• Journal of Ginseng Research
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• v.40 no.4
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• pp.382-394
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• 2016

Background: Ginsenosides are the characteristic and principal components which manifest a variety of the biological and pharmacological activities of the roots and rhizomes of Panax ginseng (GRR). This study was carried out to qualitatively and quantitatively determine the ginsenosides in the cultivated and forest GRR. Methods: A rapid and sensitive ultra-high-performance liquid chromatography coupled with diode-array detector and quadrupole/time of flight tandem mass spectrometry (UPLC-DAD-QTOF-MS/MS) was applied to the qualitative analysis of ginsenosides and a 4000 QTRAP triple quadrupole tandem mass spectrometer (HPLC-ESI-MS) was applied to quantitative analysis of 19 ginsenosides. Results: In the qualitative analysis, all ingredients were separated in 10 min. A total of 131 ginsenosides were detected in cultivated and forest GRR. The method for the quantitative determination was validated for linearity, precision, and limits of detection and quantification. 19 representative ginsenosides were quantitated. The total content of all 19 ginsenosides in the forest GRR were much higher than those in the cultivated GRR, and were increased with the growing ages. Conclusion: This newly developed analysis method could be applied to the quality assessment of GRR as well as the distinction between cultivated and forest GRR.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2425-2430
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• 2013

A simple, fast and robust analytical method was developed to determine imatinib in human plasma using liquid chromatography-tandem mass spectrometry with electrospray ionization in the positive ion mode. Imatinib and labeled internal standard were extracted from plasma with a simple protein precipitation. The chromatographic separation was performed using an isocratic elution of mobile phase involving 5.0 mM ammonium formate in water-5.0 mM ammonium formate in methanol (30:70, v/v) over 3.0 min on reversed-stationary phase. The detection was performed using a triple-quadrupole tandem mass spectrometer in multiple-reaction monitoring mode. The developed method was validated with lower limit of quantification of 10 ng/mL. The calibration curve was linear over 10-2000 ng/mL ($R^2$ > 0.99). The method validation parameters met the acceptance criteria. The spiked samples and standard solutions were stable under conditions for storage and handling. The reliable method was successfully applied to real sample analyses and thus a pharmacokinetic study in 27 healthy Korean male volunteers.

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.269-278
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• 2017

BACKGROUND: The objective of this study was to evaluate screening method of residual multi pesticides in dead birds by Orbitrap high resolution mass spectrometry (HRMS) to identify the cause of death for birds. METHODS AND RESULTS: Extraction and clean-up method of residual pesticides in liver of dead birds was used QuEChERS (Quick Easy Cheap Effective Rugged and Safe) and method validations was conducted using liquid chromatography and gas chroamtography with triple-quadrupole mass spectrometer (LC/MS/MS and GC/MS/MS) Also, we were evaluated screening method for the determination of residual pesticides in liver of dead birds by LC and GC Orbitrap Mass Spectrometry. Results of method validations, Correlation coefficients of the matrix matched calibration curves were >0.978, and the method detection limits (MDLs) and limits of quantitation (LOQ) were 2.8~72.1 ng/g (18.4 ng/g on average) and 9.0~230 ng/g (58.5 ng/g on average). The accuracy ranged from 69.1%to 130% (103% on average), and the precision values were less than 14.8%(3.8%on average). The screening of residual pesticides in liver of dead birds by LC and GC Orbitrap HRMS was detected monocrotophos, carbofuran, carbosulfan, deltametrin, benfuracarb, carbofuran, phosphamidon, prochloraz in investigated samples. CONCLUSION: This results showed that accurate mass were extraction of residual pesticides in dead birds by Orbitrap HRMS. It suggested that this screening method is applicable to the residual pesticide analysis for the cause of death as a main tool.

• Journal of Biomedical and Translational Research
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• v.19 no.4
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• pp.130-139
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• 2018

This study aimed to analyze a high-performance liquid chromatography (HPLC) separation using a pentafluorophenyl column of parent drug hydroxychloroquine (HCQ) and its active metabolite, desethylhydroxchloroquine (DHCQ) applying to determine bioequivalence of two different formulations administered to patients. A rapid, simple, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for bioanalysis of HCQ and its metabolite DHCQ in human whole blood using deuterium derivative $hydroxychloroquine-D_4$ as an internal standard (IS). A triple-quadrupole mass spectrometer was operated using electrospray ionization in multiple reaction monitoring (MRM) mode. Sample preparation involves a two-step precipitation of protein techniques. The removed protein blood samples were chromatographed on a pentafluorophenyl (PFP) column ($50mm{\times}4.6mm$, $2.6{\mu}m$) with a mobile phase (ammonium formate solution containing dilute formic acid) in an isocratic mode at a flow rate of 0.45 mL/min. The standard curves were found to be linear in the range of 2 - 500 ng/mL for HCQ; 2 - 2,000 ng/mL for DHCQ in spite of lacking a highly sensitive MS spectrometry system. Results of intra- and inter-day precision and accuracy were within acceptable limits. A run time of 2.2 min for HCQ and 2.03 min for DHCQ in blood sample facilitated the analysis of more than 300 human whole blood samples per day. Taken together, we concluded that the assay developed herein represents a highly qualified technology for the quantification of HCQ in human whole blood for a parallel design bioequivalence study in a healthy male.

• Journal of the Korean Society of Tobacco Science
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• v.33 no.1
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• pp.21-27
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• 2011

Amadori compounds(1-deoxy-1-amino-2-ketoses) are important precursors of color, flavor and aroma produced in foods. Amadori compounds occur naturally in tobacco. The contribution of amadori compounds to smoke quality has been (of) interest because of their roles of the Maillard reaction in the leaf chemistry. The amounts of these compound in tobacco are affected by the processes of aging, drying and storage conditions. In this study, eight compounds were chemically synthesized because amadori compounds (have not been sold commercially these days.) were not available for obtaining commercially. The aim of this study was to develop the analytical method of amadori compounds in tobacco leaf by the liquid chromatography mass spectrometry using triple quadrupole analyzer(LC-MS/MS). This method was simple, rapid, selective and sensitive, and eight amadori compounds were simultaneously and quantitatively analyzed within 20 minutes. This method showed excellent accuracy and precision. Recovery rates of amadori compounds ranged from 86% to 102%, with relative standard deviation(RSD) ranged from 2.6% to 5.9%. This method was applied to analysis of amadori compounds contents of tobacco leaves in different varieties. Furthermore, it was expected that the method could be extended to the analysis of other amadori compounds.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.197-203
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• 2014

A rapid, accurate and precise method for the determination of 22 amino acids in Isatidis Radix by Hydrophilic Interaction Ultra-High-Performance Liquid Chromatography Coupled with Triple-Quadrupole Mass Spectrometry (HILIC-UPLC-MS/MS) was established. Chromatographic separation was carried out on a Acquity UPLC BEH Amide column ($2.1mm{\times}100mm$, $1.7{\mu}m$) with gradient elution of acetonitrile (containing 0.05% formic acid and 2 mM ammonium formate) and water (containing 0.15% formic acid and 10 mM ammonium formate) at a flow rate of 0.4 mL/min; Waters Xevo$^{TM}$ TQ worked in multiple reaction monitoring mode. All components were separated in 17 min. All calibration curves were linear ($R^2$ > 0.991) over the tested ranges. The limits of detection (LOD) and limits of quantitation (LOQ) for these compounds were 0.21-79.55 and 0.72-294.23 ng/mL, respectively. The average recoveries were in the range of 93.75-104.16% with RSD value less than 6.56%. Therefore, this method could be an alternative assay for the determination of 22 amino acids in Isatidis Radix due to its rapidness, sensitivity, less sample and solvent consumption.

• Parasites, Hosts and Diseases
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• v.56 no.6
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• pp.553-558
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• 2018

Pathogenic Acanthamoeba spp. cause granulomatous amoebic encephalitis and keratitis. Acanthamoeba keratitis (AK) is a rare but serious ocular infection that can result in permanent visual impairment or blindness. However, pathogenic factors of AK remain unclear and treatment for AK is arduous. Expression levels of proteins secreted into extracellular space were compared between A. castellanii pathogenic (ACP) and non-pathogenic strains. Two-dimensional polyacrylamide gel electrophoresis revealed 123 differentially expressed proteins, including 34 increased proteins, 7 qualitative increased proteins, 65 decreased proteins, and 17 qualitative decreased proteins in ACP strain. Twenty protein spots with greater than 5-fold increase in ACP strain were analyzed by liquid chromatography triple quadrupole mass spectrometry. These proteins showed similarity each to inosine-uridine preferring nucleoside hydrolase, carboxylesterase, oxygen-dependent choline dehydrogenase, periplasmic-binding protein proteinases and hypothetical proteins. These proteins expressed higher in ACP may provide some information to understand pathogenicity of Acanthamoeba.

• Journal of Ginseng Research
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• v.46 no.2
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• pp.290-295
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• 2022

Background: Dried and red ginseng are well-known types of processed ginseng and are widely used as healthy food. The dried and red ginseng quality may vary with the storage period of raw ginseng. Therefore, herein, the effect of the storage period of fresh ginseng on processed ginseng quality was evaluated through multicomponent quantification with statistical analysis. Methods: A method based on ultrahigh performance liquid chromatography coupled to triple quadrupole mass spectrometry in multiple-reaction monitoring mode (UPLC-MRM-MS) was developed for quantitation of ginsenosides and oligosaccharides in dried and red ginseng. Principal component analysis and partial least squares discriminant analysis were conducted to evaluate the dynamic distributions of ginsenosides and oligosaccharides after different storage periods. Results: Eighteen PPD, PPT and OLE ginsenosides and nine reducing and nonreducing oligosaccharides were identified and quantified. With storage period extension, the ginsenoside content in the processed ginseng increased slightly in the first 2 weeks and decreased gradually in the following 9 weeks. The content of reducing oligosaccharides decreased continuously as storage time extending, while that of the nonreducing oligosaccharides increased. Chemical conversions occurred during storage, based on which potential chemical markers for the storage period evaluation of fresh ginseng were screened. Conclusion: According to ginsenoside and oligosaccharide distributions, it was found that the optimal storage period was 2 weeks and that the storage period of fresh ginseng should not exceed 4 weeks at 0 ℃. This study provides deep insights into the quality control of processed ginseng and comprehensive factors for storage of raw ginseng.

• Natural Product Sciences
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• v.28 no.4
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• pp.168-180
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• 2022

Ephedra is a genus of the Ephedraceae family and is found in temperate regions, such as Central Asia and Europe. Among the various ephedra species, Ma Huang (Ephedra herb) is derived from the aerial parts of Ephedra sinica S tapf, Ephedra equisetina Bunge, and Ephedra intermedia Schrenk & C.A. Mey. Ma Huang contains various ephedra alkaloids, including (-)-ephedrine, (+)-pseudoephedrine, (-)-norephedrine, (+)-norpseudoephedrine, (-)-methylephedrine, and (+)-methylpseudoephedrine, which are found naturally as single enantiomers, although they can be prepared as racemates. Although the use of Ma Huang in foods is prohibited in Korea, products containing Ma Huang can be imported, and so it is necessary to develop a suitable analytical technique for the detection of Ma Huang in foods. Herein, we report the development of analytical methods for the detection of ephedra alkaloids in products containing Ma Huang. Following sample purification by solid phase extraction, quantitative analysis was performed using ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS). Additionally, the enantiomers were successfully separated using HPLC-DAD. We successfully analyzed various food samples, where the ephedra alkaloids were qualitatively and quantitatively determined, and the enantiomers were separated. It is expected that these methods may contribute toward preventing the distribution of illegal products containing Ma Huang.

• Analytical Science and Technology
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• v.36 no.1
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• pp.22-31
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• 2023

As the use of e-liquid cigarettes is rapidly increasing worldwide, it multiplies the potential risk undisclosed to the health of non- and smokers. To reduce the hazard, each country has its own set of regulations for controlling e-liquids. In Korea, the narrow definition of tobacco makes it difficult and have been steadily occurring tax evasion exploiting the difference in natural and artificial nicotine. Therefore, it is very important to distinguish source of nicotine for their regulation. To find biochemical discriminant markers, this study established analysis methods based on high-performance liquid chromatography coupled with diode array detector (HPLC-DAD) and high-performance liquid chromatography coupled with triple Quadrupole mass spectrometry (HPLC-MS/MS) for nicotine enantiomers and tobacco alkaloids targeted using the difference in pathways of nicotine biosynthesis and chemical synthesis. The method was validated by experimenting linearity (R² > 0.999), recovery (80.99-108.41 %), accuracy (94.11-109.73 %) and precision (0.04-8.27 %). Then, the results for discrimination of the nicotine obtained from analysis of 65 commercial e-liquid products available in Korean market was evaluated. The method successfully applied to the e-liquids and one sample labelled 'synthetic nicotine' for tax exemption was found to contain a natural nicotine product. This method can be used to determine whether an e-liquid product uses natural or artificial nicotine and monitor non-taxable e-liquid products. The method is more scientific than the existing one, which relies only on field evidence.