• Korean Journal of Pharmacognosy
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• v.1 no.1
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• pp.35-37
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• 1970

The methanol extract of two kinds of liquorice on Korean market was examined for basic components by a general alkaloid extraction method. The hydrochloride of the components gave all positive reactions to five coloration and precipitation tests. Four coloration tests on the thin-layer chromatograms of the free bases showed three to five spots which are considered to be basic.

• Bulletin of the Korean Chemical Society
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• v.10 no.2
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• pp.196-200
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• 1989

Some s-triazine herbicides, namely simazine, atrazine, and propazine present as trace components in a complex mixture were analyzed by GC/MS and GC/MS/MS methods. Even though monitoring the molecular ions was the best in terms of sensitivity, adequate analysis could not be done when interfering species were present. When doubly charged ions which appeared at characteristic m/z values were monitored, chromatograms were rather free from interference. More importantly, selected reaction monitoring was found to provide a selective means of detection with general applicability.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.1
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• pp.17-26
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• 2013

Market available fermented indigo powders of Indian origin (FI1, FI2), Chinese origin (FC1, FC2), and raw indigo powders of Indian origin (R1, R2) were examined using TLC and HPLC analyses to investigate their pigment contents. TLC analysis gave $R_f$ values of 0.81 and 0.72 for blue and red pigments, respectively. All the powder products and the synthetic and natural indigo standards eluted at 6.9 min and 8.3 min in the HPLC chromatograms, and the peaks showed the ${\lambda}_{max}$ at 610nm and 542nm, representing indigotin and indirubin, respectively. The pigment content calculated based on the area of indigotin and indirubin peaks in the HPLC chromatograms showed that the indigotin content was higher in FC1 and FC2, while FI1 and FI2 had a higher indirubin content. The relative percentage of indirubin was the highest in R2, but the HPLC peak intensity was quite low. Despite the higher indigotin content in FC1 and FC2, cotton dyed with FI1 and FI2 (versus cotton dyed with FC1 and FC2) showed a higher blue (B) hue, the highest K/S values, and the highest antimicrobial effect.

• Mass Spectrometry Letters
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• v.11 no.2
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• pp.36-40
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• 2020

Untargeted metabolomics is a useful tool for drug development focusing on novel chemotherapeutic and chemopreventative agents against cancer cells. In recent years, quadrupole time of flight liquid chromatography-mass spectrometry (Q-TOF LC/MS)-based untargeted metabolomic approaches have gained importance to evaluate the effect of these agents at the molecular level. The researchers working on cell culture studies still do not apply standardized methodologies on sample preparation for untargeted metabolomics approaches. In this study, the rough and wet lysis techniques performed on MCF-7 breast cancer cells were compared with each other via the Q-TOF LC/MS-based metabolomic approach. The C18 and hydrophilic interaction liquid chromatography (HILIC) columns were used for the separation of the metabolites in MCF-7 cell lysates. 505 peaks were detected through the HILIC column and 551 peaks were found through the C18 column for the wet lysis technique. This situation supported by the base peak chromatograms showed that the wet lysis technique allowed us to extract higher number of non-polar metabolites. Almost equal number of metabolites was found for the C18 and HILIC columns (697 peaks for the HILIC column and 695 peaks for the C18 column) when the rough lysis technique was used. However, the intensities of polar metabolites were higher for the rough lysis technique on base peak chromatograms for both the HILIC and C18 columns. Although cell lysis technique, which is the first step in the sample preparation for cell culture studies, does not cause dramatic differences in the number of the detected metabolite peaks, it affects the polar and non-polar metabolite ratio significantly. Therefore, it must be considered carefully especially for in vitro drug development studies.

• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.737-744
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• 2007

An isotope dilution-liquid chromatography/tandem mass spectrometric method was developed as a candidate reference method for the accurate determination of acrylamide in potato chips, starch-rich foodstuff cooked at high temperature. Sample was spiked with 13C3-acrylamide and then extracted with water. The extract was further cleaned up with an Oasis HLB solid-phase extraction (SPE) cartridge and an Oasis mixed-phase cation exchange (MCX) SPE cartridge. The extract was analyzed by using LC/ESI/Tandem MS in positive ion mode. LC with a medium reversed-phase (C4) column was optimized to obtain adequate chromatographic retention and separation of acrylamide. MS was operated to selectively monitor [M+H]+ ions of the analyte and its isotope analogue at m/z 72 and m/z 75, respectively. Sample was also analyzed by the LC/MS with selectively monitoring the collisionally induced dissociation channels of m/z 72 → m/z 55 and m/z 75 → 58. Compared to the LC/MS chromatograms, the LC/MS/MS chromatograms showed substantially reduced background chemical noises coming from solvent clusters formed during ESI spray processes and interferences from sample matrix. Repeatability and reproducibility studies showed that the LC/MS/MS method is a reliable and reproducible method which can provide a typical method precision of 1.0% while the LC/MS results are influenced by chemical interferences.

• Korean Journal of Oriental Medicine
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• v.1 no.1
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• pp.441-459
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• 1995

To study stability of distilled herbal medicine, we chose changes in UV spectrum, pH, conductivity, and HPLC chromatogram. Aconiti Lateralis preparata Radix and Scutellariae Radix were selected and studied. There ws no consistancy in UV spectrums of preparatons and in duration. The changes in pH and conductivity were not correlated to those in UV spectrums. HPLC chromatograms were also compared each other depending on the preparations. One interesting peak of distilled Aconiti solution was appeared at 40 min retention time which was not identified yet. Ingeneral, UV spectrum, pH, conductivity measurements are pretty poor tool to study stability of herbal medicine although HPLC analysis should be studied further.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.6
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• pp.828-835
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• 2014

GC-TSQ CI technique was applied for analysis of samples for the $32^{nd}$ OPCW proficiency test. Eight chemical weapon convention(CWC) related chemicals were identified by product ion mode analysis with GC-TSQ in the samples. Choice of specific precursor ion made it possible to supply selective total ion chromatograms(TICs) of target molecule. GC-TSQ CI anaylsis technique was useful method for chemical warfare agent verification because analysis selectivity was improved by choice of mother molecule as precursor ion and gave mass spectra.

• Journal of Environmental Health Sciences
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• v.2 no.1
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• pp.5-9
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• 1975

For analysis of Xanthene dyes according to the developing solvent and adsorbent was applied to Thin-layer chromatography with silicagel and cellulose plate. Silicagel chromato-plate used were prepared under different condition of activation. Using eight developing solvent, the influence of the condition for activation upon the separation of Xanthene dyes was investigated. The results are shown in Table 3. Methyl ethyl ketone+Acetone+$H_2O$ (10:0.1:0.4) mixture and n-butanol+Ammonia water (4:1) mixture gave clear separation for Xanthene dyes, including Fluorescein, Erythrosine Rhodamin B, Eosine, Rose bengale, phloxine and Acid red those Rf values decrease in the described ordor. Methyl ethyl ketone+Acetone+$H_2O$ (10:0.1:0.4) was applied to two adsorbents which were purchased from different manufactures. The results of Chromatograms are obtained Figure 6.

• International Journal of Automotive Technology
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• v.6 no.3
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• pp.197-203
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• 2005

This paper investigates the effect of oxygen composition in mixed fuel on the exhaust emissions for the direct injection diesel engine. These effects were tested to estimate the change in engine performance and exhaust emission characteristics when commercial diesel fuel and oxygenates blended fuels at a certain fuel and mixed ratio are used. Individual hydrocarbons $(C_1-C_6)$ in exhaust gases, as well as the total amount of hydrocarbons, were analyzed by using gas chromatography to find the mechanism by which smoke emission was remarkably reduced for various oxygenated fuels. The chromatograms between a diesel fuel and a diesel fuel blended DGM (diethylene glycol dimethyl ether), MTBE (methyl tert-butyl ether) and EGBE (ethylene glycol mono-n-butyl ether) were compared. The results showed that the number of individual hydrocarbons as well as the total number of hydrocarbons of oxygenated fuel reduced more remarkably than those of diesel fuel.

• 한국해양학회지
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• v.20 no.1
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• pp.74-82
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• 1985

Exposed on the sea, the oils are affected by the combined effects of evaporation, solution, chemical oxidation, and biological decomposition. Therefore the samples were taken after artificial weathering, and they were analyzed by gas chromatography for sulfur and hydrocarbons. The measurement results of gas chromatography have shown characteristic patterns. The peaks of the lower hydrocarbons in pollutant oil decreased with time. But the chromatograms for sulfur compound analysed by FPD showed little changes with lapse of time. The hydrocarbon and sulfur compound analysis by gas chromatography can be effectively used for analyzing oils for comparative identification.