Solid phase microextraction SPME

SPME is intensively applied in headspace analysis. A number of books are reviewing the fundamental aspects and the applications of SPME [3,15]. On polymers such as polydimethylsiloxane (PDMS) and polyacrylate a partitioning mechanism applies while on divinylbenzenestyrene copolymers or mixtures of Carboxen (CAR) and PDMS, adsorption controls the enrichment. In headspace SPME, two mechanisms apply, firstly the partitioning of analytes between the sample matrix and the headspace, and secondly the partitioning between the headspace and the fibre coating. SPME is thus not an exhaustive extraction technique but an equilibrium technique. Maximum sensitivity is obtained at equilibrium, although commonly non-equilibrium conditions are used. This requires optimization of temperature, time and agitation for each application.

Gandini and Riguzzi applied HS-SPME for the analysis of methyl isothiocyanate, an illegal antifermentative agent, in wine [16]. Page and Lacroix applied HS-SPME to the analysis of fruit juices, soft and fruit drinks, and milk for the determination of volatiles ranging from vinyl chloride to hexachlorobenzene [17]. Recent applications include the determination of furan in baby food [18] and formaldehyde in fish [19].

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