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Forensic
Applications
Gabapentin in Serum, Plasma or Whole Blood
for GC or GC/MS Confirmations
Using 100mg 1mL HyperSep C18 Extraction Column
(Part Number: 60108-302)
Prepare Sample
To 500µL of blood, plasma or serum, add internal
standard*
Vortex tube and add 500µL of 20% acetic acid and
vortex tube again
Centrifuge as appropriate
Condition C18 Extraction Column
3mL of CH
3
OH then aspirate
3mL of DI H
2
O then aspirate
1mL of 100mM HCl
NOTE:
Aspirate at <3"Hg to prevent sorbent drying
Apply Sample
Load sample at 1 to 2mL/minute
Wash Column
3mL of DI H
2
O
3mL of ethyl acetate
3mL hexane
Dry column (5 minutes at >10"Hg or until column is dry)
Elute Gabapentin
1mL of 2% NH
4
OH in CH
3
OH
Dry Eluate
Evaporate to dryness at <40°C
Derivatize
Add 50µL of ethyl acetate and 50µL of BSTFA
(with 1% TMCS)** or
Add 50µL of MTBSTFA (with 1% TBDMCS)*** and
50µL ethyl acetate
Cap and heat at 70°C for 30 minutes
Remove and allow to cool
Quantitate
Inject 1 to 2µL onto gas chromatograph
For mass spectrometry, monitor the following ions:
Compound
Primary
Secondary
Tertiary
Gabapentin
210
225
182
Gabapentin-D10*
220
235
192
* Suggested internal standard
** Part number TS-38831 (10 x 1mL ampules)
*** Part number TS-48927 (10 x 1mL ampules)
Recommended GC Columns
Part Number
TRACE TR-DoA5 Column, 15m x 0.25mm x 0.25µm
26AF130P
TRACE TR-DoA35 Column, 15m x 0.20mm x 0.33µm
26AC497P
Reference
Wolf, C.E. II, Sady J., and Pokalis, A. (1996). Determination of gabapentin in serum
using solid phase extraction and gas chromatography.
Journal of Analytical Toxicology
,
20, 498-501.