Dispositivos hifenados para microextração em fase solida / Hyphenated devices for solid phase microextraction

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

In this work systems for Dynamic Headspace sampling (DHS) combined to Solid Phase Microextraction (SPME) were develloped, and different SPME fibers were evaluated for applications in Fiber Introducton Mass Spectrometry (FIMS). In the DHS-SPME systems assembled, analytes from solid, liquid or viscous samples can be extracted. A continuous flow of stripping gas percolates the sample and the gas containing the volatile compounds is directed to a cell, where the SPME fiber is exposed for extraction. It was observed that both the extraction time and the stripping gas flow should be optimized. Three different stripping gas propulsion methods were studied, being two of them portable and potentially useful for intralaboratorial analyses and field sampling. The devices provided high sensitivity, in addition to easy handling and low cost. For FIMS (direct coupling of SPME and Mass Spectrometry), three commercial (100 mm polydimethylsiloxane (PDMS), 65 mm PDMS / divinylbenzene (PDMS / DVB) and 65 mm Carbowax / DVB) and one home-made (~5 mm PDMS / polyvinylalcohol) SPME fibers were evaluated to the determination of phthalates in mineral water and of pesticides in passion fruit leaves, respectivelly. To the evaluated fibers, different profiles for the analytical signals were observed. Generation of extraneous peaks characterized as chemical noise happened for fibers with hydrophilic or porous coatings.

ASSUNTO(S)

gas stripping headspace dinamico spme spme-ms stripping gas dynamic headspace spme-ms spme

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