Določanje nepolarnih benzotriazolov v okolju

diplomsko delo

Maksimiljan Dekleva (Author), Helena Prosen (Mentor)

Abstract

Nepolarni benzotriazoli, ki jih v literaturi pogosto poimenujejo tudi benzotriazolni UV stabilizatorji, so zaradi zmožnosti absorpcije svetlobe v širokem delu UV področja industrijsko izredno pomembne kemikalije. Njihova uporaba narašča povsod po svetu, najpogosteje pa jih najdemo v šamponih, zobnih pastah, barvah za lase, laku za nohte, ličilih, kontaktnih lečah in podobnih izdelkih. Razširjena uporaba kot posledica antropogenih aktivnosti vodi v dokazano akumulacijo v okolju. Povišane vrednosti so bile dokazane v različnih morskih in obmorskih organizmih povsod po svetu, pa tudi v vodnih in sedimentnih vzorcih. V diplomskem delu sem se posvetil pregledu do sedaj razvitih metod za določanje nepolarnih benzotriazolov. V eksperimentalnem delu sem optimiziral pogoje za separacijo na koloni za tekočinsko kromatografijo z visoko ločljivostjo z detektorjem na serijo diod. V do sedaj razvitih metodah kot ekstrakcijski način za analizo tekočih vzorcev prevladuje ekstrakcija na trdno fazo, zasledimo pa tudi uporabo ekstrakcije na magnetno mešalo, mikroekstrakcijo na trdno fazo in ekstrakcijo tekoče-tekoče z lijem ločnikom. Med ekstrakcijskimi tehnikami za analizo sedimentnih in bioloških vzorcev pa prevladuje Soxhletova ekstrakcija, zasledimo pa lahko tudi ekstrakcijo s topili pod tlakom, ultrazvočno ekstrakcijo, ekstrakcijo s topili z visokimi hitrostmi, ekstrakcijo s stresanjem in ekstrakcijo z mikrovalovi. Separacija posameznih kemijskih zvrsti najpogosteje poteka na GC oziroma HPLC kolonah in njihovih naprednejših modifikacijah, za detekcijo pa se uporablja sklopitev z MS oz. MS/MS. V eksperimentalnem delu sem določil optimalni gradient mobilne faze in dosegel ostre in dobro ločene kromatografske vrhove s sorazmerno kratkim časom analize. Optimizirana metoda ima dobro ponovljivost v širokem linearnem območju.

Keywords

nepolarni benzotriazoli;ekstrakcija na trdno fazo;analizne metode;tekočinska kromatografija visoke ločljivosti;HPLC;diplomska dela;

Data

Language:	Slovenian
Year of publishing:	2020
Typology:	2.11 - Undergraduate Thesis
Organization:	UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher:	[M. Dekleva]
UDC:	543.544.5HPLC(043.2)
COBISS:	30109699
Views:	500
Downloads:	164
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Determination of non-polar benzotriazoles in the environment
Secondary abstract:	Non-polar benzotriazoles, commonly known as benzotriazole UV stabilizers, are capable of absorbing radiation in a broad UV spectrum, making them extremely important industrial chemicals. In recent decades, the use of non-polar benzotriazoles has increased in all parts of the world, they are frequently found in shampoo, toothpaste, hair dyes, nail polish, make-up, contact lenses and similar products. Their widespread use as a result of anthropogenic activity leads to a proven accumulation in the environment. Elevated levels have been found in a wide range of marine and coastal organisms around the world, as well as in water and sediment samples. In my diploma thesis I concentrated on the verification of the methods developed so far for the determination of nonpolar benzotriazoles. In the experimental part I optimized the conditions for the separation on a high performance liquid chromatography column with a diode array detector. In the methods developed so far, solid phase extraction predominates as an extraction technique for the analysis of liquid samples. The use of sorptive stirred rod extraction, solid-phase microextraction and liquid-liquid extraction with a funnel separator is also frequently observed. Among the extraction techniques for the analysis of sediments and biological samples, Soxhlet extraction predominates. Pressure liquid extraction, ultrasonic extraction, high speed solvent extraction, "shaking" extraction and microwave assisted extraction were also used. The separation of individual chemical species is usually performed on GC or HPLC columns and their modifications, coupled with MS or MS /MS detector. In the experimental part I successfully optimized the gradient of the mobile phase, resulting in sharp and well separated chromatographic peaks with a relatively short analysis time. The optimized method has a good repeatability over a wide linear range.
Secondary keywords:	non-polar benzotriazoles;solid phase extraction;high performance liquid chromatography;
Type (COBISS):	Bachelor thesis/paper
Study programme:	1000373
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, UNI Kemija
Pages:	33 str.
ID:	12031355