE QUALITY OF WHEAT FLOUR WITH A LACTIC ACID SOLUTION : diploma thesis
No full textZadatak ovog rada bio je ispitati utjecaj primjene otopine mliječne kiseline u amilografskim ispitivanjima bez zagrijavanja suspenzije brašna i vode te odrediti razlike u viskoznosti suspenzije u odnosu na određivanje s vodom kao otapalom. Osim toga, kako bi se utvrdila eventualna međuovisnost, provedena je usporedba dobivenih rezultata amilografskog određivanja viskoznosti suspenzije brašna i otopine mliječne kiseline s udjelima proteina i glutena, s retencijskom sposobnosti brašna prema vodi i otopini mliječne kiseline, sedimentacijskom vrijednosti te s farinografskim i ekstenzografskim pokazateljima kvalitete pšeničnog brašna. Na temelju ispitivanja provedenih u ovom radu može se zaključiti da se amilografskim ispitivanjem brašna bez klasične primjene zagrijavanja suspenzije, odnosno bez želatinizacije škroba, mogu uspješno predvidjeti kvalitativna svojstava brašna koje ovise o proteinskoj komponenti. Prilikom korištenja mliječne kiseline, a uslijed bubrenja i agregacije proteina, viskoznost suspenzije je značajno veća nego prilikom korištenja vode kao otapala što daje veći raspon rezultata, a samim tim olakšano je i uočavanje razlika između uzoraka. Rezultati amilografskog ispitavanja uz otopinu mliječne kiseline i miješanje od 10 min najbolje koreliraju s udjelom proteina i glutena, kao i s rezultatima farinografskog i ekstenzografskog ispitivanja.The aim of this study was to investigate the influence of using lactic acid solution in amylographic test without heating the flour-water suspension, and to determine the differences in the viscosity of the suspension compared to the determination using water as solvent. Comparison of the results of amylographic determination of the viscosity of the suspension of flour and lactic acid solution with the proportions of protein and gluten, with the lactic acid and water solvent retention capacity, the sedimentation value and with farinographic and extensographic quality indicators of wheat flour was carried out in order to determine a possible correlations. Based on the tests carried out in this research, it can be concluded that the qualitative properties of flour, which depend on the protein component, can be successfully predicted by the amylographic analysis of flour without the classical application of suspension heating, i.e. without gelatinization of starch. When lactic acid was used, the viscosity of the suspension was significantly higher than when water was used as a solvent, due to the swelling and aggregation of the proteins, which leads to a wider range of results and thus makes it easier to detect differences between samples. The results of the amylographic examination using lactic acid solution and a mixing time of 10 minutes correlated best with the protein and gluten content, as well as with the results of the farinographic and extensographic examination
Influence of digestate from a biogas plant on chemical characteristicsof soil : bachelor thesis
No full textU ovome radu ispitane su kemijske karakteristike tri uzorka tla: tlo bez dodanog digestata, tlo na koje je digestat dodan prije 17 mjeseci i tlo na koje je digestat dodan par dana prije uzorkovanja, kako bi se vidio utjecaj digestata na ispitivano tlo. Određena je njihova kiselost, količina humusa, udio amonijačnog dušika, sadržaj ukupnih karbonata, količina fiziološki aktivnog vapna, sadržaj zamjenjivog aluminija te udio teških metala (bakar, cink, kadmij, krom, nikal, olovo). Prema dobivenim rezultatima uzorci tla pripadaju skupini umjereno kiselih, odnosno slabo kiselih do neutralnih tala. Svi uzorci su vrlo slabo humozna tla sa niskom opskrbljenosti dušikom, karbonatima i fiziološki aktivnim vapnom. Sadržaj aluminija u tlu bez digestata je 0,05 mg te 0,15 mg u uzorcima sa digestatom. Koncentracije teških metala u ispitivanim uzorcima i digestatu određene su tehnikom masene spektrometrije s induktivno spregnutom plazmom (ICP-MS), a dobiveni rezultati međusobno uspoređeni. U uzorku digestata najniže određena koncentracija ispitivanih teških metala izmjerena je za kadmij (0,43 mg kg -1 ), a najviša za cink (318,00 mg kg -1 ). U uzorcima tala najniže određene koncentracije ispitivanih teških metala izmjerene su za kadmij, čija koncentracija doseže najvišu vrijednost u uzorku tla na koje je digestat dodan prije 17 mjeseci (0,07 mg kg -1 ). Najviše koncentracije ispitivanih teških metala izmjerene su za olovo, čija koncentracija doseže najvišu vrijednost u uzorku tla na koje je digestat dodan prije 17 mjeseci (12,38 mg kg -1 ). Usporedbom dobivenih rezultata za digestat i uzorke tala s Pravilnikom o nusproizvodima i ukidanju statusa otpada, odnosno Pravilnikom o zaštiti poljoprivrednog zemljišta od onečišćenja određene koncentracije teških metala ne prelaze granicu maksimalno dopuštenih količina (MDK).In this bachelor thesis chemical characteristics were investigated of three soil samples: soil without added digestate, soil to which digestate was added 17 months ago, and soil with digestate added a few days before sampling, to see the impact of digestate on the tested soil. The characteristics of the samples that were determined are acidity, humus, ammonium nitrogen, carbonates, physiologically active lime, exchangeable aluminum and heavy metals (copper, zinc, cadmium, chromium, nickel, lead). According to the obtained results, all samples of soils belong to the group of moderately acidic, or weakly acidic to neutral soils. All samples are very weakly humus soils with a low supply of nitrogen, carbonates and physiologically active lime. The aluminum content in the soil without digestate is 0.05 mg and 0.15 mg in samples with digestate. The concentrations of heavy metals in the tested samples and digestate were determined using the technique of inductively coupled plasma mass spectrometry (ICP-MS), and the obtained results were compared with each other. In the digestate sample, the lowest determined concentration of tested heavy metals was measured for cadmium (0.43 mg kg -1 ), and the highest for zinc (318.00 mg kg -1 ). In the soil samples, the lowest determined concentrations of the tested heavy metals were measured for cadmium, whose concentration reached the highest value in the soil sample to which the digestate was added 17 months ago (0.07 mg kg -1 ). The highest concentrations of tested heavy metals were measured for lead, whose concentration reached the highest value in the soil sample to which digestate was added 17 months ago (12.38 mg kg -1 ). By comparing the obtained results for digestate and soil samples with Pravilnikom o nusproizvodima i ukidanju statusa otpada, apropos Pravilnikom o zaštiti poljoprivrednog zemljišta od onečišćenja, certain concentrations of heavy metals do not exceed the limit of maximum permissible amounts (MDK)
Preparation of carbon paste electrodefor determination of maprotiline : diploma thesis
No full textElektrode na bazi ugljikove paste (CPE) čestose koriste u elektroanalitičkim metodama analize. Navedene elektrode su smjese pripremljene od ugljikovog materijala (grafita), različitih veziva: DPB, NPOE, T(2EH)PH i DEHA; soli Na-TPB.-a te ionsko asocijacijskog kompleksa (IAC) u različitim omjerima. Korištena su tri IAC-sa: MAPREIN, MAP PTA i MAP-MOLIB, pripremljeno je 18 pasta s ciljem pronalaska senzora za određivanje jednokationskog maprotilina u realnim uzorcima u koncentracijskom području od 3,16×10 -6 do 3,16×10 -3 mol L -1 pri pH vrijednosti 4,5. Najbolje odzivne karakteristike pokazala je pasta napravljena od grafita, Na-TPB, veziva i ionsko-asocijacijskog kompleksa MAP-TPB uz dodatak soli (pasta 8). Elektroda s membranom broj 8 pokazala je promjenu potencijala po koncentracijskoj dekadi od 59, 66 mV u linearnom koncentracijskom području od 3,16×10 -6 do 3,16×10 -3 mol L -1Carbon paste (CPE) electrodes are most commonly used in electroanalytical methods of analysis. These electrodes are mixtures of carbon paste prepared from carbon material (graphite), various binders: DPB, NPOE, T(2EH)PH and DEHA; and salts of Na-TPB and ion association complex (IAC) in different ratios. Three IAC who were used: MAPREIN, MAP PTA and MAP-MOLIB, with monitoring for the effect of paste conductivity. 18 pastes were prepared in order to find a sensor for the determination of single-cation maprotiline in real samples in the concentration range from 3.16 x 10 -6 to 3.16 x 10 -3 mol L -1 at pH 4,5. The paste made of graphite, Na-TPB, binder and ion-association complex MAP-TPB with the addition of salt (paste 8) showed the most desirable response characteristics. Membrane electrode no. 8 showed a potential change per concentration decade of 59.66 mV in the linear concentration range of 3.16 × 10-6 to 3.16 × 10 -3 mol L -1
Construction waste managment in the Republic of Croatia : bachelor thesis
No full textU ovome radu razrađena je tema građevinskog otpada i gospodarenja takvim otpadom na području Republike Hrvatske. Prvi dio ovoga rada, radi lakšeg razumijevanja, baziran je na sam pojam otpada i njegovu podjelu prema mjestu nastanka, svojstvima te se spominju i posebne kategorije definirane na području RH. Objašnjeno je i gospodarenje svim vrstama otpada na temelju kružnog gospodarstva, kojim se trebaju voditi sve članice Europske Unije. Također, naglašena je i potreba izgradnje centara za gospodarenje, reciklažnih dvorišta zajedno s pretovarnim stanicama i legalnih odlagališta, a sve u cilju smanjenja stvaranja divljih odlagališta koji nastaju isključivo neodgovornim postupanjem s otpadom od strane ljudi. Zatim, u drugom dijelu detaljno će se opisati građevinski otpad i otpad od rušenja. Razmotrit će se njegova podjela prema vrsti nastanka i stupnju opasnosti, kategorizacija koja uključuje zapis i odgovarajući ključni broj te postupak pronalaženja odgovarajuće vrste s pripadajućim ključnim brojem. Uz velike napore kroz povijest, danas uz postojeću modernu tehnologiju moguće je vrlo lako sve vrste otpada, pa tako i građevinski, iskoristiti kao sekundarnu sirovinu. Da bi to postigli neophodno je pravilno njime gospodariti. Prvenstveno ga treba spriječiti ili preusmjeriti i pretvoriti u resurs, ako nije moguće treba ga podvrgnuti nekom od postupaka oporabe. Treba spriječiti njegovo odlaganje u okoliš što je više moguće. Ovoj tematici gospodarenja građevinskim otpadom posvetit će se velika pažnja u ovome dijelu s naglaskom na proces recikliranja koji će biti opširno pojašnjen. Na samom kraju slijedi upoznavanje s trenutnim stanjem u Republici Hrvatskoj, primjerima dobrog gospodarenja i mogućnostima unaprjeđenja sustava za gospodarenje građevinskim otpadom koji je u velikom zaostatku u odnosu na razvijenije zemlje.In this paper, the topic of construction waste and the management of such waste on the territory of the Republic of Croatia has been elaborated. For better understanding, the first part of this paper is based on the very concept of waste and its division according to the place of origin and properties. Furthermore, special categories of waste defined on the territory of the Republic of Croatia are also mentioned. The management of all these types of waste based on the circular economy, which should be managed by all members of the European Union, is also explained. It also emphasized the need to build management centers, recycling yards together with transhipment stations and legal landfills, all with the aim of reducing the creation of wild landfills that are created solely by irresponsible treatment of waste by people. Then, in the second part, construction and demolition waste are described in detail. Its giveaways by type of occurrence and degree of danger, a categorisation involving a record and an corresponding key number, the process of finding the appropriate species with the corresponding key number, will be considered. With great efforts throughout history, today with the existing modern technology it is possible to easily use all types of waste, including construction, as secondary raw material. To do this, it is necessary to properly manage it. It should primarily be prevented or redirected and converted into a resource, if it is not possible it should be subjected to one of the recovery procedures. It should be prevented from being disposed of in the environment as much as possible. In this topic of construction waste management great attention will also be given to the recycling process, which will be clarified extensively. At the very end there is an introduction to the current situation in the Republic of Croatia, examples of good management and opportunities to improve the system for the management of construction waste, which is in a large lag compared to more developed countries
Prepatation of ion sensor based on graphite paste for determination of acebutolol with tetraphenlyborate and phosphomolybdate as anionic part of IAC : diploma thesis
No full textElektrode na bazi paste od ugljika (CPE) su posebne heterogene ugljikove elektrode koje čini smjesa ugljikovih pasti pripravljenih s različitim udjelima grafita, veziva, ionsko-asocijacijskog kompleksa, soli. CPE imaju široku primjenu u određivanju elektrokemijski aktivnih spojeva. U ovom radu pripravljen je potenciometrijski senzor na bazi paste od grafita uz PMA i TPB kao anionskog dijela IAC-a za određivanje acebutolola u realnim uzorcima. Pripravljene su i testirane 22 paste s različitim udjelima grafita, tekućih veziva (TEPh, DEHA, NPOE) i IAC-a (ACBTPB, ACBPMA) pri pH vrijednosti 5. U paste s najboljim odzivnim karakteristikama dodana je mala količina soli NaTPB-a. Najbolje odzivne karakteristike pokazala je pasta 16 pripravljena od 54,8% grafita, 44,8% TEPh-a, 0,3% IAC-a ACB PMA i 0,1% NaTPB. Promjena potencijala po koncentracijskoj dekadi je u rasponu od -36,3 mV do -51,8 mV. Elektroda je drugi dan mjerenja nakon prvog poliranja pokazala najbolju promjenu potencijala po koncentracijskoj dekadi od -51,0 mV odnosno -51,8 mV u području linearnosti od 3,16×10 -6 M do 3,16×10 -3 M. Vrijeme uspostave stabilnog odziva je 60 s.Carbon paste electrodes are special group of heterogeneous carbon electrodes mixture of carbon pastes are prepared with different parts of grahite, binder, ion-association complex and salt. CPE are widely used as working electrodes for the determination of electrochemically active compounds. In this experiment are prepared the potentiometric sensor based on graphite paste with tetraphenylborate and phosphomolybdate as anionic part of ionic-association complex for determination of acebutolol in real samples. 22 pastes with different proportions of graphite, liquid binders (TEPh, DEHA, NPOE) and IAC (ACBTPB, ACBPMA) were prepared and tested at pH 5. A small amount of NaTPB salt was added to the pastes with the best response characteristics. The best response characteristics were shown by paste 16 prepared from 54.8% graphite, 44.8% TEPh, 0.3% IAC ACB PMA and 0.1% NaTPB. The change in potential per concentration decade ranges from -36.3 mV to -51.8 mV. On the 2 nd day of measurement after the 1 st polish, the electrode showed the best potential change per concentration decade from -51.0 mV and -51.8 mV in the linearity range from 3.16×10 -6 M to 3.16×10 -3 M. The time to establish a stable response is 60 s
Development of electrodes based on carbon paste for the determination of acebutolol by potentiometry with different electroactive substances and binders : master thesis
No full textU elektrokemijskim mjerenjima često se primjenjuju elektrode na bazi paste od ugljika zbog njihovih dobrih fizikalno – kemijskih svojstava. Ugljikova pasta priprema se miješanjem ugljikovog materijala, veziva, ionsko – asocijacijskih kompleksa (IAC – a), a da bi se poboljšale odzivne karakteristike elektroda u ugljikovu pastu se mogu dodati modifikatori. Pripremljeno je i ispitivano 29 pasti s ciljem dobivanja senzora za potenciometrijsko određivanje acebutolola. Svaka elektroda ispitivana je u vremenskom periodu od dva dana u koncentracijskom području od 3,16 x 10 -6 mol L -1 do 3,16 x 10 -3 mol L -1 , pri pH vrijednosti od 4,5. Najbolje odzivne karakteristike pokazala je elektroda 7 koja sadrži 54,9% grafita, 44,8% dibutil-ftalata (DBP) i 0,3% acebutolol fosfovolframata (AC – PTA), a ostvareni nagib iznosi 42,9 mV. Dodatak ionskih aditiva, s ciljem poboljšanja osjetljivosti elektroda, očitovao se samo kod elektrode 28 koja sadrži 54,0% grafita, 44,1% dibutil- ftalata (DBP), 1,5% acebutolol fosfovolframata (AC – PTA) i 0,4% natrijevog tetrafenilborata (NaTPB), a ostvareni nagib iznosi 40,8 mV.Electrodes based on carbon paste are often used in electrochemical measurements due to their good physical and chemical performance. Carbon paste is prepared by mixing carbon material, binder, ion – association complexes (IAC – a), and in order to improve the response characteristics of the electrodes, modifiers can be added to the carbon paste. It was prepared and tested 29 pastes were with the aim of obtaining a sensor for the potentiometric determination of acebutolol. Each electrode was tested over a period of two days in the concentration range from 3.16 x 10 -6 mol L -1 to 3.16 x 10 -3 mol L -1 , at a pH value of 4.5. The best response characteristics were shown by electrode 7, which contains 54.9% graphite, 44.8% dibutylphthalate (DBP) and 0.3% acebutolol phosphotungstate (AC – PTA), and the achieved slope is 42.9 mV. The addition of ionic additives, with the aim of improving the sensitivity of the electrodes, manifested itself only in electrode 28, which contains 54.0% graphite, 44.1% dibutylphthalate (DBP), 1.5% acebutolol phosphotungstate (AC – PTA) and 0.4% sodium tetraphenylborate (NaTPB), and the achieved slope is 40.8 mV
Recycling of poly(ethylene terephthalate) : bachelor thesis
No full textPoli(etilen–tereftalat) (PET) polimer je širokog područja primjene. Njegova fizikalna i kemijska svojstva čine ga pogodnim za različite primjene, posebice kao ambalažnog materijala. Međutim, otpadni polimerni materijali, pa tako i PET predstavljaju veliki problem ukoliko se odbacuju u okoliš. Stoga je učinkovit sustav oporabe vrlo važan. PET ambalažu moguće je oporabiti na više načina, i to: mehanički, kemijski i energijski. Najzastupljeniji način oporabe PET-a je mehanička oporaba. Prije samog postupka oporabe materijal je potrebno prikupiti, oprati i usitniti. PET se oporabljuje zbog dobivanja polaznih sirovina ili novog materijala.Poly(ethylene terephthalate) (PET) is a polymer with a wide range of applications. Its physical and chemical properties make it suitable for various applications, especially as a packaging material. However, waste polymeric materials, including PET, are a big problem if they are discarded into the environment. Therefore, an effective recovery system is very important. PET packaging can be recovered in several ways: mechanically, chemically and energetically. The most common method of recycling of PET is mechanical recovery. The material must be collected, cleaned, and cut before beginning the recovery process. PET recycling is done in order to obtain newmaterials or the inital raw ingredients
Effect of the fulvic acids on lead ions binding on natural zeolite : bachelor thesis
No full textIspitano je vezanje iona olova iz vodenih otopina na prirodnom zeolitu u prisutsvu organske tvari. Simulacija organske tvari izvedena je dodatkom vodene otopine preparata Fertireg ® različitih početnih koncentracija. Fertireg ® je trgovački naziv za organsko gnojivo koje ima visoku koncentraciju fulvinskih i drugih organskih kiselina koje se nalaze u tlu u prirodi. Utvrđeno je da ne dolazi do kompleksiranja olova u otopini Fertireg ® za obje početne koncentracije. Također je uočeno malo odstupanje u točnosti određivanja koncentracije olova zbog nemogućnosti određivanja točke ekvivalencije. Vezanje iona olova na zeolitu u suspenziji bez i s dodatkom otopine Fertireg ® ne pokazuje značajna odstupanja u količini vezanog olova po gramu zeolita. Može se zaključiti da organsko gnojivo Fertireg ® u navedenim eksperimentalnim uvjetima ne bi trebalo imati utjecaj na remedijaciju tla onečišćenog ionima olova korištenjem prirodnog zeolita.The removal of lead ions from aqueous solutions on natural zeolite in the presence of organic matter has been examined. The simulation of organic matter has carried out by preparation of aqueous solution of the Fertireg ® of different initial concentrations. The Fertireg® is a trade name for organic fertilizer which contains high content of fulvic and other organic acids, which are found in the soil in nature. It was found that no precipitation of lead occurs in the Fertireg ® solution for both initial concentrations. A small deviation in the accuracy of determining the lead concentration has been observed due to the impossibility of determining the equivalence point. The binding of lead ions on zeolite in suspension without and with the addition of Fertireg ® solution does not show significant deviations in the amount of bound lead per gram of zeolite. It can be concluded that Fertireg ® organic fertilizer in the mentioned experimental conditions should not have an impact on the remediation of soil contaminated with lead ions using natural zeolite