Conventional and Enantioselective GC microfabricated columns versus FSOT columns in the analysis of essential oils

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Conventional and Enantioselective GC microfabricated columns versus FSOT columns in the analysis of essential oils

Cecilia Cagliero1

, Thais Uekane2, Stefano Galli3, Mario Galli3 , Fulvio Mancarella4, Ivan Elmi4, Maddalena

Belluce4_{, Barbara Sgorbini}1_{, Patrizia Rubiolo}1_{, Carlo Bicchi}1

1 _{Dipartimento di Scienza e Tecnologia del Farmaco, via P. Giuria 9, 10125 Torino (Italy)}

2_{Instituto de Química, Universidade Federal do Rio de Janeiro, 21-2562-7370 Rio de Janeiro – Brazil} 3_{MEGA s.n.c. - Via Plinio, 29 - 20025 Legnano (Milano) - Italy}

4_{CNR-IMM Bologna - Institute of Microelectronics and Microsystems - Via P. Gobetti, 101, 40129 Bologna}

(Italy)

Microfabricated columns are highly attractive for gas chromatography because of the number of possible applications in particular for on-site environmental monitoring and in-field analysis. Microfabricated columns are therefore ideal for mobile micro GC instruments because of their small size and low thermal mass affording rapid temperature programming with relatively low power. Silicon micro-electromechanical system (MEMS) technologies are often adopted for microfabricated column preparation.

This study adopts etched silicon columns (equivalent, for both pneumatic impedance and chromatographic performance, to a 100 μm dc conventional capillary column) fabricated in silicon substrates that are statically coated with a 0.1-0.2-μm-thick film of different stationary phases microfabricated columns 1.68 and 3.60 m long coated with conventional polysiloxane, polyethylene glycol and 30% 2,3 diethyl – 6 t-butyldimethylsilyl-β-cyclodextrin in PS-086. All columns showed an efficiency comparable to that of corresponding conventional columns, i.e. 10000 theoretical plates per meter for SE 52 and 7000 for CD columns respectively using hydrogen as carrier gas.

The performance of the resulting microfabricated columns were tested with a conventional GC system and their performance compared to those of conventional columns of the same length and phase ratio and under the same analysis conditions. Comparison was carried out by analyzing a set of essential oils from different plants, and evaluating the enantiomer separation of racemate standards.

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