Allen D.L., Scott K.S., Oliver J.S.

Department of Forensic Medicine and Science, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK

A comparative study for the quantitative determination of morphine from whole blood using solid phase extraction (SPE) and supercritical fluid extraction (SFE) is described.
SPE techniques are widely used for the isolation of analytes from liquid matrices. Although SPE is easy and popular in terms of extraction techniques SFE, a relatively new sample preparation technique, is becoming of greater interest.
Comparative studies were made between the two techniques for the extraction of morphine from authentic forensic blood specimens.
Quantitative results indicate that morphine levels measured using SPE correspond well to morphine levels produced using SFE. The two techniques are therefore complementary, although with the use of SFE, faster, cleaner extracts may be produced with higher analyte recoveries than with SPE. This paper presents a comparison of the two techniques and the morphine concentrations determined in blood.