• Mass Spectrometry Letters
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• 제4권4호
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• pp.59-66
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• 2013

A metabolomics study was conducted to identify urinary biomarkers for breast cancer, using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS), analyzed by principal components analysis (PCA) as well as a partial least squares-discriminant analysis (PLS-DA) for a metabolic pattern analysis. To find potential biomarkers, urine samples were collected from before- and after-mastectomy of breast cancer patients and healthy controls. Androgens, corticoids, estrogens, nucleosides, and polyols were quantitatively measured and urinary metabolic profiles were constructed through PCA and PLS-DA. The possible biomarkers were discriminated from quantified targeted metabolites with a metabolic pattern analysis and subsequent screening. We identified two biomarkers for breast cancer in urine, ${\beta}$-cortol and 5-methyl-2-deoxycytidine, which were categorized at significant levels in a student t-test (p-value < 0.05). The concentrations of these metabolites in breast cancer patients significantly increased relative to those of controls and patients after mastectomy. Biomarkers identified in this study were highly related to metabolites causing oxidative DNA damage in the endogenous metabolism. These biomarkers are not only useful for diagnostics and patient stratification but can be mapped on a biochemical chart to identify the corresponding enzyme for target identification via metabolomics.

• 분석과학
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• 제30권2호
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• pp.102-111
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• 2017

Here we reported a methodology for identification of triacylglycerols (TAGs) and diacylglycerols (DAGs) in coix seed by preparative thin layer chromatography (prep-TLC) and non-aqueous reversed-phase liquid chromatography (NARP LC)-atmospheric pressure chemical ionization (APCI) tandem mass spectrometry (MS/MS). Lipid components were extracted from coix seed by reflux extraction using n-hexane for 3 hr. TAGs and DAGs in coix seed extract were effectively purified and isolated from matrix interferences by prep-TLC and then analyzed by LC-APCI-MS and MS/MS for identification. TAGs were effectively identified taking into consideration of their LC retention behavior, APCI-MS spectra patterns, and MS/MS spectra of $[DAG]^+$ ions. In MS/MS spectra of TAGs, diacylglycerol-like fragment $[DAG]^+$ ions were useful to identify TAGs with isobaric fragment ions. Based on an established method, 27 TAGs and 8 DAGs were identified in coix seed extract. Among them, 15 TAGs and 8 DAGs were for the first time observed in coix seed. Interestingly, some of TAGs isolated by prep-TLC were partly converted into DAGs through probably photolysis process during storing in room temperature. Thus, degradation phenomenon of TAGs should be considered in the quality evaluation and nutritional property of coix seed. LC-APCI-MS/MS combined with prep-TLC will be practical method for precise TAG and DAG analysis of other herbal plants.

• 분석과학
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• 제21권6호
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• pp.518-525
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• 2008

포도, 고추, 배추, 토마토 및 감자 등 5종 농산물에 대하여 mandelamide계 신규 살균제인 mandipropamid의 잔류분석법을 확립하였다. 각 농산물을 세절한 시료에 methanol을 가하고 고속마쇄하여 잔류분을 추출하였다. 추출액을 포화식염수와 증류수로 희석하고 dichloromethane으로 분배하여 극성분순물을 제거하였으며, Florisil 흡착크로마토그래피법으로 추가 정제하였다. Mandipropamid의 HPLC/UV 검출기상 최소검출량은 2 ng (S/N>10, 0.01 AUFS)이었고 시료추출물 중 불순물에 의한 간섭은 관찰되지 않았다. 무처리 포도, 토마토, 고추, 배추 및 감자에 대하여 2수준 3반복으로 회수율을 산출한 결과 각각 $99.8{\pm}1.7$ (n=6), $89.3{\pm}5.3$(n=6), $98.7{\pm}2.2$ (n=6), $99.7{\pm}6.8$ (n=6) 및 $91.1{\pm}3.1$ (n=6)이었으며, 분석법의 정량한계는 0.02~0.04 mg/kg이었다. 아울러 검출된 잔류분은 재확인을 위하여 selected-ion monitoring (SIM)을 이용한 LC/MS법을 추가로 확립하였다. 본 연구에서 확립된 mandipropamid의 잔류분석법은 검출감도 및 재현성을 고려할 때 공정분석법으로 사용이 가능하였다.

• 한국환경성돌연변이발암원학회지
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• 제26권1호
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• pp.25-29
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• 2006

흥합 (Mytilus coruscus) 추출물 RM 60을 사용하여 E. coli D31을 대상으로 항균활성 펩타이드를 분리 정제하였다. 정제한 펩타이드는 MALDI-TOF Mass spectrometry를 사용하여 분자량을 측정한 결과, 1464.92 Da로 나타났으며 Edman 분해법을 이용한 peptide sequencer를 사용하여 일차구조를 분석 중에 있다.

• Mass Spectrometry Letters
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• 제7권1호
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• pp.12-15
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• 2016

Results of free and bound myo-inositol in infant formula (IF) are presented. Inositol was analyzed by HILIC ultra-performance liquid chromatography coupled with mass spectrometer. The levels of free myo-inositol in 27 Australian and 4 EU originated IF samples were 300-600 mg/kg of powder or 1.6-3.1 mg/100 kJ. The amount of bound inositol in lipid fraction of IF was, on average, 10% of free myo-inositol.

• 한국환경농학회지
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• 제30권4호
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• pp.432-439
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• 2011

BACKGROUND: An official analytical method was developed to determine etofenprox residues in agricultural commodities using high-performance liquid chromatography (HPLC). METHODS AND RESULTS: The etofenprox residue was extracted with acetone from representative samples of five raw products which comprised rice grain, apple, mandarin, cabbage, and soybean. The extract was then serially purified by liquid-liquid partition and Florisil column chromatography. For rice and soybean samples, acetonitrile/n-hexane partition was additionally coupled to remove nonpolar lipids. Reversed phase HPLC using an octadecylsilyl column was successfully applied to separate etofenprox from co-extractives. Intact etofenprox was sensitively detected by ultraviolet absorption at 225 nm. Recovery experiment at the quantitation limit validated that the proposed method could apparently determine the etofenprox residue at 0.02 mg/kg. Mean recoveries from five crop samples fortified at three levels in triplicate were in the range of 93.6~106.4%. Relative standard deviations of the analytical method were all less than 10%, irrespective of crop types. A selected-ion monitoring LC/mass spectrometry with positive atmospheric-pressure chemical ionization was also provided to confirm the suspected residue. CONCLUSION(s): The proposed method is simple, rapid and sensitive enough to be employed in routine inspection or monitoring of agricultural products for the etofenprox residue.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.223.2-223.2
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• 2003

A rapid, sensitive and selective liquid chromatography-tandem mass spectrometric (LC/MS/MS) method for the determination of eupatilin in human plasma was developed. Eupatilin and internal standard, (S)-[N-3-(4-(2-(1-methyl-5-tetrazolyl)-pyridine-5-y1)- 3-fluorophenyl)-2-oxo-5-oxazolidinyl]methyl acetamide (DA-7867) were extracted from human plasma by liquid-liquid extraction and analyzed on a phenyl-hexyl column with the mobile phase of acetonitrile-ammonium formate (10 mM, pH 3.0) (60:40, v/v). (omitted)

• Advances in environmental research
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• 제2권3호
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• pp.179-202
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• 2013

Bisphenol A and other alkylphenols are widely used in plastic and other industrial consumer products. Release of these compounds into the aquatic environment during their manufacture, use and disposal has been a great scientific and public concern due to their toxicity at high concentrations and endocrine disrupting effects at low concentration on aquatic wildlife and human beings. This paper reviews the published data and researches on the environmental occurrence, distribution, health effects and analytical techniques of bisphenol A and alkylphenols. The aim is to provide an overview of the current understanding about bisphenol A and alkylphenols in the environment and the difficulties faced today in order to establish standard and systematic environmental analysis and assessment process for these endocrine disruptor compounds.

• 분석과학
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• 제19권6호
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• pp.519-528
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• 2006

본 연구에서는 뇨시료를 고체상 추출법으로 추출한 후 HPLC/DAD/ESI-MS(high-performance liquid chromatograph/diode array detector/electro-spray ionitation mass spectrometry)를 사용하여 분석하였다. 7종의 thyroid hormones의 HPLC 분리조건은 Hypersil ODS(octadecylsilica) 컬럼(4.6mm I.D., 100 mm length, particle size $5{\mu}m$)을 사용하고 ammonium formate buffer와 acetonitrile을 이동상으로 하여 기울기 용리한 결과 완전 분리가 가능하였으며, UV spectra 및 질량스펙트럼을 확인할 수 있었다. 고체상 추출법에 의한 전처리 최적 조건을 조사한 결과 시료를 pH 3으로 한 후 C18 고체상을 사용하여 4 mL의 methanol/ammonium hydroxide(9:1) 혼합용액으로 용리할 경우 회수율이 89.0-113.1%로 나타났다. HPLC/DAD를 이용하여 10-1000 ng/mL범위에서 검량선을 작성한 결과 $r^2$값은 0.992-0.998 으로 나타났으며 검출한계는 2-4 ng/mL(3.8-13.0 pmol/mL)로 계산되었다.

• BMB Reports
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• 제43권7호
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• pp.506-511
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• 2010

The levels of salivary cortisol and cortisone in Korean adults were measured for the first time using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The salivary cortisol and cortisone were separated within 10 min. The regression coefficients (r) of the calibration curves were greater than 0.999 for the two steroids. The limits of quantitation (LOQ) were 0.2 ng/ml for cortisol and 1 ng/ml for cortisone. The intra-day precisions of the assay were <3.9% and 8.6% for cortisol and cortisone respectively, and the inter-day precisions were <1.9% and 4.3% for cortisol and cortisone, respectively. The salivary cortisone concentrations were approximately 4-9 times higher than those of salivary cortisol during the daytime. Diurnal rhythms, during which the cortisol and cortisone concentrations were higher in the morning than in the afternoon, were also observed. The present assay may be useful for the diagnosis of several adrenal dysfunctions in clinical biochemistry.