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Alves T.S.,Federal University of Piaui | Barbosa R.,Federal University of Piaui | De Carvalho L.H.,Federal University of Campina Grande | Canedo E.L.,Institute Tecnologia Of Pernambuco
Polimeros | Year: 2014

The flammabilities of nanocomposites made with three polypropylene grades (homo and copolymers) with 5 wt % of organoclay (Cloisite 20A), 5 or 15 wt % of maleated polypropylene as compatibilizer, and 0, 0.5 or 1 wt % of cis-13-docosenamide (Erucamide) as co-intercalant, were studied using the horizontal burning test UL94HB. Masterbatches prepared in an internal mixer were diluted in the polypropylene matrix using a corotating twin-screw extruder, with different screw configurations and operating at 240 or 480 rpm. Results indicate that the high burning rate of the composites was not affected by the processing conditions. For all formulations was observed a significant reduction in smoke release, lack of dripping and the formation of a char surface layer, that protected the core of the samples. Source

Pereira E.V.S.,University of Pernambuco | Oliveira S.P.A.,University of Pernambuco | Nobrega I.C.C.,University of Pernambuco | Lachenmeier D.W.,Chemisches und Veterinaruntersuchungsamt Karlsruhe | And 3 more authors.
Quimica Nova | Year: 2013

While in Europe vodka is mainly derived from potatoes or cereals, a large proportion of Brazilian vodka is likely obtained from sugarcane, which contains ethyl carbamate (EC) precursors. EC, in addition to several other contaminants and congeners, were investigated in 32 samples of Brazilian vodka. All samples complied with the Brazilian regulations for congeners and contaminants, having EC content below 0.01 mg/L (detection limit). These results are probably related to the processing of vodka, in particular the use of extractive and rectifying stainless steel distillation columns, which allow the production of high strength spirits with low levels of congeners and contaminants. Source

Santos P.N.D.,University of Pernambuco | MacIel M.I.S.,University of Pernambuco | De Oliveira Lavorante B.R.B.,Institute Tecnologia Of Pernambuco | De Melo Medeiros M.,Institute Tecnologia Of Pernambuco | De Albuquerque E.C.,Institute Tecnologia Of Pernambuco
Quimica Nova | Year: 2011

This work reports the optimization and method validation for sulfonamides (sulfamethazine, sulfaquinoxaline, sulfadimethoxine and sulfathiazole) in shrimp muscle using HPLC-UV. The sulfonamides were extracted with acetonitrile and acetic acid, and the extract cleaned up with a Strata SCX SPE cartridge prior to analysis. The method presented linearity in the range of 20-120 ug kg -1, good linear correlation (r > 0.99), and limits of quantification in the range of 4.7-20.2 ug kg-1. The recovery for shrimp muscles spiked with 50-150 ug kg-1 ranged from 63.2-108.0%. Precision and accuracy analysis showed acceptable relative standard deviation. Commercial shrimps were analyzed and sulfonamides don't were found above of the method limit of quantification. Source

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