• Analytical Science and Technology
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• v.5 no.2
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• pp.229-234
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• 1992

Stable Isotope Mass Spectrometric technique was studied for quality assessment of Korean Honey and compared with the current regulation for the feasibility of adaptation to the regulation.

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.414-416
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• 1999

A shkionin derivative was isolated from the roots of Lithospermum erythrorhizon with silica gel column chromatography and preparative TLC. The structure of the isolated pigment was identified as propionylshikonin by NMR and mass spectrometric analysis. The isolation of propionylshiknin was for the first time in the nature.

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.282.2-282.2
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• 2001

• Mass Spectrometry Letters
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• v.3 no.1
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• pp.25-28
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• 2012

Paint Spray is developed as a direct sampling ionisation method for mass spectrometric analysis of additives in polymer-based surface coatings. The technique simply involves applying an external high voltage (5 kV) to the wetted sample placed in front of the mass spectrometer inlet and represents a much simpler ionisation technique compared to those currently available. The capabilities of Paint Spray are demonstrated herein with the detection of four commercially available hindered amine light stabilisers; TINUVIN${(R)}$770, TINUVIN${(R)}$292, TINUVIN${(R)}$123 and TINUVIN${(R)}$152 directly from thermoset polyester-based coil coatings. Paint Spray requires no sample preparation or pre-treatment and combined with its simplicity requiring no specialised equipment makes it ideal for use by non-specialists. The application of Paint Spray for industrial use has significant potential as sample collection from a coil coating production line and Paint Spray ionisation could enable fast quality control screening at high sensitivity.

• Nuclear Engineering and Technology
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• v.38 no.3
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• pp.301-310
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• 2006

Destructive methods were used for the burnup determination of U-Zr alloy nuclear fuel irradiated in the High-flux Advanced Neutron Application Reactor (HANARO) at KAERI. The dissolution rate of unirradiated U-Zr alloy fuel in $HNO_3$/HF mixtures was investigated for the experimental conditions of a different temperature, and initial concentrations of HF and $HNO_3$. The irradiated U-Zr alloy fuel specimen was dissolved in a mixed acid condition of 3 M HNO3 and 1 M HF at $90^{\circ}C$ for 8 hours under reflux. The total burnup was determined from measurement of the Nd isotope burnup monitors. The method includes U, Pu, $^{148}Nd,\;^P{145}Nd+^{146}Nd,\;^{144}Nd+^{143}Nd$ and total Nd isotopes determination by the isotope dilution mass spectrometric method (IDMS) using triple spikes $(^{233}U,\;^{242}Pu\;and\;^{150}Nd)$. The effective fission yield was calculated from the weighted fission yields averaged over the irradiation period. The results are compared with that obtained by the destructive -spectrometric measurement of the $^{137}Cs$ monitor.

• KSBB Journal
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• v.4 no.2
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• pp.118-122
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• 1989

From the on-line mass spectrometric analyese of the exhaust gaseous composition of fermentor and the material balance equations for oxygen and carbon dioxide, oxygen uptake rate (OUR) and carbon dioxide evolution rate (CER) were calculate using a personal computer (IBM PC-AT) interfaced to a quadrupole mass spectromter. The calculate OUR and CER were used for the indirect estimation of cell and substrate concentrations during the batch culture of Candida utilis. For the estimation of sustrate concentration, the yield model of Pirt was applied. It was found that the cell and substrate (glucose) concentration could be ssatisfactorily estimataed and the results showed the more accurate estimations of both fermentation state variables when OUR data were used than CER data.

• Mass Spectrometry Letters
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• v.12 no.3
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• pp.93-105
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• 2021

Exosomes have gained the attention of the scientific community because of their role in facilitating intercellular communication, which is critical in disease monitoring and drug delivery research. Exosome research has grown significantly in recent decades, with a focus on the development of various technologies for isolating and characterizing exosomes. Among these efforts is the use of matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS), which offers high-throughput direct analysis while also being cost and time effective. MALDI is used less frequently in exosome research than electrospray ionization due to the diverse population of extracellular vesicles and the impurity of isolated products, both of which necessitate chromatographic separation prior to MS analysis. However, MALDI-MS is a more appropriate instrument for the analytical approach to patient therapy, given it allows for fast and label-free analysis. There is a huge drive to explore MALDI-MS in exosome research because the technology holds great potential, most notably in biomarker discovery. With methods such as fingerprint analysis, OMICs profiling, and statistical analysis, the search for biomarkers could be much more efficient. In this review, we highlight the potential of MALDI-MS as a tool for investigating exosomes and some of the possible strategies that can be implemented based on prior research.

• Journal of Pharmaceutical Investigation
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• v.37 no.3
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• pp.179-186
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• 2007

A simple, sensitive and selective liquid chromatographic/tandem mass spectrometric method (LC-MS/MS) was developed and validated for doxifluridine and 5-fluorouracil (5-FU) quantification in dog heparinized plasma. Sample preparation was based on liquid-liquid extraction using a mixture of isopropanol/ethyl acetate (1/9 v/v) to extract doxifluridine, 5-FU and 5-chlorouracil (5-CU, an internal standard) from plasma. Chromatography was performed on a C-18 analytical column and the retention times were 2.7, 1.5 and 1.7 min for doxifluridine, 5-FU and 5-CU, respectively with shorter analysis time within 5 min than previously reported methods. The ionization was optimized using ESI negative mode and selectivity was achieved by tandem mass spectrometric analysis by multiple reaction monitoring (MRM) using the transformations of m/z 244.8>107.6, 129.0>42.0 and 144.9>42.1 for doxifluridine, 5-FU and 5-CU, respectively. The achieved low limit of quantification was 20.0 ng/mL and the assay exhibited linear range of 20-2000 ng/mL ($R^2>0.99957$ for doxifluridine and $R^2>0.99857$ for 5-FU), using $100{\mu}L$ of plasma. Accuracy and precision of quality control samples for both doxifluridine and 5-FU met KFDA and FDA Guidance criteria of 15% for accuracy with coefficients of variation less than 15%. This method demonstrated adequate sensitivity, specificity, accuracy, precision and stability to support the simultaneous analysis of doxifluridine and 5-FU in dog plasma samples in pharmacokinetic and bioequivalence studies.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1693-1698
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• 2012

A headspace gas chromatographic mass spectrometric (GC-MS) assay method was developed for the simultaneous determination of methyl tertiary butyl ether (MTBE), $tert$-butyl alcohol (TBA) and benzene, toluene, ethyl benzene and xylene (BTEX) in soil contaminated with gasoline. 2 g of soil sample were placed in a 10 mL headspace vial filled with 5 mL of phosphoric acid solution (pH 3) saturated with NaCl, and the solution was spiked with fluorobenzene as an internal standard and sealed with a cap. The vial was heated in a heating block for 40 min at $80^{\circ}C$. The detection limits of the assay were 0.08-0.12 ${\mu}g$/kg for the analytes. For five independent determinations at 10 and 50 ${\mu}g$/kg, the relative standard deviations were less than 10%. The method was used to analyze fifty six soil samples collected from various regions contaminated with gasoline in Korea. The developed method may be valuable for the monitoring of the analytes in soil.

• Analytical Science and Technology
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• v.24 no.6
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• pp.407-413
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• 2011

Over the last decade sophisticated and powerful microcapillary HPLC for proteomic analysis have been developed increasingly and interfaced with high resolution tandem mass spectrometers. Separation prior to mass spectrometric (MS) analysis removes impurities, and concentrates analytes in the narrow elution peaks, resulting in increased sensitivity of MS analysis. This review will focus on the recent advances of on-line highperformance separation techniques based on microfluidic chips for complex proteomic analysis.