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Type: Artigo de periódico
Title: Neuro-genetic Multioptimization Of The Determination Of Polychlorinated Biphenyl Congeners In Human Milk By Headspace Solid Phase Microextraction Coupled To Gas Chromatography With Electron Capture Detection.
Author: Kowalski, Cláudia Hoffmann
da Silva, Gilmare Antônia
Poppi, Ronei Jesus
Godoy, Helena Teixeira
Augusto, Fabio
Abstract: Polychlorinated biphenyls (PCB) can eventually contaminate breast milk, which is a serious issue to the newborn due to their high vulnerability. Solid phase microextraction (SPME) can be a very convenient technique for their isolation and pre-concentration prior chromatographic analysis. Here, a simultaneous multioptimization strategy based on a neuro-genetic approach was applied to a headspace SPME method for determination of 12 PCB in human milk. Gas chromatography with electron capture detection (ECD) was adopted for the separation and detection of the analytes. Experiments according to a Doehlert design were carried out with varied extraction time and temperature, media ionic strength and concentration of the methanol (co-solvent). To find the best model that simultaneously correlate all PCB peak areas and SPME extraction conditions, a multivariate calibration method based on a Bayesian Neural Network (BNN) was applied. The net output from the neural network was used as input in a genetic algorithm (GA) optimization operation (neuro-genetic approach). The GA pointed out that the best values of the overall SPME operational conditions were the saturation of the media with NaCl, extraction temperature of 95 degrees C, extraction time of 60 min and addition of 5% (v/v) methanol to the media. These optimized parameters resulted in the decrease of the detection limits and increase on the sensitivity for all tested analytes, showing that the use of neuro-genetic approach can be a promising way for optimization of SPME methods.
Subject: Calibration
Chemistry Techniques, Analytical
Chromatography, Gas
Genetic Techniques
Milk, Human
Multivariate Analysis
Neural Networks (computer)
Polychlorinated Biphenyls
Reproducibility Of Results
Citation: Analytica Chimica Acta. v. 585, n. 1, p. 66-75, 2007-Feb.
Rights: fechado
Identifier DOI: 10.1016/j.aca.2006.11.073
Date Issue: 2007
Appears in Collections:Unicamp - Artigos e Outros Documentos

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