Supercritical fluid extraction SFE

The excellent properties offered by a supercritical fluid namely tuneable solvating power (selectivity), high diffusivity and low viscosity have resulted in analytical usage for many years. Despite early promise, the utility of supercritical fluids for extraction was dormant for many years until the mid-1980s when analytical-scale SFE instrumentation became commercially available. SFE was received with high expectations by the analytical community, but in recent years enthusiasm has declined as the disadvantages have become clearer. The most important disadvantage is definitely the complexity of the extraction procedure which is strongly matrix dependent and needs careful optimization. A procedure developed for one particular matrix does not automatically work for another matrix. Chuang et al. [23] applied SFE for the analysis of pesticides in baby food but they could not obtain quantitative recoveries for all monitored pesticides. SFE is therefore not really accepted for routine work and remains a research tool. The determination of PAHs in vegetable oils by SFE was recently described by Lage and Cortizio [24]. In Section 3.2.5, the determination of pesticides by supported liquid-SFE will be presented.

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