Direct Determination Of Cu, Mn, Pb, And Zn In Beer By Thermospray Flame Furnace Atomic Absorption Spectrometry

In this work, thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) was employed for Cu, Mn, Pb, and Zn determination in beer without any sample digestion. The system was optimized and calibration was based on the analyte addition technique. A sample volume of 300 μl was introduced into the hot Ni tube at a flow-rate of 0.4 ml min-1 using 0.14 mol l -1 nitric acid solution or air as carrier. Different Brazilian beers were directly analyzed after ultrasonic degasification. Results were compared with those obtained by graphite furnace atomic absorption spectrometry (GFAAS). The detection limits obtained for Cu, Mn, Pb, and Zn in aqueous solution were 2.2, 18, 1.6, and 0.9 μg l-1, respectively. The relative standard deviations varied from 2.7% to 7.3% (n=8) for solutions containing the analytes in the 25-50 μg l-1 range. The concentration ranges obtained for analytes in beer samples were: Cu: 38.0-155 μg l-1; Mn: 110-348 μg l-1, Pb: 13.0-32.9 μg l-1, and Zn: 52.7-226 μg l-1. Results obtained by TS-FF-AAS and GFAAS were in agreement at a 95% confidence level. The proposed method is fast and simple, since sample digestion is not required and sensitivity can be improved without using expensive devices. The TS-FF-AAS presented suitable sensitivity for determination of Cu, Mn, Pb, and Zn in the quality control of a brewery. © 2005 Elsevier B.V. All rights reserved.605749753Matsushige, I., Oliveira, E., Determination of trace-elements in Brazilian beers by ICP-AES (1993) Food Chem., 47, pp. 205-207Matusiewicz, H., Kopras, M., Methods for improving the sensitivity in atom trapping flame atomic absorption spectrometry: Analytical scheme for the direct determination of trace elements in beer (1997) J. Anal. At. Spectrom., 12, pp. 1287-1291Moll, M.M., Food science and technology (1995) Handbook of Brewing, 64, pp. 133-156. , W.A. Hardwick Marcel Dekker New YorkLi, Y., Van Loon, J.C., Barefoot, R.R., Preconcentration of trace elements in potable liquids by means of a liquid membrane emulsion for flame atomic absorption determination (1993) Fresenius' J. Anal. Chem., 345, pp. 467-470Andersen, M.L., Skibsted, L.H., Electron spin resonance spin trapping identification of radicals formed during aerobic forced aging of beer (1998) J. Agric. Food Chem., 46, pp. 1272-1275Helin, T.R.M., Slaughter, J.C., Determination of metals in brewing materials by flameless atomic absorption spectrometry (1997) J. Inst. Brew., 83, pp. 15-16Svendsen, R., Lund, W., Speciation of Cu, Fe and Mn in beer using ion exchange separation and size-exclusion chromatography in combination with electrothermal atomic absorption spectrometry (2000) Analyst, 125, pp. 1933-1937Concon, J.M., (1988) Food Toxicology, , Marcel Dekker New YorkOnianwa, P.C., Adeyemo, A.O., Idowu, O.E., Ogabiela, E.E., Copper and zinc contents of Nigerian foods and estimates of the adult dietary intakes (2001) Food Chem., 72, p. 89Watson, C.A., (1994) Official and Standardized Methods of Analysis, pp. 688-689. , 3rd ed. Royal Society of Chemistry CambridgeBellido-Milla, D., Oñate-Jaén, A., Palacios-Santander, J.M., Palacios-Tejero, D., Hernández-Artiga, M.P., Beer digestions for metal determination by atomic spectrometry and residual organic matter (2004) Mikrochim. Acta, 144, pp. 183-190Bellido-Milla, D., Moreno-Perez, J.M., Hernández-Artiga, M.P., Differentiation and classification of beers with flame atomic spectrometry and molecular absorption spectrometry and sample preparation assisted by microwaves (2000) Spectrochim. Acta, Part B, 55, pp. 855-864Gáspár, A., Berndt, H., Thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS)-a simple method for trace element determination with microsamples in the μg l-1 concentration range (2000) Spectrochim. Acta, Part B, 55, pp. 587-597Davies, J., Berndt, H., Improvements in thermospray flame furnace atomic absorption spectrometry (2003) Anal. Chim. Acta, 479, pp. 215-223Pereira-Filho, E.R., Berndt, H., Arruda, M.A.Z., Simultaneous samples digestion and determination of Cd, Cu and Pb in biological samples using thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) with slurry sample introduction (2002) J. Anal. At. Spectrom., 17, pp. 1308-1315Nascentes, C.C., Arruda, M.A.Z., Nogueira, A.R.A., Nóbrega, J.A., Direct determination of Cu and Zn in fruit juices and bovine milk by thermospray flame furnace atomic absorption spectrometry (2004) Talanta, 64, pp. 912-917Welz, B., Sperling, M., (1999) Atomic Absorption Spectrometry, , 3rd ed. Wiley-VCH WeinheimAlcázar, A., Pablos, F., Martín, M.J., González, A.G., Multivariate characterisation of beers according to their mineral content (2002) Talanta, 57, pp. 45-5

Acid Extraction And Cloud Point Preconcentration As Sample Preparation Strategies For Cobalt Determination In Biological Materials By Thermospray Flame Furnace Atomic Absorption Spectrometry

A thermospray flame furnace atomic absorption spectrometer (TS-FF-AAS) was employed for Co determination in biological materials. Cobalt presents a high atomization temperature and consequently poor sensitivity is obtained without changing its thermochemical behavior. The effect of different complexing agents on sensitivity was evaluated based on the formation of Co volatile compounds. A cloud point procedure was optimized for Co preconcentration for further improvement of sensitivity. Samples were treated with 1 mol l- 1 hydrochloric acid solution for quantitative extraction of Co without simultaneous extraction of Fe, since it is a strong interferent. After the extraction and preconcentration steps, a sample volume of 150 μl was introduced into the hot Ni tube using air as carrier at a flow-rate of 0.4 ml min- 1. The best sensitivity was attained using ammonium pyrrolidinedithiocarbamate (APDC) and Triton X-114 was employed for implementation of the cloud point procedure. The detection limit obtained for Co was 2.1 μg l- 1 and the standard deviation was 5.8% for a solution containing 100 μg l- 1 (n = 10). Accuracy was checked using two certified reference materials (tomato leaves and bovine liver) and results were in agreement with certified values at a 95% confidence level. Employing the developed procedure, Co were quantified in different biological materials (plant and animal tissues). The proposed method presents suitable sensitivity for cobalt determination in the quality control of foods. © 2006 Elsevier B.V. All rights reserved.822189195Underwood, E.J., (1977) Trace Elements in Human and Animal Nutrition, , 4th ed. Academic Press New YorkBelitz, H.D., Grosch, W., (1987) Food Chemistry, , Springer-Verlag BerlinAtsdr, (2001) Toxicological Profile for Cobalt, , U.S. Department of Health and Human Services AtlantaEvans, E.H., Day, J.A., Price, W.J., Smith, C.M.M., Sutton, K., Tyson, J.F., (2003) J. Anal. At. Spectrom., 18, pp. 808-833Berndt, H., (1998) Fresenius Z. Anal. Chem., 331, pp. 321-323Delves, H.T., (1970) Analyst, 95, pp. 431-438Bradshaw, S., Gascoigne, A.J., Headridge, J.B., (1987) Anal. Chim. Acta, 197, pp. 323-325Berndt, H., Messerschmidt, J., (1982) Anal. Chim. Acta, 136, pp. 407-441Gáspár, A., Berndt, H., (2000) Spectrochim. Acta, Part B, 55, pp. 587-597Davies, J., Berndt, H., (2002) Anal. Chim. Acta, 479, pp. 215-223Gáspár, A., Széles, E., Berndt, H., (2002) Anal. Bioanal. Chem., 372, pp. 136-140Pereira-Filho, E.R., Berndt, H., Arruda, M.A.Z., (2002) J. Anal. At. Spectrom., 17, pp. 1308-1315Nascentes, C.C., Arruda, M.A.Z., Nogueira, R.A., Nóbrega, J.A., (2004) Talanta, 64, pp. 912-917Tarley, C.R.T., Arruda, M.A.Z., (2004) Anal. Sci., 20, pp. 961-966Giokas, D.L., Paleologos, E.K., Tzouwara-Karayanni, S.M., Karayannis, M.I., (2001) J. Anal. At. Spectrom., 16, pp. 521-526Manzoori, J.L., Bivili-Tabrizi, A., (2002) Microchem. J., 72, pp. 1-7Bezerra, M.A., Arruda, M.A.Z., Ferreira, S.L.C., (2005) Appl. Spectrosc. Rev., 40, pp. 269-299Miyazawa, M., Pavan, M.A., Bloch, M.F.M., (1984) Commun. Soil Sci. Plant Anal., 15, pp. 141-147Sebastiani, E., Ohls, K., Riemer, G., (1973) Fresenius Z. Anal. Chem., 264, pp. 105-109Berndt, H., Jackwerth, E., (1975) Spectrochim. Acta, Part B, 30, pp. 169-177Manning, D.C., (1975) At. Absorpt. Newsl., 14, pp. 99-102Paleologos, E.K., Stalikas, C.D., Tzouwara-Karayanni, S.M., Karayannis, M.I., (2001) Anal. Chim. Acta, 436, pp. 49-57Böyükbayram, A.E., Volkan, M., (2000) Spectrochim. Acta, B, 55, pp. 1071-1078Lurie, J., (1975) Handbook of Analytical Chemistry, , Mir Publisher MoscowNascentes, C.C., Arruda, M.A.Z., (2003) Talanta, 61, pp. 759-768Page, V., Feller, U., (2005) Ann. Bot. (London), 96, pp. 425-434Wang, H.F., Takematsu, N., Ambe, S., (2000) Appl. Radiat. Isotopes, 52, pp. 803-811Underwood, E.J., Suttle, N.F., (1999) Cobalt in Mineral Nutrition of Lifestock, , CABI Publishing New YorkKawashima, T., Henry, P.R., Ammerman, C.B., Littell, R.C., Price, J., (1997) Nutr. Res., 17, pp. 957-974Kincaid, R.L., Lefebvre, L.E., Cronrath, J.D., Socha, M.T., Johnson, A.B., (2003) J. Dairy Sci., 86, pp. 1405-141

On-line micro-solid phase preconcentration of Cd2 + coupled to TS-FF-AAS using a novel ion-selective bifunctional hybrid imprinted adsorbent

A novel hybrid ion imprinted polymer (HIIP) is proposed aiming at the development of an online micro-solid phase preconcentration system of Cd2 + coupled to TS-FF-AAS. To evaluate the selective and adsorptive performance of HIIP towards Cd2 +, hybrid non-imprinted polymer (HNIP), organic ion imprinted polymer (OIIP), and the inorganic ion imprinted polymer (IIIP) were synthesized and compared with each other. Adsorption capacity of HIIP was 53% higher than HNIP, and dual-site Langmuir–Freundlich isotherm model showed the best fit for data of both polymers. The preconcentration system coupled to TS-FF-AAS was performed by loading 10.0 mL of Cd2 + solution at pH 7.5 through 80.0 mg of HIIP packed into a micro-column with posterior online elution using 1.0 mol L− 1 HCl/ethanol 1:1 (v/v) mixture. The developed method was highly tolerant for other metal ions Zn2 +, Pb2 +, Cu2 +, Co2 +, Fe2 +, and Hg2 + at analyte:interferent (1:50, m/m) ratio and Ca2 + and Mg2 + at 1:500 (m/m) ratio. Analytical curve ranging from 0.5 to 7.0 μg L− 1, limit of detection of 30 ng L− 1 and preconcentration factor of 14-fold were obtained. Intra-day and inter-day (3 days) experiment precision (n = 10) was, respectively, 3.9 and 0.6% (relative standard deviation, RSD), and 4.4 and 2.4% for concentrations of 0.7 and 6.5 μg L− 1. Sensitivity of method (Abs L μg− 1) was about 3.3, 2.2 and 1.9-fold higher when compared to preconcentration method using HNIP, OIIP and IIIP, respectively, thus clearly showing that hybrid polymer and imprinting process enhance Cd2 + adsorption. Addition and recovery experiments ranging from 94 to 106% in mineral, lake water and tap water, urine and cigarette samples attested the feasibility of method for analysis of matrices containing different components. Moreover, the accuracy of method was checked from analysis of certified reference material (DOLT-4, fish liver), being the obtained value of 23.9 ± 0.6 mg kg− 1 (n = 3) statistically equal to the certified value of 24.3 ± 0.8 mg kg− 1, by applying Student t-test at 95% confidence level.1315769CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES481669/2013-2; 305552/2013-9; 472670/2012-325/201

On-line Micro-solid Phase Preconcentration Of Cd2 + Coupled To Ts-ff-aas Using A Novel Ion-selective Bifunctional Hybrid Imprinted Adsorbent

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)A novel hybrid ion imprinted polymer (HIIP) is proposed aiming at the development of an online micro-solid phase preconcentration system of Cd2 + coupled to TS-FF-AAS. To evaluate the selective and adsorptive performance of HIIP towards Cd2 +, hybrid non-imprinted polymer (HNIP), organic ion imprinted polymer (OIIP), and the inorganic ion imprinted polymer (IIIP) were synthesized and compared with each other. Adsorption capacity of HIIP was 53% higher than HNIP, and dual-site Langmuir–Freundlich isotherm model showed the best fit for data of both polymers. The preconcentration system coupled to TS-FF-AAS was performed by loading 10.0 mL of Cd2 + solution at pH 7.5 through 80.0 mg of HIIP packed into a micro-column with posterior online elution using 1.0 mol L− 1 HCl/ethanol 1:1 (v/v) mixture. The developed method was highly tolerant for other metal ions Zn2 +, Pb2 +, Cu2 +, Co2 +, Fe2 +, and Hg2 + at analyte:interferent (1:50, m/m) ratio and Ca2 + and Mg2 + at 1:500 (m/m) ratio. Analytical curve ranging from 0.5 to 7.0 μg L− 1, limit of detection of 30 ng L− 1 and preconcentration factor of 14-fold were obtained. Intra-day and inter-day (3 days) experiment precision (n = 10) was, respectively, 3.9 and 0.6% (relative standard deviation, RSD), and 4.4 and 2.4% for concentrations of 0.7 and 6.5 μg L− 1. Sensitivity of method (Abs L μg− 1) was about 3.3, 2.2 and 1.9-fold higher when compared to preconcentration method using HNIP, OIIP and IIIP, respectively, thus clearly showing that hybrid polymer and imprinting process enhance Cd2 + adsorption. Addition and recovery experiments ranging from 94 to 106% in mineral, lake water and tap water, urine and cigarette samples attested the feasibility of method for analysis of matrices containing different components. Moreover, the accuracy of method was checked from analysis of certified reference material (DOLT-4, fish liver), being the obtained value of 23.9 ± 0.6 mg kg− 1 (n = 3) statistically equal to the certified value of 24.3 ± 0.8 mg kg− 1, by applying Student t-test at 95% confidence level. © 2016 Elsevier B.V.1315769163/2014, Fundação Araucária25/2014, CAPES, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior305552/2013-9, CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico472670/2012-3, CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico481669/2013-2, CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoSETI, Secretário de Ciência, Tecnologia e Ensino Superior, Governo do Estado de ParanaCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Atividade respiratória da microbiota e conteúdo de glicose em resposta à adição de fósforo em solo de Cerrado Respiratory activity of soil microbiota and glucose content in response to phosphorus addition in Cerrado soil- Brazil

A atividade metabólica dos microrganismos é um dos principais processos reguladores das transformações de nutrientes no solo. No entanto, a atividade microbiana do solo é influenciada por fatores como a disponibilidade de nutrientes, incluindo o P. Este trabalho teve como objetivo avaliar o efeito da adição de P (de 50 a 500 mg kg-1 de P no solo) na atividade respiratória da microbiota e nos teores de glicose extra e intracelular em um Latossolo Vermelho distrófico fase Cerrado. As amostras de solo foram avaliadas quanto ao C liberado (C-CO2) pela atividade microbiana; pelo C orgânico total e pela glicose extra e intracelular. Durante o período de incubação (31 dias), a adição de P aumentou a atividade respiratória diária de 6,30 para 23,59 (mg kg-1 dia-1 de C-CO2 no solo), quando comparado com o controle. No entanto, a relação entre C-CO2 liberado por dia, por unidade de P adicionado, diminuiu, mostrando uma redução da eficiência na utilização do P adicionado. O teor de glicose extracelular no solo foi menor do que o encontrado intracelularmente. Ao final de 31 dias de incubação, o teor de glicose intracelular reduziu-se em decorrência da adição de P no solo, sugerindo maior consumo de glicose pelos microrganismos nas condições de adição do nutriente. Houve correlação negativa (r= -0,98, p < 0,01) entre a respiração diária e a glicose intracelular. Aos 31 dias de incubação, o CO total do solo diminuiu com a adição de 500 mg kg-1 de P no solo. A estreita relação entre o aumento da atividade e a diminuição de glicose intracelular sugere que a resposta da microbiota à adição de P pode estar associada ao conteúdo do açúcar no solo.<br>Metabolic activity of microorganisms is one of the main processes of control on the nutrient transformation in soil. However, the activity of the soil microbiota is affected by various factors such as the available nutrients, including phosphorus. The present work had as objective to show an approach of the effect of phosphorus addition (50 to 500 mg kg-1 P of dry soil) on the respiratory response of soil microbiota and the amount of extra and intracellular glucose in typic acrustox of Cerrado.The following analyses were carried: amount of C-CO2 evolved; total organic carbon e; extra and intracellular glucose in soil. During the incubation for 31 days, the respiratory activity (daily activity) increased in 6,30 to 23,59 with phosphorus addition, when compared to the control. However, the ratio between the daily carbon evolved (C-CO2) and the added phosphorus decreased, showing a reduction of the efficiency of nutrient utilization. The amount of the extracellular glucose was very smaller than the intracellular glucose. At end of 31 days of incubation, the amount of glucose decreased due to phosphorus addition, showing the consumption of sugar by microorganisms under experimental conditions. Negative metabolic correlation (r= -0.97, p<0.01) between the daily respiration and the intracellular glucose was shown. The soil organic carbon decreased only in the treatment with 500 mg P kg-1of dry soil, being other treatments similar to the control. The strong relation between an increasing of microorganism activity and a decreasing of intracellular glucose occurred, suggesting that the response of soil microbiota to phosphorus addition can be associated to the intracellular glucose content