Microwave-Induced Combustion

Barin, Juliano Smanioto; Flores, Érico M.M.; Mesko, Márcia F.; Mello, Paola A.; Pereira, Juliana S.F.

doi:10.1016/b978-0-444-59420-4.00005-2

Cited by 12 publications

(7 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In general, methods based on combustion enable complete decomposition of the matrix with low residual carbon content (RCC) in a relatively short time. In addition, to avoid losses of analytes by volatilization, the combustion must be carried out in closed vessels . In this sense, the microwave-induced combustion (MIC) system may be considered as an interesting alternative for preparing samples prior to Br and I determination.…”

Section: Introductionmentioning

confidence: 99%

Bromine and Iodine Contents in Raw and Cooked Shrimp and Its Parts

Mesko

Toralles

Hartwig

et al. 2016

J. Agric. Food Chem.

Self Cite

View full text Add to dashboard Cite

The concentration of bromine and iodine was determined in shrimp and its parts (tissue and shells), and changes in the analyte concentration were evaluated after the cooking procedure. Bromine and iodine concentrations were determined by a method recently developed by our research group based on microwave-induced combustion for sample preparation and inductively coupled plasma mass spectrometry for analyte determination. The accuracy was evaluated using a reference material (NIST 8414) that was digested using the proposed method. No statistical difference was observed between certified and determined values (Student's t test, 95% confidence level). Suitable limits of detection (Br, 0.02 μg g(-1) and I, 0.01 μg g(-1)) were obtained for both analytes. Higher concentrations of both analytes were observed in shrimp shells in comparison to shrimp tissue for raw and cooked samples. Moreover, losses of Br and I (between 24 and 43%) were observed after cooking.

show abstract

Section: Introductionmentioning

confidence: 99%

Bromine and Iodine Contents in Raw and Cooked Shrimp and Its Parts

Mesko

Toralles

Hartwig

et al. 2016

J. Agric. Food Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

“…O método da MIC foi desenvolvido, inicialmente, para a decomposição de amostras sólidas, 19 sendo que outros tipos de amostras necessitam ser adaptadas para um melhor desempenho deste método. Neste sentido, o uso de cápsulas de policarbonato e de invólucros com filmes de PE podem ser uma alternativa para que as amostras possam ser colocadas no suporte.…”

Section: Otimização Da Mic: Preparação Dos Invólucros Para As Amostrasunclassified

“…Para a determinação de metais, há diversos trabalhos na literatura que utilizam HNO 3 como solução absorvedora. 19 Dessa maneira, neste trabalho foram avaliadas três concentrações de HNO 3 (3, 7 e 14,5 mol L -1 ) para a determinação de metais e S, em RAT e em RV. No procedimento da MIC, foram decompostos 500 mg de RAT e de RV com uma etapa de refluxo de 5 min nos ciclos de decomposição.…”

Section: Avaliação Da Solução Absorvedora No Procedimento Da Micunclassified

Simultaneous Determination of Metals and Sulfur in Crude Oil Distillation Residues by Icp-Oes

Druzian¹,

Giesbrecht²,

Rosa³

et al. 2016

Química Nova

Self Cite

View full text Add to dashboard Cite

, VR) using microwave-induced combustion (MIC) was developed for simultaneous determination of metals (Ba, Co, Fe, Mg, Mn, Ni and V) and sulfur by inductively coupled plasma optical emission spectrometry (ICP-OES). Samples were wrapped in polyethylene films and combusted using 20 bar of oxygen. Nitric acid solutions were evaluated using 5 min of reflux after combustion. Accuracy was evaluated using certified reference material and comparison with the results obtained by microwave-assisted wet digestion (MAWD). No statistical difference was observed between the certified values and those obtained using MIC as well as between the values obtained using MAWD or MIC. In spite of both methods have been apparently suitable for crude oil digestion, MIC was preferable in view of the possibility of using 3 mol L -1 HNO 3 as absorbing solution. Furthermore, it is important to notice that using MIC, C content in digests was lower than 10 mg L -1 , preventing interferences in ICP-OES. In addition, the simultaneous digestion of eight samples was possible in less than 30 min and without using concentrated acids and/or longer heating times, making the proposed method well-suited for routine analysis.Keywords: crude oil fractions, crude oil distillation residues, microwave-assisted digestion, microwave-induced combustion, ICP-OES. INTRODUÇÃOO resíduo de destilação atmosférico (RAT) e o resíduo de destilação a vácuo (RV) são oriundos do processo de destilação do petróleo, possuindo ponto de ebulição de cerca de 340 e 540 ºC, respectivamente.1,2 Apesar de tais frações serem, majoritariamente, constituídas por hidrocarbonetos, também estão presentes compostos contendo N, O e S, bem como metais, 3,4 cuja concentração varia em função da origem do petróleo. Como consequência, tais elementos podem ser transferidos a outras frações durante o processamento, causando a contaminação de produtos finais. 5,6 O RAT, por exemplo, pode ser usado como matéria--prima para a produção de combustíveis ou transferido para a unidade de destilação a vácuo. 2,7,8 O resíduo desse processo (RV) 1,8 é comumente utilizado na produção de asfalto e coque de petróleo 6 , o qual pode ter sua qualidade prejudicada caso haja a presença de constituintes metálicos ou de S. Efeitos nocivos sobre os catalisadores utilizados em processos industriais, além da contribuição para a poluição ambiental, estão entre os problemas ocasionados pela presença de metais e S em RAT e RV. 1,8,9 Dessa forma, considerando a possibilidade desses elementos serem incorporados nas frações após o refino e poderem ser transferidos aos produtos finais, torna-se importante a determinação rotineira de metais e S no RAT e no RV.A determinação de metais em frações de petróleo pode ser feita empregando técnicas de espectrometria atômica, tais como a espectrometria de absorção atômica com chama (FAAS), 10 a espectrometria de absorção atômica com forno de grafite (GFAAS), 11 a espectrometria de emissão óptica com plasma indutivamente acoplado (ICP-OES) 12,13 e a espectrometria de massa com plasma ...

show abstract

“…Literature data showed halogen losses through the formation of volatile compounds, such as HX or X 2 (X = halogen), which can be formed during acid digestion, resulting in non‐quantitative recoveries 17 . Thus, when choosing a sample preparation method, the analyst should consider the type of analytes and their concentrations, as well as the nature of the sample, the determination technique, and the precision and accuracy desired 18 …”

Section: Introductionmentioning

confidence: 99%

“…Thus, MIC provides high throughput and low reagent consumption, and allows the use of several types of solution for analyte absorption, including alkaline reagents. It has also been recommended for the determination of non‐metals in organic samples 18, 31 . In addition, the digests obtained by MIC, in general, are compatible with analysis by various determination techniques 18 …”

Section: Introductionmentioning

confidence: 99%

Ion chromatography coupled to mass spectrometry as a powerful technique for halogens and sulfur determination in egg powder and its fractions

Mesko

Toralles

Coelho

et al. 2020

Rapid Comm Mass Spectrometry

View full text Add to dashboard Cite

Rationale To increase the consumption of egg powder and its fractions a suitable quality control method is required to obtain more information on its nutritional composition. The proposed method enables the quantification of important elements for the functioning of the human organism, such as halogens and sulfur, in egg powder and its fractions. Methods Up to 350 mg of egg powder or its fractions (egg white powder and egg yolk powder) were digested by microwave‐induced combustion using 20 bar pressure of oxygen. The analytes were absorbed in 100 mmol L−1 of NH4OH solution. The determination of halogens (chlorine, bromine, fluorine, and iodine) and sulfur was performed in a single analysis using ion chromatography with conductivity detection coupled to mass spectrometry. Results Using the proposed method, spike recoveries between 99% and 104% for all analytes were obtained, and results agreed with certified values of reference materials (agreements were between 100% and 109%). The relative standard deviations were below 8%. The variation in elemental concentration over a wide range in different fractions (whole egg powder, egg white powder, and egg yolk powder) and different brands was also observed. Conclusions The proposed method provides reliable information about minerals in whole egg powder and its fractions, contributing to better quality control of these products. Because these food products are widely consumed, these results suggest the safe ingestion levels of these elements.

show abstract

Microwave-Induced Combustion

Cited by 12 publications

References 66 publications

Bromine and Iodine Contents in Raw and Cooked Shrimp and Its Parts

Bromine and Iodine Contents in Raw and Cooked Shrimp and Its Parts

Simultaneous Determination of Metals and Sulfur in Crude Oil Distillation Residues by Icp-Oes

Ion chromatography coupled to mass spectrometry as a powerful technique for halogens and sulfur determination in egg powder and its fractions

Contact Info

Product

Resources

About