Biomedical subjects

F C Silva

Publications and source records attributed to F C Silva.

4 recordsLinked to original sources

PubMed2001

A headspace solid-phase microextraction method for the determination of some secondary compounds of Brazilian sugar cane spirits by gas chromatography.

A headspace solid-phase microextraction (SPME) method was developed for the determination of secondary compounds from Brazilian sugar cane spirits, or cachaça, by GC-FID. An SPME holder with an 85 microm polyacrylate coating was utilized. The novel method is compared with an optimized method: liquid-liquid extraction (LLE). Both methods showed good linearity, but the repeatability for analyses done with the SPME technique (%RSD = 1.8-3.9) was better than for those done with LLE (%RSD = 10.3-11.7). The concentrations of the analytes obtained in the analysis of 12 cachaça samples with the SPME technique were higher than those obtained with LLE. In the SPME method the extraction wastes are smaller. Cachaça samples were qualitatively analyzed for GC-MS.

Gas Chromatography-Mass Spectrometry↗

PubMed2000

Solid-phase microextraction method for the quantitative analysis of styrene in water.

A headspace solid-phase microextraction (HS-SPME) method is developed for the determination of styrene in drinking water. Gas chromatography (GC)-mass spectrometry is utilized for qualitative analysis. A manual SPME holder with 85-microm polyacrylate coating is used to extract the styrene from water, which is determined to have good linearity (correlation coefficient r = 0.9999 for 1.00-100.00 microg/L range), a relative standard deviation of 1.9%, and a detection limit of 0.30 microg/L. This method is compared with a classical headspace GC method.

Gas Chromatography-Mass Spectrometry↗

PubMed1996

Perinatal mortality in lambs in southern Brazil.

Hypothermia and dystocia were found to be the most common causes of perinatal mortality in 8 commercial wool flocks in one region of southern Brazil. It was established that low birth weight and poor maternal instinct in the ewes predisposed to losses due to hypothermia but that there appeared to be no association with adverse weather conditions. Other factors possibly predisposing to losses are discussed.

Animals↗

PubMed1994

Near-UV light protection effect against lethality induced by stannous chloride in Escherichia coli.

Stannous chloride (SnCl2) is a reducing agent largely employed in industry and in medical procedures. To evaluate its potential genotoxicity, several Escherichia coli strains were treated with SnCl2 and their survival rates determined. Results showed that the double mutant on specific genes for the repair of deoxyribonucleic acid damage was the most sensitive strain. Simultaneous near-UV illumination inhibited the lethal effect of SnCl2 in the wild type strain. Although the nature of the induced lesions are not known these results indicate the potential genotoxicity of SnCl2.

DNA Repair↗