SPE
Definition
Solid-phase extraction. Sample is loaded onto a packed sorbent cartridge (C18, mixed-mode MCX/MAX, polymeric Oasis HLB), washed and selectively eluted. The dominant modern clean-up step in Indian SFSL toxicology.
- Full name
- Solid-phase extraction
- Sorbents
- C18, mixed-mode MCX/MAX, polymeric Oasis HLB cartridges
- Steps
- Load, wash, selective elution
- Status
- Dominant modern clean-up step in Indian SFSL toxicology
Common questions
Why has SPE become dominant over older liquid-liquid extraction in toxicology labs?+
SPE cartridges give more reproducible recoveries, use less solvent, and are easier to standardise across a large casework volume than manual liquid-liquid extraction, which is why state forensic science laboratories have shifted toward SPE-based clean-up for viscera and body-fluid poison extraction.
How does mixed-mode SPE (MCX/MAX) differ from a simple C18 cartridge for drug screening?+
A C18 cartridge retains analytes mainly by nonpolar interaction, while mixed-mode cartridges add an ion-exchange group, so basic drugs (MCX) or acidic drugs (MAX) can be selectively retained and cleanly eluted even from complex viscera extracts, improving selectivity over a single-mode sorbent.
Related terms
- ASE
- Accelerated solvent extraction (Dionex ASE). Pressurised solvent at elevated temperature pushes the analyte off the tissue matrix in minutes, replacing overnight Soxhlet.
- Conway Microdiffusion Cell
- A two-compartment glass or ceramic dish with a central well and an outer ring, sealed at the rim. The poison is released...
- QuEChERS
- Quick, Easy, Cheap, Effective, Rugged and Safe sample-prep protocol for pesticide residues. Acetonitrile extraction, MgSO4 + NaCl partition, dispersive SPE clean-up with...
- SLE
- Supported liquid extraction. Diatomaceous earth columns absorb the aqueous sample as a thin film and a single pass of organic solvent elutes...
- SPME
- Solid-phase microextraction. A polymer-coated fused-silica fibre (typically PDMS or PDMS-DVB) is exposed to vial headspace, then thermally desorbed in the GC injector....
- Stas-Otto Procedure
- Classical 1851/1856 acid-base liquid-liquid fractionation. Acidify with tartaric acid and extract acidic and neutral organics into ether, then alkalise and extract bases...
- Steam Distillation
- Passing live steam through a sample so that volatile organic compounds co-distil with water at a temperature below their own boiling point....
- Viscera
- The standard set of organs and fluids collected at a suspected poisoning autopsy in India: stomach with contents, a length of upper...