Este trabalho fez parte de um projeto de pesquisa financiado pelo ITV - Instituto Tecnológico Vale, realizado em parceria com a UFRGS. Devido a heterogeneidade dos carvões, partículas que apresentam baixo ou nenhum contéudo de carbono estão misturadas ao carvão de excelente qualidade podendo representar uma parcela significativa do carvão ROM, implicando em aumento de custos no processamento de estéreis e transporte de rejeitos. Diante da disponibilidade de equipamento comerciais utilizados na separação de minerais grosseiros em unidades móveis ou semi-móveis junto as minas, estima-se que a técnica de SBS possa ser utilizada na pré-concentração de carvões Moçambicanos, com objetivo de reduzir a quantidade de rejeitos enviados a planta de beneficiamento, reduzindo custos operacionais e impactos ao meio ambiente, uma vez que a pré-concentração é realizada a seco. A técnica de SBS foi aplicada a 4 diferentes camadas do carvão da mina de Moatize e sua eficiência avaliada. Os resultados demonstraram ser possível reduzir o teor de cinzas da alimentação de minério ROM. Por meio da remoção de minério de baixa qualidade foi possível reduzir de 10 a 14% da massa, promovendo a redução do teor de cinzas de 10 a 20%, na fração grosseira estudada. / This research is part of a project financed by ITV - Vale Technological Institute, in partnership of UFRGS. Due to coal heterogeneity, particles with low or no content of carbon are mixed with high quality coals and constitute a significant part of the run of mine, which promotes an increase in costs of waste processing and transportation. Commercially available mobile and semi-mobile sorting equipments for mining ores implement dry processes for preconcentration. Therefore, it is estimated that the SBS technique could be used in preconcentration of Mozambique's coal, with the aim to reduce the waste sent to the concentration plant, thus reducing operational costs and environmental impacts. The SBS technique was applied to four different coal's of the Moatize Mine seam and the efficiency was evaluated. The results shows it is possible reduce the ash content in the coarse fraction from feed plant. Through removal of the low quality ore was possible reduce 10 to 14% of mass, which promoted the reduction of ash content from 10 to 20% in coarse fraction feeding the concentration plant.

MSc (Chemistry) / Department of Chemistry / In this work, modern pre-concentration techniques, namely dispersive liquid-liquid micro-extraction (DLLME) and QuEChERS, were used to analyse pesticides and heavy metals in complex matrices. The work is divided into six papers. In Papers 1, the recent developments and applications of DLLME during analysis of pesticides in food matrices were reviewed. The DLLME technique has captured the interests of many researchers in recent years. The major advantage, among others, of DLLME is miniaturisation in which the acceptor-to-donor ratio is reduced tremendously leading to high enrichment compared to other sample preparation techniques. In the present work, the different complex matrices where the DLLME technique has been employed for the analysis of pesticides are reviewed as well as the challenges associated with this technique. Papers II reviewed the recent applications and developments of the QuEChERS technique during the analysis of pesticides in food matrices. QuEChERS is a versatile pre-concentration method whose application spans the whole breath of organic compounds. There are three common standard methods used during QuEChERS and these are the original QuEChERS, AOAC and the EN methods. In this paper, recent developments and applications of QuEChERS techniques in the analysis of pesticides in food samples were reviewed. In Paper III, green pre-concentration techniques employed during analysis of pesticides were reviewed. Recently, the parameter of “greenness” during sample pre-concentration of pesticides in food matrices is as important as selectivity in order to avoid using large amounts of harmful organic solvents during sample preparation. Developing new green pre-concentration techniques is one of the key subjects in green chemistry in order to minimize the release of large volume of toxic organic solvents into the environment. Thus, to reduce the impact on the environment during trace analysis of pesticides in food matrices, new developments in pesticide pre-concentration have gone in three separate directions (which are reviewed in this paper): one is the search for more environmentally friendly solvents, the second one is miniaturization and the third one is the development of solvent-free pre-concentration techniques. Eco-friendly solvents such as supercritical fluids, ionic liquids and natural deep eutectic solvents have been developed for use as extraction solvents during pre-concentration of pesticides in food matrices. Also miniaturized pre-concentration techniques such as QuEChERS, dispersive liquid-liquid micro-extraction and hollow-fibre liquid phase micro-extraction have been used during trace analysis of pesticides in food samples as well as solvent-free techniques such as solid phase micro-extraction and stir bar sorptive extraction. All these developments are geared to ensure that pesticide pre-concentration in food matrices is green and were reviewed in this paper. The effect of vehicular emissions on the concentrations of selected heavy metals was investigated in Paper IV. The samples were pre-concentrated using DLLME prior to analysis with flame atomic absorption spectroscopy. Dithizone, chloroform and methanol were used as chelating agent, extraction solvent and dispersion solvent respectively during the DLLME technique. The pH of the sample was adjusted to around 8 using sulphuric acid or sodium hydroxide solution. The influential DLLME parameters, such as pH volume and type of extraction solvent, and voume of disperser solvent, were optimized prior to the application of the developed method to real samples (roadside dust, fruits and vegetables). In Paper V, chromium speciation in fruits and vegetables was studied. The chromium in fruit and vegetable sample juices was pre-concentrated using DLLME prior to analysis with flame atomic absorption spectroscopy. Diphenylcarbazide (DPC) was used as a chelating agent in this study, and salting out of the complex from the aqueous medium into the organic phase was effected using sodium acetate. Chloroform and methanol were used as extraction and dispersion solvents respectively in the DLLME method for the determination of chromium (VI). For total chromium, the trivalent chromium was oxidised using acidified KMnO4 to hexavalent chromium before performing the DLLME technique. The concentration of chromium (III) was determined by finding the difference between total chromium and concentration of chromium (VI). The important parameters that influence the efficiency of the DLLME technique were also optimized using the univariate approach. After optimization, the developed method was applied to real samples. In Paper VI, the concentration of malathion pesticide in fruits was determined using QuECHERS for pre-concentration and UV-Vis spectrophotometry for instrumental analysis. Acetonitrile was used as the extraction solvent and Z-sep+/PSA sorbent combination was used for sample clean-up. The acetonitrile extract from QuEChERS was then hydrolysed using KOH followed by reaction with acidified potassium bromate for colour development. The coloured product formed was then analysed using UV-Vis spectrophotometry. Among the fruits analysed, Oranges had no malathion residue in them. However, trace amounts of malathion, below WHO maximum allowable limits, were found in pears and apples. / NRF

The metabolism of amino acids produces important chemical signaling molecules called neurotransmitters, which are responsible for carrying out important actions within the human body. There are approximately one hundred identified neurotransmitters. Neurotransmitter study is important due to their involvement in biological, physiological, pharmacological, and pathological functions. Commonly employed methods for neurotransmitter detection are mainly based upon microdialysis. However, the methods suffer from disadvantages. Microdialysis fails to determine the absolute concentration of analytes and therefore requires it to be tied in with an analytical technique such as high performance liquid chromatography or capillary electrophoresis. Although high performance liquid chromatography is the most powerful analytical technique to date, it necessitates high maintenance and suffers from poor temporal resolution. While capillary electrophoresis affords more rapid separations than high performance liquid chromatography, it suffers from poor concentration limits of detection and requires large sample dilutions of highly conductive samples, such as biological fluids. Consequently, research is focused on detection of various amino acids and neurotransmitters employing novel analytical techniques along with traditional capillary electrophoresis. First, a method was developed using traditional capillary electrophoresis with laser induced fluorescence detection to detect two major excitatory neurotransmitters, glutamate and aspartate in planaria. The method was later applied to detect several biogenic amines using micellar electrokinetic chromatography with laser induced fluorescence detection in planaria to study the effect of feeding on the levels of biogenic amines within individual planaria homogenates. The concentration sensitivity issue of capillary electrophoresis led to the use of a new method for sensitive neurotransmitter measurements, gradient elution isotachophoresis. Gradient elution isotachophoresis is an efficient capillary-based enrichment and separation technique based on balancing hydrodynamic counter-flow against electrophoresis. Enrichment is achieved with the aid of high concentrations of leading electrolyte in the counter-flow solution that creates an ionic interface near the capillary inlet. Discrete electrolyte spacers or carrier ampholyte mixtures are used to separate analyte zones. The method was applied to the enrichment and separation of physiologically relevant concentrations of aspartate and glutamate labeled with dansyl chloride, phenyl isothiocyanate, or carboxyfluorescein, succinimidyl ester in artificial cerebrospinal fluid using ultraviolet absorbance detection. Finally, gradient elution isotachophoresis was combined with capillary zone electrophoresis to eliminate the use of spacers and provide rapid separations and enrichment. The technique was applied for the detection of biogenic amines in a glass microfluidic device. / Chemistry

O COMEX Lab-Sorter MSX-400-VL-XR-3D (Sorter) foi avaliado, sob diferentes condições operacionais em relação a sua capacidade de realizar testes de pré-concentração em escala laboratorial, visando o uso dos resultados gerados para aplicação industrial. Para tal, 24 testes de separação (bem como mais testes de calibração) foram realizados para dois minérios diferentes (a base de ferro e zinco). Nesses testes, aproximadamente 73 kg de minério foram avaliados para fins de separação no equipamento acima citado. Este mostrou a capacidade de aumentar o teor do minério de ferro acima de 60% Fe, aproveitando assim de 46% da massa do material no tamanho Lump (-31 +12,7mm) que era anteriormente classificado como rejeito pela mina e tinha um teor de apenas 53% de Fe. Com respeito do Zinco, o equipamento recuperou 93% do minério de zinco, aumentando seu teor acima de 27% Zn. Dessa forma, o Sorter eliminou 27% da massa do ROM a ser alimentado na planta de benefíciamento da mina de zinco. As configurações de porcentagem ideal para o ferro eram de 150-220 threshold e 75% porcentagem, e para o zinco as configurações ideais eram de 0-100 threshold para a granulometria maior (-50 +19 mm) e de 0-150 para a granulometria menor (-25 +8mm), ambos com 75% porcentagem. / The MS-400-VL-XR-3D COMEX Lab-Sorter (Sorter) was evaluated under different operating conditions for its ability to carry out pre-concentration tests at the laboratory scale, with the intention of using the results generated for industrial application. To this end, 24 separation tests (and many more calibration tests) were performed for two different ores (iron and zinc). In these tests, more than 73 kg of ore was passed, particle per particle in the equipment. The Sorter showed the ability to increase the iron ore content to over 60% Fe, thus taking advantage of 46% of the mass of the Lump size material (-31 + 12.7mm) that was previously classified as waste and had a grade of only 53% Fe. With respect to Zinc, the Sorter recovered 93% of the zinc ore, increasing its content above 27% Zn. In this way, the Sorter eliminated 27% of the ROM mass to be fed into the zinc mine beneficiation plant. The ideal percentage configurations for the iron were 150-220 threshold and 75% percentage, and for zinc the ideal configurations were 0-100 threshold for the large particle size (-50 +19 mm) and 0-150 for the small particle size (-25 + 8mm), both with 75% percentage.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Sabendo que os peixes são bioacumuladores de contaminantes do ambiente aquático e com isso representam riscos para seus consumidores, podendo ampliar tal poluentes para a cadeia trófica, este estudo tem por objetivo determinar os níveis de cádmio e chumbo presentes na espécie de peixe Acará (Geophagus brasiliensis), tradicional do consumo da população ribeirinha, devido a grande quantidade de indivíduos na região industrial do Sul Fluminense, no rio Paraíba do Sul, do estado do Rio Janeiro, além de comparar as faixas de concentração destes elementos-traço com dados estabelecidos pela ANVISA, utilizando estes peixes como bioindicadores das regiões estudadas. Os peixes foram capturados ao longo do rio Paraíba do Sul, nos municípios de Pinheiral, Barra Mansa e Volta Redonda. A identificação e quantificação dos metaisforam realizados, por um sistema de pré-concentração, baseado na adsorção de metais por uma resina quelante (chelex100) acoplada em linhacom um espectrômetro de absorção atômica com chama (FAAS). O método de pré-concentração permitiu a detecção de cádmio em níveis maiores que ao limite de detecção do FAAS e quando comparados com os valores estabelecidos pela ANVISA, indicou que o peixe estaria impróprio para o consumo humano. Nas análises de pré-concentração para chumbo, não houve sinal expressivo a ser comparado, apresentando somente sinais de ruído do equipamento. O cádmio e o chumbo foram escolhidos para análise uma vez que são regulamentados como contaminantes inorgânicos pela ANVISA e não foi encontrado na literatura nenhum dado sobre esses metais em Geophagus brasiliensis / Knowing that the fish are bio-accumulators of aquatic contaminants and thus pose risks to its consumers which may extend such pollutants into the food chain, this study aims to determine the levels of cadmium and lead present in the species of Cichlid fish (Geophagus brasiliensis), traditional consumption of the local population, due to the large number of individuals in the industrial region of South Fluminense, in Paraíba do Sul, state of Rio de Janeiro and to compare the concentration ranges of these trace elements with data established by ANVISA using these fish as bioindicators of the regions studied. Fish were caught along the Paraíba do Sul River, in the municipalities of Pinheiral, Barra Mansa and Volta Redonda. The identification and quantification of metals were achieved by a pre-concentration system based on adsorption by a metal chelating resin (chelex100) coupled in line with an atomic absorption flame spectrometry ("F-AAS"). The method of preconcentration allowed cadmium detection levels greater than the detection limit of the "FAAS" and compared to the values established by ANVISA indicated that the fish would be unfit for human consumption. In the analyzes of pre-concentration for lead, no significant signal to be compared, presenting only equipment noise signals. Cadmium and lead were chosen for analysis since they are regulated as inorganic contaminants by ANVISA and was not found in the literature no data on these metals in Geophagus brasiliensis

In this master thesis, during 2009, 2010 and 2011, has been done measurement of total content of mercury in ambient air and soil air in urban and rural locations agglomeration of České Budějovice. The goal was to develop suitable method in order to provide sampling of air to evaluate rate of contamination from chosen locations. The aquaristic compressor was used for admission of air, thus collected air could pass through external amalgamator, which secured pre-concentration of mercury from air. Consecutively, captured mercury has been determined in laboratory by atomic absorption spectrometer AMA-254. In urban background locations has been found total average concentration of mercury in rate 4,01 +/- 3,5 ng.m-3 and urban locations influenced by traffic in rate 29,5 +/- 50,07 ng.m-3. The concentration of mercury in soil air taken from filter bed of constructed wetland (CW) was 16 +/- 9,44 ng.m-3 with average mercury flux 14,5 +/- 8,3 ng.m-2.h-1. In rural compared location has been concentration of mercury in rate 15,4 +/- 7,83 ng.m-3 and mercury flux in soil air was 16 +/- 9,3 ng.m-2.h-1 at this location. Significant differences in contamination of mercury among partial locations have not been ascertained to the exception. The statutory limit for amount of mercury in atmosphere is 50 ng.m-3, whose value has not been mostly reached in any of measured locations. Thus, it has been proved that air contamination is low at selected locations.

O COMEX Lab-Sorter MSX-400-VL-XR-3D (Sorter) foi avaliado, sob diferentes condições operacionais em relação a sua capacidade de realizar testes de pré-concentração em escala laboratorial, visando o uso dos resultados gerados para aplicação industrial. Para tal, 24 testes de separação (bem como mais testes de calibração) foram realizados para dois minérios diferentes (a base de ferro e zinco). Nesses testes, aproximadamente 73 kg de minério foram avaliados para fins de separação no equipamento acima citado. Este mostrou a capacidade de aumentar o teor do minério de ferro acima de 60% Fe, aproveitando assim de 46% da massa do material no tamanho Lump (-31 +12,7mm) que era anteriormente classificado como rejeito pela mina e tinha um teor de apenas 53% de Fe. Com respeito do Zinco, o equipamento recuperou 93% do minério de zinco, aumentando seu teor acima de 27% Zn. Dessa forma, o Sorter eliminou 27% da massa do ROM a ser alimentado na planta de benefíciamento da mina de zinco. As configurações de porcentagem ideal para o ferro eram de 150-220 threshold e 75% porcentagem, e para o zinco as configurações ideais eram de 0-100 threshold para a granulometria maior (-50 +19 mm) e de 0-150 para a granulometria menor (-25 +8mm), ambos com 75% porcentagem. / The MS-400-VL-XR-3D COMEX Lab-Sorter (Sorter) was evaluated under different operating conditions for its ability to carry out pre-concentration tests at the laboratory scale, with the intention of using the results generated for industrial application. To this end, 24 separation tests (and many more calibration tests) were performed for two different ores (iron and zinc). In these tests, more than 73 kg of ore was passed, particle per particle in the equipment. The Sorter showed the ability to increase the iron ore content to over 60% Fe, thus taking advantage of 46% of the mass of the Lump size material (-31 + 12.7mm) that was previously classified as waste and had a grade of only 53% Fe. With respect to Zinc, the Sorter recovered 93% of the zinc ore, increasing its content above 27% Zn. In this way, the Sorter eliminated 27% of the ROM mass to be fed into the zinc mine beneficiation plant. The ideal percentage configurations for the iron were 150-220 threshold and 75% percentage, and for zinc the ideal configurations were 0-100 threshold for the large particle size (-50 +19 mm) and 0-150 for the small particle size (-25 + 8mm), both with 75% percentage.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Sabendo que os peixes são bioacumuladores de contaminantes do ambiente aquático e com isso representam riscos para seus consumidores, podendo ampliar tal poluentes para a cadeia trófica, este estudo tem por objetivo determinar os níveis de cádmio e chumbo presentes na espécie de peixe Acará (Geophagus brasiliensis), tradicional do consumo da população ribeirinha, devido a grande quantidade de indivíduos na região industrial do Sul Fluminense, no rio Paraíba do Sul, do estado do Rio Janeiro, além de comparar as faixas de concentração destes elementos-traço com dados estabelecidos pela ANVISA, utilizando estes peixes como bioindicadores das regiões estudadas. Os peixes foram capturados ao longo do rio Paraíba do Sul, nos municípios de Pinheiral, Barra Mansa e Volta Redonda. A identificação e quantificação dos metaisforam realizados, por um sistema de pré-concentração, baseado na adsorção de metais por uma resina quelante (chelex100) acoplada em linhacom um espectrômetro de absorção atômica com chama (FAAS). O método de pré-concentração permitiu a detecção de cádmio em níveis maiores que ao limite de detecção do FAAS e quando comparados com os valores estabelecidos pela ANVISA, indicou que o peixe estaria impróprio para o consumo humano. Nas análises de pré-concentração para chumbo, não houve sinal expressivo a ser comparado, apresentando somente sinais de ruído do equipamento. O cádmio e o chumbo foram escolhidos para análise uma vez que são regulamentados como contaminantes inorgânicos pela ANVISA e não foi encontrado na literatura nenhum dado sobre esses metais em Geophagus brasiliensis / Knowing that the fish are bio-accumulators of aquatic contaminants and thus pose risks to its consumers which may extend such pollutants into the food chain, this study aims to determine the levels of cadmium and lead present in the species of Cichlid fish (Geophagus brasiliensis), traditional consumption of the local population, due to the large number of individuals in the industrial region of South Fluminense, in Paraíba do Sul, state of Rio de Janeiro and to compare the concentration ranges of these trace elements with data established by ANVISA using these fish as bioindicators of the regions studied. Fish were caught along the Paraíba do Sul River, in the municipalities of Pinheiral, Barra Mansa and Volta Redonda. The identification and quantification of metals were achieved by a pre-concentration system based on adsorption by a metal chelating resin (chelex100) coupled in line with an atomic absorption flame spectrometry ("F-AAS"). The method of preconcentration allowed cadmium detection levels greater than the detection limit of the "FAAS" and compared to the values established by ANVISA indicated that the fish would be unfit for human consumption. In the analyzes of pre-concentration for lead, no significant signal to be compared, presenting only equipment noise signals. Cadmium and lead were chosen for analysis since they are regulated as inorganic contaminants by ANVISA and was not found in the literature no data on these metals in Geophagus brasiliensis

O COMEX Lab-Sorter MSX-400-VL-XR-3D (Sorter) foi avaliado, sob diferentes condições operacionais em relação a sua capacidade de realizar testes de pré-concentração em escala laboratorial, visando o uso dos resultados gerados para aplicação industrial. Para tal, 24 testes de separação (bem como mais testes de calibração) foram realizados para dois minérios diferentes (a base de ferro e zinco). Nesses testes, aproximadamente 73 kg de minério foram avaliados para fins de separação no equipamento acima citado. Este mostrou a capacidade de aumentar o teor do minério de ferro acima de 60% Fe, aproveitando assim de 46% da massa do material no tamanho Lump (-31 +12,7mm) que era anteriormente classificado como rejeito pela mina e tinha um teor de apenas 53% de Fe. Com respeito do Zinco, o equipamento recuperou 93% do minério de zinco, aumentando seu teor acima de 27% Zn. Dessa forma, o Sorter eliminou 27% da massa do ROM a ser alimentado na planta de benefíciamento da mina de zinco. As configurações de porcentagem ideal para o ferro eram de 150-220 threshold e 75% porcentagem, e para o zinco as configurações ideais eram de 0-100 threshold para a granulometria maior (-50 +19 mm) e de 0-150 para a granulometria menor (-25 +8mm), ambos com 75% porcentagem. / The MS-400-VL-XR-3D COMEX Lab-Sorter (Sorter) was evaluated under different operating conditions for its ability to carry out pre-concentration tests at the laboratory scale, with the intention of using the results generated for industrial application. To this end, 24 separation tests (and many more calibration tests) were performed for two different ores (iron and zinc). In these tests, more than 73 kg of ore was passed, particle per particle in the equipment. The Sorter showed the ability to increase the iron ore content to over 60% Fe, thus taking advantage of 46% of the mass of the Lump size material (-31 + 12.7mm) that was previously classified as waste and had a grade of only 53% Fe. With respect to Zinc, the Sorter recovered 93% of the zinc ore, increasing its content above 27% Zn. In this way, the Sorter eliminated 27% of the ROM mass to be fed into the zinc mine beneficiation plant. The ideal percentage configurations for the iron were 150-220 threshold and 75% percentage, and for zinc the ideal configurations were 0-100 threshold for the large particle size (-50 +19 mm) and 0-150 for the small particle size (-25 + 8mm), both with 75% percentage.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-05-30T13:01:39Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE DILMO MARQUES_2016.pdf: 3410115 bytes, checksum: ef2c4a31a389b0d7af33d59ec444fa24 (MD5) / Made available in DSpace on 2017-05-30T13:01:39Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE DILMO MARQUES_2016.pdf: 3410115 bytes, checksum: ef2c4a31a389b0d7af33d59ec444fa24 (MD5) Previous issue date: 2016-03-21 / CNPQ / Neste trabalho foram desenvolvidos métodos analíticos, baseados no conceito de multicomutação, para análise de espécies químicas em alimentos. Para isto, foram sintetizados dois materiais: um composto de coordenação usado como fase sólida na determinação de açúcares redutores e uma rede de sílica utilizada como resina de pré-concentração de percloratos. O composto de coordenação cobre (II) - 4,4 '- bipiridina foi usado no desenvolvimento do método para a determinação de açúcares redutores em água de coco e sucos empregando sistema em fluxo multicomutado com detecção espectrofotométrica. A metodologia de análise baseou-se na reação de oxi-redução em meio alcalino entre o reagente sólido e os açúcares redutores. A reação entre a fase sólida (de coloração azul) com (glicose + frutose) resulta em produto de cor amarelada, monitorada em 420 nm. A fase sólida foi fixada em 50 mg e temperatura de 90ºC. Com volume de zona de amostragem de 160 L, que corresponde a 20 ciclos, obtendo resposta linear entre 1,0 e 20,0 g L-1 de AR com RSD de 4,47% (n = 7 ), limite de detecção de 0,2250 g L-1, limite de quantificação de 0,7496 g L-1, freqüência analítica de 75 determinções por hora e geração de efluentes de 320 μL por determinação. Os teores de açúcar redutor encontrados em sucos e água de coco variaram de 38,35 a 98,50 g L-1 e 61,80 a 68,70 g L-1 respectivamente. A rede de sílica, 2,5,8,11,14-pentaoxa-1-silaciclotetradecano, foi empregada num sistema multicomutado como coluna de pré-concentração de perclorato. O sistema foi acoplado a um detector potenciométrico para determinar percloratos em vegetais. Usou-se um eletrodo tubular com membrana constituída por 1% (m/m) de BNIP 4,4 Dapm LC1 solubilizado em 68% (m/m) de 2-nitrodifeniléter, como solvente mediador e 31% (m/m) de poli (cloreto de vinila). Obteve-se limite de detecção de 2,8x10-7 mol L-1, resposta linear no intervalo de 1,0x10-9 a 1,0x10-1 mol L-1, coeficiente de correlação linear de 0,9998 e a coluna apresentou uma capacidade de retenção de 2,86x10-3 mol de perclorato. O sistema foi aplicado às amostras de diferentes vegetais e foram encontradas concentrações de percloratos de 1,30 a 5,08 µg L-1 o teste recuperação variou de 96,5 a 110,8 %. / Two new multicommutation-based analytical methods were developed aiming to the quantification of chemical species in food. The first method is intended to the determination of reducing sugars in coconut water and fruit juices, while the second one is a potentiometric determination of perchlorates in horticultural products. The method eveloped for the determination of reducing sugars uses a multicommuted flow system with spectrophotometric detection employing a (copper (II) - 4,4’ – bipyridyl) coordination compound as the solid-phase reagent. The reaction of the solid blue phase with glucose/fructose resulted in a yellowish solution, which was monitored at 420 nm; 50 mg of the solid phase was used and the temperature was set at 90ºC. The volume of the sample zone was, 160 L, corresponding to 20 cycles, with a linear response of 1.0 e 20.0 g L-1 to the RA and RSD of 4.47% (n = 7), detection limit of 0.2250 g L-1, the limit of quantification was 0.7496 g L-1, analytical frequency of 75 determination per hour and effluent generation of 320 L per determination. The potentiometric method used to determine perchlorates used a tubular electrode formed by a polymeric membrane which showed the best features consisted of 1% (w/w) BNIP Dapm LC1 solubilized in 68% (w/w) of 2-nitrodiphenyl ether as a mediator solvent and 31% (w/w) poly(vinyl chloride) as the polymeric matrix. A limit of detection of 2.8x10-7 mol L-1 was obtained with a linear response in the range of 1.0x10-9 at 1.0x10-1 mol L-1, linear correlation coefficient of 0.9998 and the column retention capacity 2.86x10-3 mol perchlorate. Was applied to samples of different vegetables found perchlorates 1.30 to 5.08 µg L-1 and recovery between 96.5 and 110.8%.