Methylmercury and inorganic mercury determination in blood by using liquid chromatography with inductively coupled plasma mass spectrometry and a fast sample preparation procedure

Despite the necessity to differentiate chemical species of mercury in clinical specimens, there area limited number of methods for this purpose. Then, this paper describes a simple method for the determination of methylmercury and inorganic mercury in blood by using liquid chromatography with inductively coupled mass spectrometry (LC-ICP-MS) and a fast sample preparation procedure. Prior to analysis, blood (250 mu L) is accurately weighed into 15-mL conical tubes. Then, an extractant solution containing mercaptoethanol, L-cysteine and HCI was added to the samples following sonication for 15 min. Quantitative mercury extraction was achieved with the proposed procedure. Separation of mercury species was accomplished in less than 5 min on a C18 reverse-phase column with a mobile phase containing 0.05% (v/v) mercaptoethanol, 0.4% (m/v) L-cysteine, 0.06 mol L(-1) ammonium acetate and 5% (v/v) methanol. The method detection limits were found to be 0.25 mu g L(-1) and 0.1 mu Lg L(-1) for inorganic mercury and methylmercury, respectively. Method accuracy is traceable to Standard Reference Material (SRM) 966 Toxic Metals in Bovine Blood from the National Institute of Standards and Technology (NIST). The proposed method was also applied to the speciation of mercury in blood samples collected from fish-eating communities and from rats exposed to thimerosal. With the proposed method there is a considerable reduction of the time of sample preparation prior to speciation of Hg by LC-ICP-MS. Finally, after the application of the proposed method, we demonstrated an interesting in vivo ethylmercury conversion to inorganic mercury. (C) 2009 Elsevier B.V. All rights reserved.

Determination of total and inorganic mercury in whole blood by cold vapor inductively coupled plasma mass spectrometry (CV ICP-MS) with alkaline sample preparation

A simple method with a fast sample preparation procedure for total and inorganic mercury determinations in blood samples is proposed based on flow injection cold vapor inductively coupled plasma mass spectrometry (FI-CVICP-MS). Aliquots of whole blood (500 mL) are diluted 1 + 1 v/v with 10.0% v/v tetramethylammonium hydroxide (TMAH) solution, incubated for 3 h at room temperature and then further diluted 1 + 4 v/v with 2.0% v/v HCl. The inorganic Hg was released by online addition of L-cysteine and then reduced to elemental Hg by SnCl(2). On the other hand, total mercury was determined by on-line addition of KMnO(4) and then reduced to elemental Hg by NaBH(4). Samples were calibrated against matrix-matching. The method detection limit was found to be 0.80 mu g L(-1) and 0.08 mu g L(-1) for inorganic and total mercury, respectively. Sample throughput is 20 samples h(-1). The method accuracy is traceable to Standard Reference Material (SRM) 966 Toxic Metals in Bovine Blood from the National Institute of Standards and Technology (NIST). For additional validation purposes, human whole blood samples were analyzed by the proposed method and by an established CV AAS method, with no statistical difference between the two techniques at 95% confidence level on applying the t-test.

Mercury speciation in whole blood by gas chromatography coupled to ICP-MS with a fast microwave-assisted sample preparation procedure

A simple and fast method is described for simultaneous determination of methylmercury (MeHg), ethylmercury (Et-Hg) and inorganic mercury (Ino-Hg) in blood samples by using capillary gas chromatography-inductively coupled plasma mass spectrometry (GC-ICP-MS) after derivatization and alkaline digestion. Closed-vessel microwave assisted digestion conditions with tetramethylammonium hydroxide (TMAH) have been optimized. Derivatization by using ethylation and propylation procedures have also been evaluated and compared. The absolute detection limits (using a 1 mu L injection) obtained by GC-ICP-MS with ethylation were 40 fg for MeHg and Ino-Hg, respectively, and with propylation were 50, 20 and 50 fg for MeHg, Et-Hg and Ino-Hg, respectively. Method accuracy is traceable to Standard Reference Material (SRM) 966 Toxic Metals in Bovine Blood from the National Institute of Standards and Technology (NIST). Additional validation is provided based on the comparison of results obtained for mercury speciation in blood samples with the proposed procedure and with a previously reported LC-ICP-MS method. With the new proposed procedure no tedious clean-up steps are required and a considerable improvement of the time of analysis was achieved compared to other methods using GC separation.

Applications of accurate, high-precision Pb isotope ratio measurement by multi-collector ICP-MS

The isotope composition of Ph is difficult to determine accurately due to the lack of a stable normalisation ratio. Double and triple-spike addition techniques provide one solution and presently yield the most accurate measurements. A number of recent studies have claimed that improved accuracy and precision could also be achieved by multi-collector ICP-MS (MC-ICP-MS) Pb-isotope analysis using the addition of Tl of known isotope composition to Pb samples. In this paper, we verify whether the known isotope composition of Tl can be used for correction of mass discrimination of Pb with an extensive dataset for the NIST standard SRM 981, comparison of MC-ICP-MS with TIMS data, and comparison with three isochrons from different geological environments. When all our NIST SRM 981 data are normalised with one constant Tl-205/Tl-203 of 2.38869, the following averages and reproducibilities were obtained: Pb-207/Pb-206=0.91461+/-18; Pb-208/Ph-206 = 2.1674+/-7; and (PbPh)-Pb-206-Ph-204 = 16.941+/-6. These two sigma standard deviations of the mean correspond to 149, 330, and 374 ppm, respectively. Accuracies relative to triple-spike values are 149, 157, and 52 ppm, respectively, and thus well within uncertainties. The largest component of the uncertainties stems from the Ph data alone and is not caused by differential mass discrimination behaviour of Ph and Tl. In routine operation, variation of sample introduction memory and production of isobaric molecular interferences in the spectrometer's collision cell currently appear to be the ultimate limitation to better reproducibility. Comparative study of five different datasets from actual samples (bullets, international rock standards, carbonates, metamorphic minerals, and sulphide minerals) demonstrates that in most cases geological scatter of the sample exceeds the achieved analytical reproducibility. We observe good agreement between TIMS and MC-ICP-MS data for international rock standards but find that such comparison does not constitute the ultimate. test for the validity of the MC-ICP-MS technique. Two attempted isochrons resulted in geological scatter (in one case small) in excess of analytical reproducibility. However, in one case (leached Great Dyke sulphides) we obtained a true isochron (MSWD = 0.63) age of 2578.3 +/- 0.9 Ma, which is identical to and more precise than a recently published U-Pb zircon age (2579 3 Ma) for a Great Dyke websterite [Earth Planet. Sci. Lett. 180 (2000) 1-12]. Reproducibility of this age by means of an isochron we regard as a robust test of accuracy over a wide dynamic range. We show that reliable and accurate Pb-isotope data can be obtained by careful operation of second-generation MC-ICP magnetic sector mass spectrometers. (C) 2002 Elsevier Science B.V. All rights reserved.

Currículo e atendimento educacional especializado na educação infantil : possibilidades e desafios à inclusão escolar

Esta pesquisa teve como objetivo geral compreender a proposta/ prática curricular do Atendimento Educacional Especializado (AEE) na Sala de Recursos Multifuncionais (SRM) enquanto função complementar na educação da criança pequena com deficiência e Transtornos Globais do Desenvolvimento (TGD). Partimos das constatações de que, nas duas últimas décadas, documentos oficiais, assim como pesquisas na área, apontam a necessidade de um trabalho pedagógico inclusivo, que atenda às demandas e características dos diferentes sujeitos matriculados. Questionamos se a proposta e prática curricular complementar do AEE, por meio da SRM, têm contribuído para a inclusão da criança pequena, público alvo da educação especial, nas práticas pedagógicas da sala de aula comum? Teoricamente buscamos as contribuições da Abordagem Histórico-Cultural para compreender o desenvolvimento e aprendizagem da criança com deficiência, assim como procuramos a interlocução com os teóricos do currículo, entre os quais Sacristán. Como metodologia, utilizamos a pesquisa-ação colaborativo-crítico. O lócus da pesquisa foi um Centro de Educação Infantil, situado em Vitória/ES, com uma sala de recurso multifuncional, modelo proposto pelo Ministério da Educação (MEC). Os sujeitos participantes foram crianças de 3 a 7 anos matriculadas no Centro Municipal de Educação Infantil (CMEI) e encaminhadas para o AEE, na SRM (seis crianças surdas, sete crianças com manifestações de TGD e uma criança com Síndrome de Down); dois professores de educação especial da SRM (uma professora da área da área de Deficiência Intelectual (DI), uma professora bilíngue e um instrutor surdo); professores regentes do turno da manhã CMEI e dois pedagogos. Como perspectiva teórico-metodológica, optamos pela rede significações (Rossetti-Ferreira, 2004) que tem seus pressupostos fundamentados na teoria histórico-cultural, que compreende os processos de desenvolvimento humano como atos de significação constituídos por múltiplas interações estabelecidas social e culturalmente pelos sujeitos durante toda a vida. A organização e análise dos dados ocorreram por meio dos movimentos, cenários e atores; as práticas curriculares inclusivas na/da escola: a SRM e a sala de aula comum em seus encontros e desencontros; a preocupação com o desenvolvimento psicomotor da criança; o brincar versus a aquisição da leitura e escrita; o diálogo entre o currículo da SRM e a sala de aula comum e os encontros colaborativos com os professores de educação especial, com as pedagogas e com as professoras regentes do CMEI. Algumas considerações importantes se destacam, entre as quais: a falta de formação e desconhecimento por parte dos professores de educação especial sobre a proposta curricular da educação infantil e práticas pedagógicas descontextualizadas e fragmentadas desenvolvidas na SRM, que dificultam a ação complementar ao trabalho da classe comum. Para as professoras das salas de atividades o AEE é viável na escola de educação infantil, mas não somente na SRM, concordam que deve haver o atendimento educacional especializado no turno em que a criança esteja matriculada; que ele pode ajudar na inclusão da criança público alvo da educação especial, por meio de práticas sociais e culturais lúdicas, linguísticas e intelectuais. Concluímos que as professoras desejam um AEE dinâmico, interlocutor, que se movimente na escola como um todo.

Tecnologia assistiva e computacional : contribuições para o atendimento educacional especializado e desafios na formação de professores

Neste trabalho, analisamos aspectos relacionados a como a tecnologia computacional é utilizada no Atendimento Educacional Especializado (AEE) e como se deu a formação de professores para utilizar esses recursos. Para tanto, delimitamos os seguintes objetivos específicos: investigar a utilização da tecnologia assistiva (TA) computacional no âmbito das salas de recursos multifuncionais (SRM); problematizar as tensões, dificuldades e possibilidades relacionadas à TA com ênfase na tecnologia computacional para o AEE; analisar a formação do professor de educação especial para o AEE tendo como recurso a TA com ênfase na tecnologia computacional, visando à mediação dos processos de aprendizagem. O aporte teórico deste trabalho foi a abordagem histórico-cultural, tomando por referência os estudos de Vigotski e seus colaboradores. Trata-se de uma pesquisa qualitativa que fez uso de diferentes instrumentos metodológicos como, os grupos focais, o questionário online e a entrevista semiestruturada. Para desenvolvê-lo, realizamos a coleta de dados em diferentes contextos, começando pelos grupos focais da pesquisa inaugural do Oneesp, que serviram como dispositivo para esta pesquisa, seguida da aplicação de um questionário aos professores participantes da pesquisa-formação desenvolvida como um desdobramento no estado do Espírito Santo da pesquisa inaugural do Oneesp pelos integrantes do Oeeesp e da aplicação in loco de entrevistas semiestruturadas com professores de educação especial, de uma SRM do Tipo II. Foram oitenta e nove professores participantes na pesquisa do Oneesp, trinta professores na pesquisa-formação do Oeeesp e dois professores para aplicação da entrevista semiestruturada in loco, respectivamente. Esses dois professores participaram tanto da pesquisa do Oneesp como da pesquisa do Oeeesp. Analisamos esses três momentos, dos quais emergiram os apontamentos que nos proporcionaram pensar, com base nas narrativas orais e escritas dos professores: sua formação para uso da TA computacional; seu entendimento sobre sua formação para este fim; seus anseios por uma formação mais direcionada; a forma como utilizam a tecnologia na sala de recursos; seus entendimentos sobre as dificuldades e possibilidades relacionadas a TA com ênfase na tecnologia computacional para o AEE. Após essas análises, concluímos que poucos professores que atuam nas SRM tiveram uma formação que possibilitasse a aplicação das tecnologias computacionais em sua mediação pedagógica, aliando teoria e prática, com momentos de formação que privilegiassem os momentos presenciais e em laboratórios, onde possam interagir com os computadores e suas ferramentas simbólicas. Sem essa familiaridade com os recursos computacionais, os professores acabam sentindo-se inseguros para utilizá-los, deixando de potencializar, pela via desses recursos, os processos de ensinoaprendizagem do aluno com deficiência. Faz-se necessário um investimento nesse tipo de formação e, mais do que isso, que se viabilize para os professores que atuam ou que pretendem atuar nas SRM. A partir de uma formação apropriada é possível fazer com que os professores utilizem os recursos computacionais como mediadores dos processos de ensino-aprendizagem de seus alunos.

Analysis of polycyclic aromatic hydrocarbons in fish: optimisation and validation of microwave-assisted extraction

An accurate and sensitive method for determination of 18 polycyclic aromatic hydrocarbons (PAHs) (16 PAHs considered by USEPA as priority pollutants, dibenzo[a,l]pyrene and benzo[j]fluoranthene) in fish samples was validated. Analysis was performed by microwave-assisted extraction and liquid chromatography with photodiode array and fluorescence detection. Response surface methodology was used to find the optimal extraction parameters. Validation of the overall methodology was performed by spiking assays at four levels and using SRM 2977. Quantification limits ranging from 0.15–27.16 ng/g wet weight were obtained. The established method was applied in edible tissues of three commonly consumed and commercially valuable fish species (sardine, chub mackerel and horse mackerel) originated from Atlantic Ocean. Variable levels of naphthalene (1.03–2.95 ng/g wet weight), fluorene (0.34–1.09 ng/g wet weight) and phenanthrene (0.34–3.54 ng/g wet weight) were detected in the analysed samples. None of the samples contained detectable amounts of benzo[a]pyrene, the marker used for evaluating the occurrence and carcinogenic effects of PAHs in food.

Conversão das contas do Plano Oficial de Contas em contas do Sistema de Normalização Contabilística e Upgrade do sistema SAP do Grupo REFER

Trabalho apresentado para obtenção do Título de Especialista, pelo Instituto Superior de Contabilidade e Administração de Lisboa, do Instituto Politécnico de Lisboa

Analysis of polycyclic aromatic hydrocarbons in fish: evaluation of a quick, easy, cheap, effective, rugged, and safe extraction method

QuEChERS method was evaluated for extraction of 16 PAHs from fish samples. For a selective measurement of the compounds, extracts were analysed by LC with fluorescence detection. The overall analytical procedure was validated by systematic recovery experiments at three levels and by using the standard reference material SRM 2977 (mussel tissue). The targeted contaminants, except naphthalene and acenaphthene, were successfully extracted from SRM 2977 with recoveries ranging from 63.5–110.0% with variation coefficients not exceeding 8%. The optimum QuEChERS conditions were the following: 5 g of homogenised fish sample, 10 mL of ACN, agitation performed by vortex during 3 min. Quantification limits ranging from 0.12– 1.90 ng/g wet weight (0.30–4.70 µg/L) were obtained. The optimized methodology was applied to assess the safety concerning PAHs contents of horse mackerel (Trachurus trachurus), chub mackerel (Scomber japonicus), sardine (Sardina pilchardus) and farmed seabass (Dicentrarchus labrax). Although benzo(a)pyrene, the marker used for evaluating the carcinogenic risk of PAHs in food, was not detected in the analysed samples (89 individuals corresponding to 27 homogenized samples), the overall mean concentration ranged from 2.52 l 1.20 ng/g in horse mackerel to 14.6 ± 2.8 ng/ g in farmed seabass. Significant differences were found between the mean PAHs concentrations of the four groups.

Study of nuclear reactions relevant for astrophysics by Micro-AMS

Dissertação para obtenção do Grau de Doutor em Física

Overstock and stock-out in Volkswagen Autoeuropa

The following work is a case study of overstock and stock-out problems at Volkswagen Autoeuropa (VWAE). It introduces the supply chain of Autoeuropa and specializes then on failures connected to inventory problems. Having a successful supply chain is important in a world where products become more and more similar as it can give to companies an edge over their competitors. The case shows three practices that VWAE uses to prevent and to overcome stock problems. Information was gathered by doing interviews with different managers, by analyzing the company’s key processes and by literature research related to the topics of supply chain management and flexibility in the supply chain. Three practices were further investigated: the use of alternative parts, support of the supplier and a rating system of suppliers. In the question section of this work the importance of flexibility and Supplier Relationship Management (SRM) when connected to supply chain management are explained. The described different practices are numerically analyzed and it is concluded that each practice brings both cost savings and the possibility of achieving target numbers to the company, showing the company’s flexibility to react to supply chain disturbances. Because of confidentiality reasons, persons in the case are fictionalized and numbers are wherever possible equalized to 100 in order to display true proportions.

Determinação de psicofármacos em cabelo humano por técnicas cromatográficas hifenadas: um método alternativo não-invasivo

Dissertação de mestrado em Técnicas de Caracterização e Análise Química

Validity, reliability and responsiveness of the French language translation of the Western Ontario Shoulder Instability Index (WOSI).

BACKGROUND: The WOSI (Western Ontario Shoulder Instability Index) is a self-administered quality of life questionnaire designed to be used as a primary outcome measure in clinical trials on shoulder instability, as well as to measure the effect of an intervention on any particular patient. It is validated and is reliable and sensitive. As it is designed to measure subjective outcome, it is important that translation should be methodologically rigorous, as it is subject to both linguistic and cultural interpretation. OBJECTIVE: To produce a French language version of the WOSI that is culturally adapted to both European and North American French-speaking populations. MATERIALS AND METHODS: A validated protocol was used to create a French language WOSI questionnaire (WOSI-Fr) that would be culturally acceptable for both European and North American French-speaking populations. Reliability and responsiveness analyses were carried out, and the WOSI-Fr was compared to the F-QuickDASH-D/S (Disability of the Arm, Shoulder and Hand-French translation), and Walch-Duplay scores. RESULTS: A French language version of the WOSI (WOSI-Fr) was accepted by a multinational committee. The WOSI-Fr was then validated using a total of 144 native French-speaking subjects from Canada and Switzerland. Comparison of results on two WOSI-Fr questionnaires completed at a mean interval of 16 days showed that the WOSI-Fr had strong reliability, with a Pearson and interclass correlation of r=0.85 (P=0.01) and ICC=0.84 [95% CI=0.78-0.88]. Responsiveness, at a mean 378.9 days after surgical intervention, showed strong correlation with that of the F-QuickDASH-D/S, with r=0.67 (P<0.01). Moreover, a standardized response means analysis to calculate effect size for both the WOSI-Fr and the F-QuickDASH-D/S showed that the WOSI-Fr had a significantly greater ability to detect change (SRM 1.55 versus 0.87 for the WOSI-Fr and F-QuickDASH-D/S respectively, P<0.01). The WOSI-Fr showed fair correlation with the Walch-Duplay. DISCUSSION: A French-language translation of the WOSI questionnaire was created and validated for use in both Canadian and Swiss French-speaking populations. This questionnaire will facilitate outcome assessment in French-speaking settings, collaboration in multinational studies and comparison between studies performed in different countries. TYPE OF STUDY: Multicenter cohort study. LEVEL OF EVIDENCE: II.

Simultaneous LC-MS/MS quantification of P-glycoprotein and cytochrome P450 probe substrates and their metabolites in DBS and plasma.

BACKGROUND: An LC-MS/MS method has been developed for the simultaneous quantification of P-glycoprotein (P-gp) and cytochrome P450 (CYP) probe substrates and their Phase I metabolites in DBS and plasma. P-gp (fexofenadine) and CYP-specific substrates (caffeine for CYP1A2, bupropion for CYP2B6, flurbiprofen for CYP2C9, omeprazole for CYP2C19, dextromethorphan for CYP2D6 and midazolam for CYP3A4) and their metabolites were extracted from DBS (10 µl) using methanol. Analytes were separated on a reversed-phase LC column followed by SRM detection within a 6 min run time. RESULTS: The method was fully validated over the expected clinical concentration range for all substances tested, in both DBS and plasma. The method has been successfully applied to a PK study where healthy male volunteers received a low dose cocktail of the here described P-gp and CYP probes. Good correlation was observed between capillary DBS and venous plasma drug concentrations. CONCLUSION: Due to its low-invasiveness, simple sample collection and minimal sample preparation, DBS represents a suitable method to simultaneously monitor in vivo activities of P-gp and CYP.

Effects of different Incentives on Attrition and Fieldwork Effort in Telephone Household Panel Surveys

Little is known about sample behavior and fieldwork effects of different incentives introduced in a household panel survey. This is especially true for telephone surveys. In a randomized experiment, the Swiss Household Panel implemented one prepaid and two promised nonmonetary incentives in the range of 10 to 15 Swiss Francs (7-10 e), plus a no incentive control group. The aim of the paper is to compare effects of these incentives especially on cooperation, but also on sample selection and fieldwork effort, separated by the household and the subsequent individual level. We find small positive cooperation effects of the prepaid incentive on both the household and the individual level especially in larger households. Sample composition is affected to a very minor extent. Finally, incentives tend to save fieldwork time and partially the number of contacts needed on the individual level.