SOFT 2004 Meeting Abstracts - Society of Forensic Toxicologists

F15
METHOD VALIDATION FOR THE ANALYSIS OF AMPHETAMINE, METHAMPHETAMINE,
MDAAND MDMA IN URINE
Mee-lung Park, Sang-Kit Choi, Eun-Mi Kim, Mi-Ae Lim*, Myungyoon PyOI), Hee-Sun Chung
Division ofNarcotic Analysis, National Institute of Scientific Investigation, Seoul, Korea
I)The school of Pharmacy, Sookmyung Women's University, Seoul, Korea
The purpose of this study is to provide the standard method for the. assay of stimulants in urine, especially
ATS (amphetamine type stimulants; amphetamine (AM), methamphetamine (MA),
methylenedioxyamphetamine (MDA) and methylenedioxymethamphetamine (MDMA». We performed
method validation for these drugs in urine according to EURACHEM Guide (A laboratory guide to method
validation).
Analytical method for AM, MA, MDA and MDMA in urine was as follows. For the analysis of
amphetamines in urine. immunoassay (fluorescence polarization immunoassay, TDxFLx) was used for
screening test and confirmation test was performed with GC/MS. After the analysis by immunoassay, the
positive specimens were alkalized with 6 M-NaOH and the analytes were extracted with ethyl acetate. After
centrifugation of specimens, the supernatants were evaporated to dryness under the nitrogen stream at 450
with vacuum. The residues were derivatized with pentafluoropropionic anhydride (PFPA). They were
analyzed by gas chromatography/mass spectrometry (GC/MS). Ds-deuterated amphetamines were used as
internal standards. To validate this method, selectivity, linearity of calibration, within- and between-run
reproducibility (precision), accuracy, limit ofdetection and quantification were studied.
As a result, the calibration curves were ranged from 100 to 8,000 ng/ml with the correlation coefficients of
greater than 0.9. Within- and between-run precisions were measured in three different concentrations (250
ng/ml, 500 ng/ml, 1,000 ng/ml). Coefficients ofvariance (CV %) of their precisions were under 10 % at all
concentrations. Those accuracies (% bias) were also under 10 %. The limit ofdetection (LOD) and limit of
quantification (LOQ) for all analytes studied were 20 ng and 100 ng, respectively. The selectivity of
amphetamines in urine was observed by spiking high concentrations of those, which have similar chemical
structures such as ephedrine, pseudoephedrine and norephedrine into low QC urine samples (500 ng).
Those chemicals did not show any inferences in the analysis ofATS in urine by this method.
It was concluded that validation data by Eurachem guide was proved to be adequate for the analysis of
amphetamine, methamphetamine, MDA and MDMA in urine Samples ..
Keywords; method validation, ATS (amphetamine type stimulants), urinalysis
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