BERTUCCI-NETO, V.

CONSOLIN-FILHO, N.

FERREIRA, E. J.

MATTOSO, L. H. C.

VIERA, A. H.

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'.:'.. "/ .....',.. .~:(":'t;,:;,.J,,-,·;J;,'..h .1.'".,.,· ', 1. '1:/..• ': :"1"International Conference on-~C a acte •a,'i':5-1Q ~ugust 2007 i..~ .',,',;':;~.: ;,.:;1 ~.:;{.... :.~ I.: .) .•..••.'i/ .t~/..;" I. r,,',,7• t· j~!. . I,' .' 1 •!-,:.'" -:~,•. I,-.: '1 t;~. .~: •• :[0 ,':/ t, ; I .~ :'0-/~'. "I-I! .:' ,",t. ,:.,o .~ •• ,;. .~' "'4 •':': ..~ '._ o:~ ":)' ". ~t ;,. o): :."o} ).' .• fI! ••.~o''-'~r'I".""~ • '. t,,,,, • "-.0;:'.',x,I!iI'I1.' .Poster PresentationDeleclion MelhodsDM19NEW SENSOR FOR IDENTIFICATION OF TOXINS AND DISSOLVED ORGANIC MATTER FROMCYANOBACTERIABertucci-Neto, V.. 1; Consolin-Filho, N.1; Viera, A.H.2; Ferreira, E.J.l; Mattoso, L.H.C.l'Embrapa InstrumentaçãoAgropecuária, Brazil; 2Universidade Federal de São Carlos, Brazil.Usually, the rnost used method for detection of cyanotoxins is the HPLC plus mass spectroscopy. The absenceof a field instrument for detection of safe concentration of these toxins is an apparent lack. Based on this, it ispresented in this work the description of a system based on a multiarray of nanostructured conducting polymersensors that by using impedance measurements are able to sense and classify the following species: Anabaenaspiroides (A), Cy/indrospermopsis raciborskii (C), Microcistis aeruginosa (M), and P/anktothrix lropica/is (P).The sensory system is based on the concept of global sensibility consisting of ten interdigitated electrodessheathed with a layer of an ultra-fine film of conductor polymer. Electrodes are excited by an AC signal generatedby an impedance analyzer. Samples with concentration around 106 (Iive and dead) cells/liter of each speciewere used for the experiments. Electrodes were immersed in each sample and the signal frequency was sweptin order to seek peaks of sensitivity. Higher sensitivity was obtained with a 1KHz signal. Samples were dilutedin 80%, 60%, and 40% ofthe total concentration. Electrodes were immersed in each sample again (from 100%to 40% of the total concentration) and it was applied a 1 KHz signal. Data from 10 measurements on eachelectrode were collected. The data set was used to feed a Principal ComponentAnalysis routine (PCA). Thediagrams resulting from the application of PCA's method showed clearly the clusters formed by the responsedue to each species live ar dead, with more than 99% of the whole information being described by the firstprincipal component. Poar results appeared when 40% concentrations were used, getting difficultto distinguishthe clusters formed between P and C species. These preliminary results indicate that this new technique canbe promising at least for fast detection. It is also important to note that the electrodes were not previouslyprepared to detect anyone species, this is, by the inclusion of proper related substances in the film sensor isexpected a higher sensibility in the presence of one of the live species or related toxins.Support by Embrapa and CNPqDM20NIES CERTIFIED REFERENCE MATERIAL FOR QUANTIFICATION OF TOTAL MICROCYSTINSTakagi, H.' 1;Sano, P; Nishikawa, M.1; Kaya, K.2'Nationallnstitute for Environmental Studies, Japan; 2TohokuUniversity, Japan.Th(~ certified reference material (CRM) for total microcystin analysis was prepared by National Institute forEnvironmenlal Studies (NIES). In the CRM, at least seven microcystin variants were found by HPLC analysis.Tho major microcyslin variants in the CRM were [Dha'jrnicrocystin-Rk and -LR. The slandard materiais ofthcse microcystin variants were not able to obtain from commercial sources. Thereupon, the total microcystincontem in lhe CRM was determined according to the MMPB method. Furthermore, we purified each microcystinvarlants for lhe slructure elucidation. From the results of lhe analyses of the NMR and MS spectra and aminoaclds, lhe ro.nained five minor variants in the CRM were elucidated to be [D-Asp3, Dha'[rnicrocystin-Rlc and-U~.IDh;1'1Illicrocystin- YR, -ThTyrR and -HilR. The CRM is very useful not only as the standard material for thequantilicntion uf total microcystins but also as the reference varianls for the identification of [Dha'lmicrocystinV:lI i:lIlls TI1IJNlfS CRM No. 26 (water bloom) with analytical data of microcystin variants has been suppliedaiound lho world0'- • __•__• _18 r- ICTC

New sensor for identification of toxins and dissolved organic matter from cyanobacteria.

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http://www.alice.cnptia.embrapa.br/alice/bitstream/doc/30660/1/Proci07.00133.pdf

New sensor for identification of toxins and dissolved organic matter from cyanobacteria.

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