SFE-GC with quantitative transfer of the extraction effluent to a megabore capillary column
Supercritical fluid extraction was directly coupled with gas chromatography such that the entire extraction effluent was directed onto the GC column. A sealed connection between the restrictor and the column ensured that no loss of analyte could occur. The elevated pressure generated in the column itself resulted in a reduced flow rate through the column, making efficient trapping possible. Metal-jacketed capillary columns were used as they can tolerate the elevated pressures required. In addition to maximizing sensitivity, very practical extraction parameters were possible. For a 25-min extraction, with a 2.2 mL/min flow rate, and the column at 40 degrees C, analytes as volatile as C-14 were trapped and separated. Trapping efficiency improved further with shorter extraction times, mild cooling of the column, or lower flow rates.
Stone
MA
Virginia Polytechnic Institute and State University, Department of Chemistry, Blacksburg, 24061-0212, USA.
Taylor
LT