Focused microwave-assisted extraction combined with solid-phase microextraction and gas chromatography-mass spectrometry for the selective analysis of cocaine from coca leaves.
Level 5 - mechanism / opinion, no new human data
Level 5 by design analogy (laboratory analytical chemistry method development)
PubMed 16384568 · doi:10.1016/j.chroma.2005.12.028
What was done
Method development and validation were conducted to selectively extract and quantify cocaine from coca leaves (Erythroxylum coca) using focused microwave-assisted extraction (FMAE) coupled with direct-immersion solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). The extraction utilized an aqueous medium compatible with a 100 microm polydimethylsiloxane (PDMS) coated fiber. Parameters including solution pH, sampling time, temperature, and cocaine stability in alkaline aqueous media (monitored via capillary electrophoresis) were evaluated.
What was found
Cocaine degradation in the alkaline aqueous extraction conditions was less than 5% after 60 minutes. SPME clean-up enabled the use of shorter GC columns, reducing GC analysis time from 35 minutes to 6 minutes. Cocaine content in dry leaves was determined to be 0.70 +/- 0.04% with a relative standard deviation (RSD) under 5%.
Why it matters
This approach demonstrates an aqueous-compatible microextraction workflow that simplifies sample preparation and markedly decreases instrument run times for quantitative alkaloid profiling in plant materials.
Limits
The abstract does not state the number, source, or variety of coca leaf samples evaluated. Limits of detection, limits of quantitation, and comparative recovery rates against standard regulatory organic solvent extraction protocols are not reported in the abstract.
Cited by
- supports The potency difference between a coca leaf and purified cocaine is approximately 65 times.