Acs. Lucas et al., Use of solid-phase microextraction (SPME) for the determination of methadone and EDDP in human hair by GC-MS, FOREN SCI I, 107(1-3), 2000, pp. 225-232
Solid-phase microextraction (SPME) is a new extraction technique with many
advantages: small sample volume, simplicity, quickness and solvent-free. It
is mainly applied to environmental analysis, but is also useful for the ex
traction of drugs from biological samples. In this paper the use of SPME is
proposed for the: determination of methadone and its main metabolite EDDP
in hair by GC-MS. The hair samples were washed, cut into l-mm segments, and
incubated with Pronase E(R) for 12 h, A 100-mu m polydimethylsiloxane (PDM
S) film fibre was submerged for 30 min in a diluted solution of the hydroly
sis liquid (1:4 with borax buffer) containing methadone-d(3) and EDDP-d(3)
as internal standards. Once the microextraction was concluded the fibre was
directly inserted into the CG injection port. Linearity was found for meth
adone and EDDP in the range studied, 1.0-50 ng/mg hair, with correlation co
efficients higher than 0.99. Interassay relative standard deviation (R.S.D)
was determined to be less than 13.30% for methadone and less than 8.94% fo
r EDDP, at 3.0 and 30.0 ng/mg. Analytical recoveries were close to 100% for
both compounds on spiked samples. The method was applied to the analysis o
f real hair samples from eight patients of a methadone maintenance programm
e. The concentration of methadone in hair ranged from 2.45 to 78.10 ng/mg,
and for EDDP from 0.98 to 7.76 ng/mg of hair. (C) 2000 Elsevier Science Ire
land Ltd. All rights reserved.