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  1. 1

    Microwave treatment of biological samples for methylmercury determination by high performance liquid chromatography-cold vapour atomic fluorescence spectrometry

    Publication
    by Ramalhosa, Elsa
    Other Authors: Río-Segade, Susana; Pereira, Eduarda; Vale, Carlos; Duarte, Armando
    A simple and rapid microwave-assisted alkaline digestion procedure was developed in combination with high performance liquid chromatography-ultraviolet post-column oxidation-cold vapour atomic fluorescence spectrometric detection for methylmercury determination in biological tissues. Since the stability of methylmercury in methanolic potassium hydroxide solution under microwave irradiation was verified, the microwave-assisted extraction procedure was optimized in terms of quantitative recovery of methylmercury and minimum time required. The alkaline extracts were subjected to clean-up steps with dichloromethane and hydrochloric acid in order to reduce matrix interferences in methylmercury determination. The effects of matrix interferences were checked by comparison of the slopes corresponding to calibration and standard addition curves. The accuracy of the method was evaluated by the analysis of two biological certified reference materials, NRC TORT-2 and BCR 463. The results obtained by the proposed method were in good agreement with the certified values of methylmercury concentration in both materials. The detection limit was 10 mug kg(-1) and the relative standard deviation was < 8% for methylmercury concentrations ranging from 0.15 to 3.0 mg kg(-1).
    2001 article Portugal open access
  2. 2

    Green Extraction Techniques as Advanced Sample Preparation Approaches in Biological, Food, and Environmental Matrices: A Review

    Publication
    by Câmara, José S.
    Other Authors: Perestrelo, Rosa; Berenguer, Cristina V.; Andrade, Carolina F. P.; Gomes, Telma M.; Olayanju, Basit et al.
    Green extraction techniques (GreETs) emerged in the last decade as greener and sustain able alternatives to classical sample preparation procedures aiming to improve the selectivity and sensitivity of analytical methods, simultaneously reducing the deleterious side effects of classical extraction techniques (CETs) for both the operator and the environment. The implementation of improved processes that overcome the main constraints of classical methods in terms of efficiency and ability to minimize or eliminate the use and generation of harmful substances will promote more efficient use of energy and resources in close association with the principles supporting the concept of green chemistry. The current review aims to update the state of the art of some cutting-edge GreETs developed and implemented in recent years focusing on the improvement of the main analytical features, practical aspects, and relevant applications in the biological, food, and environmental fields. Approaches to improve and accelerate the extraction efficiency and to lower solvent consumption, including sorbent-based techniques, such as solid-phase microextraction (SPME) and fabric-phase sorbent extraction (FPSE), and solvent-based techniques (µQuEChERS; micro quick, easy, cheap, effective, rugged, and safe), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE), in addition to supercritical fluid extraction (SFE) and pressurized solvent extraction (PSE), are highlighted.
    2022 article Portugal open access
  3. 3

    Portuguese and the biobanks: profiles and attitudes of the Portuguese population towards biobanks for health research

    Publication
    by Riso, Brígida
    Other Authors: Santos, Mário J. D. S.; Ávila, Patrícia
    Biobanks for clinical research collect human biological samples and associated data for biomedical research. The establishment of biobanks in Portugal is still an understudied phenomenon, although there are signs of a growing trend in setting up these repositories to support biomedical research. Among another factors, individuals’ willingness to donate samples and public trust in biobanks play a crucial role in sustaining biobanking activities. In this article, we analyse public attitudes in Portugal towards biobanking, based on data from the biotechnology survey conducted by Eurobarometer in 2010. Different assumptions about science and technology enabled profiling the Portuguese population into four distinct groups: the optimistic, the cautious, the sceptical and the pessimistic. Each profile implies a diverse range of intentions and attitudes regarding biobanks. Furthermore, we found that previous study of science could be an important predictor of the willingness to donate information to biobanks.
    2025 article Portugal restricted access
  4. 4

    New microfluidic paper-based analytical device for iron determination in urine samples

    Publication
    by Ferreira, Francisca T. S. M.
    Other Authors: Catalão, Karina A.; Mesquita, Raquel B. R.; Rangel, António O. S. S.
    Iron is an important micronutrient involved in several mechanisms in the human body and can be an important biomarker. In this work, a simple and disposable microfluidic paper-based analytical device (µPAD) was developed for the quantification of iron in urine samples. The detection was based on the colorimetric reaction between iron(II) and bathophenanthroline and the reduction of iron(III) to iron(II) with hydroxylamine. The developed µPAD enabled iron determination in the range 0.07–1.2 mg/L, with a limit of detection of 20 µg/L and a limit of quantification of 65 µg/L, thus suitable for the expected values in human urine. Additionally, targeting urine samples, the potential interference of the samples color was overcome by incorporating a sample blank assessment for absorbance subtraction. Stability studies revealed that the device was stable for 15 days prior to usage and that the formed colored product was stable for scanning up to 3 h. The accuracy of the developed device was established by analyzing urine samples (#26) with the developed µPAD and with the atomic absorption spectrometry method; the relative deviation between the two sets of results was below 9.5%. Graphical abstract: [Figure not available: see fulltext.]
    2021 article Portugal open access
  5. 5

    Desenvolvimento de um m?todo de triagem eletroqu?mico para aplica??o no controle de doping da amilorida em amostras de urina usando o eletrodo de diamante dopado com boro

    Publication
    by Souza, Karla Aparecida de Oliveira
    Origin: Oasisbr
    Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2021-11-10T20:05:27Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) karla_aparecida_oliveira_souza.pdf: 4546467 bytes, checksum: 8aaf42a8528d549718ea15c13ef78846 (MD5)
  6. 6

    Avaliação de processos de coleta e transporte de amostras biológicas para diagnósticos de erros inatos do metabolismo em centros de referência

    Publication
    by Trapp, Franciele Barbosa
    Origin: Oasisbr
    Introdução: A coleta e o transporte de amostras biológicas fazem parte da fase pré- analítica do processo operacional de realização de exames laboratoriais, sendo essa uma fase crítica para as análises. O Serviço de genética Medica (SGM) do Hospital de Clínicas de Porto Alegre (HCPA) é conhecido como um centro de referência nacional e internacional em diagnóstico laboratorial e pesquisa de diferentes doenças genéticas raras, onde são recebidas amostras de todo Brasil e diversos outros países. Devido à importância das avaliações laboratoriais e com o avanço tecnológico na área de diagnósticos verificamos a necessidade de investigação e otimização dos processos de coleta e transporte de amostras biológicas. Objetivo: O principal objetivo desse projeto foi avaliar diferentes métodos de coleta e transporte de amostras biológicas para a realização de testes diagnósticos para erros inatos do metabolismo, assim facilitando o acesso ao diagnóstico, minimizando o número de solicitações de novas amostras, bem como apoiar o desenvolvimento de pesquisas na área. Metodologia: O presente trabalho avaliou 2848 amostras biológicas encaminhadas para o Serviço de Genética Médica do HCPA por 276 instituições, de 25 estados diferentes, verificamos os dados de identificação, volume, temperatura de transporte, tempo decorrido entre a coleta e o transporte em comparação com diferentes sistemas de coleta utilizados pelos serviços associados às redes, entre si e com um sistema padrão desenvolvido pelo nosso serviço. Após uma avaliação inicial realizamos também uma intervenção com material informativo, estratégias educacionais, treinamento de profissionais sobre procedimentos adequados de coleta, remessa e transporte de amostras biológicas. Resultados: 1308 amostras foram enviadas pré-intervenção sendo que destas 254 (19%) apresentaram alguma inconformidade. Após a realização da intervenção através do uso de instruções de coleta e envio uma redução de 62% foi encontrada (119 amostras de 1540). Conclusão: Uma redução considerável no número de amostras inadequadas para uso foi obtida através do uso deste material informativo, tal redução tem considerável impacto nos exames de pesquisa e assistência do HCPA. Este projeto contribuiu para o aperfeiçoamento dos processos de coleta, armazenamento e transporte de material biológico. Protocolos como este podem vir a proporcionar a melhora na qualidade do serviço diagnóstico prestado no SGM e demais utilizadores deste. Além disto, o diagnóstico precoce de uma doença genética poderá facilitar a intervenção mais precoce, através de tratamentos que sabidamente tem um melhor resultado quanto mais cedo se iniciar. Além do mais, o impacto de um diagnóstico preciso e precoce é extremamente benéfico para o sistema de saúde, visando também fortalecer e dar continuidade ao treinamento dos profissionais de saúde e divulgação de informações especializadas.
    2020 master thesis Brazil open access
  7. 7
  8. 8

    Internet das coisas aplicada ao gerenciamento de rastreabilidade de amostras biológicas

    Publication
    by Ferrasi, Emerson Carlos Sarti
    Origin: Oasisbr
    Pós-graduação em Mídia e Tecnologia (doutorado) - FAAC
    2023 doctoral thesis Brazil open access
  9. 9

    Estudo comparativo de m?todos de extra??o para determina??o de fluazuron em plasma bovino por cromatografia l?quida de alta efici?ncia com detec??o em ultravioleta

    Publication
    by Ferreira, Thais Paes
    Origin: Oasisbr
    Submitted by Leticia Schettini (leticia@ufrrj.br) on 2016-10-04T13:00:01Z No. of bitstreams: 1 2016 - Thais Paes Ferreira.pdf: 1131707 bytes, checksum: c98267296d6293f703188fe1291622db (MD5)
    2016 master thesis Brazil open access
  10. 10

    Determinação de elementos essenciais e contaminantes em amostras biológicas empregando espectrometria atômica

    Publication
    by Santos, Luiz Raimundo Seneterri Silva Rodrigues dos
    Origin: Oasisbr
    Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2016-09-06T15:11:17Z No. of bitstreams: 1 DISSERTAÇÃO LUIZ RAIMUNDO S.S.R.SANTOS.pdf: 1266644 bytes, checksum: 450e692c86f2ffc5bc25ffa7e76b9e3d (MD5)
    2016 master thesis Brazil open access