Sample preparation combined with electroanalysis to improve simultaneous determination of antibiotics in animal derived food samples.

A procedure based on liquid-liquid extraction (LLE) and phase separation using magnetically stirred salt-induced high-temperature liquid-liquid extraction (PS-MSSI-HT-LLE) was developed to extract and pre-concentrate ciprofloxacin (CIPRO) and enrofloxacin (ENRO) from animal food samples before electroanalysis. Firstly, simple LLE was used to extract the fluoroquinolones (FQs) from animal food samples, in which dilution was performed to reduce interference effects to below a tolerable threshold. Then, adapted PS-MSSI-HT-LLE protocols allowed re-extraction and further pre-concentration of target analytes in the diluted acid samples for simultaneous electrochemical quantification at low concentration levels. To improve the peak separation, in simultaneous detection, a baseline-corrected second-order derivative approach was processed. These approaches allowed quantification of target FQs from animal food samples spiked at levels of 0.80 to 2.00 µmol L-1 in chicken meat, with recovery values always higher than 80.5%, as well as in milk samples spiked at 4.00 µmol L-1, with recovery values close to 70.0%.

Avaliação de membrana experimental implantada em cavidade cirurgicamente confeccionada em calota craniana de coelhos: estudo histológico / The evaluation of a novel membrane implanted into bone cavities in the rabbit calvarian: histological study

O objetivo desse estudo foi avaliar histológicamente o comportamento de uma membrana experimental, de procedência nacional, membrana de Fluoreto de Polivinilideno-Trifluoreto/ CerâmicaTitanato de Bário (PVDF-TrFE/BT) e comparar com os resultados da membrana de colágeno. Para tanto foram confeccionados defeitos ósseos de 6mm de diâmetro em calvária de coelhos. Foram utilizados, um total de 30 coelhos, adultos machos, divididos em quarto grupos: Grupo I: cavidade cirúrgica confeccionada no lado direito da calota craniana do animal, preenchida com osso autógeno e coberta pela membrana experimental de PVDF-TrFE/BT. Grupo II: cavidade cirúrgica confeccionada no lado esquerdo da calota craniana do animal, preenchida com coágulo e coberta pela membrana experimental de PVDF-TrFE/BT. Grupo III: cavidade cirúrgica confeccionada no lado direito da calota craniana do animal, preenchida com osso autógeno e coberta pela membrana de colágeno. Grupo IV: cavidade cirúrgica confeccionada no lado esquerdo da calota craniana do animal, preenchida com coágulo e coberta pela membrana de colágeno. Os animais foram eutanásia nos períodos de 07, 30 e 120 dias. Os espécimes foram tramitados para análise histológica. O grupo I apresentou o melhor resultado em relação à consistência histological do osso neoformado bem como acelerou o processo. Nos grupos I e II, a membrana experimental manteve o espaço do defeito para a reparação óssea. No grupo III e IV, a membrana de colágeno permitiu apenas que houvesse uma reparação parcial da cavidade cirúrgica confeccionada. Por meio dos resultados obtidos, podemos concluir que: a utilização do enxerto ósseo proporcionou a formação de ósseo de melhor consistência com total reparação das cavidades ósseas; a membrana experimental apresentou melhor biocompatibilidade e qualidades compatíveis para uso como barreira para a Regeneração Óssea Guiada, enquanto que a membrana de colágeno serviu apenas para recobrimento do defeito

The purpose of this study was to histologically evaluate the behavior of a novel membrane of the composite poly(vinylidenetrifluoroethylene)/ barium titane and compare the results with a collagen membrane. The defects were surgically created into the calvarian bone. The study used 30 adult, male rabbits were into from groups follow: Group I – the bone defect of the right side was filled with autogenous bone graft and covered with the novel membrane. Group II – the bone defect of the left side was filled with blood clot and covered with the novel membrane. Group III - the bone defect of the right side was filled with autogenous bone graft and covered with the collagen membrane. Group IV – the bone defect of the left side was filled with blood clot and covered with the collagen membrane. The animals were sacrificed at 07, 30 and 120 days. The results: The group I showed the better bone formation and the accelerated repair. The novel membrane kept the bone space to repair. In the group III and IV, the collagen membrane influenced the bone repair process, so the defects were partial filled by bone. The conclusion: The autogenous bone grafts stimulated the osteogenesis; the novel and the collagen membranes showed biocompatibility and the novel membrane has quality to serve as Bone Gide Regeneration Process; the collagen membrane can be used to cover the grafts or implants materials.