Soo-Yeun Lee

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In order to aid the interpretation of hair results from methamphetamine (MA) abusers the MA and amphetamine (AP) concentrations in 2070 hair samples were statistically evaluated. The MA and AP concentrations in hair were put into three groups arbitrarily representing low, medium and high ranges and the metabolite-to-parent drug ratios of each group were(More)
Oxethazaine, an over-the-counter (OTC) antacid, is a precursor of phentermine, which is the most abused anorectic by methamphetamine users in Korea. However, no studies have investigated the abuse potential of oxethazaine. Therefore, we examined and compared the consequences of oxethazaine and phentermine treatment on animal models of conditioned place(More)
There is limited published data to aid interpretation of analytical findings from hair analysis. The aim of the study was to collate 6-monoacetylmorphine (6-AM) and morphine concentrations in head and pubic hair from heroin users and to propose reference ranges and relate these to the amount of heroin used. The ratio of morphine-to-6-AM was also(More)
γ-Hydroxybutyricacid (GHB) has been used as a prescription medicine for the treatment of narcolepsy and alcohol dependence. Quantification of GHB in biological fluids from GHB intoxication cases is not clear for verifying exposure to GHB due to the presence of endogenous GHB, which is rapidly metabolized, via GABA and/or succinic semialdehyde, to succinic(More)
Accurate measurement of trace levels of endogenous compounds remains challenging despite advancements in analytical technologies. In particular, monoamine neurotransmitters such as dopamine (DA) and serotonin (5-HT) are polar compounds with low molecular weights, which complicates the optimization of retention and detection on liquid chromatography-mass(More)
Products in the food and beverage industry have varying levels of dimensionality ranging from pure water to multicomponent food products, which can modify sensory perception and possibly influence discrimination testing results. The objectives of the study were to determine the impact of (1) sample dimensionality and (2) complex formulation changes on the(More)
The quantitative analysis of 11-nor-D(9)-tetrahydrocannabinol-9-carboxylic acid (THCCOOH) in hair requires a sensitive method to detect a low-pg level. Before applying the method to real hair samples, the method was validated; in this study, we examined the uncertainty obtained from around the cut-off level of THCCOOH in hair. We calculated the measurement(More)
Pubic hair is often analyzed as an alternative to scalp hair to prove previous drug use. However, urine is a potential source of external contamination. In the present study, the concentrations of methamphetamine (MA) and amphetamine (AP) in both scalp and pubic hair from illegal MA users were compared. Furthermore, in order to investigate the external(More)
The measurement uncertainties (MUs) were estimated for the determination of methamphetamine (MA) and its main metabolite, amphetamine (AP) at the low concentrations (around the cut-off value of MA) in human hair according to the recommendations of the EURACHEM/CITAC Guide and "Guide to the expression of uncertainty in measurement (GUM)". MA and AP were(More)
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