Comparison of liquid/liquid and solid-phase extraction for alkaline drugs
Matthew P Juhascik1, Amanda J Jenkins
1UMass Memorial Forensic Toxicology Laboratory, Worcester, MA 01605, USA.
Journal of Chromatographic Science
|September 24, 2009
Summary
Solid-phase extraction (SPE) offers improved drug detection limits and faster processing in forensic toxicology compared to traditional liquid/liquid extraction (LLE). This method enhances the ability to identify a wider range of substances in postmortem samples.
Area of Science:
- Forensic Toxicology
- Analytical Chemistry
- Biochemistry
Background:
- Drug extraction from biological matrices is crucial in forensic postmortem analysis.
- Liquid/liquid extraction (LLE) has been the traditional method, but solid-phase extraction (SPE) is gaining prominence due to improved column availability.
Purpose of the Study:
- To evaluate the feasibility of transitioning from LLE to SPE in forensic postmortem laboratories.
- To compare the limits of detection (LOD) of drugs in blood using SPE versus LLE.
Main Methods:
- Determined LODs for 122 drugs and metabolites in blood using SPE.
- Compared SPE LODs with previously established LLE LODs for 41 drugs.
- Assessed extraction efficiency for weakly acidic and neutral drugs.
Main Results:
- SPE demonstrated lower LODs for 39% of drugs compared to LLE.
- SPE enabled detection of drugs like morphine and benzoylecgonine, not detectable by LLE.
- SPE processing was faster, doubling specimen throughput per analyst.
Conclusions:
- SPE is a feasible and advantageous alternative to LLE for forensic drug screening.
- SPE offers improved sensitivity for certain drugs and increased laboratory efficiency.
- The SPE method facilitates the extraction of a broader spectrum of drug types.
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