A tecnologia da informação no auxílio à gestão do grupo alfa de restaurantes

Appeal from the Judgment of the Second Judicial District Court In and For Davis County, State of Utah, The Honorable Rodney S. Page, Presidin

Processing of green tea (Camellia sinensis) extract applying membrane filtration

The consumption of functional beverages and food has increased in the last years mainly due to people concerning about their health and well-being. Camellia sinensis leaves are traditionally used for infusion preparations. Furthermore, considering the high bioactive compounds concentration in its extracts, this herb has been catching the attention of researchers as well as of the food and pharmaceutical industries. Membrane filtration processes may be used for clarification, purification, and concentration of several products. From this point of view, this study focused on the green tea processing, including leaves characterization, extraction, clarification, and purification of polyphenols. In this sense, water was used as a solvent for extraction; macroscopic pre-treatments was applied for clarification (centrifugation and addition of coagulants agent, such as chitosan and Moringa oleífera seeds) and sequentially, a membrane filtration was employed for purification. Initially, the tea was ground, sifted and classified granulometrically. Then, different parameters were evaluated in order to find the best polyphenol extraction condition from tea leaves. The influence of the tea particle was analysed at 80ºC for 30 min for a water-to-tea ratio 50 g L-1 and a tea particle size (0.05-2.83 mm) besides unground leaves. The best tea particle size for polyphenols extraction was 0.15-0.74 mm and it was then used for all further conventional and ultrasound assisted extraction experiments. The optimum ratio was determined by extractions at 80ºC for 30 min with a tea-to-water ratio ranging from 10 to 120 g L-1. The impact of time and temperature on the conventional extraction of polyphenols was evaluated at 50 g L-1 tea-to-water ratio by ranging the time and the temperature from 10 to 120 min and from 40 to 90ºC respectively. Ultrasound-assisted extraction (UAE) consisted of two steps. In the first step of UAE, an experimental design using Response Surface Methodology (RSM) was performed with three replicates at the central point, orthogonality alpha of 1.3531 and at a significance level of 95%. For extraction time of 30 min, temperature, tea-to-water ratio, and amplitude ranged from 22 to 83ºC, 12 to 73 g L-1, 23 to 77% respectively. In the second step of UAE, using the best amplitude determined in step one (77%) and for a water-to-tea ratio 50 g L-1, similarly to conventional extraction, time and temperature varied from 10 to 120 min and from 40 to 90ºC respectively. The optimum extraction condition found in this study was 80ºC, 50 g L-1 for 60 min and a particle size (0.15-0.74 mm). Sequentially, the pre-treatments were performed: centrifugation (8000 rpm, 20 min), chitosan addition (0-2000 mg L-1) and Moringa oleífera seeds addition (0-10.000 mg L-1). Microfiltration processes were carried out at 0.8 bar applying a flat membrane of 0.22 µm and hollow fibres without coating coupled in a home-made cartridge. Microfiltration through hollow fibres without coating presented less polyphenol retention (2.33%), greater solids removal (4.23%), greater turbidity reduction (89.91%) and the greatest steady-state flux (19.37 L h-1m-2) comparatively to flat membrane of 0.22 μm. After the microfiltration processes, a sequential filtration was executed at 1.5 bar employing a home-made cartridge using hollow fibres with a polymeric coating. This sequential process achieved a steady-stead flux of 3.51 L h-1m-2 and a reduction of 9.17% of polyphenols, 12.89% de solids, 80.65% of turbidity and 16.92% of soluble solids (ºbrix). The obtained flux in each filtration process was used to calculate the fouling mechanism and the membrane resistance. In this way, fouling mechanisms (n) and pore resistance values (RP) found for flat membrane of 0.22 µm, hollow fibre without coating and for hollow fibre with coating were internal pore blocking (n=1.5) e (RP = 0.7 x 10-13), cake formation (n=0) e (Rc = 2.80 x 10-13) and intermediary pore blocking (n=1) e (RP = 7.38 x 10-13) respectively. Extract and permeates stability, stored at 5ºC for 30 days, were evaluated using as reference the parameters polyphenols concentration, turbidity and tea cream formation. Only the permeate obtained through filtration by the coated hollow fibre (S5) presented stability (turbidity value less than 4 NTU) and no formation of tea cream during the 30 days of storage at 5ºC. In conclusion, this study found the best polyphenol extraction conditions and proposed the utilisation of centrifugation for clarification followed by filtration through hollow fibres membranes without and with coating for green tea extract purification.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorDissertação (Mestrado)O consumo de bebidas e alimentos funcionais tem crescido no mundo nos últimos anos principalmente devido ao aumento da preocupação das pessoas com a saúde e o bem estar. As folhas da planta Camellia sinensis são tradicionalmente utilizadas para o preparo de infusões e, além disso, devido à alta concentração de compostos bioativos em seus extratos, essa erva tem chamado a atenção de pesquisadores e das indústrias alimentícia e farmacêutica. Os processos de filtração por membranas podem ser utilizados para clarificação, purificação e concentração de diversos produtos. Nessa perspectiva, este trabalho teve como objetivo o processamento do chá verde incluindo a caracterização das folhas, a extração, a clarificação e a purificação dos polifenóis presentes no chá usando água como solvente, pré-tratamentos macroscópicos para a clarificação (centrifugação e adição de agentes coagulantes - quitosana e sementes de Moringa oleífera) e, sequencialmente, filtração por membranas para purificação dos extratos. Inicialmente fez-se a moagem, o peneiramento e a classificação granulométrica das folhas de chá verde. A influência da granulometria na extração foi analisada em uma extração aquosa conduzida a 80ºC por 30 min a uma razão chá-água de 50 g L-1 utilizando folhas de chá com granulometria na faixa de 0,05-2,83 mm e também folhas de chá não moídas. A melhor granulometria para extração de polifenóis encontrada foi para a faixa de partículas de 0,15-0,74 mm e essa foi utilizada em todos os experimentos de extração convencional e com ultrassom subsequentes. O impacto da razão chá-água foi avaliado variando-a de 10 a 120 g L-1 para extrações a 80ºC por 30 min. Para a verificação do melhor tempo e da melhor temperatura na extração convencional, o preparo do chá foi realizado com uma razão chá-água de 50 g L-1, variando-se o tempo de 10 a 120 min e a temperatura de 40 a 90°C. A extração ultrassônica foi feita em duas etapas, na primeira etapa foi feito um planejamento composto central (PCC), com três réplicas no ponto central, com alfa de ortogonalidade igual a 1,3531, a um nível de significância de 95%. Para bateladas de 30 min variou-se a temperatura de 22 a 83ºC, a razão chá-água de 12 a 73 g L-1 e a amplitude de 23 a 77%. Na segunda etapa da extração ultrassônica, utilizou-se a razão chá-água de 50 g L-1, a melhor amplitude encontrada na primeira etapa (77%) e, similarmente à extração convencional, avaliou-se o efeito da temperatura em função do tempo variando-se o tempo de 10 a 120 min e a temperatura de 40 a 90ºC. A melhor condição de extração encontrada nesse trabalho foi a extração convencional a 80ºC, 50 g L-1 por 60 min utilizando partículas de chá na faixa (0,15-0,74 mm). Em seguida, avaliou-se como pré-tratamentos: centrifugação (8000 rpm, 20 min), adição de quitosana (0-2000 mg L-1) e adição de sementes de Moringa oleífera (SMO) (0-10.000 mg L-1). As microfiltrações foram feitas a 0,8 bar utilizando como alimentação o extrato centrifugado. Para tal empregou-se uma membrana plana de éster de celulose de 0,22 μm e um cartucho de membranas cerâmicas do tipo fibra-oca sem revestimento polimérico fabricado em laboratório. A microfiltração através das membranas do tipo fibra-oca sem revestimento apresentaram menor retenção de polifenóis (2,33%), maior retenção de sólidos (4,23%), maior redução da turbidez (89,91%) e maior fluxo estabilizado (19,37 L h-1m-2) em relação à membrana comercial plana de 0,22 μm. Posteriormente à microfiltração fez-se uma filtração sequencial empregando um cartucho com membranas de alumina do tipo fibra-oca com revestimento polimérico a 1,5 bar. Para esse processo obteve-se um fluxo estabilizado de 3,51 L h-1m-2, uma redução de 9,17% de polifenóis, 12,89% de sólidos, 80,65% da turbidez e 16,92% de sólidos solúveis (ºbrix). Os fluxos obtidos nas filtrações foram utilizados para calcular o mecanismo de fouling e para calcular as resistências das membranas. O mecanismo de fouling predominante (n) e o valor da resistência dos poros (RP) encontrados para a membrana plana de 0,22 µm, para a fibra oca sem revestimento e para fibra oca com revestimento foram bloqueio interno dos poros (n=1,5) e (RP = 0,7 x 10-13), formação de torta (n=0) e (Rc = 2,80 x 10-13) e bloqueio intermediário dos poros (n=1) e (RP = 7,38 x 10-13), respectivamente. Avaliou-se a estabilidade do extrato de alimentação e dos permeados das filtrações, quando armazenados por 30 dias à 5ºC, tomando como referência os parâmetros concentração de polifenóis, turbidez e formação de tea cream. Observou-se que apenas o permeado obtido através da filtração pela fibra oca revestida (S5) apresentou estabilidade (turbidez menor que 4 NTU) e sem a formação de tea cream ao longo dos 30 dias de armazenamento à 5ºC. Assim, este trabalho encontrou as melhores condições de extração de polifenóis presentes em folhas de chá verde e evidenciou a utilização de centrifugação para clarificação e a aplicação filtração com membranas de alumina do tipo fibra oca sem e com revestimento polimérico para purificação do extrato de chá de chá verde. O resultado final foi a produção do chá verde como uma bebida mais clarificada e estável

Fish liver (Mugil Liza) nitro-sulfuric digestion in a focused microwave system to determine elements of environmental interest by ICPMS

O presente estudo propõe uma metodologia para dissolução de tecidos biológicos em sistema de micro-ondas com radiação focalizada e posterior análise elementar por espectrometria de massas com plasma acoplado indutivamente (ICPMS). Foram determinados os elementos arsênio (As), cádmio (Cd), cobre (Cu), chumbo (Pb), níquel (Ni), vanádio (V) e zinco (Zn). A matriz nitro-peroxo-sulfúrica foi comparada com outra sem o ácido sulfúrico e apresentou melhor padrão de recuperação (acima de 90%) na quantificação dos elementos certificados no material de referência TORT-2. As interferências causadas pela presença do ácido sulfúrico na matriz digestora foram contornadas com o uso da célula de reação/colisão com gás hélio (He) e adição deste ácido na composição da curva de quantificação. O ganho analítico proporcionado pelo método de digestão em matriz sulfúrica, em sistema não pressurizado, baseia-se no incremento da temperatura reacional e na degradação completa da matéria orgânica. As digestões tradicionalmente realizadas para quantificação por ICPMS, compostas unicamente de ácido nítrico (HNO3) e peróxido de hidrogênio (H2O2), não apresentam a mesma eficiência na degradação da matéria orgânica em sistemas abertos. Por fim, este método foi aplicado satisfatoriamente em amostras de tecido hepático de peixe Mugil liza (tainha), comprovando sua eficiência em monitorar a bioacumulação, utilizando-se da sensibilidade da técnica multielementar de ICPMSThis study proposes a methodology for dissolution of biological tissues in microwave system with focused radiation and subsequent elemental analysis by mass spectrometry with inductively coupled plasma (ICPMS). The elements arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), vanadium (V) and zinc (Zn) were identified and quantified. The nitro-peroxo-sulfuric acid matrix was compared to another without sulfuric acid and showed better recovery (above 90%) in the quantification of elements in certified reference material TORT-2. The interferences caused by the presence of sulfuric acid in digesting matrix were bypassed by the use of ORS (octapole reaction system) with helium (He) gas and the addition of this acid in the composition of the quantification curve. The gain provided by the analytical method of digestion with sulfuric acid matrix in non-pressurized system, is based on increasing the reaction temperature and the complete degradation of organic matter. Digestions traditionally performed for quantification by ICPMS, composed only with nitric acid (HNO3) and hydrogen peroxide (H2O2), are not as efficient in the degradation of organic matter in open systems. Finally, this method was satisfactorily applied in samples of liver tissue of fish Mugil liza (mullet), proving its effectiveness in monitoring the bioaccumulation, using the sensitivity of multielemental ICPMS techniqu

Bioaccumulation of Tributyltin by Blue Crabs

O presente estudo avaliou a bioacumulação de tributilestanho (TBT) pelo siri azul (Callinectes sapidus). Os animais foram alimentados com comida contaminada com 30 µg g -1 de TBT, expresso como Sn. Os analitos foram determinados nas brânquias, hepatopâncreas e músculo. Realizou-se uma digestão ácida para determinação da concentração total de Sn, e a técnica de extração em fase sólida foi utilizada para determinação seletiva de TBT. Obteve-se limites de detecção de 44,6 e 4,46 ng g -1 para HG-ICP OES (geração de hidretos (HG) por espectrometria de emissão óptica com plasma indutivamente acoplado) e ICP-MS (ICP-espectrometria de massas), respectivamente. Os resultados para os tecidos dos animais não contaminados foram inferiores a 50 ng g -1 , enquanto os submetidos à alimentação contaminada mostraram elevadas concentrações de Sn (até 6229 ng g -1 ) e TBT (até 3357 ng g -1 ) relacionadas aos dias de exposição. De acordo com os resultados, Sn é acumulado pelo siri azul em elevadas concentrações no hepatopâncreas. Para a maioria dos animais, os resultados sugerem que o Sn é bioacumulado como TBT. This study evaluated the bioaccumulation of tributyltin (TBT) by the blue crab (Callinectes sapidus). Animals were fed with contaminated food containing 30 µg g -1 of TBT expressed as Sn. The analytes were determined in the gills, hepatopancreas and muscle. Acid digestion was used in the total Sn determination, and a solid-phase extraction technique was used for the selective determination of TBT. Limits of detection of 44.6 and 4.46 ng g -1 were found for HG-ICP OES (hydride generation-inductively coupled plasma optical emission spectroscopy) and ICP-MS (ICP-mass spectrometry), respectively. The results for non-contaminated animals were below 50 ng g -1 , while the animals subjected to the contaminated food showed higher tissue concentrations of Sn (until 6229 ng g -1 ) and TBT (until 3357 ng g -1 ) related to the number of exposure days. According to the results, Sn is bioaccumulated by the blue crab in higher concentrations in the hepatopancreas. For most of these animals, the results suggest that Sn is bioaccumulated as TBT. Keywords: tin bioaccumulation, speciation, HG-ICP OES, ICP-MS Introduction Bioaccumulation is the result of absorption (by surface, breathing and diet) and the excretion processes (by breathing, defecation, metabolic biotransformation and dilution) of substances in organisms. For crustaceans and marine bivalves, accumulation can occur from an aquatic environment, ingested food and sediment. The presence of antifouling paints and biocides containing tributyltin (TBT) in coastal ecosystems is of great environmental concern. Although TBT can persist in sediments for years 7 Many studies attempting to evaluate the TBT bioaccumulation process and its effects using amphipods, 8 fish 9-11 and molluscs 12-17 can be found in the literature. Even at low concentration level in sediments, TBT causes imposex in molluscs. 18 For fish, TBT can lead to a bias of sex toward males. 19 However, few studies using crabs exposed to TBT have been reported. Weis and Kim 20 studied U. pugilator crabs exposed to 0.5 mg L -1 TBT and concluded that the presence of the compound in the organism can delay tissue regeneration and ecdysis. In addition, anatomical abnormalities were found during tissue regeneration and basal growing, indicating that the compound has teratogenic effects on tissue development. Botton et al. Rouleau et al. Although there have been several studies evaluating metallic elements bioaccumulation (Cd, Cr, Cu, Hg, Pb and Zn) by the Callinectes sapidus crab, The main objective of this work was to investigate the TBT bioaccumulation process in C. sapidus. Additionally, the objectives focused on evaluating which form (organic or inorganic) the metallic element is stored and in which tissue the bioaccumulation predominates (gill, hepatopancreas or muscle). Thus, the animals were subjected to TBT-contaminated food, and after exposure, the total Sn and TBT concentrations in different tissues were determined. Several variables, such as time of exposure (days) and amount of ingested food, were evaluated. Experimental Materials Instruments In this study, an Agilent 7500ce inductively coupled plasma mass spectrometer (ICP-MS) and a GBC model Integra XL inductively coupled plasma optical emission spectrometer (ICP OES) were used. Operations conditions for the instruments and for hydride generation (HG) are described below: ICP-MS condition: plasma RF power of 1500 W; sample depth from load coil of 7.5 mm; carrier gas flow of 0.8 L min ; spray chamber temperature at 2 °C; sample flow rate of 0.6 µL min -1 ; concentric micromist nebulizer; nickel sample and skimmer cones interface; m/z 118; 120; integration time of 0.1000 s; reaction/collision cell without gas; detector mode in pulse HV. HG-ICP OES condition: forward power of 1200 W; plasma gas flow of 10 L min -1 ; auxiliary gas flow of 0.5 L min ; and carrier gas flow of 0.6 L min -1 . Reagents and solutions Deionized water (18.2 MW cm) was produced in a Milli-Q system (Millipore, Bedford, MA, EUA). The nitric acid used for the ICP-MS analysis was purified by distillation below its boiling point. The other reagents were analytical grade. Solutions of 3% NaBH 4 (m/v) (MP Biomedicals, EUA) in 0.05 mol L -1 NaOH (Synth, São Paulo, Brazil) were used in the hydride generation system and prepared immediately before analysis. All solid phase extraction (SPE) tests for the TBT determination were conducted using commercially obtained dehydrated Saccharomyces cerevisiae yeast (Fermix, São José dos Campos, Brazil). Bioaccumulation of Tributyltin by Blue Crabs J. Braz. Chem. Soc. 1644 The working solutions were prepared from stock solutions of 1000 mg L -1 Sn (IV) made from Sn 0 (Aldrich, Milwaukee, EUA) and 1000 mg L -1 TBT made from TBTCl (tributyltin chloride, Aldrich). Methods Field work Callinectes sapidus, known as blue crab, were caught in the Santos city (São Paulo, Brazil) ocean coast (S 23º 54' 750" WO 45º 25' 460") using traps made of plastic mesh and by manual catching. All of the collected individuals were carried to the laboratory (Centro de Estudos Ambientais, Universidade Estadual Paulista). Exposure Four crabs were kept for 14 days and fed non-contaminated food (controls). Nine other crabs were incubated for 40 days and fed contaminated food. The crabs were individually kept in plastic bottles. The seawater used in the experiments was collected at the same place and in the same period in which the crabs were caught. This water was analyzed and it showed no significant amount of tin. The water was cleaned daily by suction of the eventual residue and renewed every 5 days. The concentration of TBT in contaminated food (30 µg g -1 ) was stated by considering a previously related exposure experiment. 22 Hake (Merluccius hubbsi) fillet was cut into pieces and 5 g samples were then separated into flasks. The food was contaminated by adding 150 µL of a TBT stock solution to the 5 g fish samples, resulting in a final TBT concentration of 30 µg g -1 . After this addition, the mixture was mixed into the fish meat using a vortex agitator for 5 min. The mixture visually seemed very homogeneous slurry. The flasks were then stored at 4 ºC. The contamination of the food with Sn from TBT was prepared one day before use. Each animal was fed 3 times a week with small pieces of fish (with or without contamination). The food was given to the animals until they refused to ingest it, and the eaten fish mass was registered for each animal. The mass of ingested food for each contaminated animal is shown in After exposure, all of the animals were euthanized by chilling at −10 ºC and classified by sex (6 females and 10 males), mass (average of 55.9 g), carapace length (3.9-5.2 cm) and width (8.1-11.4 cm). Using stainless materials, the gills, hepatopancreas and muscle tissues were removed from each individual, weighed and stored in 2 mL Eppendorf tubes at −10 ºC until analysis. All of the glassware and plastics used during exposure, tissue dissection and determination of Sn concentrations were decontaminated with 20% HNO 3 (v/v) and rinsed with deionized water before use. Total Sn determination The collected tissues were digested using a nitro-perchloric digestion as previously reported. 33,34 The digestion process was conducted with blank samples to evaluate any occasional contamination due to the reagents and/or the flasks. To evaluate the accuracy of the method, the total Sn concentrations in the digested samples were determined by hydride generation combined with inductively coupled plasma optical emission spectrometry (HG-ICP OES) and inductively coupled plasma mass spectrometry (ICP-MS). The experimental conditions for total Sn determination by HG-ICP OES were previously evaluated. 35 TBT determination TBT determination (and other tin organic compounds) in sediments and biological tissues has been effectively performed by coupling gas chromatography and inductively coupled plasma mass spectrometric (CG-ICP-MS). 35 The tin extraction from biological material was performed with a procedure described by Silva et al. After the extraction of Sn from the tissues, a SPE was performed to separate the organic Sn compound (TBT) from the inorganic forms potentially present in the samples. The resulting suspensions were vigorously agitated and centrifuged. During this procedure, TBT is retained by the yeast (solid phase), while any inorganic Sn remains in the liquid phase. Finally, the solid phase was treated with nitric acid and analyzed by HG-ICP OES Results and Discussion Non-contaminated blue crabs HG-ICP OES and ICP-MS techniques were used to determine the total amount of Sn in the gills, hepatopancreas and muscle of the non-contaminated crabs. The results were similar for both techniques. The limit of detection (LOD) for Sn using ICP-MS (0.055 µg L -1 ) was 10 times lower than the one obtained using HG-ICP OES (0.55 µg L -1 ) and allowed for analyte determination in the majority of samples The accuracy of the results obtained by both techniques was evaluated through recovery tests (by spiking Sn (IV) before the digestion step). The determinations made by ICP-MS presented better recoveries than those obtained by HG-ICP OES, with average values between 73 to 89% and 64 to 87%, respectively. All tissues showed relatively low Sn concentrations (highest value of 45.18 ng g -1 for the hepatopancreas sample), except for the concentration obtained from muscle sample 2 Contaminated blue crabs Total Sn concentration Figures 1 and 2 show the total Sn concentrations found in each animal in relation to the number of days they were exposed to the contaminated food determined by HG-ICP OES and ICP-MS, respectively. The limits of detection (wet basis) for total Sn As observed in the figures, the results from both techniques were similar and yielded graphs with similar patterns. However, higher Sn concentrations (mainly for two hepatopancreas samples) were observed when ICP-MS determinations were used. Signal suppression due to change on stannane generation by the presence of organic material in these samples is a possible interference in HG-ICP OES determination. Due to the large variations observed in both data sets, the results could only be compared statistically by performing a logarithmic standardization of the data. After standardization, an F-test was applied to determine if it was possible to compare the samples. A paired t-test was performed after the F-test (significance level 95%). The t-test showed that both data sets were not significantly different (significance level 95%). Therefore, despite the observed increase in Sn concentration values, a significant difference between the results obtained by the HG-ICP OES and ICP-MS techniques was not statistically confirmed. By studying the mass of the contaminated food eaten by the crabs, an identical pattern was observed compared with the data obtained for the number of exposure days To evaluate the differences between the Sn concentrations in the tissues, a Friedman statistic test was used. This test allows for comparisons between dependent variables (different tissues from the same animal). The results showed significant statistical differences (p < 0.05), i.e., there were differences between the total Sn concentrations found in the different tissues. When comparing the gills and hepatopancreas separately, there was no significant statistical difference between the tissues. In addition, the same behavior (no significant statistical difference) occurred when the gills and muscle were compared. However, the hepatopancreas and muscle samples showed a statistically significant (p < 0.05) difference (12), suggesting that the hepatopancreas bioaccumulated more Sn than the muscle. This characteristic suggests that these animals preferentially store the metallic element in the hepatopancreas. When the differences between the gills and muscle (9), gills and hepatopancreas (3) and hepatopancreas and muscle (12) were analyzed, the data showed the following sequence for Sn concentrations in contaminated crabs: muscle < gills < hepatopancreas. The factors for the total amount of Sn bioaccumulation were calculated for all of the samples by dividing the final concentration of Sn (obtained for each tissue from each animal) by the Sn concentration of the food given during the experiment (30 µg g -1 ). It was observed that BCF increased as the time of exposure increased for all tissues. The highest values for the bioaccumulation factors were found in the TBT concentration The relationships found between the TBT concentrations and number of exposure days determined by HG-ICP OES and ICP-MS are shown in Figures 4 and 5 indicate that the results for the total Sn and TBT concentrations are consistent. The highest TBT concentrations were found in the samples that presented the highest total Sn concentrations. For almost all samples, the TBT concentrations represent a significant part of the total Sn concentrations (especially considering the results in T h e r e s u l t s f r o m t h i s s t u d y s u g g e s t t h a t Callinectes sapidus is a potentially good bioindicator for the presence of TBT in an environment. Therefore, further studies with this species are of great importance because the deleterious effects of Sn on ecosystems, especially in its organic form (TBT), are well defined and related to many research studies. 2-22 Conclusion HG-ICP OES and ICP-MS techniques can be effectively used to evaluate total Sn concentration in contaminated crabs. However, the limit of detection for HG-ICP OES method does not allow the determination of Sn in non-contaminated crabs. Determinations of Sn in crab tissue digest by ICP-MS presented better recoveries values as compared with HG-ICP OES. Also, the results found by HG-ICP OES in some samples were lower than those found by ICP-MS. However, the two data sets were not significantly different (significance level 95%). The analysis of tissue samples from crabs subjected to contaminated food with TBT showed that these animals accumulate Sn in their tissues (gills, hepatopancreas and muscle). According to BCF, it appears that there is no mechanism for the regulation or excretion of TBT. Among the tissues analyzed in this work, the hepatopancreas showed the highest capacity for TBT bioaccumulation. By comparing the total Sn and TBT concentrations found in the tissues, we inferred that most of the accumulated Sn was present as TBT. In this sense, Sn could be used as a biomarker for TBT exposure in environment

Bioaccumulation of Tributyltin by Blue Crabs

This study evaluated the bioaccumulation of tributyltin (TBT) by the blue crab (Callinectes sapidus). Animals were fed with contaminated food containing 30 µg g-1 of TBT expressed as Sn. The analytes were determined in the gills, hepatopancreas and muscle. Acid digestion was used in the total Sn determination, and a solid-phase extraction technique was used for the selective determination of TBT. Limits of detection of 44.6 and 4.46 ng g-1 were found for HG-ICP OES (hydride generation-inductively coupled plasma optical emission spectroscopy) and ICP-MS (ICP-mass spectrometry), respectively. The results for non-contaminated animals were below 50 ng g-1, while the animals subjected to the contaminated food showed higher tissue concentrations of Sn (until 6229 ng g-1) and TBT (until 3357 ng g-1) related to the number of exposure days. According to the results, Sn is bioaccumulated by the blue crab in higher concentrations in the hepatopancreas. For most of these animals, the results suggest that Sn is bioaccumulated as TBT.O presente estudo avaliou a bioacumulação de tributilestanho (TBT) pelo siri azul (Callinectes sapidus). Os animais foram alimentados com comida contaminada com 30 µg g-1 de TBT, expresso como Sn. Os analitos foram determinados nas brânquias, hepatopâncreas e músculo. Realizou-se uma digestão ácida para determinação da concentração total de Sn, e a técnica de extração em fase sólida foi utilizada para determinação seletiva de TBT. Obteve-se limites de detecção de 44,6 e 4,46 ng g-1 para HG-ICP OES (geração de hidretos (HG) por espectrometria de emissão óptica com plasma indutivamente acoplado) e ICP-MS (ICP-espectrometria de massas), respectivamente. Os resultados para os tecidos dos animais não contaminados foram inferiores a 50 ng g-1, enquanto os submetidos à alimentação contaminada mostraram elevadas concentrações de Sn (até 6229 ng g-1) e TBT (até 3357 ng g-1) relacionadas aos dias de exposição. De acordo com os resultados, Sn é acumulado pelo siri azul em elevadas concentrações no hepatopâncreas. Para a maioria dos animais, os resultados sugerem que o Sn é bioacumulado como TBT