Utjecaji matrice s visokim udjelom kalcija u emisijskoj plazma spektrometriji pri analizi elementnog profila školjki

master's thesis

• Title (english): High-content calcium matrix effects on elemental profiling of shell samples in emission plasma spectrometry
• Author: Kristina Kobelja
• Mentor: Sanda Rončević (mentor)
• Committee member: Sanda Rončević (predsjednik povjerenstva)
• Committee member: Ines Primožič (član povjerenstva)
• Committee member: Biserka Prugovečki (član povjerenstva)
• Committee member: Predrag Novak (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2016-09-23, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Školjke su najčešće proučavani bio-indikatorski organizmi u istraživanjima antropogenih utjecaja na stanje okoliša. Sadržaj metala u ljušturama školjaka uvelike ovisi o uvjetima u okolišu, budući da se metali akumuliraju procesima biomineralizacije, precipitacije ili adsorpcije. Koncentracije metala inkorporiranih u mineralnoj strukturi ljušture se vrlo sporo mijenjaju, za razliku od tkiva gdje su promjene koncentracije uzrokovane izmjenom fizioloških ili reproduktivnih uvjeta. Analitičke spektrometrijske metode temeljene na plazma izvoru omogućavaju precizno i istodobno određivanje koncentracije metala u realnim uzorcima. Međutim, interferencije uzrokovane matricom s visokim udjelom kalcijevih soli mogu značajno utjecati na kvantitativno određivanje sadržaja metala na način da povećavaju ili reduciraju ukupni intenzitet promatranih spektralnih linija.
U ovom istraživanju, koncentracije osamnaest metala mjerene su metodom ICP-AES, u uzorcima s visokim sadržajem kalcijevog karbonata kao što su ljušture kunjki (lat. Arca noae, Linnaeus, 1758.). Usporedbom mjerenih detekcijskih granica i područja linearnosti za standardne vodene otopine i otopine s prethodno ugođenom matricom, ispitana je prisutnost spektralnih i ne-spektralnih interferencija. Odabrani ugođeni uvjeti mjerenja primijenjeni su na reprezentativnim uzorcima kunjki prikupljenih tijekom nekoliko mjeseci 2014. godine u Parku prirode Telašćica i Pašmanskom kanalu. Zadovoljavajuća analitička točnost primijenjenih postupaka obrade i mjerenja uzoraka utvrđena je poredbenom analizom certificiranih referentnih materijala. Elementni profil uzoraka izveden je iz mjerenih podataka upotrebom kemometrijskih alata, tj. univarijatnim i multivarijatnim statističkim testovima. Utjecaj različitih uvjeta okoliša na sadržaj metala u ljušturi promatran je kroz analizu glavnih komponenata (PCA). Određivanjem elementnog profila ljušture kunjke dobiven je uvid u stanje vrste i utjecaja okoliša na promatranim lokacijama.

Abstract (english)

Mussels are commonly probed bio-marker species in studies of anthropogenic influences on environment. Metal content in shells mostly depends on environmental conditions, since metals tend to accumulate through biomineralization, precipitation and adsorption processes. Concentration of incorporated metals in mineral structure of the shell changes slowly, in contrast to variable concentration of metals in mussels' tissue caused by changes in physical and reproductive conditions. Analytical spectrometric methods based on plasma source provide precise and simultaneous determination of metal concentrations in real samples. However, interferences caused by high-content calcium matrix can have a significant influence on quantitative determination of the metal content in samples, in a manner of increasing or decreasing total intensity of the observed spectral lines.
In this study, concentrations of the eighteen elements were measured using ICP-AES method, in samples with hight-content calcium matrix, such as the Noah Ark's shell crust (lat. Arca noae, Linnaeus, 1758.). Comparison of the measured detection limits and linearity ranges for standard aqueous solutions and matrix-matched calibration solutions was used to test the presence of spectral and no-spectral inerferences. The chosen measuring conditions were applied on representative samples of Noah's Ark shells collected in Pašman channel and in Nature park Telašćica during several months in 2014. Satisfying analytical accuracy of applied analytical procedures and sample measurements was established in comparison with certified reference materials. The elemental profile of the shell samples was derived from measured set of data using chemometric tools, univariate and multivariate analysis. The impact of different environmental conditions on elements content in shell samples was observed by use of multivariate statistical method (PCA). Elemental profiling of mussel shell Noah's Ark provides an insight in species status as well as in environmental status on the observed locations.

• Keywords: ICP-AES; kunjka; metali
• Keywords (english): ICP-AES; metals; Noah's Ark shell
• Language: croatian
• URN:NBN: urn:nbn:hr:217:792808
• Study programme: Title: Graduate university studies in chemistry; specializations in: Research programme; Course: Research programme; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra kemije (magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2018-09-23
• Created on: 2017-03-15 12:29:24