• Mass Spectrometry Letters
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• 제4권4호
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• pp.83-86
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• 2013

A new interface for coupling CIEF and MS using a four-way cross has been developed in a single mechanical system. This new interface could be operated without the electric discontinuity and reinstallation of lines. Additionally, a bare fused silica capillary was facilitated as a spray needle to produce electrospray and to guide catholyte or sheath liquid. Focusing for CIEF was completed in a hanging droplet at the end of spray needle. This capillary spray needle also provided stable spray, enhanced the ionization efficiency and increased sensitivity. Results with carbonic anhydrase I showed that focusing and spraying were well completed with the new interface and the new spray needle.

• 분석과학
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• 제14권5호
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• pp.384-391
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• 2001

본 연구에서는 ESI-MS/MS를 이용해 혈액내에서 아실카르니틴과 아미노산을 신속하게 정량분석하는 방법을 개발하였다. 아실카르니틴과 아미노산은 3N butanolic hydrogen chloride를 사용하여 유도체화 과정을 거친 뒤 이중질량분석기로 분석하였다. 아실카르니틴은 precursor 85 ion scan을 사용하여 분석하였고, 아미노산들중 알라닌, 발린, 루신/이소루신, 메티오닌, 페닐알라닌, 타이로신, 아스파르트산, 글루탐산 등은 neutral loss 102 scan, 오르니틴과 시트롤린은 neutral loss 119 scan, 글리신은 neutral loss 56 scan, 아르기닌은 neutral loss 161 scan 그리고 아르기니노석시닉산은 product ion 459 scan을 사용하여 분석하였다. 이 방법은 일반적인 액체 크로마토그래피나 아미노산 분석기에 비해서 시료의 전처리가 비교적 간단하며, 높은 감도와 좋은 재현성을 보여주었다.

• Mass Spectrometry Letters
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• 제3권3호
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• pp.68-73
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• 2012

Fat malabsorption is an important cause of poor growth in infancy and childhood. Steatorrhea tests have been developed using various methods. Traditional measurements of stool fat, however, require large samples and it often takes as a week to complete the analysis. In this paper, a liquid chromatography-electrospray ionization/mass spectrometry (LC-ESI/MS) method was developed for simultaneous quantitative analysis of triacylglycerols, triolein, diolein and monoolein, in mouse feces. Moreover, the procedure was rapid, simple as well as compatible with LC-ESI/MS. Chloroform-isopropyl alcohol solution was used for fat-soluble sample extraction. After centrifugation and filtration, an analytical solution was prepared. Triolein, diolein and monoolein were separated using non-aqueous reversed-phase column with the mobile phase consisting of A (methanol) and B (acetone-isopropyl alcohol). The precision (% CV) and accuracy (% bias) of the assay were 3.8-14.7% and 85.2-114.9%, respectively. This method has been successfully applied to simultaneous determination of triolein, diolein and monoolein in feces from 30 mice. This method can therefore be applied to measure triacylglycerols in mouse feces accurately and precisely by LC-ESI/MS, thereby helping to predictive biomarker in fat malabsorption and diagnostic research.

• 생약학회지
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• 제43권2호
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• pp.137-146
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• 2012

Dipsaci Radix (Dipsacaceae) has been used as a tonic, an analgesic, anti-inflammatory and anti-complement agents in traditional herbal medicine for the therapy of low back pain, knee pain, rheumatic arthritis, traumatic hematoma, and bone fractures. A high-performance liquid chromatography-electrospray ionization-mass spectrometric method (HPLC-ESI-MS) was developed for the simultaneous quantitation method of the five compounds from the herbal drug: asperosaponin VI and asperosaponin XII (terpene glycosides), sweroside, loganin and dipsacus A(iridoid glycosides). HPLC separation of the analytes was achieved on a C18 column ($150{\times}2.0$ mm i.d., 5 ${\mu}m$) using the aqueous methanol containing 5 mM ammonium acetate with gradient flow of the mobile phase. Detection of the analytes was performed by positive ion electrospray ionization, and selected ion monitoring was used for data acquisition using m/z corresponding molecular adduct ion, $[M+NH_4]^+$ and $[M+H]^+$. Calibration graphs showed good linearity ($r^2$=0.9997) over the wide range of the analytes; intra- and inter-day precisions (RSD, %) were within 9.1% and the accuracy between 94.0-111.0%. Recoveries of the analytes through the assay procedure were in the range of 93.7-110.8%. Analytical results of the herbal drugs of Dipsaci Radix (17 samples) show wide distribution of the five marker compounds and clear difference of the species from Phlomidis Radix (4 samples). The developed method would provide a practical guide for the quality control of the herbal drug.

• Archives of Pharmacal Research
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• 제22권2호
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• pp.189-193
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• 1999

Reversed-phase high-performance liquid chromatography/mass spectrometry (HPLC/MS) with an eletcrospray ionization (ESI) interface was applied to the identification of metabolites of IY81149 in the rat plasma. Fragments obtained using collision-induced dissociation (CID) in both positive and negative modes were utilized to elucidate the structure of metabolites. The eluent from the conventional HPLC column was split and directly introduced into an ESI-mass spectrometer for the identification of the structures. the CID technique allowed the sensitive identification of sulfonyl-IY81149 and hydroxy-IY81149 from the rat plasma.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1339-1342
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• 2010

$^{31}P$ NMR and ESI-MS studies of $Cu^{2+}$ binding to Fenitrothion (FN) were performed by experimentally and theoretically. The calculated $^{31}P$ NMR chemical shifts for FN-$Cu^{2+}$ complexes are in good agreement with experimental chemical shifts in order, and the results present an important information for organophosphorus pesticide metal complexes. ESI-MS and low energy CID MS/MS experiments of FN-$Cu^{2+}$ complexes combined with accurate mass measurements give insight into the metal localization and allow unambiguous identification of fragments and hydrolysis products.

• 한국식품위생안전성학회지
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• 제32권2호
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• pp.89-95
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• 2017

에너지 음료는 카페인을 주성분으로 타우린, 비타민 같은 다른 energy-enhancing 성분을 함유하고 있다. 미국과 유럽에서는 글루쿠로노락톤이 에너지 음료에 첨가될수 있으나, 국내에서 의약품으로는 허가되어 있다. 따라서 식품 첨가물로는 그 사용이 금지 되어 있어, 지속적으로 수입 및 유통 음료에서 시험검사를 하여 규제하고 있다. 현재 분석법으로 사용하는 LC-PDA 법은 복잡한 유도체화 과정을 거치고, 음료 중에 당류들이 위양성 결과를 나타내기도 한다. 이런 기존 방법의 단점을 개선하기 위해 HILIC-ESI-MS/MS(hydrophilic interaction liquid chromatography coupled to electrospray ionization tandem mass spectrometry)를 이용한 분석법을 개발하고, 선택성, 직선성, 검출한계, 정량한계, 정밀도, 정확성, 재현성에 대하여 분석법 유효성 검증을 수행했고, AOAC, EURACHEM 가이드라인에 부합되는 결과를 얻었다.

• Journal of Microbiology and Biotechnology
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• 제20권6호
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• pp.959-967
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• 2010

Down syndrome (DS) is an abnormality of the 21st chromosome that commonly occurs in children born to older women. Thus, amniotic fluid (AF) is usually collected from such women for prenatal diagnosis. This study analyzed human AF supernatants (AFS) using a mass spectrometric (MS) approach to search for candidate biomarkers of a DS pregnancy. The AFS were collected from older pregnant women at weeks 16-18 of their gestation by amniocentesis for cytogenetic analysis. The AFS from the pregnancies carrying DS (n=4) or chromosomally normal (n=6) fetuses, as revealed by the cytogenetic analysis, were then subjected to global protein profiling based on liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Affinity chromatography was also applied prior to the LC-ESI-MS/MS to minimize the masking effect of highly abundant albumin and immunoglobulin and thereby increase the diversity of the identified proteins. As a result, at least 30 new AFS proteins were identified and 44 AFS proteins were found to be differentially expressed between the DS and normal cases, where 6 of the proteins were unique to the DS cases and 11 were unique to the chromosomally normal cases. In addition, in the DS cases, 19 AFS proteins were downregulated and 8 were upregulated to varying degrees. A Western blot analysis confirmed the LC-ESI-MS/MS data, indicating that the combined detection of apolipoprotein A-II (apoA-II) and alpha-fetoprotein (AFP) could be a potential tool for diagnosing DS cases.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2010년도 정기총회 및 춘계학술발표회
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• pp.18-18
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• 2010

Glucosinolates(GSLs) are major secondary products($\beta$-thioglucoside N-hydroxysulfates) containing sulfates that are found mainly in Cruciferae family such as cabbage, broccoli, radish, turnip, kale, mustard and rapeseed as the important crops in agronomic and economic aspects. Especially, isothiocyanates(ITCs) have been shown to inhibit carcinogenesis with regulation cancer cell development followed by regulating target enzymes, inducing cell cycle arrest and apoptosis against various human cancer cell lines. Total desulfo(DS)-GSLs of nine type in 210 Korean leaf mustard accessions were isolated and confirmed using electrospray ionization mass spectrometric(ESI-MS/MS) method and DS-GSLs powerful library maked from several reference data. The isolated individual DS-GSLs were identified by removed $\beta$-D-glucopyranose residue ($C_6H_{11}O_5$, MW 163) from MS/MS data. Among them sinigrin(41.7%), glucoiberverin(21.7%) and gluconasturtiin(12.6%) were major components, Especially, despite gluconapin was minor component, accession K046197-1 and K046197-2 showed higher content of 4.11 and 3.31 mg/g(DW), respectively. The total GSLs contents in 210 accessions were ranged from 5.3 to 23.2 mg/g(DW) with a mean value of 13.0 mg/g(DW). As a result of principal component analysis(PCA), the individual GSLs loading plots were composed of three groups and components belonged to each group showed correlationship in quantitative pattern.

• 생약학회지
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• 제43권1호
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• pp.10-15
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• 2012

An accurate and sensitive analysis method was established for simultaneous determination of three bioactive compounds (glycyrrhizin, 6-gingerol and ginsenoside Rg3) in the Ejung Tang with high-performance liquid chromatography (HPLC)-photodiode array detection (DAD)-electrospray ionization (ESI)-Mass spectrometry (MS). The optimizing chromatographic separations a were acquired by an $C_{18}$ column ($5{\mu}m$, $4.6I.D{\times}250mm$, SHISHEDO) using gradient elution with water comprising 0.1% TFA(trifluoroacetic acid) and acetonitrile at a performing temperature of $35^{\circ}C$. Flow rate was 1.0 ml/min. A detection UV wavelength set at 205 nm and 250 nm. The three compounds were identified by electrospray ionization mass spectrometry. All calibration curves indicated great linear regression within test ranges ($R^2>0.9997$). The established method provided acceptable precision and accuracy. The relative standard deviations (RSDs) of intra-day and inter-day were less than 2.00% and 3.00%, respectively. The recoveries were found to range from 94.49 to 101.10% for the three compounds analyzed. These results showed that this method was effective and reliable for quality control of Eiung-Tang.