No description available.

Thesis (M.Sc. (Chemistry)) - Rhodes University, 2008

Photodegradation of 4-nitrophenol (4-Np) in the presence of water-soluble zinc phthalocyanines and water-insoluble metallophthalocyanines is reported. The water-soluble phthalocyanines employed include zinc tetrasulphophthalocyanine (ZnPcS[subscript 4]), zinc octacarboxyphthalocyanine (ZnPc(COOH)[subscript 8]) and a sulphonated ZnPc containing a mixture of differently sulphonated derivatives (ZnPcS[subscript mix]), while the water-insoluble phthalocyanines used include unsubstituted magnesium (MgPc), zinc (ZnPc) and chloroaluminium (ClAlPc) phthalocyanine complexes and the ring-substituted zinc tetranitro (ZnPc(NO[subscript 2])[subscript 4]), zinc tetraamino (ZnPc(NH[subscript 2])[subscript 4]), zinc hexadecafluoro (ZnPcF[subscript 16]) and zinc hexadecachloro (ZnPcCl[subscript 16]) phthalocyanines. The most effective water-soluble photocatalyst is ZnPcS[subscript mix] in terms of the high quantum yield obtained for 4-Np degradation (Φ[subscript 4-Np]) as well as its photostability. While ZnPc(COOH)[subscript 8] has the highest Φ[subscript 4-Np] value relative to the other water-soluble complexes, it degrades readily during photocatalysis. The Φ[subscript 4-Np] values were closely related to the singlet oxygen quantum yields Φ[subscript Δ] and hence aggregation. The rate constants for the reaction with 4-Np were kr = 0.67 x 10[superscript 6] mol[superscript -1] dm[superscript 3] s[superscript -1] for ZnPcS[subscript mix] and 7.7 x 10[superscript 6] mol[superscript -1] dm[superscript 3] s[superscript -1] for ZnPc(COOH)[subscript 8]. ClAlPc is the most effective photocatalyst relative to the other heterogeneous photocatalysts for the phototransformation of 4-Np, with 89 ± 8.4 % degradation of 4-Np achieved after 100 min. The least effective catalysts were ZnPcCl[subscript 16] and MgPc. The final products of the photocatalysis of 4-Np in the presence of the homogeneous photocatalysts include 4-nitrocatechol and hydroquinone, while degradation of 4-Np in the presence of the heterogeneous photocatalysts resulted in fumaric acid and 4-nitrocatechol. ClAlPc was employed for the heterogeneous photocatalysis of the non-systemic insecticide, methyl paraoxon. Complete degradation of the pesticide was confirmed by the disappearance of the HPLC trace for methyl paraoxon after 100 min of irradiation with visible light. The removal of 4-Np from an aqueous medium using commercially available Amberlite[superscript ®] IRA-900 modified with metal phthalocyanines was also investigated. The metallophthalocyanines immobilised onto the surface of Amberlite[superscript ®] IRA-900 include Fe (FePcS[subscript 4]), Co (CoPcS[subscript 4]) and Ni (NiPcS[subscript 4]) tetrasulphophthalocyanines, and differently sulphonated phthalocyanine mixtures of Fe (FePcS[subscript mix]), Co (CoPcS[subscript mix]) and Ni (NiPcS[subscript mix]). Adsorption rates were fastest for the modified adsorbents at pH 9. Using the Langmuir-Hinshelwood kinetic model, the complexes showed the following order of 4-Np adsorption: CoPcS[subscript mix] > NiPcS[subscript 4] > NiPcS[subscript mix] > FePcS[subscript 4] > FePcS[subscript mix] > CoPcS[subscript 4]. The adsorbents were regenerated using dilute HNO[subscript 3], with 76 % (7.6 x 10[superscript -5] mol) of 4-Np recovered within 150 min.

The voltammetric behavior of selected nitrophenols (2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol and 2,4,6-trinitrophenol) was investigated by differential pulse voltammetry (DPV) and by adsorptive stripping voltammetry (AdSV) at an unmodified electrode (CPE) and a clay-modified carbon paste electrodes modified by montmorillonite (MMT-CPE) and sepiolite (SEP-CPE) using electrochemical reduction and oxidation in Britton-Robinson buffer. For reduction, optimum conditions have been found at pH 2 for 2-NP and 4-NP, at pH 3 for 2,4-DNP and at pH 4 for 2,4,6-TNP. For oxidation, optimum conditions have been found at pH 2 for 2-NP and 4-NP and at pH 5 for 2,4-DNP. Voltammetric determination using electrochemical oxidation is not a suitable method for 2,4,6-TNP. The lowest detection limits were obtained for 2-NP using cathodic AdSV on SEP-CPE with 2,9·10-7 mol.dm-3 , for 4-NP using cathodic DPV on MMT-CPE with 2·10-6 mol.dm-3 , for 2,4-DNP using cathodic AdSV on SEP-CPE with 2,7·10-7 mol.dm-3 and for 2,4,6-TNP using cathodic DPV on unmodified electrode with 4,8·10-7 mol.dm-3 . Determination of mixture 2-NP and 4-NP and the possibility of the selective determination using open circuit sorption with DPV detection was further studied.

4 ABSTRACT Development and testing of novel non-toxic electrode materials, detection arrangements and analytical methods applicable in determination of selected agrochemicals is the main aim of this Ph.D. Thesis. New working electrodes based on silver solid amalgam paste (AgSA-PE) with organic pasting liquid and other based on crystallic silver amalgam (CAgAE) were developed, their electrochemical behaviour investigated and further used in voltammetric determination of widespread and toxic environmental pollutant 4-nitrophenol (4-NP). This analyte could be determined by DPV at AgSA-PE with limit of detection (LD) 1×10í6 mol lí1 and using CAgAE with LD 4×10í7 mol lí1 , both in 0.2 mol lí1 acetate buffer pH 4.8. Attempts to decrease LDs by utilization of adsorptive stripping voltammetry were not successful in either case. Crystallic silver amalgam was also successfully used for construction of microcylindric flow-through cell and tested for amperometric determination of nitrophenol mixture in HPLC-ED system. Both novel electrodes were found to be suitable alternatives to toxic mercury electrodes and the CAgAE seems to be promising working electrode for flowing systems. Method for sample preparation and voltammetric determination of broad-spectrum herbicide Glyphosate in contaminated soil samples was also...

FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / Neste trabalho foram realizados estudos de adsorÃÃo em batelada e de oxidaÃÃo avanÃada para a remoÃÃo de fenol (F), 2-nitrofenol (2NF) e 4-nitrofenol (4NF) em soluÃÃo aquosa. Nos estudos de adsorÃÃo foram empregados como adsorventes o pà de bagaÃo da casca de coco in natura (BIN), pà de bagaÃo in natura tratado com HCl 1,0 M (BT) e carvÃo ativado (CA) proveniente da carbonizaÃÃo a 250ÂC do pà de bagaÃo tratado com Ãcido. Experimentos de equilÃbrio e cinÃtica de adsorÃÃo foram realizados nas temperaturas de 28, 40 e 50ÂC. Isotermas de Langmuir e Freundlich correlacionaram bem os dados de equilÃbrio, indicando capacidades de adsorÃÃo (qmÃx) que aumentaram na ordem: CA >>> BT > BIN. Este comportamento denota uma adsorÃÃo caracterizada pelas interaÃÃes entre os elÃtrons  dos anÃis aromÃticos e os elÃtrons  das camadas grafÃticas do carvÃo, a qual à mais intensa que a verificada nos materiais celulÃsicos onde predomina a formaÃÃo de complexos doador-receptor entre os sÃtios oxigenados localizados na superfÃcie do adsorvente e o anel aromÃtico dos compostos fenÃlicos. Os melhores resultados de qmÃx em carvÃo ativado e pà de bagaÃo tratado com Ãcido foram obtidos para a adsorÃÃo de 2-nitrofenol à temperatura ambiente (28ÂC), correspondentes aos valores de 17,1 e 1,39 mg/g, respectivamente. Do ponto de vista cinÃtico o modelo de pseudo-segunda ordem apresentou melhor ajuste dos dados experimentais. Por outro lado, processos oxidativos avanÃados (POAs) das molÃculas fenÃlicas foram conduzidos para os tratamentos fotolÃtico (UV), fotoquÃmico (UV/H2O2), Fenton (Fe2+/H2O2) e eletroquÃmico com anodos dimensionalmente estÃveis (ADEs) de Ru0,3Ti0,7O2, Ru0,3Ti0,4Sn0,3O2 e Ru0,3Sn0,7O2. Os processos Fenton e fotoassistidos apresentaram condiÃÃes Ãtimas nas concentraÃÃes de 1,0 mM em Ãons Fe2+e 3,0 mM em H2O2 e taxa de radiaÃÃo (I0) de 64 mW/cm2. Os Ãxidos eletrocatalÃticos foram preparados por termodecomposiÃÃo de cloretos precursores a 500oC atà a formaÃÃo de filmes com 2,0 Âm de espessura sobre um suporte de titÃnio. A caracterizaÃÃo pelas tÃcnicas de EDX, MEV e Voltametria CÃclica mostrou composiÃÃes praticamente estequiomÃtricas, morfologia estrutural tipo cracked mud e elevado sobrepotencial para a reaÃÃo de desprendimento de oxigÃnio (RDO). Estudos de oxidaÃÃo para as molÃculas fenÃlicas mostraram o 2-nitrofenol como a espÃcie mais oxidÃvel e o fenol comum como a espÃcie menos reativa. As eficiÃncias de degradaÃÃo dos processos fotoassistidos foram particularmente elevadas (superiores a 80%) enquanto o sistema Fenton apresentou taxas de remoÃÃo entre 60 e 78%. A modelagem cinÃtica segundo o modelo de pseudo-primeira ordem adotado permitiu um bom ajuste dos dados experimentais. Os valores da constante cinÃtica 1/ (min-1) a 28ÂC mostraram a seguinte ordem: Fenton (8,16 min-1) > fotoquÃmico (6,95 min-1) >> fotolÃtico (1,98 min-1). Em adiÃÃo, estudos usando anodos eletrocatalÃticos (ADEs) a potencial constante de eletrÃlise de 2,0 V mostraram degradaÃÃes superiores a 93% para os nitrofenÃis e entre 65 e 86% para o fenol. Em termos, considerado o tipo de ADE empregado, a eficiÃncia de eletrooxidaÃÃo à temperatura ambiente obedece a seguinte ordem de eficiÃncia: Ru0,3Ti0,7O2 > Ru0,3Ti0,4Sn0,3O2 > Ru0,3Sn0,7O2. A anÃlise espectroscÃpica para identificaÃÃo de co-produtos indicou completa mineralizaÃÃo dos compostos fenÃlicos nos processos fotoquÃmico e eletroquÃmico, enquanto que nos processos Fenton e fotolÃtico foram detectados traÃos de produtos hidroxilados. Em geral, os resultados obtidos confirmam os processos adsortivos e oxidativos como tratamentos promissores para a despoluiÃÃo de sistemas aquosos contendo fenÃis e nitrofenÃis / In the present work the batch adsorption and advanced oxidation of phenol (F), 2-nitrophenol (2NF) and 4-nitrophenol (4NF) in aqueous phase has been studied. The adsorption experiments were conducted onto coconut shell powder (BIN), coconut shell powder treated with HCl 1.0M (BT) and coconut shell-based activated carbon (CA) obtained from carbonization at low temperature (250ÂC). Equilibrium and kinetic studies were carried out at temperatures of 28, 40 and 50ÂC. Langmuir and Freundlich isotherms correlated well the equilibrium data, indicating the adsorption capacity (qmax) increased in the order: AC>>> BT> BIN. This behavior denotes an adsorption characterized by dispersive interactions between the -electrons of the graphitic carbon basal planes and those of the aromatic rings of the adsorbate, which is more intense when compared to the cellulose materials where are dominant the donor-acceptor complex formation between the oxygenated sites onto adsorbent and aromatic rings of phenol compounds. The best results of qmax in activated carbon and coconut shell powder treated with acid were obtained for the adsorption of 2-nitrophenol at room temperature (28ÂC), corresponding to values of 17.1 and 1.39 mg/g, respectively. In all cases, the adsorption kinetics could be satisfactorily fitted by a pseudo-second order model. Advanced oxidation processes (AOP) were carried out for treatments such photolytic (UV), photochemical (UV/H2O2), Fenton (Fe2+/H2O2) and electrochemical oxidation with dimensionally stable anodes (DSA) type Ti/Ru0.3Ti0.7O2, Ti/Ru0.3Ti0.4Sn0.3O2 and Ti/Ru0,3Sn0,7O2. The Fenton and photoassisted tests were performed to optimized conditions of 1.0 mM of Fe2+ ions, 3.0 mM of H2O2 and radiation intensity (I0) of 64 mW/cm2. Particularly, electrocatalytic oxides were prepared by thermal decomposition of chloride precursors to 500oC until the formation of films with thickness constant of 2μm on titanium support. The characterization by EDX, SEM and Cyclic Voltammetry techniques showed a nearly stoichiometric composition, morphology type âcracked mudâ and elevated overpotencial from oxygen evolution reaction (OER). Degradation efficiencies in photoassisted processes were particularly high (> 80%) while in the Fenton system this values ranged between 60 and 78%. The kinetic modelling using the equation of pseudo-first order adopted allowed a good fit of experimental data. The values of kinetic constant 1/ (min-1) at room temperature showed the following order: Fenton (8.16 min-1) > Photochemical (6.95 min-1) >> photolytic (1.98 min-1). In addition, studies using the electrocatalytic anodes at constant potential electrolysis of 2.0 V showed almost total degradation for the nitrophenols (> 93%) and moderate removal efficiencies for phenol (between 65 and 86%). In terms, considered the type of anode employed the electrooxidation efficiency at room temperature increase in the following order of reactivity: Ru0.3Ti0.7O2 > Ru0.3Ti0.4Sn0.3O2 > Ru0.3Sn0.7O2. Thus, the results confirm the applicability of adsorption and advanced oxidation processes as promising treatments in the remediation of aqueous systems containing phenol and nitrophenols

<p>U&nbsp; radu&nbsp; je&nbsp; ispitan&nbsp; uticaj&nbsp; amida&nbsp; kao&nbsp; modela&nbsp; AOM-a (Algalne organske materije)&nbsp; na adsorpciju nitrofenola iz vodene&nbsp; sredine&nbsp; na&nbsp; aktivnom&nbsp; uglju.&nbsp; Istraţivanje&nbsp; se sastojalo&nbsp; iz&nbsp; tri&nbsp; faze:&nbsp; ispitivanje&nbsp; uticaja&nbsp; karateristika amida&nbsp; na&nbsp; adsorpciju&nbsp; nitrofenola,&nbsp; ispitivanje&nbsp; uticaja granulacije na adsorpciju nitrofenola u prisustvu amida i ispitvanje karakterisitka samih nitrofenola na adsorpciju u&nbsp; prisustvu&nbsp; amida.&nbsp; Pre&nbsp; ispitivanja&nbsp; adsorpcije&nbsp; u dvokomponentnim&nbsp; sistemima&nbsp; ispitana&nbsp; je&nbsp; adsorpcija jednokomponentnih&nbsp; sistema&nbsp; 4-nitrofenola,&nbsp; 2,4-dinitrofenola&nbsp; i&nbsp; 2,4,6-trinitrofenola,&nbsp; kao&nbsp; i&nbsp; amida&nbsp; Nmetilbenzamid,&nbsp; nikotinamida&nbsp; i&nbsp; N-benzilbenzamida&nbsp; na komercijalnim&nbsp; aktivnim&nbsp; ugljevima&nbsp; NORIT&nbsp; SA2&nbsp; i&nbsp; dve granulacije&nbsp; aktivnog&nbsp; uglja&nbsp; DARCO.&nbsp; Aktivni&nbsp; ugljevi&nbsp; su ispitani&nbsp; metodom&nbsp; FTIR&nbsp; spektroskopije,&nbsp; SEM&nbsp; analizom, analizom&nbsp; povr&scaron;ine&nbsp; adsorpcijom&nbsp; azota&nbsp; na&nbsp; niskoj temperaturi&nbsp; i&nbsp; određivanjem&nbsp; taĉke&nbsp; nultog&nbsp; naelektrisanja. Urađena&nbsp; je&nbsp; geometrijska&nbsp; optimizacija&nbsp; modela&nbsp; molekula ispitivanih nitrofenola i amida i izraĉunati su molekulski parametri.&nbsp; Uticaj&nbsp; amida&nbsp; kao&nbsp; modela&nbsp; AOM-a&nbsp; je&nbsp; ispitan kori&scaron;ćenjem&nbsp; razliĉitih&nbsp; ravnotežnih&nbsp; i&nbsp; difuzionih adsorpcionih&nbsp; modela.&nbsp; Kao&nbsp; kriterijum&nbsp; za&nbsp; određivanje najsporije&nbsp; adsorpcione&nbsp; faze&nbsp; kori&scaron;ćen&nbsp; je&nbsp; Biotov&nbsp; broj.<br />Adsorpcioni&nbsp; parametri&nbsp; dobijeni&nbsp; u&nbsp; eksperimentima&nbsp; sa dvokomponentnim&nbsp; sistemima&nbsp; su&nbsp; upoređivani&nbsp; sa parametrima dobijenim za adsorpciju samih nitrofenola.</p> / <p>In this research influence of selected amides, as a model of&nbsp; AOM&nbsp; (Algal&nbsp; organic&nbsp; matter),&nbsp; on&nbsp; adsorption&nbsp; of nitrophenols&nbsp; from&nbsp; water&nbsp; on&nbsp; activated&nbsp; carbon&nbsp; has&nbsp; been<br />investigated.&nbsp; Research&nbsp; is&nbsp; divided&nbsp; in&nbsp; three&nbsp; phases: investigation&nbsp; of&nbsp; influence&nbsp; of&nbsp; amide&nbsp; molecule characteristics&nbsp; on&nbsp; the&nbsp; adsorption&nbsp; of&nbsp; nitrophenols, investigation&nbsp; of&nbsp; granulation&nbsp; influence&nbsp; on&nbsp; nitrophenol adsorption in&nbsp; the&nbsp; presence of amide and investigation of nitrophenol characteristics that can influence adsorption in&nbsp; the&nbsp; presence&nbsp; of&nbsp; amides.&nbsp; Adsorption&nbsp; of&nbsp; nitrophenols and&nbsp; amides&nbsp; in&nbsp; single- component&nbsp; systems&nbsp; has&nbsp; also&nbsp; been carried&nbsp; out.&nbsp; Adsorption&nbsp; kinetics&nbsp; of&nbsp; 4-nitrophenol,&nbsp; 2,4-dinitrophenol,&nbsp; 2,4,6-trinitrophenol,&nbsp; N-methylbenzamide,<br />nicotinamide&nbsp; and&nbsp; N-benzylbenzamide&nbsp; has&nbsp; also&nbsp; been investigated. Commercial activated carbons NORIT SA2 and&nbsp; two&nbsp; granulations&nbsp; of&nbsp; DARCO&nbsp; were&nbsp; used.&nbsp; Activated carbons&nbsp; were&nbsp; characterized&nbsp; using&nbsp; FTIR&nbsp; spectroscopy, SEM&nbsp; analysis,&nbsp; internal&nbsp; surface&nbsp; analysis&nbsp; using&nbsp; nitrogen adsorption&nbsp; on&nbsp; low&nbsp; temperature&nbsp; and&nbsp; determination&nbsp; of point&nbsp; of&nbsp; zero&nbsp; charge.&nbsp; Geometry&nbsp; optimization&nbsp; of nitrophenol&nbsp; and&nbsp; amide&nbsp; molecules&nbsp; has&nbsp; been&nbsp; carried&nbsp; out and different molecular parameters have been calculated. Influence&nbsp; of&nbsp; amides&nbsp; as&nbsp; AOM&nbsp; model&nbsp; has&nbsp; been investigated by using diffusion and equilibrium models. Biot number has been obtained&nbsp; in order to establish the limiting&nbsp; step&nbsp; in&nbsp; adsorption&nbsp; process.&nbsp;&nbsp; Adsorption parameters&nbsp; obtained&nbsp; in&nbsp; two-component&nbsp; adsorption systems&nbsp; were&nbsp; compared&nbsp; to&nbsp; parameters&nbsp; obtained&nbsp; for adsorption of nitrophenols alone.</p>

The increased use of pesticides has resulted in a corresponding increase in concern for the effect they may have on the health of humans and other non-target organisms. The two main areas of concern are the toxicological effects that mixtures of pesticides may have as well as the endocrine disrupting effects. Although the individual pesticides may be present at concentrations below the levels deemed to be detrimental to health, it has been argued that their combined effect may still result in elevated health risks. Another important aspect of pesticide risk assessment requires a consideration of the breakdown products of pesticides and their effect on human health. There has been very little research into the effects of degradation products and this issue should be addressed as these could potentially pose a higher risk than their parent compounds. One of the most important bio-markers available for use is the ubiquitous enzyme acetylcholinesterase (AChE). This enzyme is responsible for one of the most important functions in the body; namely nerve impulse transmission, upon which all life depends. The inhibition of this enzyme indicates toxicity and as a subsequence, a threat to the organism’s well-being. Bioassays have also recently been developed to test chemicals for endocrine disrupting effects. These tests rely on a dose response equivalent to that of the most potent well known estrogen 17-β estradiol. Any chemical that has a measurable response is deemed to display endocrine disrupting effects. This first aim of this study was to investigate the toxicological and endocrine disrupting effects of three organophosphorus pesticides; aldicarb, parathion and demeton-S-methyl, in addition to two breakdown products; aminophenol and p-nitrophenol. Two carbamate pesticides; carbaryl and carbofuran were also analysed. The toxicological effects of mixtures of the parent pesticide compounds were tested to assess if any antagonistic, additive or synergistic effects were observed. This data was then used in conjunction with an artificial neural network to assess if individual pesticides could be distinguished from mixtures of pesticides. A final objective was to sample various Eastern Cape water sources, utilising the enzymatic assay to determine the presence of any of these pesticides in these samples. There were several conclusions drawn from this study. AChE was successfully used as an assay to test the toxicity of the pesticides under investigation, based on their inhibition of this enzyme. An important factor for consideration throughout the study was the need to establish basal and monitor AChE activity (i.e. the need to monitor AChE activity in the absence of any pesticide). This ensured accurate comparison of the results obtained. It was found that demeton-S-methyl was the most potent of these pesticides followed by carbaryl, parathion, aldicarb and finally carbofuran, and that carbofuran could potentiate AChE. The results indicated that pesticide mixtures generally exhibited an additive inhibitory effect on AChE, although at some concentrations of pesticides, synergistic and antagonistic effects were noted. From the data using mixtures of pesticides, a feed forward neural network was created that was successfully able to distinguish individual pesticides from mixtures within its training parameters. None of the pesticides tested displayed endocrine disrupting properties in the Yeast Estrogen Screen (YES), T47D-KBluc and MDA-kb2 bio-assays. Other studies reported mixed results in this regard and thus no final conclusions could be drawn. The Blaauwkrantz River, Kariega River, Sundays River, Swartkops River and Kowie River were all tested for pesticides and although positive results were recorded, conventional methods indicated that there were no pesticides in the rivers. There were, however, trace metals present which are known to inhibit AChE, thus causing a false positive result. These results indicated that AChE can be used as a high throughput initial pre-screening tool, but that it cannot serve as a substitute for more accurate conventional testing methods.

Se desarrolló cinco sistemas automatizados utilizando análisis por inyección secuencial (SIA) y análisis por inyección en flujo multijeringa (MSFIA). Se desarrolló un SI-analizador para la determinación de formaldehído utilizando la reacción de Hantzsch. El analizador fue aplicado a la monitorización en un cultivo de P. pastoris. Se desarrolló un SI-analizador para la determinación de glicerol y sorbitol. Se utilizó periodato para la reacción de Malaprade. El formaldehído generado fue cuantificado con la reacción de Hantzsch. El sistema incluyó la dilución de la muestra y procedimientos seleccionado por decisión inteligente del programa o por el usuario. Se lo aplicó a la monitorización en cultivos de P. pastoris.Se desarrolló un sistema de electroforesis capilar (CE) acoplado a un SIA aplicado a la separación de nitrofenoles. Se acopló por primera vez MSFIA con CE para pre-concentración en fase sólida y separación de nitrofenoles. Ambos sistemas mostraban recuperaciones satisfactorias para aguas ambientales. / Five analytical systems using Sequential Injection Analysis (SIA) and Multisyringe Flow Injection Analysis (MSFIA) were developed and applied with satisfactory analytical performance. A SI-analyzer for formaldehyde was developed automating Hantzsch reaction. It was successfully applied to formaldehyde monitoring in continuous medium filtrate of P. pastoris cultivation. A second SI-analyzer was developed for the determination of glycerol and sorbitol. Periodate was used as additional reagent to carry out Malaprade reaction and formaldehyde generated by polyalcohol oxidation was quantified. The system included automated sample dilution and procedures for two working ranges, selected by smart software decision or user-input. It was applied to monitoring of P. pastoris cultivations.A capillary electrophoresis (CE) system was developed and coupled to SIA. It was applied to the determination of nitrophenols. MSFIA and CE were coupled for the first time. Solid phase concentration and separation of nitrophenols were automated. The systems were applied to environmental water samples.

Presented Ph.D. Thesis is focused on the use of the boron-doped diamond (BDD) electrodes for voltammetric and amperometric determination of selected nitrophenols: 2-nitrophenol (2NP), 4-nitrophenol (4NP), and 2,4-dinitrophenol (2,4DNP). These compounds are listed as "priority pollutants" by United States Environmental Protection Agency (US EPA) due to their negative impact on living organisms and are mainly used in agriculture as plant growth stimulators. BDD electrodes are used for determination of wide range of electrochemically both reducible and oxidisable organic compounds and have become a popular electrode material thanks to its commercial availability and excellent mechanical and electrochemical properties. A differential pulse voltammetric method was developed for the determination of 2NP, 4NP and 2,4DNP at a BDD film electrode using electrochemical reduction and of 4NP and 2,4DNP using electrochemical oxidation. The method was successfully applied for the direct determination of these compounds in drinking and river water in the concentration range from 4×10-7 to 2×10-5 mol.L-1 . To improve the limit of quantification, a preconcentration by solid phase extraction from 100 mL (drinking and river water) and 1000 mL (drinking water) of water samples was used with limit of determination...