• Bulletin of the Korean Chemical Society
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• 제19권6호
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• pp.619-624
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• 1998

A simple and reproducible pretreatment method was developed for the determination of dioxins in milk sample. Liquid-liquid extraction (LLE) was used for the initial extraction of the analyte from milk. For the elimination of interferences coextracted from milk, acid treatment followed by multilayer silica gel, and then alumina column clean-up were performed. The clean extract could be obtained without carbon column or high performance liquid chromatographic (HPLC) clean-up procedure. Polychlorinated biphenyles (PCBS) and dioxins were separated on neutral alumina activated at 180 ℃ for 12 hours. The final extract was analyzed by HPLC and high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The recovery of dioxins spiked in milk at 75-300 ppt level was 83.3-98.9% and their relative standard deviation was 4.1-14%.

• 생명과학회지
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• 제22권11호
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• pp.1456-1462
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• 2012

소라페닙은 멀티카이네즈 억제제로서 신세포암, 전이성 간세포암 환자의 치료에 효과가 입증된 경구용 항암제이다. 이 연구의 목적은 고속액체크로마토그래피 텐덤질량분석기법(LC/MS/MS)을 이용하여 사람 혈장 내 소라페닙의 농도를 측정하는 효율적인 방법을 개발하고 한국식품의약품안전청(KFDA) 기준에 따라 분석법을 검정하는 것이다. 혈장시료($100{\mu}l$)에 내부표준물질인 chlorantraniliprole을 첨가한 후 이소프로필알콜과 에틸아세테이트로 구성(1:4, v/v)된 0.1% 포름산 함유 추출용액을 혼합하였다. 원심분리 후 상층액을 취하여 원심감압농축하였다. 잔사를 이동상에 재용해하고 Waters사의 역상 XTerra$^{TM}$ C18 칼럼(입자크기 $3.5{\mu}m$)을 장착한 고속액체크로마토그래피 장치에 주입하였다. 액체크로마토그래피는 0.1% 포름산과 10 mM 암모늄 포메이트를 함유한 버퍼용액과 메탄올, 아세토나이트릴을 각각 1:6:3으로 혼합한 용액을 이동상으로 사용하였으며 5분 내에 측정을 완료하였다. 분석대상 물질들은 텐덤질량분석기에서 electrospray 양이온 이온화($ES^+$) 검출방식으로 확인하였으며 소라페닙은 'm/z 465.2 ${\rightarrow}$ 252.5', chlorantraniliprole은 'm/z 484.4 ${\rightarrow}$ 286.2'으로 구성한 multiple reaction monitoring 방법을 사용하였다. 검정 결과, 2-5,000 ng/ml의 농도 구간에서 양호한 직선성($r^2$ > 0.99)과 정확도(90.7-103.9%), 정밀도(10% 이하)를 나타내었다. 새롭게 개발된 LC/MS/MS을 이용한 사람 혈장 내 소라페닙의 농도 측정법은 KFDA 기준을 만족하였으며, 기존의 방법에 비해 민감도가 높은 방법이었다.

• Mass Spectrometry Letters
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• 제3권3호
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• pp.78-81
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• 2012

The hydrophobic hydrocarbon chain and the polar sulfate group confer surfactant properties and enable them to be used as anionic surfactants. Anionic surfactants (AS) are known for their adverse impact on environment, particularly on aquatic ecosystem. In the present study a fast, sensitive and selective method for the determination and subsequent quantification of six anionic surfactants was developed using hydrophilic interactive liquid chromatography (HILIC) coupled to a electrospray ionization (ESI) mass spectrometer (MS), in the concentration range 15-20 ${\mu}g/L$. The capability of the method was established using regression analysis and ANOVA. The method performance was evaluated by analyzing real time surface water spiked with 1-dodecyl hydrogen sulfate at 15 ${\mu}g/L$. Combined efficiency of solid phase extraction and MS detection established recovery of 89% in presence of natural matrix. These results point out that HILIC coupled to multistage MS procedures can be a powerful technique for environmental applications concerning the screening of polar contaminants.

• Mass Spectrometry Letters
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• 제5권1호
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• pp.16-23
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• 2014

Liquid chromatography based mass spectrometry (LC-MS) is a key technology for analyzing highly complex and dynamic proteome samples. With highly accurate and sensitive LC-MS analysis of complex proteome samples, efficient data processing is another critical issue to obtain more information from LC-MS data. A typical proteomic data processing starts with protein database search engine which assigns peptide sequences to MS/MS spectra and finds proteins. Although several search engines, such as SEQUEST and MASCOT, have been widely used, there is no unique standard way to interpret MS/MS spectra of peptides. Each search engine has pros and cons depending on types of mass spectrometers and physicochemical properties of peptides. In this study, we describe a novel data process pipeline which identifies more peptides and proteins by correcting precursor ion mass numbers and unifying multi search engines results. The pipeline utilizes two open-source software, iPE-MMR for mass number correction, and iProphet to combine several search results. The integrated pipeline identified 25% more proteins in mouse epididymal adipose tissue compared with the conventional method. Also the pipeline was validated using control and colitis induced colon tissue. The results of the present study shows that the integrated pipeline can efficiently identify increased number of proteins compared to the conventional method which can be a breakthrough in identification of a potential biomarker candidate.

• 대한화학회지
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• 제60권2호
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• pp.118-124
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• 2016

파라벤은 화장품, 식품, 의약품 등에 첨가되는 살균성 보존제로 미생물의 성장을 억제한다. 그러나 체내에서 에스트로겐과 유사한 작용을 하는 내분비계 교란물질이며, 특히 독성물질에 민감한 영유아 및 태아에게 노출될 경우 생식기 기형, 고환암, 성조숙증 등 성장발달에 큰 영향을 미친다. 따라서 본 연구에서는 영아가 주로 섭취하는 모유에서의 파라벤 수준을 확인하기 위하여 모유 중 4가지 파라벤(methyl paraben, ethyl paraben, propyl parabne, butyl paraben)의 분석법을 확립하였다. 시료는 액체상추출(Liquid-liquid extraction, LLE)을 통하여 전처리 한 후, 액체크로마토그래피 텐덤 질량분석기(liquid chromatography tandem mass spectrometry, LC-MS/MS)를 사용하여 정량분석 하였다. 확립된 분석조건에서 얻어진 검량선의 직선성은 r² > 0.999이고, 검출한계(LOD)는 0.019~0.044 ng/mL이었다. 또한 정확도는 85.3~105.9%, 정밀도는 10% 이하의 값을 나타내었다. 10개의 모유시료 중 파라벤류의 평균농도 ± 표준편차는 MP 0.660 ± 0.519 ng/mL, EP 1.631 ± 2.081 ng/mL, PP 0.326 ± 0.320 ng/mL이었고, BP는 불검출 되었다.

• 분석과학
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• 제23권6호
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• pp.524-530
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• 2010

클로람페니콜은 미생물과 박테리아들의 활동을 억제시킴으로써 동물 치료에 효과적인 축산 항생제 중의 하나이다. 그러나 사람에게 재생 불량성 빈혈과 같은 치명적인 부작용이 발생하여 식용으로 사육하는 동물들에 대한 클로람페니콜의 사용을 유럽을 포함한 많은 나라에서 금지하였다. 본 연구에서는 돼지고기 시료 중 클로람페니콜을 분석하기 위하여 동위원소희석 액체크로마토그래피-질량분석법(IDLC/MS/MS)을 이용하여 정확하고 정밀한 정량분석을 하였다. 돼지고기 시료중의 클로람페니콜은 에틸아세테이트로 추출하였으며, 회수율을 높이기 위하여 고체상 추출법(Solid Phase Extraction)을 이용하였다. 액체크로마토그래피/질량분석기는 전기 분무 이온화 장치(Electrospray Ionization, ESI)를 장착하여 음이 온 모드로 선택반응분석법(Selected Reaction Monitoring mode)에서 수행하였다. 클로람페니콜의 분자이온 $[M-H]^-$이온이 조각이온인 $[M-H-(HCOCl)]^-$로 가는 m/z 321 ${\rightarrow}$ 257와 동위원소의 m/z 326 ${\rightarrow}$ 262 채널을 선택하여 분석하였다. 클로람페니콜을 약 0.2, 1, 10, $25\;{\mu}g$/kg의 농도가 되도록 첨가한 돼지고기 시료로부터 제조값과 측정 분석값을 비교하여 검토한 결과, 측정값들은 불확도 범위 내에서 제조값과 일치함을 보였다. 또한 IRMM(Institute for Reference Materials and Measurement)의 클로람페니콜 분석용 돼지고기 시료인 인증 표준물질 BCR 445를 분석한 결과, 본 실험의 측정값은 불확도 범위 내에서 인증값과 일치함을 보였으며 불확도의 경우에는 IRMM이 제공한 값보다 훨씬 향상된 값을 보였다.

• 분석과학
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• 제30권4호
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• pp.174-181
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• 2017

Bio-liquid is a liquid by-product of the hydrothermal carbonization (HTC) reaction, converting wet biomass into solid hydrochar, bio-liquid, and bio-gas. Since bio-liquid contains various compounds, it requires efficient sampling method to extract the target compounds from bio-liquid. In this research, fatty acid methyl ester (FAME) in bio-liquid was extracted based on hollow fiber supported liquid phase microextraction (HF-LPME) and determined by Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography/Mass Spectrometry (GC/MS). The well-known major components of biodiesel, including methyl myristate, palmitate, methyl palmitoleate, methyl stearate, methyl oleate, and methyl linoleate had been selected as standard materials for FAME analysis using HF-LPME. Physicochemical properties of bio-liquid was measured that the acidity was 3.30 (${\pm}0.01$) and the moisture content was 100.84 (${\pm}3.02$)%. The optimization of HF-LPME method had been investigated by varying the experimental parameters such as extraction solvent, extraction time, stirring speed, and the length of HF at the fixed concentration of NaCl salt. As a result, optimal conditions of HF-LPME for FAMEs were; n-octanol for extraction solvent, 30 min for extraction time, 1200 rpm for stirring speed, 20 mm for the HF length, and 0.5 w/v% for the concentration of NaCl. Validation of HF-LPME was performed with limit of detection (LOD), limit of quantitation (LOQ), dynamic range, reproducibility, and recovery. The results obtained from this study indicated that HF-LPME was suitable for the preconcentration method and the quantitative analysis to characterize FAMEs in bio-liquid generated from food waste via HTC reaction.

• Applied Biological Chemistry
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• 제35권1호
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• pp.55-63
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• 1992

봉동산 생강(Zingiber officinale Roscoe)의 정유성분조성을 분석코자 액체 이산화탄소 주출법으로 분리하여 silica gel column chromatography범에 의해 탄화수소 화합물 분획과 함산소 화합물 분획으로 분류한 다음 GC 및 GC-MS로 성분을 검토하였다. 추출물의 수율은 6.96%이었으며, SCC에 의해 분리된 분획의 분석결과 mass spectrum에 의해서 잠정적으로 확인된 58종을 포함하여 102종의 향기성분이 확인되었다. 중 탄화수소 화합물 분획에서는 zingiberene, ${\beta}-sesquiphellandrene,\;{\gamma}-bisabolene,\;{\gamma}-cadinene,\;ar-curcumene$ 등이 주성분이었고, 함산소 화합물 분획에서는 gernal, sesquisabinene hydrate, borneol, zingiberenol 등이 주성분 이었다. 총 essential oil의 조성은 $zingiberene,\;citronellol+{\beta}-sesquiphellandrene,\;geranial,\;{\gamma}-bisabolene,\;ar-curcumene+geranyl\;acetate$ 등이 주성분으로 sesquiterpene hydrocarbon의 함량이 높게 나타났다.

• Food Science and Biotechnology
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• 제18권5호
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• pp.1237-1242
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• 2009

Polymethoxylated flavones (PMFs) extracted from Citrus sinensis 'Jincheng' peel were characterized by chromatographic and spectroscopic techniques. Seven individual PMF were identified. 3, 3', 4', 5, 6, 7-hexamethoxyflavone (HEX), nobiletin (NOB), heptamethoxyflavone (HEP), 5-demethylnobiletin (DN), and tangeretin (TAN) were characterized through electrospray ionization mass spectrometry (ESI-MS) in positive mode of protonated molecular ions $[M+H]^+$, the diagnostic fragment ions, together with the UV-Vis spectra and high performance liquid chromatography (HPLC) elution order from literature data. Sinensetin (SIN) and tetramethyl-O-scutellarein (SCU) were isolated and identified through their MS, $^1H$ nuclear magnetic resonance (NMR) and UV-Vis spectral studies. The levels of PMFs in peels from different cultivars of citrus fruits grown in China were determined for the first time. The results showed that C. aurantium 'Bitter orange' peel was the most promising variety for HEP. C. sinensis peel was a good source for SIN and SCU.

• Journal of Applied Biological Chemistry
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• 제64권2호
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• pp.141-151
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• 2021

Insects affect crop harvest yield and quality, making plant response mechanisms to insect herbivores a heavily studied topic. However, analysis of plant responses to honeybees is rare. In this study, comprehensive metabolic profiling of Arabidopsis thaliana exposed to honeybees was performed to investigate which metabolites were changed by the insect. A total of 85 metabolites-including chlorophylls, carotenoids, glucosinolates, policosanols, tocopherols, phytosterols, β-amyrin, amino acids, organic acids, sugars, and starch-were identified using high performance liquid chromatography, gas chromatography-mass spectrometry, and gas chromatography-time-of-flight mass spectrometry. The metabolite profiling analysis of Arabidopsis exposed to honeybees showed higher levels of stress-related metabolites. The levels of glucosinolates (glucoraphanin, 4-methoxyglucobrassicin), policosanols (eicosanol, docosanol, tricosanol, tetracosanol), tocopherols (β-tocopherol, γ-tocopherol), putrescine, lysine, and sugars (arabinose, fructose, glucose, mannitol, mannose, raffinose) in Arabidopsis exposed to honeybees were higher than those in unexposed Arabidopsis. Glucosinolates act as defensive compounds against herbivores; policosanols are components of plant waxes; tocopherols act as an antioxidant; and putrescine, lysine, and sugars contribute to stress regulation. Our results suggest that Arabidopsis perceives honeybees as a stress and changes its metabolites to overcome the stress. This is the first step to determining how Arabidopsis reacts to exposure to honeybees.