Seocho Gu, South Korea
Seocho Gu, South Korea

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Jin M.J.,Korea Institute of Science and Technology | Jin C.,Korea Institute of Science and Technology | Kim J.Y.,Drug Analysis Laboratory | In M.K.,Drug Analysis Laboratory | And 2 more authors.
Journal of Forensic Sciences | Year: 2011

5-Methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT) is a designer hallucinogen derived from tryptamine and is reportedly abused and involved in criminal activities. For the detection of 5-MeO-DIPT use, a liquid chromatography-tandem mass spectrometric method for 5-MeO-DIPT and its metabolites, 5-hydroxy-N,N-diisopropyltryptamine (5-OH-DIPT) and 5-methoxy-N,N-isopropyltryptamine (5-MeO-IPT) was developed and validated in rat urine. The urine samples were pretreated by protein precipitation with acetonitrile and introduced into a BDS HYPERSIL C 18 column (50×2.0mm, 5μm) for chromatographic separation. Mobile phases consisted of methanol, water, and 1% formic acid, and gradient elution was used at a flow rate of 0.2mL/min. For the MS detection, multiple-reaction monitoring analysis was adopted. The linear range was 0.01-10μg/mL, and the lower limit of quantification was 10ng/mL for all analytes. The intra- and interday accuracies and precisions met the criteria (<15%). The developed method was successfully applied to the drug-treated rat urine. © 2011 American Academy of Forensic Sciences.


Jin M.J.,Korea Institute of Science and Technology | Jin M.J.,Hanyang University | Lee J.,Korea Institute of Science and Technology | In M.K.,Drug Analysis Laboratory | And 2 more authors.
Journal of Forensic Sciences | Year: 2013

CP 47,497, a potent cannabinoid receptor type 1 agonist, is the main active ingredient in the herbal mixture "Spice" sold in European countries. The illegal use of "Spice" for its psychoactive effects has become a social issue. In this study, the in vitro metabolism of CP 47,497 was investigated in human liver microsomes to characterize the metabolic fate of CP 47,497. CP 47,497 was incubated with human liver microsomes, and the reaction mixture was analyzed using liquid chromatography-tandem mass spectrometry. A total of eight metabolites were detected in human liver microsomes and structurally characterized based on mass spectral data. The main metabolic pathways involved hydroxylations or oxygenations. The identified metabolites were mono-oxygenated metabolites (M1 and M4), mono-hydroxylated metabolites (M3, M5, M6, M7, and M8), and a di-oxygenated metabolite (M2). The detection of these metabolites could confirm the presence of CP 47,497 in biological samples; therefore, collectively, they would be excellent indicators of "Spice" drug abuse. © 2012 American Academy of Forensic Sciences.


Cheong J.C.,Drug Analysis Laboratory | Cheong J.C.,Inha University | Suh S.I.,Drug Analysis Laboratory | Ko B.J.,Drug Analysis Laboratory | And 3 more authors.
Journal of Separation Science | Year: 2010

A simple and rapid GC-MS method has been developed for the screening and quantifi-cation of many illicit drugs and their metabolites in human urine by using automatic SPE and trimethylsilylation. Sixty illicit drugs, including parent drugs and their metabolites that are possibly abused in Korea, can be monitored by this method. Among them, 24 popularly abused illicit drugs were selected for quantification. Very delicate optimizations were carried out in SPE, trimethylsilylation derivatization, and GC/MS to enable such remarkable achievements. Trimethylsilylated analytes were well separated within 21 min by GC-MS. In the validation results, the LOD of all the analytes were in the range of 2-75 ng/mL. The LOQ of the quantified analytes were in the range of 5-98 ng/mL. The linearity (r2) of the quantified analytes ranged 0.990-1.000 in each concentration range between 10 and 1000 ng/mL. The mean recoveries ranged from 62 to 126% at three different concentrations of each analyte. The inter-day and inter-person accuracies were within -13.3-14.9%, and -10.1-13.0%, respectively, and the inter-day and inter-person precisions were less than 12.9%. The method was reliable and efficient for the screening and quantification of abused illicit drugs in routine urine analysis. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.


Kim S.Y.,Yonsei University | Kim J.Y.,Drug Analysis Laboratory | Kwon W.,Drug Analysis Laboratory | In M.K.,Drug Analysis Laboratory | And 2 more authors.
Microchemical Journal | Year: 2013

In this study, the method for simultaneous determination of amphetamine-type stimulant drugs and cannabinoids using GC-MS was developed for urinalysis. For the improvement of analytical efficiency, tri-fluoroacetic anhydride and pentafluoropropanol were used as derivatization reagents and derivatization conditions such as compositions, reaction time, and temperature were optimized. Also metabolically generated glucuronides such as 11-nor-9-carboxy-δ9-tetrahydrocannabinol were removed through alkaline hydrolysis. The extraction method was optimized by changing the pH of urine and extraction time. The limit of detection (LOD) was 0.49-1.71ng/mL as 3 signal-to-noises (s/n) whereas the limit of quantification (LOQ) of 10 s/n was 1.62-5.70ng/mL. Repeatability and reproducibility were obtained as inter-day (n=5), intra-day (n=3), and inter-person (n=3). The measured accuracy ranged as inter-day: -9.0-9.1%, intra-day: -10.2-12.6%, and inter-person: -12.9-8.2%, and the precisions were estimated as inter-day: 0.5-16.1%, intra-day: 2.1-14.2%, and inter-person: 0.8-19.3%. This method was also successfully applied to real samples. © 2013 Elsevier B.V.


Kim J.Y.,Drug Analysis Laboratory | Shin S.H.,Drug Analysis Laboratory | In M.K.,Drug Analysis Laboratory
Forensic Science International | Year: 2010

A gas chromatography-mass spectrometry (GC-MS) method was developed and validated for the simultaneous qualification and quantification of methamphetamine (MA), amphetamine (AP), 3,4-methylenedioxy-N-methylamphetamine (MDMA), 3,4-methylenedioxy-N-amphetamine (MDA), ketamine (KET) and norketamine (NKT) in fingernails. Fingernail samples (20 mg) were washed with distilled water and methanol, digested with 1.0 M sodium hydroxide at 95 °C for 30 min, and then extracted with ethyl acetate. Extract solutions were evaporated to dryness, derivatized using heptafluorobutyric anhydride (HFBA) at 60 °C for 30 min, and analyzed by GC-MS. The linear ranges were 0.1-20.0 ng/mg for AP, MDMA and NKT, 0.2-20.0 ng/mg for MA and MDA, and 0.4-20.0 ng/mg for KET, with the coefficients of determination (r2 ≥ 0.9989). The intra- and inter-day precisions were within 7.1% and 10.6%, respectively. The intra- and inter-day accuracies were -10.9% to 0.8% and -4.3% to 4.5%, respectively. The limits of detections (LODs) and the limits of quantifications (LOQs) for each analyte were lower than 0.094 ng/mg and 0.314 ng/mg, respectively. The recoveries were in the range of 72.3-94.9%. The average fingernail growth rates of two subjects for three years and six subjects for two months were 3.12 mm/month and 3.16 mm/month, respectively. The method proved to be suitable also for the simultaneous detection and quantification of MA, MDMA, KET and their metabolites in fingernails. © 2009 Elsevier Ireland Ltd. All rights reserved.


Kwon W.,Drug Analysis Laboratory | Kim J.Y.,Drug Analysis Laboratory | Suh S.,Drug Analysis Laboratory | In M.K.,Drug Analysis Laboratory
Biomedical Chromatography | Year: 2013

A direct injection liquid chromatography-electrospray ionization-tandem mass spectrometric method (LC-ESI-MS/MS) was developed and validated for the rapid and simple determination of 13 phenylalkylamine derivatives. Eight deuterium-labeled compounds were prepared for use as internal standards (ISs) to quantify the analytes. Urine samples mixed with ISs were centrifuged, filtered through 0.22μm filters and then injected directly into the LC-ESI-MS/MS system. The mobile phase was composed of 0.2% formic acid and 2mM ammonium formate in distilled water and 0.2% formic acid and 2mM ammonium formate in acetonitrile. The analytical column was a Capcell Pak MG-II C18 (150×2.0mm i.d., 5μm, Shiseido). Separation and detection of the analytes were accomplished within 10min. The linear ranges were 5-750ng/mL (ephedrine and fenfluramine), 10-750ng/mL (3,4-methylenedioxyamphetamine, phendimetrazine, methamphetamine, 3,4-methylenedioxyethylamphetamine and benzphetamine), 20-750ng/mL (norephedrine, amphetamine, phentermine and ketamine) and 30-1000ng/mL (3,4-methylenedioxymethamphetamine and norketamine), with determination coefficients, R2, ≥ 0.9967. The intra-day and inter-day precisions were within 19.1%. The intra-day and inter-day accuracies ranged from -16.0 to 18.7%. The lower limits of quantification for all the analytes were lower than 26.5ng/mL. The applicability of the method was examined by analyzing urine samples from drug abusers (n=30). © 2012 John Wiley & Sons, Ltd.


Kim J.Y.,Drug Analysis Laboratory | Cheong J.C.,Drug Analysis Laboratory | Lee J.I.,Drug Analysis Laboratory | In M.K.,Drug Analysis Laboratory
Forensic Science International | Year: 2011

A gas chromatography-negative ion chemical ionization tandem mass spectrometric (GC-NCI-MS/MS) method was developed and validated for the determination of 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) in human hair. After decontamination, hair samples were weighed (25mg), mechanically pulverized with a bead mill, and incubated in 0.7mL of 1.0M sodium hydroxide at 95°C for 30min. Bead-assisted liquid-liquid extraction was performed with n-hexane:ethyl acetate (9:1, v/v), a method developed in our laboratory. The extract was evaporated to dryness, derivatized with pentafluoropropanol and pentafluoropropionic anhydride, and analyzed by GC-MS/MS in the negative ion chemical ionization mode using methane as the reagent gas. The linear ranges were 0.05-10.0pg/mg for THC-COOH with the coefficient of determination (r2=0.9976). The intra-day and inter-day precisions were within 1.7 and 13.8%, respectively. The intra-day and inter-day accuracies were -4.8 to 10.0% and -3.9 to 3.8%, respectively. The limit of detection and quantification were 0.015 and 0.05pg/mg, respectively. The recoveries were in the range of 79.4-87.1%. The results indicate that the proposed method is simple, rapid, accurate, and precise for determination of THC-COOH in hair. The method identified THC-COOH in hair specimens from suspected marijuana abusers. © 2011.


Kwon W.,Drug Analysis Laboratory | Kim J.Y.,Drug Analysis Laboratory | Suh S.,Drug Analysis Laboratory | In M.K.,Drug Analysis Laboratory
Forensic Science International | Year: 2012

A simple liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated to simultaneously determine creatinine (Cr) and uric acid (UA) levels as a confirmatory method for adulteration or dilution of urine. Centrifuged urine samples (10μL) were diluted with 390μL of distilled water. 30μL of internal standard solution (Cr-d3, 5μg/mL) and 10μL of acetonitrile were added to 20μL aliquots of diluted urine samples and filtered. The samples (1μL) were introduced into LC-MS/MS with no further pretreatment. Cr and UA were separated on a multi-mode ODS column (Scherzo SM-C18, 75mm×2.0mm I.D., 3μm) and quantified by LC-MS/MS with polarity-switching electrospray ionization. Cr requires the positive-ion mode, whereas the negative-ion mode is required for the analysis of UA. The linear ranges were 1.0-300mg/dL for Cr and 0.5-300mg/dL for UA, with good determination coefficients (R2≥0.9988). The intra-day and inter-day precision of the analytes was within 13.0% and 14.4%, respectively. The intra-day and inter-day accuracy was -8.8 to 3.7% and -0.3 to 6.6%, respectively. The lower limits of detection (LLODs) were 0.3mg/dL for Cr and 0.07mg/dL for UA. The applicability of the developed method was examined by analyzing urine samples from suspected drug abusers (n=46). © 2012 Elsevier Ireland Ltd.


Kim U.,Korea Institute of Science and Technology | Kim U.,Chung - Ang University | Jin M.J.,Hanyang University | Lee J.,Korea Institute of Science and Technology | And 3 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2012

(6aR,10aR)-9-(Hydroxymethyl)-6,6-dimethyl-3-(2-methyloctan-2-yl)-6a,7,10,10a-tetrahydrobenzo[c]chromen-1-ol (HU-210) is a synthetic cannabinoid, with a classical cannabinoid structure similar to Δ 9-tetrahydrocannabinol (Δ 9-THC). In this study, the in vitro metabolism of HU-210 was investigated in human liver microsomes to characterize associated phase I metabolites. HU-210 was incubated with human liver microsomes, and the reaction mixture was analyzed using LC-MS/MS. HU-210 was metabolized in human liver microsomes, yielding about 24 metabolites. These metabolites were structurally characterized on the basis of accurate mass analyses and MS/MS fragmentation patterns. The major metabolic route for HU-210 was oxygenation. Metabolites M1-M7 were identified as mono-oxygenated metabolites; M8-M15, mono-hydroxylated metabolites; M16-M20, di-oxygenated metabolites; and M21-M24, di-hydroxylated metabolites. These results provide evidence for in vivo HU-210 metabolism, and they may be applied to the analysis of HU-210 and its relevant metabolites in biological samples. © 2012 Elsevier B.V.


Kim J.Y.,Drug Analysis Laboratory | Shin S.H.,Drug Analysis Laboratory | Lee J.I.,Drug Analysis Laboratory | In M.K.,Drug Analysis Laboratory
Forensic Science International | Year: 2010

A gas chromatography-mass spectrometric (GC-MS) method was developed and validated for the determination of five psychotropic phenylalkylamine derivatives (amphetamine, AP; methamphetamine, MA; 3,4-methylenedioxyamphetamine, MDA; 3,4-methylenedioxymethamphetamine, MDMA; norketamine, NKT) in human hair. Hair samples (10 mg) were washed with distilled water and acetone, mechanically pulverized for 1.5 min with a bead mill, and then incubated in 1 mL of methanol under ultrasonication at 50 °C for 1 h. The resulting solutions were evaporated to dryness, derivatized using heptafluorobutyric anhydride (HFBA) at 50 °C for 30 min, and analyzed by GC-MS. The linear ranges were 0.1-20.0 ng/mg for AP and MA and 0.05-20.0 ng/mg for MDA, MDMA, and NKT, with the coefficients of determination (r2 > 0.9982). The intra-day and inter-day precisions were within 11.5% and 12.8%, respectively. The intra-day and inter-day accuracies were -4.1% to 5.8% and -6.6% to 4.2%, respectively. The limits of detections (LODs) for each compound were lower than 0.028 ng/mg. The recoveries were in the range of 78.9-101.2%. Based on these results, the method proved to be effective for the rapid and simple determination of phenylalkylamine derivatives in hair specimens. © 2009 Elsevier Ireland Ltd. All rights reserved.

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