Analytical methods gaseous effluents

In off-line collection, the effluent is depressurized, and the analyte is collected in a solvent, an open container, or an analyte trap packed with a solid support. Off-line collection is simpler, and the collected sample can be analyzed by several methods. Thus, the SFE instrument is decoupled from the analytical instruments. Other advantages of the off-line approach are accommodation of larger sample sizes, feasibility of multiple analyses from a single extraction, and accommodation of a wider range of analyte concentrations. In the analyte trap approach, the use of different solvents for elution can serve as an additional experimental parameter for increased selectivity and cleanup. In the open-container collection approach, aerosol may form because depressurization of the supercritical fluid produces a high flow rate of gaseous carbon dioxide. 

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