Inorganic ions are one of the most important group chemicals. Their importance is crucial for all living organisms on the planet and monitoring of their content is essential for this purpose in clinical or environmental analysis but also in the food industry, agriculture or many other industries. Many analytical methods for ion detection have been designed and used, depending on the area of their use. Recently, numerous methods have been adapted to areas where not primarily intended. One such methods may be, for example, laser ablation with inductively coupled plasma mass spectrometry, which has recently begun to affect the analysis of biological samples. As a complementary method, able to detect also non-metallic ions is capillary electrophoresis. In this master thesis, the possibility of applying capillary electrophoresis with indirect photometric detection for the separation of inorganic ions in cell lysates of HeLa cells by capillary electrophoresis was verified. Main attention was paid to chloride ions. The ability to separate inorganic compounds in cellular material using salicylic acid as an absorbing anion in the base electrolyte was tested.

This work deals with the determination of L-carnitine in food supplements. L-carnitine is a substance naturally occurring in organism, essential for metabolism of fatty acids. In food supplements is used especially for reducing body weight as a "fat burner". L-carnitine is popular with athletes for improve athletic performance. While data are not available to support these positive effects of carnitine, the positive results of carnitine supplementation in the medicine were found, mainly on cardiovascular system. The literary part of this study describes the properties and the use of carnitine in the diet of human. Furthermore, a review of methods used for determination of L-carnitine in variety of samples is mentioned. In the experimental section the efficiency of SPE method for preparation matrix of real samples was investigated. A cation exchange solid phase extraction seems to be the most effective. The optimal conditions for isolation of L-carnitine by SPE extraction were not developed. L-carnitine was determined in six various food supplements by reverse phase chromatography with UV/VIS detection.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This paper describes the development of methodology for capillary electrophoresis with UV detection for the determination of 14 polyphenolic antioxidants in extracts of Connarus perrottetii var. angustifolius Radlk, a native plant of the Amazon forest. The method using capillary zone electrophoresis (CZE) allows simultaneous determination of 3-acetyilcoumarine, resveratrol, 6-hydroxycoumarin, catechin, rutin, ferulic acid, quercitrin, kaempferol, fisetin, myricetin, quercetin, caffeic acid, gallic acid and 4 hydroxicinnamic acid in the optimized conditions: borate buffer 20 mmol L-1 (pH 9.2) as work electrolyte containing 15% methanol (v /v), -20 kV potential separation, temperature 25 °C; hydrodynamic injection gravity 20 cm for 60 s. The method was validated on parameters of linearity, limit of detection, quantification limit, precision and accuracy, and was used in the analysis of aqueous infusion and ethanol, butanol and ethyl acetate plant fractions. The method was capable of identifying the antioxidants present in samples with high selectivity and sensitivity. In infusion and in ethanol and butanol fractions was found the presence of catechin and rutin as major compounds, which makes up about 0.5% of the total mass of medicinal plant. The obtained dry extracts (ethanol and butanol) allowed the concentration of rutin and catechin around 20 times compared to the dry plant. In addition, tests were performed to measure the antioxidant activity of the extracts against DPPH radical, superoxide anion radical, hydroxyl and peroxyl. A sample of aqueous infusion of 10% showed the highest activity against most free radicals. It corroborates the results of characterization by capillary electrophoresis, where catechin and rutin were determined in relatively high concentrations in the aqueous infusion. But all treatments of the samples showed good antiradicalar behavior with the methodologies applied. Against DPPH, for example, the ethyl acetate fraction showed a potential of 94,43%. Against superoxide and hydroxyl radicals, the butanol fraction showed the best performance: 64,23% and 74,97%, respectively. / Este trabalho descreve o desenvolvimento de metodologia em eletroforese capilar com detecção UV para a determinação de 14 antioxidantes polifenólicos em extratos de Connarus perrottetii var. angustifolius Radlk, planta nativa da Amazônia brasileira. O método empregando eletroforese capilar de zona (CZE) permite a determinação simultânea de 3-acetilcumarina, resveratrol, 6-hidroxicumarina, catequina, rutina, ácido ferúlico, quercitrina, canferol, fisetina, miricetina, quercetina, ácido cafeico, ácido gálico e ácido 4-hidroxicinâmco nas condições otimizadas: eletrólito de trabalho tampão borato 20 mmol L-1 (pH 9,2) contendo metanol 15% (v/v), potencial de separação -20 Kv, temperatura 25 °C; injeção hidrodinâmica por gravidade em 20 cm durante 60 s. O método foi validado nos parâmetros de linearidade, limite de detecção, limite de quantificação, precisão e exatidão e foi aplicado na análise da infusão aquosa e frações etanólica, butanólica e acetato de etila da planta. O método foi capaz de identificar os antioxidantes presentes nas amostras com alta seletividade e sensibilidade. Na infusão e nas frações etanólica e butanólica foi encontrada a presença de catequina e rutina como compostos majoritários, os quais compõe cerca de 0,5% da massa total de planta medicinal. Os extratos secos obtidos (etanólico e butanólico) possibilitaram a concentração de rutina e catequina em torno de 20 vezes em relação à planta seca. Além disso, foram realizados testes para mensurar a atividade antioxidante dos extratos frente aos radicais DPPH, ânion radical superóxido, hidroxila e peroxila. A amostra de infusão aquosa a 10% foi a que apresentou maior atividade frente à maioria dos radicais livres. Esse resultado corrobora os resultados de caracterização por eletroforese capilar, onde catequina e rutina foram determinadas em concentrações relativamente altas na infusão aquosa. Porém, todos os tratamentos das amostras apresentaram bom comportamento anti-radicalar com as metodologias aplicadas. Frente ao radical DPPH, por exemplo, a fração acetato de etila demonstrou um potencial de 94,43%. Frente aos radicais superóxido e hidroxila, a fração butanólica apresentou o melhor desempenho: 64,23% e 74,97%, respectivamente.

Presented Diploma Thesis is focused on electroanalytical determination of genotoxic 4-nitroindane, one of the nitrated polycyclic aromatic hydrocarbons (NPAHs). A hydrocarbon indane (a component of petrol) is a precursor of 4-nitroindane. NPAHs are produced all above by combustion processes in gasoline and diesel engines. It has been shown that NPAHs can be many times more mutagenic or carcinogenic than their parent PAHs, so the analysis of these dangerous pollutants becomes important for modern environmental analytical chemistry. Optimal conditions for determination of 4-nitroindane have been investigated in buffered water-methanolic solutions and electrochemical transformations of 4-nitroindane have been studied by DC voltammetry (DCV), differential pulse voltammetry (DPV) and cyclic voltammetry at a hanging mercury drop electrode (HMDE) and at a mercury meniscus modified silver solid amalgam electrode (m-AgSAE). For voltammetric determination of 4-nitroindane, the following techniques were used: DCV (limit of quantification (LQ) ~ 7. 10-8 mol. l-1 ), DPV (LQ ~ 1. 10-7 mol. l-1 ) and adsorptive stripping voltammetry (AdSV; LQ ~ 7. 10-9 mol. l-1 ) at HMDE, and DCV (LQ ~ 1. 10-7 mol. l-1 ) and DPV (LQ ~ 1. 10-7 mol l-1 ) at m-AgSAE. The applicability of the newly developed...