Primerjava metod za določanje arzena

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Language:	Slovenian
Year of publishing:	2013
Source:	Ljubljana
Typology:	2.11 - Undergraduate Thesis
Organization:	UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher:	[U. Rebernik]
UDC:	543.632.472(043.2)
COBISS:	9799241
Views:	2983
Downloads:	623
Average score:	0 (0 votes)
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Secondary language:	English
Secondary title:	Comparison methods for the determination of arsenic
Secondary abstract:	All over the world, even in our own country, millions of people are faced with the daily problem of drinking water saturated with arsenic. Half of those, today, still have no alternative and survive by drinking arsenic-ridden water. Therefore, in recent years, people often wonder what the quality of water here actually is. Water quality is the term for the physical, chemical and biological characteristics of water, which are under the supervision of the Environment Agency of the Republic of Slovenia at all times. In the first part of the thesis, I compared and optimized two different methods for the determination of arsenic; electrothermal atomic absorption spectrometry (ETAAS) and the volumetric method, redox-titration (oxidation-reduction) with potassium bromate(V) (KBrO3), and for each method, the content of arsenic in real samples of suspected contaminated areas was also set. I found that the ETAAS instrumental method is better for measurements in the low concentration range, while the oxidation-reduction titration using potassium bromate(V) is more suitable for measurement in higher concentration ranges. In actual samples, it is therefore only possible to detect the presence of arsenic with electrothermal atomic absorption spectrometry, since the concentration in the sample is too low to be determined by oxidation-reduction titration with potassium bromate(V). The study could therefore be extended with a larger selection of actual samples. In addition to water from the allegedly contaminated areas, one could also analyze soil, sediment and biological samples. In the second part of the thesis, I presented content transferred from practical training as part of an optional high school Chemistry and Food Chemistry course, where, in two lessons, students learned redox-titration (oxidation-reduction) as one of the methods for determining vitamin C concentrations in various samples of effervescent tablets.
Secondary keywords:	chemistry;kemija;
File type:	application/pdf
Type (COBISS):	Undergraduate thesis
Thesis comment:	Univ. Ljubljana, Pedagoška fak., Biotehniška fak., Fak. za kemijo in kemijsko tehnologijo, Naravoslovnotehniška fak., Kemija in biologija
Pages:	XI, 70 str.
Type (ePrints):	thesis
Title (ePrints):	Comparison methods for the determination of arsenic
Keywords (ePrints):	analitske metode
Keywords (ePrints, secondary language):	analytical methods
Abstract (ePrints):	Povsod po svetu, tudi pri nas, se na milijone ljudi vsakodnevno sooča s problemi pitne vode, nasičene z arzenom. Polovica prebivalstva danes še vedno nima druge možnosti in mora za svoje preživetje uživati vodo, polno arzena, kar je zaskrbljujoče. Zato se v zadnjih letih ljudje pogosto sprašujemo, kakšna je kakovost slovenske vode. Kakovost vode je izraz za fizikalne, kemične in biološke značilnosti vode in je ves čas pod nadzorom Agencije RS za okolje. V prvem delu diplomskega dela sem primerjala in optimizirala dve različni metodi za določanje arzena, elektrotermično atomsko absorpcijsko spektrometrijo (ETAAS) in volumetrijsko metodo, redoks-titracijo (oksidacijsko-redukcijsko) s kalijevim bromatom(V) (KBrO3), ter z obema določila vsebnost arzena v realnih vzorcih z domnevno onesnaženega področja. Ugotovila sem, da je instrumentalna metoda ETAAS boljša za merjenje v nižjem koncentracijskem območju, medtem ko je oksidacijsko-redukcijska titracija s kalijevim bromatom(V) ustreznejša za merjenje v višjem koncentracijskem območju. V realnih vzorcih je bilo zato mogoče samo z elektrotermično atomsko absorpcijsko spektrometrijo zaznati prisotnost arzena, saj je bila koncentracija v vzorcu prenizka, da bi jo lahko določili tudi z oksidacijsko-redukcijsko titracijo s kalijevim bromatom(V). Raziskavo bi lahko v nadaljevanju razširili z večjim izborom realnih vzorcev. Poleg vode z domnevno onesnaženega področja bi lahko analizirali še vzorce tal, sedimenta in različne biološke vzorce. V drugem delu diplomskega dela sem predstavila vsebino, ki sem jo prenesla v šolsko prakso v sklopu izbirnega predmeta Kemija in hrana pri predmetu Kemija za gimnazijski program, kjer dijaki v dveh učnih urah spoznajo redoks-titracijo (oksidacijsko-redukcijsko) kot eno izmed metod za določanje vitamina C v različnih vzorcih šumečih tablet.
Abstract (ePrints, secondary language):	All over the world, even in our own country, millions of people are faced with the daily problem of drinking water saturated with arsenic. Half of those, today, still have no alternative and survive by drinking arsenic-ridden water. Therefore, in recent years, people often wonder what the quality of water here actually is. Water quality is the term for the physical, chemical and biological characteristics of water, which are under the supervision of the Environment Agency of the Republic of Slovenia at all times. In the first part of the thesis, I compared and optimized two different methods for the determination of arsenic; electrothermal atomic absorption spectrometry (ETAAS) and the volumetric method, redox-titration (oxidation-reduction) with potassium bromate(V) (KBrO3), and for each method, the content of arsenic in real samples of suspected contaminated areas was also set. I found that the ETAAS instrumental method is better for measurements in the low concentration range, while the oxidation-reduction titration using potassium bromate(V) is more suitable for measurement in higher concentration ranges. In actual samples, it is therefore only possible to detect the presence of arsenic with electrothermal atomic absorption spectrometry, since the concentration in the sample is too low to be determined by oxidation-reduction titration with potassium bromate(V). The study could therefore be extended with a larger selection of actual samples. In addition to water from the allegedly contaminated areas, one could also analyze soil, sediment and biological samples. In the second part of the thesis, I presented content transferred from practical training as part of an optional high school Chemistry and Food Chemistry course, where, in two lessons, students learned redox-titration (oxidation-reduction) as one of the methods for determining vitamin C concentrations in various samples of effervescent tablets.
Keywords (ePrints, secondary language):	analytical methods
ID:	8311751