Application of Direct Aqueous Supercritical Fluid Extraction for the Dynamic Recovery of Testosterone Liberated from the Enzymatic Hydrolysis of Testosterone--D-Glucuronide

The first report demonstrating the feasibility of supercritical fluids as solvent media for performing enzymatic reactions was published in 1986 (
1
). Since then several reports have confirmed that the relatively low critical temperature and pressure of supercritical fluid carbon dioxide provides potential for the use of enzymes with thermally labile substrates. These applications, which generally involve the use of immobilized enzymes in feasibility studies for batch scale processes, have been reviewed (
2
). One study (
3
) has demonstrated that the stability of nine commercially available enzyme preparations are largely unaffected using supercritical carbon dioxide containing ethanol (3–6%) and water (0.1%), at 35�C, 200 atm for 1 h. On the analytical scale, a few applications have described the use of enzymes in conjunction with supercritical fluid extraction (SFE) for sample preparation of liquid matrices (
4
).