Generation efficiency of four mercury species, namely elemental mercury and hydrides of methyl-, ethyl- and phenylmercury from liquid samples was quantified. The species chemically generated were quantitatively trapped on a gold-coated amalgamator to be subsequently determined by AMA-254 technique. Three types of construction of volatile species generators were compared. Generation effciciency among the species was comparable, fluctuating around 60% in the conventional flow injection generator equipped with a gas liquid separator with forced outlet. Better results were reached for elemental mercury and methylmercury hydride in an automated batch generator system. Generation efficiency was higher than 90% for these two species and between 60 to 80% for ethyl- and phenylmercury hydrides, respectively. Speciation analysis of elemental mercury and sublimate in gaseous samples was optimized. These two species dominate in flue gases produced during coal combustion or waste incineration. Combination of two sorbent tubes packed with alumina and gold-coated alumina enables selective and quantitative retention of both species. Sublimate is trapped on a column packed with alumina while elemental mercury is retained on gold-coated alumina. The capacity of both sorbents was investigated as well as the effect of...

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The topic of this diploma thesis was the speciation analysis of the toxicological important forms of the arsenic in urban particulate matter samples. The detection technique used in this work was atomic absorption spectrometry with quartz atomizer. Acetic acid, ammonium acetate, hydroxylamine, potassium hydroxide and sodium carbonate are recommended leaching agents for extraction of metals from urban particulate matter samples. Results of the presenting work are following: Acidic extraction reagents can be not recommended for the speciation analysis of the arsenic, because these reagents lower sensitivity of the determination of As3+ and As5+ too and destroy the quartz atomizer. Alkaline extraction reagents don't lower sensitivity of the determination of As3+ and these reagents don't destroy the atomizer, but lower sensitivity of the determination of As5+ was obtained. Recommended reagents aren't useful for extraction of the metals from urban particulate matter samples for the speciation analysis.

Alkyl derivatives of mercury, especially methylmercury, bring a significant risk to the environment and the human population. Methylmercury is highly toxic compound, which have the potential to bioaccumulate and biomagnify in tissues of aquatic organisms. This diploma thesis deals with issues of alkyl derivatives of mercury in biotic matrices. The goal of this thesis was to analyze fish tissues. Fish were caught from the river Svratka at the inflow and at the outflow of wastewater treatment plant. Methylmercury was determined in fish muscles and skin. Total mercury was determined in fish muscles. The extraction based on acidic digestion in hydrochloric acid and subsequent extraction with toluene was used for isolation of methylmercury from fish tissues. There was used gas chromatography with electron capture microdetector for determination of methylmercury. Total mercury was determined by special analyzer AMA 254.

[pt] A qualidade de produtos alimentícios tem recebido especial atenção devido a sua importância na nutrição e saúde humanas. Neste sentido, a determinação de metais traço em alimentos tem se convertido em importante campo na análise de alimentos. Em relação aos óleos vegetais, a sua composição em termos de metais traço é um critério relevante para a avaliação da qualidade, uma vez que se sabe que estes metais afetam a sua taxa de oxidação, influenciando as suas características e no seu armazenamento. Por outro lado, cereais e outros alimentos de origem vegetal são especialmente relevantes na alimentação humana, uma vez que são a base da dieta de muitas populações do mundo. No presente trabalho, foi desenvolvido um método analítico para determinação direta de Cu e Ni em óleos vegetais por Espectrometria de Absorção Atômica no Forno de Grafite (GFAAS): as amostras foram pesadas diretamente em uma plataforma de grafite e introduzidas no atomizador, com o auxílio de um acessório de amostragem de sólidos. O programa de temperatura otimizado permitiu o uso de soluções de calibração aquosas. A exatidão do procedimento foi confirmada pela boa concordância entre os resultados obtidos pelo procedimento proposto e por procedimentos comparativos. Os limites de detecção foram de 0,001 e 0,002 μg g-1 para Cu e Ni, respectivamente, nas amostras originais. Em continuação, empregou-se a técnica de fluorescência atômica para a determinação do conteúdo total de As, Sb, Se, Te e Bi em amostras vegetais, de cereais e legumes, após calcinação por via seca. Foram otimizados os parâmetros relativos a geração dos hidretos, assim como os parâmetros de fluorescência. Testes de adição de analito, assim como a análise de materiais certificados de referência, garantiram a exatidão do procedimento. Os resultados encontrados mostraram que as amostras estudadas encontraramse todas, nos limites preconizados pela legislação européia. Finalmente, uma metodologia analítica não cromatográfica, rápida, sensível e simples foi desenvolvida para a quantificação de espécies tóxicas de arsênio em arroz, sêmola, acelga e berinjela. Estas espécies foram extraídas com H3PO4 1 mol L-1 + Triton XT-114 0,1%, assistida por ultra-som, seguindo-se a lavagem com EDTA 0,1% (m/v). As espécies As(III), As(V), DMA e MMA foram quantificadas no extrato por espectrometria de fluorescência atômica por geração de hidretos utilizando um sistema de equações proporcionais, que correspondem a quatro condições experimentais diferentes. Os valores de limite de detecção do método foram 1,3 (3,15); 0,9 (2,97); 1,5 (0.46) e 0,6 (0,37) ng g- 1 para As(III), As(V), DMA e MMA, respectivamente, nas amostras de cereais e vegetais, expressos em termos do peso seco da amostra. Os estudos da recuperação mostraram porcentagens maiores que 90% para as quatro espécies consideradas. A análise de especiação de um material de referência de farinha de arroz certificado para arsênio total mostrou resultados coerentes e concordantes com outros estudos com ele realizados. / [en] The quality of food products has received a special attention due to its influence in the human health and nutrition. Thus, trace metal determination in foods has turned an important field in food analysis. Concerning vegetal oils, its metal trace metal composition is a criterion for the assessment of their quality since it is known that these metals affect their rate of oxidation, influencing its characteristics and storage management. As part of the present work the direct determination of Cu and Ni in vegetal oils by Graphite Furnace Atomic Absorption Spectrometry (GFAAS), using the solid sampling strategy was developed: The samples were weighed on a graphite platform boat and inserted in the graphite tube. An adequate temperature program allowed the calibration by external aqueous calibration curves. A good agreement between the results arisen from the proposed and two comparative procedures (EPA 3031 and EPA 3051) confirmed the accuracy of the proposed procedure. The limits of detention in the original samples were 0.002 and 0.001 ìg g-1 for Cu and Ni, respectively. A second part of the work has dealt with the determination of the total content of As, Sb, Se, Te and Bi in samples of vegetable, cereals and pulses by HG AFS. The samples were dry ashed by a proper ashing program, and the hydride generation parameters were optimized, as well as those related to the fluorescence emission. Recovery testes and the analysis of certified reference materials testified the accuracy of the procedure. The content of the studied elements in studied samples were all below those of the European regulation. Finally, a fast, sensitive and simple non chromatographic methodology was developed for the speciation analysis of toxic arsenic species in rice, wheat semolina, chard and aubergines samples. Ultrasound assisted extraction of the toxic arsenic species was carried with 1 mol of L-1 H3PO4 and 0.1% (m/v) Triton XT-114. After the extraction, As(III), As(V), DMA and MMA were quantified by hydride generation atomic fluorescence spectrometry at four different experimental conditions. The fluorescence intensities derived from these four measurements were introduced in a system of four proportional equations, permitting the calculation of the individual species concentration.. The detection limits were 1.3 (3.2), 0.9 (3.0), 1.5 (0.5)) and 0.6 (0,5) ng g-1 for As(III), As(V), DMA and MMA, respectively in the cereals and (vegetable) samples, expressed in terms of the dry weight. Recoveries greater than 90% for the four considered species in samples spiked at 100 ng g-1 level were obtained as well as the assurance of no species interconversion. The speciation analysis of a rice flour reference material certified for total arsenic led to coherent results, which were also in agreement with other speciation studies made on the same CRM.

A aplicação de fertilizantes aos solos é frequente devido à atual demanda mundial pela produção de alimentos e às projeções feitas para o futuro. Fertilizantes orgânicos têm sido uma opção amplamente explorada devido ao seu preço, possibilidade de reuso de resíduos agriculturais e urbanos, além do caráter sustentável. Podem ser provenientes de diversas origens como lodo de esgoto, estercos e restos de animais e vegetais submetidos a processos de compostagem. Neste trabalho, foi desenvolvido método para determinação elementar total em fertilizantes orgânicos, substratos e condicionadores de solo, e realizados estudos de fracionamento e análise de especiação em fertilizante orgânico. Assim, foi realizada a caracterização geral das amostras com fracionamento por tamanho de partícula, análises dos teores de C e N, difração de Raios-X e determinação elementar total. Para este último, foi desenvolvido método de digestão assistida por radiação micro-ondas, com análise por ICP OES. O procedimento foi otimizado para diferentes misturas ácidas, as quais foram avaliadas quanto aos erros relativos para diversos elementos em CRM de lodo de esgoto, utilizando PCA como ferramenta estatística. A mistura escolhida, constituída por 3 mL HNO3 + 1 mL HBF4 + 2 mL H2O, foi utilizada para digestão das amostras. Apenas a concentração total não traz informações a respeito da mobilidade e disponibilidade dos elementos, então estudos de fracionamento elementar também foram realizados. Na primeira abordagem foi executado fracionamento por tamanho de partícula, no qual foi observado que quanto menor o tamanho de partícula menor o teor de C e maior o teor de N, e maior a concentração de micronutrientes e contaminantes (Cr, Cu, Fe, Mn, Pb e Zn), indicando que estes elementos podem estar mais associados a frações com mais características inorgânicas e maior teor de humificação (dado pela razão C/N). A segunda abordagem refere-se à associação dos elementos com diferentes componentes da matriz seguindo o procedimento de extração sequencial do BCR e extrações em etapa única para avaliar a mobilidade, sendo os extratos analisados por ICP-MS. O elemento Cr mostrou baixa mobilidade e bioacessibilidade. Cu está associado, principalmente, à fração orgânica da matriz, porém também pouco móvel. Fe e Pb também apresentaram baixa mobilidade e associados, principalmente, a óxidos da amostra. Mn e Zn mostraram alta mobilidade, sendo também associados a matéria orgânica e aos óxidos. A análise de especiação dos extratos obtidos foi realizada por SEC-ICP-MS, de modo a investigar a associação dos elementos extraídos com ácidos húmicos e fúlvicos. Nenhum sinal de Cr estava relacionado com a matéria orgânica, enquanto que os elementos Cu, Fe e Pb mostraram associação com ácidos húmicos. Mn apresentou espécies associadas a ácidos fúlvicos, enquanto que o Zn, não está associado a espécies orgânicas. / Fertilizers are frequently applied to soils due to actual global food demand and its future projections. Organic fertilizers have been extensively employed due to its price, as a reuse possibility to agricultural and urban wastes, and its sustainable character. They can be prepared from various sources, such as sewage sludge, manure and plants and animal scraps, submitted to composting process. In this work, it was developed a total elements determination method, as well as fractionating studies and speciation analysis of organic fertilizer. Thus, organic fertilizer samples were generally characterized using particle size fractionating, C and N content analysis, X-Ray diffraction and total elements determination. To the last, it was developed a sample preparation method by microwave-assisted digestion and ICP OES analysis. Digestion procedure was optimized using various acid mixtures, which were evaluated due to its relative errors related to sewage sludge CRM values, using PCA as a statistical tool. The chosen acid mixture constituted of 3 mL HNO3 + 1 mL HBF4 + 2 mL H2O was applied to samples digestion and their total elements determination. As total concentration is not enough to predict elements mobility and bioavailability, fractionation studies were conducted. The first approach was the particle size fractionation, were it was observed that the smaller the particle size the higher the micronutrients and contaminants concentration (Cr, Cu, Fe, Mn and Zn), along with lower C contents and higher N contents, indicating that these elements are associated with inorganic fractions, or with highly humified compounds (due to the lower C/N ratio). A second approach refers to elements association with various matrix components, using BCR and single-step extraction procedures to investigate elements mobility and bioavailability, with ICP-MS analysis of extracts. Cr was poorly mobile and bioavailable. Cu was bound to organic fraction, but also poorly mobile and bioavailable. Fe and Pb were also weakly mobile, and were mostly associated with oxides on matrix. Mn and Zn were greatly mobile and bioavailable, and were also mainly associated with oxides on matrix. Speciation analysis of extract was performed by SEC-ICP-MS, investigating elements association with humic and fulvic acids on previous extracts. Cr could not be associated with any humic substance, as expected with previous extractions results. Cu, Fe and Pb had identifiable species associated with humic acids, while Mn was associated with fulvic acids. Zn, even though high mobile, was not associated with any organic species.

A aplicação de fertilizantes aos solos é frequente devido à atual demanda mundial pela produção de alimentos e às projeções feitas para o futuro. Fertilizantes orgânicos têm sido uma opção amplamente explorada devido ao seu preço, possibilidade de reuso de resíduos agriculturais e urbanos, além do caráter sustentável. Podem ser provenientes de diversas origens como lodo de esgoto, estercos e restos de animais e vegetais submetidos a processos de compostagem. Neste trabalho, foi desenvolvido método para determinação elementar total em fertilizantes orgânicos, substratos e condicionadores de solo, e realizados estudos de fracionamento e análise de especiação em fertilizante orgânico. Assim, foi realizada a caracterização geral das amostras com fracionamento por tamanho de partícula, análises dos teores de C e N, difração de Raios-X e determinação elementar total. Para este último, foi desenvolvido método de digestão assistida por radiação micro-ondas, com análise por ICP OES. O procedimento foi otimizado para diferentes misturas ácidas, as quais foram avaliadas quanto aos erros relativos para diversos elementos em CRM de lodo de esgoto, utilizando PCA como ferramenta estatística. A mistura escolhida, constituída por 3 mL HNO3 + 1 mL HBF4 + 2 mL H2O, foi utilizada para digestão das amostras. Apenas a concentração total não traz informações a respeito da mobilidade e disponibilidade dos elementos, então estudos de fracionamento elementar também foram realizados. Na primeira abordagem foi executado fracionamento por tamanho de partícula, no qual foi observado que quanto menor o tamanho de partícula menor o teor de C e maior o teor de N, e maior a concentração de micronutrientes e contaminantes (Cr, Cu, Fe, Mn, Pb e Zn), indicando que estes elementos podem estar mais associados a frações com mais características inorgânicas e maior teor de humificação (dado pela razão C/N). A segunda abordagem refere-se à associação dos elementos com diferentes componentes da matriz seguindo o procedimento de extração sequencial do BCR e extrações em etapa única para avaliar a mobilidade, sendo os extratos analisados por ICP-MS. O elemento Cr mostrou baixa mobilidade e bioacessibilidade. Cu está associado, principalmente, à fração orgânica da matriz, porém também pouco móvel. Fe e Pb também apresentaram baixa mobilidade e associados, principalmente, a óxidos da amostra. Mn e Zn mostraram alta mobilidade, sendo também associados a matéria orgânica e aos óxidos. A análise de especiação dos extratos obtidos foi realizada por SEC-ICP-MS, de modo a investigar a associação dos elementos extraídos com ácidos húmicos e fúlvicos. Nenhum sinal de Cr estava relacionado com a matéria orgânica, enquanto que os elementos Cu, Fe e Pb mostraram associação com ácidos húmicos. Mn apresentou espécies associadas a ácidos fúlvicos, enquanto que o Zn, não está associado a espécies orgânicas. / Fertilizers are frequently applied to soils due to actual global food demand and its future projections. Organic fertilizers have been extensively employed due to its price, as a reuse possibility to agricultural and urban wastes, and its sustainable character. They can be prepared from various sources, such as sewage sludge, manure and plants and animal scraps, submitted to composting process. In this work, it was developed a total elements determination method, as well as fractionating studies and speciation analysis of organic fertilizer. Thus, organic fertilizer samples were generally characterized using particle size fractionating, C and N content analysis, X-Ray diffraction and total elements determination. To the last, it was developed a sample preparation method by microwave-assisted digestion and ICP OES analysis. Digestion procedure was optimized using various acid mixtures, which were evaluated due to its relative errors related to sewage sludge CRM values, using PCA as a statistical tool. The chosen acid mixture constituted of 3 mL HNO3 + 1 mL HBF4 + 2 mL H2O was applied to samples digestion and their total elements determination. As total concentration is not enough to predict elements mobility and bioavailability, fractionation studies were conducted. The first approach was the particle size fractionation, were it was observed that the smaller the particle size the higher the micronutrients and contaminants concentration (Cr, Cu, Fe, Mn and Zn), along with lower C contents and higher N contents, indicating that these elements are associated with inorganic fractions, or with highly humified compounds (due to the lower C/N ratio). A second approach refers to elements association with various matrix components, using BCR and single-step extraction procedures to investigate elements mobility and bioavailability, with ICP-MS analysis of extracts. Cr was poorly mobile and bioavailable. Cu was bound to organic fraction, but also poorly mobile and bioavailable. Fe and Pb were also weakly mobile, and were mostly associated with oxides on matrix. Mn and Zn were greatly mobile and bioavailable, and were also mainly associated with oxides on matrix. Speciation analysis of extract was performed by SEC-ICP-MS, investigating elements association with humic and fulvic acids on previous extracts. Cr could not be associated with any humic substance, as expected with previous extractions results. Cu, Fe and Pb had identifiable species associated with humic acids, while Mn was associated with fulvic acids. Zn, even though high mobile, was not associated with any organic species.

Studies have been carried out on specific ion-exchange (Dowex 50W-X8 and Dowex 1-X8) and chelation (Chelex-100) resins, in order to determine their physical and chemical characteristics, to understand and explain their limits of function and to optimise their use as substrates in trace metal and speciation measurement by EDXRF. Structural information was obtained by scanning electron microscopy and x-ray microanalysis showing a homogeneous distribution of functional groups and retained ions on both sectioned and whole resins. Particle size experiments performed on Dowex 50W-X8 (38 - 840 µm) showed that this parameter has no effect on the relationship between intensity of fluorescence and concentration or mass of resin. Inter-element effects were not observed in the analysis of multielemental specimens prepared on ion-exchange / chelation media by EDXRF. This indicates that the proposed method has a significant advantage when compared with other methodologies. A theoretical ‘model’, based on the formation of thin films on the surface of the resin beads, has been proposed in order to link and explain the effects observed in these experiments. The use of a batch retention system has shown distinct advantages over using columns in terms of linearity, accuracy, precision, rapidity and simplicity. Parameters such as pH and ionic strength of the solution, concentration of competing ions and volume of the sample have been proven to be critical. The maximum retention capacity has been determined as 3.2, 1.1 and 0.67 mEq/g for Dowex 50W-X8, Dowex 1-X8 and Chelex-100 respectively. The optimum mass of resin for XRF analysis was found to be 0.5 g, for all resins tested. The linear range covered 4 to 5 orders of magnitude. These findings show the potential of the investigated media to overcome instrumental and sample limitations. Based on the physico-chemical information found, methodologies for three different applications of the resins to EDXRF determinations have been developed and their analytical possibilities explored. The multi-elemental determination of metals in sewage sludge digests was achieved by retaining the metals on Dowex 50W-X8 at pH 2 and Chelex-100 at pH 4. Chelex-100 allows quantitative recoveries for Cu and Zn. A wider range of elements was determined on Dowex 50W-X8, although with poorer recoveries (60 - 90%). The limits of detection were 10 - 21 µg when Dowex 50W-X8 was used and 8 - 49 µg for Chelex-100. The method was validated by the analysis of a certified material. The determination of Kβ/Kα intensity ratios for Cr and Mn species and its potential as a tool for direct elemental speciation has also been studied. A difference in Kβ/Kα between the oxidation states of the analytes was only observed during the analysis of solutions of the metal species by EDXRF at the 98% level of confidence. Finally, the speciation and preconcentration of Cr(III) and Cr(VI) in waters has been performed by retention on Dowex 50W-X8 and Dowex 1-X8 followed by EDXRF determination. Efficient recoveries and preconcentration factors of up to 500 were achieved, leading to limits of detection of 30 µg/L for Cr(VI) and 40 µg/L for Cr(III). This method is simple, fast and inexpensive, allowing quantitative recoveries in the speciation of chromium in waste waters.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work aimed to explore the speciation analysis of chromium, selenium and antimony, elements of clinical and geochemical relevance, in the saline samples seawater, hydrothermal fluid and hemodialysis fluid. These samples, although linked to different research areas, have many similarities relating to their chemical compositions or the presence of metallic species as contaminants as well as major components. Voltammetric methods were used to the determination of the analytes in high salt media without the use of dilution, masking agents or separation steps. Since changes in the matrix composition may affect the analyte peak current magnitude, factors affecting the voltammetric behavior of the species related to sample composition (e.g., presence of dissolved organic matter and ionic strength) were evaluated. The chromium speciation analysis was performed by the adsorptive collection of the Cr-DTPA complex on the mercury working electrode, followed by stripping in combination to a catalytic step. Cr(III) species was found as predominant in the hydrothermal fluid sample and, Cr(VI), in the seawater sample, whereas in hemodialysis fluids an ignorable concentration was determined. Selenium was determined by the co-electrolysis of Cu2Se followed by a cathodic stripping in acidic medium. The UV-irradiation pre-treatment step was used for the reductively conversion of non-electroactive species into Se(IV) as well as for dissolved organic matter photo-oxidation, and the speciation was applied to the real sample analysis, where no selenium species were found. The combined use of adsorptive and anodic stripping voltammetry was employed for antimony determination. Chloranilic acid was chosen as the Sb(III) complex forming reagent (pH 3.0) and the total antimony concentration was evaluated by anodic stripping voltammetry in a 5.0 mol L-1 HCl medium. Sb(III) was found as the predominant species in the hydrothermal fluid sample, whereas Sb(V) is predominant in the seawater sample. No antimony species were found in the hemodialysis fluid. Concerning chromium, selenium and antimony species, remarkable peak current dependences on peak potential, deposition potential, deposition time and scan rate were observed for all investigated media. The limit of detection values were appropriate to the analytes determination, so that the present techniques consist in simple, fast and low cost procedures for the speciation analysis of elements of clinical and geochemical relevance in high salt content samples with accuracy and sensitivity. / Este trabalho teve como objetivo explorar a análise de especiação de cromo, selênio e antimônio, elementos de relevância clínica e geoquímica, em amostras salinas água do mar, fluido hidrotermal e concentrado salino de hemodiálise. Tais amostras, embora ligadas a diferentes áreas de pesquisa, apresentam similaridades relacionadas à presença de espécies metálicas como contaminantes, assim como a componentes majoritários. Métodos voltamétricos foram usados na determinação dos analitos em meios de alta concentração salina sem diluição, agentes mascarantes ou etapas de separação. Uma vez que mudanças na composição da matriz em análise podem afetar a magnitude da corrente de pico para os analitos, fatores que influenciam o comportamento voltamétrico das espécies e relacionados à composição das amostras (presença de matéria orgânica dissolvida e força iônica) foram avaliados. A análise de especiação de cromo foi executada pela adsorção de complexos Cr-DTPA no eletrodo de trabalho de mercúrio seguida de redissolução aliada a um passo catalítico. Observou-se a predominância de Cr(III) em fluido hidrotermal e, de Cr(VI), em água do mar, sendo o analito determinado em concentração desprezível na amostra de concentrado salino de hemodiálise. Determinou-se selênio por uma etapa de co-eletrólise de Cu2Se com posterior redissolução catódica do composto em meio ácido. Empregou-se o pré-tratamento por irradiação UV para a redução fotolítica de espécies não-eletroativas em Se(IV), assim como para a foto-oxidação da matéria orgânica, sendo a análise de especiação aplicada a amostras reais, para as quais não se evidenciou a presença de espécies de selênio. Fez-se o uso combinado de voltametria adsortiva e voltametria anódica de redissolução, para a determinação de antimônio. Escolheu-se o reagente ácido cloranílico para a formação de complexos com Sb(III) (pH 3,0), sendo a concentração total de antimônio avaliada por voltametria de redissolução anódica em HCl 5,0 mol L-1. Observou-se a predominância de Sb(III) em fluido hidrotermal e, de Sb(V), em água do mar. Não se evidenciou a presença de espécies de antimônio na amostra de concentrado salino de hemodiálise. Levando-se em conta as espécies de cromo, selênio e antimônio, uma dependência entre corrente de pico, potencial de deposição, tempo de deposição e velocidade de varredura foi observada em todos os meios investigados. Obtiveram-se limites de detecção adequados para a determinação dos analitos, sendo que as técnicas otimizadas consistem em procedimentos simples, rápidos e de baixo custo, aplicados à análise de especiação de elementos de relevância clínica e geoquímica, em amostras de alta concentração salina, com exatidão e sensibilidade.

The extraction of mercury species (methylmercury, ethylmercury, phenylmercury and inorganic mercury(II)) from fish tissue, its determination by reverse phase HPLC, UV-photochemical generation of cold vapour, and detection by atomic absorption spectrometry is described in this work. Various extraction agents and digestion methods were compared in order to find the best alternative. The mixture of 6.25% tetramethylammonium hydroxide and 0.05 mol·l-1 hydrochloride acid was chosen as the best extraction agent. In addition to the high extraction efficiency, the solution involved positively not only UV-photochemical generation, but also separation of observed species. On the contrary, the poor repeatability was achieved with the microwave-assisted digestion due to the proved sorption of mercury species on the Teflon vessels. Therefore, the extraction by high temperature (50-60 řC) in glass bottles was preferred. The results of the determination of the mercury species after the extraction from the real samples were compared to the outcomes obtained by AMA 254. The proposed extraction technique together with the RP-HPLC-UV-CVG-QTAAS is suitable for the speciation analysis of mercury.