Collection efficiency of solid surface and sorbent traps in supercritical fluid extraction with modified carbon dioxide

Abstract

The effect of modifier on solid-phase trapping efficiency in off-line supercritical fluid extraction was studied. Two types of traps-solid surface (stainless steel) and sorbent (octadecyl silica)-were studied with pure carbon diocide and 1%, 2%, 4% and 8% methanol-modified carbon dioxide. The trapping efficiency of a polarity test mix consisting of N,N-dimethylanilline, acetophenone, naphthol, decanoic acid, and n-tetracosane was studied at trap temperatures ranging from 5 to 80 o C with each fluid. For low concentrations of methanol and the ODS sorbent, trap temperatures below 20 o C were necessary for volatile (bp<200 o C) analytes