Determination of inorganic contaminants in polyamide textiles used for manufacturing sport T-shirts

AbstractAn acid microwave closed vessel digestion method was used for the determination of inorganic contaminants (Sb, As, Pb, Cd, Cr, Co, Cu, Ni and Hg) in polyamide raw materials (pellets) and textiles by inductively coupled plasma optical emission spectrometry (ICP OES). The initial tests were carried out with samples of polyamide pellets, which is the main raw material used to manufacture sport textiles. The recovery factors obtained were 94.4–105.7% with relative standard deviation (RSD) of 0.5–2.2%. The proposed method was evaluated by addition and recovery tests and also using certified reference materials (ERM-BCR680 and ERM-BCR681) showing good accuracy. The residual acidity was about 4% HNO3 (w/w) and the quantification limits were from 0.1 to 6.6mgkg−1. After the development of these parameters for the raw material, the method was applied to textile samples from different sport fabrics obtained from three different brands. The residual carbon after sample digestion was 0.2% (w/w) and the most significant result was obtained for chromium, 901mgkg−1, in black fabric. Lixiviation tests using synthetic sweat and temperature were carried out on two black samples, showing that only 0.3% of the initial concentration migrated to the solution

Evaluation of metal ions in rice samples: extraction and direct determination by ICP OES

A method for extraction of metal ions present in rice samples using ammoniacal EDTA solution, pH &gt; 10, as extractor agent is proposed under the following optimized conditions: 0.20 g of rice sample and 5.00 mL of ammoniacal EDTA (ethylenediaminetetraacetic acid) solution, with 5 min of ultrasound exposure time. Using robust ICP OES (inductively coupled plasma atomic emission spectrometry) conditions, direct analysis of the extraction solution was allowed, and the recovery values obtained were above 90% for most of the studied elements (P, K, Mg, Ca, Zn, Mn, Cu and Mo) with RSD < 5%. The results were in good agreement with those obtained by microwave-assisted extraction and for the reference material of rice flour (NIST SRM 1568a). The limits of detection of method were in the range of 0.007 mg kg-1 (Mn) - 48.68 mg kg-1 (K), showing adequate detectability for the determination of the analytes. The analysis of different samples indicated that Brazilian integral rice contains higher contents of the constituents studied, followed by parboiled rice, and the agulhinha rice a long and thin grain type.Foi desenvolvido um método de extração de íons de metais presentes em amostras de arroz, usando solução amoniacal de EDTA (ácido etilenodiamino tetraacético), pH &gt; 10, como agente extrator, sob as seguintes condições otimizadas: 0,20 g de amostra de arroz e 5,00 mL da solução amoniacal de EDTA, com 5 min de tempo de exposição em ultrassom. Usando condições robustas de ICP OES (espectrometria de emissão atômica por plasma acoplado indutivamente), foi possível analisar a solução extraída, obtendo-se valores de recuperação acima de 90% para a maioria dos elementos estudados (P, K, Mg, Ca, Zn, Mn, Cu e Mo) com RSD < 5%. Os resultados mostraram concordância com aqueles obtidos por extração assistida por microondas e para o material de referência certificado de farinha de arroz (NIST SRM 1568a). Os limites de detecção do método ficaram no intervalo de 0,007 mg kg-1 (Mn) - 48,68 mg kg-1 (K), mostrando uma detectabilidade adequada para a determinação das espécies de interesse. A análise das diversas amostras indicou que o arroz brasileiro integral contém teores mais elevados dos constituintes estudados, seguido pelo arroz parboilizado e o arroz agulhinha.838845Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Flame atomic absorption determination of cobalt in water after extraction of its morpholinedithiocarbamate complex

A preconcentration system for the determination of cobalt in water was developed. The studied system uses a glass column packed with Amberlyst A-26 resin modified with ammonium morpholinedithiocarbamate. The metal was quantitatively retained in the column containing 1.30 g of resin modified with 6% (m/m) of chelating reagent, at pH 5.5, resulting in a coloured complex which was eluted with 10.0 mL of ethanol. The final solution was analysed by flame atomic absorption spectrometry at 240.7 nm. Using these conditions a preconcentration factor of 25 was obtained and depending on the concentration of cobalt present in the solution it was possible to re-utilise the packed column several times. The limit of quantification was 2.0 µg L-1 with RSD of 2.9%. The foreign ions effect was studied and only Cd(II) and Ni(II) showed interference. The proposed method showed to be simple, of low cost, easy to handle and has been applied for the determination of cobalt in natural water samples.Este trabalho descreve um sistema de pré-concentração para cobalto utilizando a resina Amberlyst A-26 modificada com morfolinaditiocarbamato de amônio. O metal foi retido quantitativamente em uma coluna de vidro contendo 1,30 g da resina modificada com 6% (m/m) de reagente quelante, em pH 5,5. O complexo colorido formado foi dissolvido com etanol e analisado por espectrometria de absorção atômica com chama em 240,7 nm. A eluição do complexo com 10 mL de etanol permitiu um fator de pré-concentração igual a 25, sendo possível a re-utilização de uma mesma coluna. O limite de quantificação obtido foi de 2,0 µg L-1 com RSD de 2,9%. O estudo de concomitantes mostrou que somente Cd(II) e Ni(II) interferem no sistema. O método proposto é simples e de baixo custo, podendo ser usado para determinação de cobalto em águas naturais.957962Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Analysis of liquid stevioside and cyclamate-saccharin dietetic sweeteners by inductively coupled plasma optical emission spectrometry without sample treatment

An analytical method for the determination of inorganic species in liquid cyclamate-saccharin and stevioside sweeteners is presented. The method is based on inductively coupled plasma optical emission spectrometry and allowed analysis without prior sample treatment. Instrumental parameters were optimized according to plasma robustness and the signal to background ratio. The accuracy of the method was evaluated for As, Ca, Cd, Co, Cu, Fe, Mg, Mn, Ni, Pb, and Zn employing analyte addition and recovery experiments. The recovery values were between 90 and 110% for the majority of the analytes, the RSDs obtained were, in general, lower than 5% and the limits of detection were in the range 0.7 (Mg) - 71 (Pb) µg L-1. The analyses of different samples indicated that the average values of many of the analytes studied were different for the two types of samples. Copper and Zn concentrations were in the same range and As, Co, and Pb were not detected in any samples.A determinação de espécies inorgânicas em adoçantes líquidos à base de ciclamato-sacarina e esteviosídeo é descrita. O método, sem tratamento prévio da amostra, é baseado na espectrometria de emissão óptica em plasma com acoplamento indutivo. Parâmetros instrumentais foram otimizados de acordo com a robustez do plasma e a razão sinal analítico/ sinal de fundo. A exatidão foi avaliada para As, Ca, Cd, Co, Cu, Fe, Mg, Mn, Ni, Pb e Zn empregando experimentos de adição e recuperação. Os valores de recuperação ficaram entre 90 e 110% para a maioria dos analitos, os RSDs obtidos foram, em geral, menores que 5% e os limites de detecção ficaram na faixa de 0,7 (Mg) a 71 (Pb) µg L-1. Não foi detectada a presença de As, Co e Pb. As concentrações de Cu e Zn foram semelhantes para as amostras de ciclamato-sacarina e esteviosídeo enquanto as demais espécies mostraram diferenças.13931399Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

O papel da pós-graduação na formação do químico

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Higher silver bioavailability after nanoparticle dietary exposure in marine amphipods

On release into surface waters, engineered silver nanoparticles (AgNPs) tend to settle to sediments and, consequently, epibenthic fauna will be exposed to them through diet. We established Ag uptake and accumulation profiles over time in the hemolymph of a marine amphipod fed with a formulated feed containing AgNPs or AgCl. Silver bioavailability was higher in organisms exposed to AgNPs, indicating that the nanoparticles pose a higher risk of toxicity compared to similar concentrations of AgCl384806810CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo2013/26301‐7sem informação400362/2014‐7; 552120/2011‐

A espectrometria atômica e a determinação de elementos metálicos em material polimérico

Polymeric materials are widely used in the chemical industry and are part of our daily lives. Inorganic species may be added to them as additives, anti-oxidizing agents, stabilizers, plasticizers, colorants and catalysts and may be present in a wide range of concentrations. Their determination demands the development of analytical methods considering different kinds of polymeric materials, their composition and the final use of the material. Although many different analytical techniques may be used, this review emphasizes those based on atomic absorption and emission spectrometry. Solid sampling techniques and digestion methods are described and discussed and compared considering published results

Atomic spectrometry and the determination of metals in polymeric materials

Polymeric materials are widely used in the chemical industry and are part of our daily lives. Inorganic species may be added to them as additives, anti-oxidizing agents, stabilizers, plasticizers, colorants and catalysts and may be present in a wide range of concentrations. Their determination demands the development of analytical methods considering different kinds of polymeric materials, their composition and the final use of the material. Although many different analytical techniques may be used, this review emphasizes those based on atomic absorption and emission spectrometry. Solid sampling techniques and digestion methods are described and discussed and compared considering published results.1533154

Determination of cadmium by flame-atomic absorption spectrometry after preconcentration on silica gel modified with cupferron

A method for the determination of cadmium by flame atomic absorption spectrometry (FAAS) after its preconcentration onto a column containing silica gel modified with cupferron was developed. The pH, amount of adsorbent material, concentration of eluent, volume of sample and amount of Cd were optimized. The effect of several foreign ions was also investigated and showed that the retention of cadmium depended on the amounts of Zn(II) and Cu(II) present and that these interferences could be overcome by using a 0.05 mmol KI. An enrichment factor of up to 30 was obtained , the LOD was 0.5 µg L-1 (3sigma) and the LOQ was 2.0 µg L-1 (10sigma) with rsd of 1.1% (n = 10). The accuracy of the proposed method was ascertained by using certified reference material and the obtained result (3.93 ± 0.01 µg g-1) agrees with the certified value (4.15 ± 0.38 µg g-1). The determination of Cd in nail polish showed quantitative recoveries for the spiked samples. The proposed method is characterized by simplicity, efficiency and low cost.Este trabalho descreve um método para a pré-concentração de cádmio com sílica gel modificada com cupferron e sua determinação por espectrometria de absorção atômica com chama. O efeito do pH, a quantidade do material adsorvente, a concentração de eluente, volume da amostra e quantidade do analito adsorvido foram otimizados. O efeito de interferentes foi avaliado para diversos íons mostrando que a extração de cádmio somente é afetada por Zn(II) e Cu(II), dependendo da concentração dos mesmos, mas pode ser minimizada pela adição de 0,05 mmol de KI. Foi obtido um fator de enriquecimento de até 30 vezes. Os limites de detecção e de quantificação foram de 0,5 µg L-1 (3sigma) e 2,0 µg L-1 (10sigma), respectivamente, com rsd de 1,1% (n=10). A exatidão foi avaliada com material de referência certificado e o resultado obtido (3,93 ± 0,01 µg g-1) concordou com o valor certificado (4,15 ± 0,38 µg g-1). O teor de cádmio em esmalte de unhas foi determinado, obtendo-se recuperações quantitativas para as amostras enriquecidas com o analito. O método proposto caracteriza-se pela simplicidade, eficiência e baixo custo.31331

Evaluation of direct analysis for trace elements in tea and herbal beverages by ICP-MS

In general, inductively coupled plasma mass spectrometry (ICP-MS) food analysis requires numerous sample treatment steps that imply an increase of analysis time and the use of chemicals. In this study, the main objective was to evaluate the applicability of the direct analysis by ICP-MS to determine twelve elements (Al, As, Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se and Zn) in tea and herbal beverages. Direct analysis method was compared with two other sample treatments: minimum treatment (acid dilution) and using a destructive method (microwave assisted digestion). Besides the lowest time of analysis, direct analysis provides a reliable response and agrees with the “green chemistry” principles. High sensitivity was also observed by low values of limits of detection and quantification, in general, below 2.5 µg L-1. The method accuracy was evaluated by spiked experiments and values ranged between 82 and 120%. Low values of coefficient of variation were also observed, 2 to 17%, for all analytes. The method exhibited applicability for commercial tea samples as well as for drinks made by herb infusion26612111217CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informaçãosem informação2012/19142-