Primena prirodnih minerala kao senzora za elektrohemijska određivanja različitih jedinjenja u vodenoj i nevodenoj sredini
Application of natural minerals as sensors for electrochemical determination of various compounds in aqueous and non-aqueous media
Докторанд
Stepanović, JelenaМентор
Stanić, ZorkaЧланови комисије
Joksović, LjubinkaLolić, Aleksandar
Ćirić, Andrija
Метаподаци
Приказ свих података о дисертацијиСажетак
Apstrakt:
Pirit, halkopirit, galenit, arsenopirit i magnetit su sulfidni/oksidni
monokristali veoma rasprostranjeni u prirodnom okruženju. Indikatorske elektrode
na bazi ovih prirodnih materijala imaju izraženu mehaničkou otpornost, hemijsku
inertnost, poluprovodljivost i netoksičnost. Zahvaljujući ovim karakteristikama
primenjuju se kao elektrohemijski senzori za različita analitička određivanja u vodi
i nevodenim rastvaračima.
Minerali arsenopirit i magnetit su, pod uticajem sredine, skloni formiranju
hidroksid/sulfidnog, odnosno hidroksid/oksidnog sloja koji služi kao senzor sa
karakteristikama pH elektroda. Minerali, pirit, halkopirit i galenit, zahvaljujući
jonima bakra inkorporiranim u kristalnu rešetku minerala, predstavljaju odlične
redoks indikatorske elektrode osetljive na jone bakra. Indikatorske elektrode sa
senzorima na bazi ovih minerala pokazuju stabilan potencijal, relativno brz odziv,
linearnu zavisnost potencijala od koncentracije p-toluensulfonske kiseli...ne sa
sub-Nernstovskim nagibom (odnosi se na arsenopirit i magnetit), odnosno linearnu
zavisnost potencijala od koncentracije Cu2+ jona sa sub-Nernstovskim nagibom
(odnosi se na pirit, halkopirit i galenit), uz visoku selektivnost, dobru
reproduktivnost dobijenih rezultata, potvrđenu inertnost u γ-butirolaktonu,
propilenkarbonatu i smeši rastvarača voda-acetonitril, kao i uz mogućnost primene
bez vremenskog ograničenja.
Arsenopiritna i magnetitna elektroda su uspešno primenjene za acido-bazna
određivanja benzoeve, salicilne i antranilne kiseline. Piritna, halkopiritna i
galenitna elektroda su korišćene za redoks određivanja organskih jedinjenja ferocena,
tiouree, tetrabutilamonijum-jodida i fenilhidrazina, kao i za redoks određivanje
L-askorbinske kiseline u farmaceutskim preparatima u nevodenoj sredini.
Relativna standardna devijacija određivanja ispitivanih jedinjenja manja je od
±1,00%.
Abstract:
Pyrite, chalcopyrite, galena, arsenopyrite and magnetite are sulfide/oxide monocrystals
widespread in the natural environment. Thanks to their mechanical resistance, chemical
inertness, semiconductivity and non-toxicity, indicator electrodes based on these natural
materials, have significant applications as electrochemical sensors for various analytical
determinations in water-based and nonaqueous solvents.
Minerals, arsenopyrite and magnetite, influenced by the environment, can form a
hydroxide/sulfide or hydroxide/oxide layer on the surface of the mineral, which acts as a sensor
with the characteristics of the pH electrodes. Minerals, pyrite, chalcopyrite and galena, thanks
to copper ions incorporated into the crystal lattice of the minerals, are excellent redox indicator
electrodes sensitive to copper ions. Indicator electrodes with sensors based on these minerals
show a stable potential, relatively short response time, linear dependence of potential on the
con...centration of p-toluenesulfonic acid with sub-Nernstian slope (pertaining to arsenopyrite
and magnetite), or linear dependence of potential on the concentration of Cu2+ ions with
sub-Nernstian slope (pertaining to pyrite, chalcopyrite and galena), with high selectivity, good
reproducibility of the obtained results, confirmed inertness in γ-butyrolactone, propylene
carbonate and in water-acetonitrile solvent, as well as with the possibility of application
without a time limit.
Arsenopyrite and magnetite electrodes have been successfully used for acid-base
determinations of benzoic, salicylic and anthranilic acid. Pyrite, chalcopyrite and galena
electrodes have been used for redox determination of the organic compounds of ferrocene,
thiourea, tetrabutylammonium iodide and phenylhydrazine as well as for the redox
determination of L-ascorbic acid in pharmaceutical preparations in a non-aqueous media.
The relative standard deviation of determination of the investigated compounds is less
than ±1.00%.