Evaluation of a FI-HG-MF-AAS system and microwave-assisted extraction on inorganic arsenic speciation

Orientadores: Marco Aurélio Zezzi Arruda, Anne-Hélène FostierDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de QuímicaResumo: Nessa Dissertação foram avaliados um sistema de injeção em fluxo com geração de hidretos acoplado a um espectrômetro de absorção atõmica com atomizador forno metálico de liga Inconel 600® (FI-HG-MF-AAS), bem como a técnica de extração assistida por micro-onda (MAE) como método de preparo de amostra para especiação de arsênio inorgânico. Para o sistema FI-HG-MF-AAS, condições brandas (pH tamponado em 4,5 e concentração de tetraidridoborato(1-) 0,1% (m/v)) foram utilizadas para que apenas a espécie Asi(III) gerasse o seu respectivo hidreto (arsano - AsH3), atingindo-se limites de detecção de 2,0 mg L e quantificação de 6,6 mg L, tornando o método adequado para uso em análises que atendam a portaria de potabilidade de água de acordo com o Ministério da Saúde e Organização Mundial da Saúde (WHO). O Asi(V) não apresentou qualquer sinal nas condições brandas, e apenas o uso de L-cisteína como pré-redutor foi eficiente para sua conversão a Asi(III). O teste de recuperação foi realizado utilizando material de referência NIST 1643e, Traços de elementos em água, com 60,45 mg L de arsênio total. O resultado mostra que Asi(III) não está presente na amostra em concentração acima do limite de detecção, e usando L-cisteína na concentração de 3% (m/v), obteve-se 60,5 mg L de Asi total, atingindo 100% de recuperação. A técnica de extração assistida por micro-onda mostrou-se eficaz para a extração de As total no material certificado de plâncton BCR414, atingindo um nível 93% de recuperação. Também se mostrou eficiente para manter as espécies de As inorgânico (Asi(III) e Asi(V)) inalteradas, sendo assim uma técnica promissora para o preparo de amostras para a análise de especiaçãoAbstract: In this work a Flow Injection - Hydride Generation - Metallic Furnace - Atomic Absorption Spectrometry (FI-HG-MF-AAS) system was evaluated, using an Incone600 ® alloy tube as a metallic oven, as well as the technique of microwave-assisted extraction (MAE) for sample preparation aiming speciation of inorganic arsenic. For the FI-HG-MF-AAS system, mild conditions (buffered media at pH 4.5 and concentration of tetrahydridoborate (1-) 0.1% (m/v)) allow that only iAs(III) generates hydride (arsane - AsH3), reaching a detection limit of 2.0 m gL and limit of quantification of 6.6 mg L, making suitable for its use in analysis according to Brazilian's Ministry of Health and World Health Organization (WHO) for drinking water. The inorganic As(V) did not show signal in mild conditions, and only the use of L-cysteine as pre-reducing agent was efficient in its conversion to inorganic As(III). The recovery test was carried out using reference material NIST 1643e, Trace elements in water, with 60.45 mg L of total arsenic. The result shows that inorganic As(III) is not present at concentration above the limit of detection, and using L-cysteine 3% (w/v), was obtain a total inorganic As concentration of 60.5 mg L, reaching a recovery of 100%. Microwave-assisted extraction technique was effective for the extraction of the total arsenic in certified plankton BCR414material, reaching a recovery level of 93%. Additionally, it also proved to be effective in preserving the species of unchanged inorganic arsenic, making it a promising technique for sample preparation aiming a speciation analyzesMestradoQuimica AnaliticaMestre em Químic

Use of inorganic mass spetrometry and its hyfenation in the analysis of samples of forensic interest

Orientador: Marco Aurelio Zezzi ArrudaTese (doutorado) - Universidade Estadual de Campinas, Instituto de QuímicaResumo: Nesta Tese de Doutorado foi utilizado a espectrometria de massas inorgânica com fonte de plasma indutivamente acoplado (ICP-MS) para a análise de amostras de interesse forense, no caso, a verificação do mito do chá de fita com droga bizarra de abuso e avaliação de nota de Real e Carteiras Nacionais de Habilitação (CNH) falsificadas. Para tanto, esta Tese está dividida em 3 capítulos. No primeiro capitulo, empregou-se a técnica de ICP-MS para a identificação e quantificação de elementos em uma droga bizarra, o chá de fita, que consiste na ingestão de infusão preparada com tarjas magnéticas de fitas K7 e/ou VHS. Foram verificados teores de Mn e Co que tornam o mito plausível; contudo, também foram observadas concentrações elevadas de Ni e Cr, o que torna a ingestão de tais infusões nocivas à saúde. Além disso, foi utilizado um FT-ICR-MS para a identificação de possíveis compostos orgânicos, e não foi observado nenhum compostos com razão massa/carga compatível com compostos conhecidos como drogas de abuso, e os compostos encontrados não apresentaram uma fragmentação conclusiva. No segundo capítulo, utilizou-se o deslocamento de massas para a redução da interferência na determinação de 56Fe+, 55Mn+ e 58Ni+, utilizando O2 na cela de reação do ICP-MS para formas os respectivos óxidos iônicos. Após a otimização dos parâmetros da cela, a exatidão foi avaliada empregando material certificado de referencia de água, atingindo valores de recuperação para tais elementos entre 90 e 100%. Este método foi então utilizando para a determinação destes elementos em amostras de chá de fita, e os valores de concentração encontrados estão na mesma ordem de grandeza daqueles encontrados no capítulo anterior. No terceiro capítulo, utilizaram-se as técnicas sem preparo de amostra para identificação da falsificação de notas de real de carteiras nacionais de habilitação, que são LA-ICP-MS e µXRF EDS empregadas para tal avaliação. Para as notas de real, foi observado nas verdadeiras alto teores de Ti, que é empregado como carga no papel moeda; já nas falsificadas, tal elemento não estava presente; para as CNH¿s, as falsificas apresentaram Mn na composição, proveniente da tinta empregada na impressão não oficialAbstract: In this thesis, inductively coupled plasma mass spectrometry (ICP-MS) was used for the analysis of samples of forensic interest, in this case, verification of the myth of tape tea as a abuse bizarre drug and evaluation of counterfeiting of Real banknote and National Driver¿s Licence. Therefore, this thesis is divided into 3 chapters. In the first chapter, the technique of ICP-MS was used to identify and quantify elements in a bizarre drug, the tape tea, which consists of the ingestion fof an infusion prepared with magnetic stripes of K7 and / or VHS tape. The contents of Mn and Co were verified, which make the myth plausible; however, high concentrations of Ni and Cr have also been observed in some infuions, which makes the ingestion of such infusions harmful to health. In addition, a FT-ICR-MS was used for the identification of possible organic compounds, and no one with mass / charge ratio compatible with compounds known as drugs of abuse were observed, additionaly the compounds found did not show conclusive fragmentation. In the second chapter, the mass shift was used to reduce interference in the determination of 56Fe+, 55Mn+ and 58Ni+, using O2 in the ICP-MS reaction cell to form the respective ionic oxides. After the optimization of the cell parameters, the accuracy was evaluated using certified reference material of water, reaching recovery values for such elements between 90 and 100%. This method was then used for the determination of these elements in samples of tape tea, and the concentration values found are in the same order of magnitude as those found in the previous chapter. In the third chapter, the techniques without sample preparation were used to identify the counterfeiting of the Brazilian currency and Driver¿s License, which are LA-ICP-MS and ?XRF EDS used for such evaluation. For the Real banknotes, it was observed in the real banknotes high contents of Ti, which is employed as a charge on paper money; even in the falsified ones, such an element was not present; for the Driver¿s License, the falsifiers presented Mn in the composition, coming from the ink used in the unofficial printDoutoradoQuimica AnaliticaDoutor em Ciência

Minimalist strategies applied to analysis of forensic samples using elemental and molecular analytical techniques

Forensic science is an emerging field driven by a number of factors, and the development of different methods of analyses, instruments, and techniques is of great help to experts in the field. Sampling and sample preparation in forensic cases are of utmost importance, and therefore, the methods for processing (or not) the samples are critical for acquiring accurate results. Some alternatives for attaining the minimalist concept, i.e. little or no sample treatment, are discussed in this review. For elemental analysis, analytical techniques, such as X-ray spectrometry, laser-ablation mass spectrometry, laser-induced breakdown spectrometry, inductively coupled plasma mass spectrometry and optical emission spectrometry, and Mossbauer spectrometry are overviewed. Molecular analysis, such as Raman spectroscopy, and ambient ionization mass spectrometry are discussed. Some representative examples are presented that involve in situ analysis, counterfeit bank notes and documents, post-mortem and bone analyses, and forensic analysis of drugs, glass, fingerprints, biological fluids and explosives1063917CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo88887.115406/2015401170/2016-02016/07384-7The authors thank the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, São Paulo, Brazil, 2016/07384-7), the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brasília, Brazil, 401170/2016-0), the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brasília, Brazil, 88887.115406/2015), and the Petrobrás – Petróleos Brasileiros (Rio de Janeiro, Brazil, 5241), for financial support and fellowship

Benchtop and handheld energy-dispersive x-ray fluorescence (EDXRF) as alternative for selenium concentration measurement in biofortified broccoli seedling

Biofortification of crops with selenium (Se) is an effective strategy to increase the consumption of this micronutrient. Inductively coupled plasma mass spectrometry (ICP-MS) is one of the most used techniques in quantifying Se. However, due to some disadvantages (high cost, long analysis time, and being destructive), there is a need for new alternatives to Se quantification. This study aimed at establishing instrumental parameters for Se quantification, using two energy-dispersive X-ray fluorescence spectrometry (EDXRF) techniques (benchtop and handheld) in Se-biofortified broccoli seedlings and comparing it with ICP-MS. The results showed that the selection of proper filters for both EDXRF systems was crucial for determining Se and, when compared with ICP-MS, presented similar results for selenium-biofortified broccoli seedling treatments (BS50Se). In addition, the EDXRF techniques presented a Se limit of detection (LOD) at 0.6–0.9 mg kg−1. This study demonstrates that EDXRF systems were successfully applied to concentration measurement of Se in biofortified samples and linked to low cost and shorter analysis time12715201527CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPESP – Fundação de Amparo à Pesquisa Do Estado De São PauloFINEP - Financiadora de Estudos E Projetos001; 88887.115406/2015401170/2016-0; 52412015/05942-026480

Direct and non-destructive proof of authenticity for the 2nd generation of brazilian real banknotes via easy ambient sonic spray ionization mass spectrometry

Using a desorption/ionization technique, easy ambient sonic-spray ionization coupled to mass spectrometry (EASI-MS), documents related to the 2nd generation of Brazilian Real currency (R$) were screened in the positive ion mode for authenticity based on chemical profiles obtained directly from the banknote surface. Characteristic profiles were observed for authentic, seized suspect counterfeit and counterfeited homemade banknotes from inkjet and laserjet printers. The chemicals in the authentic banknotes' surface were detected via a few minor sets of ions, namely from the plasticizers bis(2-ethylhexyl)phthalate (DEHP) and dibutyl phthalate (DBP), most likely related to the official offset printing process, and other common quaternary ammonium cations, presenting a similar chemical profile to 1st-generation R$. The seized suspect counterfeit banknotes, however, displayed abundant diagnostic ions in the m/z 400-800 range due to the presence of oligomers. High-accuracy FT-ICR MS analysis enabled molecular formula assignment for each ion. The ions were separated by 44 m/z, which enabled their characterization as Surfynol® 4XX (S4XX, XX=40, 65, and 85), wherein increasing XX values indicate increasing amounts of ethoxylation on a backbone of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (Surfynol® 104). Sodiated triethylene glycol monobutyl ether (TBG) of m/z 229 (C10H22O4Na) was also identified in the seized counterfeit banknotes via EASI(+) FT-ICR MS. Surfynol® and TBG are constituents of inks used for inkjet printing.Using a desorption/ionization technique, easy ambient sonic-spray ionization coupled to mass spectrometry (EASI-MS), documents related to the 2nd generation of Brazilian Real currency (R$) were screened in the positive ion mode for authenticity based on c546459464sem informaçãosem informaçã