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Registro Completo |
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Biblioteca(s): |
Embrapa Algodão. |
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Data corrente: |
22/12/2017 |
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Data da última atualização: |
08/01/2018 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
RIBEIRO, W. F.; COSTA, D. J. E. da; LOURENO, A. S.; MEDEIROS, E. P. de; SALAZAR-BANDA, G. R.; NASCIMENTO, V. B. do; ARAÚJO, M. C. U. |
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Afiliação: |
WILIAME F. RIBEIRO, UFPB; DANIEL J. E. da COSTA, UFPB; ANABEL S. LOURENÇO, UFPB; EVERALDO PAULO DE MEDEIROS, CNPA; GIANCARLO R. SALAZAR-BANDA, UNIVERSIDADE TIRADENTES - ARACAJU; VALBERES B. do NASCIMENTO, UFRPE; MÁRIO C. U. ARAÚJO, UFPB. |
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Título: |
Adsorptive stripping voltammetric determination of trace level Ricin in castor seeds using a boron-doped diamond electrode. |
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Ano de publicação: |
2017 |
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Fonte/Imprenta: |
Electroanalysis, v.29, n. 7, p. 1783-1793, 2017 |
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DOI: |
10.1002/elan.201700100 |
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Idioma: |
Inglês |
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Conteúdo: |
Ricin, (Ricinus communis agglutinin, RCA) is one of the most poisonous of naturally occurring substances and has great potential for bioterrorism because no antidote exists. Fast detection at low concentrations is a challenge, and vital to the development of proper countermeasures. In this study, a square wave adsorptive stripping voltammetric (SWAdSV) method for determining RCA using a cathodically polarized boron-doped diamond (BDD) electrode is presented. An irreversible electrochemical RCA oxidation peak was identified on the BDD electrode by different voltammetric techniques using both direct and adsorptive stripping modes. An adsorption-controlled (slope log Ip vs log v of 0.80) pHdependent process was observed. For values of 1.0pH 9.0, the numbers of protons and electrons associated with the oxidation reaction were estimated (ca. 1.0) by differential pulse voltammetry. The RCA oxidation step may correspond to the oxidation of tryptophan amino acid residues, and occurs in a complex mechanism. The excellent analytical performance of the cathodically polarized BDD electrode in combination with the stripping mode ramp was verified with RCA by using a short deposition time in an open circuit potential (120 s). Under optimized analysis conditions, a linear response in the range of (3.3?94.0)3109 mol L1 (r2=0.9944) and a limit of detection of 6.231010 mol L1 were estimated. This LOD is lower than several methods found in the literature. For example, it is 168 times lower than that obtained by using square wave voltammetric with a glassy carbon electrode. Moreover, an even lower LOD might be achieved by using the SWAdSV method with a higher pre-concentration time. In addition, trace levels of RCA were successfully determined in different castor seed cultivars with an overall average recovery from 99.2 1.6% for the three different RCA-A concentration levels. The high accuracy of the analytical data highlights the use of the proposed method for determining RCA in other samples. MenosRicin, (Ricinus communis agglutinin, RCA) is one of the most poisonous of naturally occurring substances and has great potential for bioterrorism because no antidote exists. Fast detection at low concentrations is a challenge, and vital to the development of proper countermeasures. In this study, a square wave adsorptive stripping voltammetric (SWAdSV) method for determining RCA using a cathodically polarized boron-doped diamond (BDD) electrode is presented. An irreversible electrochemical RCA oxidation peak was identified on the BDD electrode by different voltammetric techniques using both direct and adsorptive stripping modes. An adsorption-controlled (slope log Ip vs log v of 0.80) pHdependent process was observed. For values of 1.0pH 9.0, the numbers of protons and electrons associated with the oxidation reaction were estimated (ca. 1.0) by differential pulse voltammetry. The RCA oxidation step may correspond to the oxidation of tryptophan amino acid residues, and occurs in a complex mechanism. The excellent analytical performance of the cathodically polarized BDD electrode in combination with the stripping mode ramp was verified with RCA by using a short deposition time in an open circuit potential (120 s). Under optimized analysis conditions, a linear response in the range of (3.3?94.0)3109 mol L1 (r2=0.9944) and a limit of detection of 6.231010 mol L1 were estimated. This LOD is lower than several methods found in the literature. For example, it is 168 times lower tha... Mostrar Tudo |
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Palavras-Chave: |
Castor; Seed. |
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Thesagro: |
Boro; Mamona; Ricinus communis; Semente. |
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Thesaurus Nal: |
Bioterrorism; Boron. |
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Categoria do assunto: |
-- |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/169734/1/Adsorptive-Stripping.pdf
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Marc: |
LEADER 02876naa a2200301 a 4500
001 2083413
005 2018-01-08
008 2017 bl uuuu u00u1 u #d
024 7 $a10.1002/elan.201700100$2DOI
100 1 $aRIBEIRO, W. F.
245 $aAdsorptive stripping voltammetric determination of trace level Ricin in castor seeds using a boron-doped diamond electrode.$h[electronic resource]
260 $c2017
520 $aRicin, (Ricinus communis agglutinin, RCA) is one of the most poisonous of naturally occurring substances and has great potential for bioterrorism because no antidote exists. Fast detection at low concentrations is a challenge, and vital to the development of proper countermeasures. In this study, a square wave adsorptive stripping voltammetric (SWAdSV) method for determining RCA using a cathodically polarized boron-doped diamond (BDD) electrode is presented. An irreversible electrochemical RCA oxidation peak was identified on the BDD electrode by different voltammetric techniques using both direct and adsorptive stripping modes. An adsorption-controlled (slope log Ip vs log v of 0.80) pHdependent process was observed. For values of 1.0pH 9.0, the numbers of protons and electrons associated with the oxidation reaction were estimated (ca. 1.0) by differential pulse voltammetry. The RCA oxidation step may correspond to the oxidation of tryptophan amino acid residues, and occurs in a complex mechanism. The excellent analytical performance of the cathodically polarized BDD electrode in combination with the stripping mode ramp was verified with RCA by using a short deposition time in an open circuit potential (120 s). Under optimized analysis conditions, a linear response in the range of (3.3?94.0)3109 mol L1 (r2=0.9944) and a limit of detection of 6.231010 mol L1 were estimated. This LOD is lower than several methods found in the literature. For example, it is 168 times lower than that obtained by using square wave voltammetric with a glassy carbon electrode. Moreover, an even lower LOD might be achieved by using the SWAdSV method with a higher pre-concentration time. In addition, trace levels of RCA were successfully determined in different castor seed cultivars with an overall average recovery from 99.2 1.6% for the three different RCA-A concentration levels. The high accuracy of the analytical data highlights the use of the proposed method for determining RCA in other samples.
650 $aBioterrorism
650 $aBoron
650 $aBoro
650 $aMamona
650 $aRicinus communis
650 $aSemente
653 $aCastor
653 $aSeed
700 1 $aCOSTA, D. J. E. da
700 1 $aLOURENO, A. S.
700 1 $aMEDEIROS, E. P. de
700 1 $aSALAZAR-BANDA, G. R.
700 1 $aNASCIMENTO, V. B. do
700 1 $aARAÚJO, M. C. U.
773 $tElectroanalysis$gv.29, n. 7, p. 1783-1793, 2017
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Registro original: |
Embrapa Algodão (CNPA) |
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 | Acesso ao texto completo restrito à biblioteca da Embrapa Agroindústria Tropical. Para informações adicionais entre em contato com cnpat.biblioteca@embrapa.br. |
Registro Completo
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Biblioteca(s): |
Embrapa Agroindústria Tropical. |
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Data corrente: |
20/09/2011 |
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Data da última atualização: |
16/10/2018 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Circulação/Nível: |
B - 2 |
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Autoria: |
MIRANDA, F. R. de; MESQUITA, A. L. M.; MARTINS, M. V. V.; ARAGAO, F. A. S. de; FERNANDES, C. M. F. |
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Afiliação: |
FABIO RODRIGUES DE MIRANDA, CNPAT; ANTONIO LINDEMBERG MARTINS MESQUITA, CNPAT; MARLON VAGNER VALENTIM MARTINS, CNPAT; FERNANDO ANTONIO SOUZA DE ARAGAO, CNPAT. |
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Título: |
Evaluation of a control system based on the Irrigas® Sensor for irrigation scheduling of hydroponic tomato in Ceará, Brazil. |
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Ano de publicação: |
2011 |
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Fonte/Imprenta: |
Acta Horticulturae, v. 889, p. 431-438, 2011. |
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Idioma: |
Inglês |
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Conteúdo: |
The study aimed to evaluate two irrigation scheduling techniques for hydroponic tomato production in Ceará, northeastern Brazil. The experiment was set up as a split-plot randomized block design, with six replications. As main factor, two irrigation scheduling techniques were tested: (a) Automatic scheduling using matric sensors, a closed loop irrigation control system based on the Irrigas® sensor, was used to start irrigation whenever matric potential in the substrate reached -4 kPa. (b) Time clock scheduling - irrigation applications were programmed at fixed intervals and rates, according to drainage fraction observed on the previous day and water retention capacity of the substrate. Tomato hybrids ?Miramar? and ?Ellen? were evaluated in the subplots. The growing medium was coconut fiber in bags of 40 L. The automatic irrigation scheduling based on Irrigas® sensors did not affect significantly the tomato marketable yield, fruit weight, and number of fruits per plant (p>0.05) as compared to time clock scheduling. The automatic irrigation control reduced water application by 6.3% as compared to time clock scheduling, without affecting pH and EC levels of the drainage solution. The tomato hybrid ?Miramar? presented significantly higher (p<0.01) marketable yield and number of fruits per plant than hybrid ?Ellen?, which presented higher fruit weight. |
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Palavras-Chave: |
Greenhouse; Irrigation control; Matric potential. |
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Thesagro: |
Lycopersicon Esculentum. |
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Thesaurus NAL: |
soilless culture. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02084naa a2200229 a 4500
001 1900986
005 2018-10-16
008 2011 bl uuuu u00u1 u #d
100 1 $aMIRANDA, F. R. de
245 $aEvaluation of a control system based on the Irrigas® Sensor for irrigation scheduling of hydroponic tomato in Ceará, Brazil.
260 $c2011
520 $aThe study aimed to evaluate two irrigation scheduling techniques for hydroponic tomato production in Ceará, northeastern Brazil. The experiment was set up as a split-plot randomized block design, with six replications. As main factor, two irrigation scheduling techniques were tested: (a) Automatic scheduling using matric sensors, a closed loop irrigation control system based on the Irrigas® sensor, was used to start irrigation whenever matric potential in the substrate reached -4 kPa. (b) Time clock scheduling - irrigation applications were programmed at fixed intervals and rates, according to drainage fraction observed on the previous day and water retention capacity of the substrate. Tomato hybrids ?Miramar? and ?Ellen? were evaluated in the subplots. The growing medium was coconut fiber in bags of 40 L. The automatic irrigation scheduling based on Irrigas® sensors did not affect significantly the tomato marketable yield, fruit weight, and number of fruits per plant (p>0.05) as compared to time clock scheduling. The automatic irrigation control reduced water application by 6.3% as compared to time clock scheduling, without affecting pH and EC levels of the drainage solution. The tomato hybrid ?Miramar? presented significantly higher (p<0.01) marketable yield and number of fruits per plant than hybrid ?Ellen?, which presented higher fruit weight.
650 $asoilless culture
650 $aLycopersicon Esculentum
653 $aGreenhouse
653 $aIrrigation control
653 $aMatric potential
700 1 $aMESQUITA, A. L. M.
700 1 $aMARTINS, M. V. V.
700 1 $aARAGAO, F. A. S. de
700 1 $aFERNANDES, C. M. F.
773 $tActa Horticulturae$gv. 889, p. 431-438, 2011.
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Embrapa Agroindústria Tropical (CNPAT) |
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