Talanta
January 15, 2008
Bo-Hong Chen, Ju-Tsung Liu, Wen-Xiong Chen et al.
32 citations
Mass spectrometry methods—GC-EI/MS, LC-ESI/MS, and MALDI/TOFMS—were compared for analyzing 13 tryptamine and phenethylamine compounds, including AMT, DMT, 5-MeO-AMT, DET, DPT, DBT, DIPT, 5-MeO-DMT, 5-MeO-DIPT, methamphetamine, 3,4-MDA, 3,4-MDMA, and MBDB. Parent ions were difficult to obtain by GC/MS, but protonated molecular ions were clearly observed by ESI/MS and MALDI/TOFMS. Two major characteristic fragmentations occurred: alpha-cleavage (producing [3-vinylindole]+) and beta-cleavage (producing [CH2N(+)R(N1)R(N2)]). With ESI, alpha-cleavage was the major process; with MALDI, beta-cleavage dominated. The ionization efficiency and fragments from either cleavage depended on the degree of alkylation of the side chain nitrogen.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences
December 25, 2003
Li-Chan Lin, Ju-Tsung Liu, Shiu-Huey Chou et al.
29 citations
A gas chromatography-mass spectrometry method identified four metabolites of the psychoactive compound 2C-T-2 in rat urine after a single 20 mg/kg dose. The metabolites included 2-(4-ethylthio-2,5-dimethoxyphenyl)-ethanol, 4-ethylthio-2,5-dimethoxyphenyl acetic acid, and two isomeric acetamido metabolites. Based on these findings, a metabolic pathway for 2C-T-2 in rats is proposed.
Electrophoresis
March 1, 2003
Ching Fang, Ju-Tsung Liu, S.‐s. Chou et al.
27 citations
Capillary electrophoresis combined with fluorescence spectroscopy, using sodium dodecyl sulfate as a surfactant, separates and concentrates lysergic acid diethylamide (LSD) in mouse blood. Two on-line concentration techniques—sweeping micellar electrokinetic chromatography and cation-selective exhaustive injection-sweep-micellar electrokinetic chromatography—were optimized. In a test mouse fed 0.1 mg LSD (about one-tenth the LD50 value for a 20 g mouse), LSD concentrations of 120 ng/mL and 30 ng/mL were detected in blood at 20 and 60 minutes after ingestion, respectively.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences
November 25, 2004
Yu-Chih Chiu, Shiu-Huey Chou, Ju-Tsung Liu et al.
18 citations
Oral administration of 2,5-dimethoxy-4-ethylthiophenethylamine (2C-T-2) to mice decreased nitric oxide (NO) production by T and B lymphocytes in the spleen and T cells in the thymus, suggesting the drug may weaken immune defense functions. In rats, the parent drug was detected in urine using capillary electrophoresis with UV absorbance. Without sample concentration, detection limits were 4.5 and 5.0 μg/mL; with stacking and sweeping-micellar electrokinetic chromatography, limits improved to 19.2 and 9.1 ng/mL. After intra-peritoneal injection of 20 μg/g body weight in three male rats, 2.9 μg/mL and 0.25 μg/mL of 2C-T-2 were found in first- and second-day urine fractions.
Journal of chromatography. A
February 15, 2008
Man-Juing Wang, Ju-Tsung Liu, Hung-Ming Chen et al.
12 citations
Nine tryptamines were compared using GC, HPLC, and CE separation techniques. GC/MS and LC/UV-absorption detection limits ranged from 0.5 to 15 µg/mL and 0.3 to 1.0 µg/mL, respectively. CZE/UV-absorption gave detection limits of 0.5–1 µg/mL, while sweeping-MEKC improved detection dramatically to 2–10 ng/mL. Migration times ranged from 11 to 15 minutes by GC, 8 to 23 minutes by HPLC, and 20 to 26 minutes by sweeping-MEKC. The migration order of DMT, DET, DPT, and DBT follows molecular weight, while the order for AMT, 5-MeO-AMT, DIPT, and 5-methoxy-tryptamines can be altered by changing separation conditions.
Journal of Separation Science
January 9, 2009
M Wang, Chih‐hsin Tsai, Wei‐ya Hsu et al.
11 citations
Optimal separation and online concentration methods for nine tryptamines, including DMT, AMT, and 5-MeO-DMT, were developed using micellar electrokinetic chromatography with UV detection. Limits of detection ranged from 1.0 to 1.8 μg/mL with standard MEKC, improved to 2.2–8.0 ng/mL using sweeping-MEKC, and further to 1.3–2.7 ng/mL using cation-selective exhaustive injection-sweep-MEKC. The migration order of the tryptamines was determined. A spiked human urine sample containing DMT was successfully analyzed, demonstrating practical applicability for drug testing.
Applied Sciences
June 22, 2018
Bo-Hong Chen, Ju-Tsung Liu, Hung-Ming Chen et al.
10 citations
Three analytical methods—matrix-assisted laser desorption/time-of-flight mass spectrometry, gas chromatography–electron ionization–mass spectrometry, and liquid chromatography–electrospray ionization/mass spectrometry—were compared for characterizing 20 phenethylamine and tryptamine standards. For GC-EI/MS, three characteristic peaks (the molecular ion and fragments from Cβ-Cα bond breakage) uniquely identified 2C series compounds. For ESI/MS and MALDI/TOFMS, the protonated molecular ion and fragments from α-cleavage and β-cleavage provided useful information for rapid screening and confirmation of phenethylamine and tryptamine derivatives. The assay successfully determined samples containing illicit drugs.