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        검색결과 77

        41.
        2011.10 구독 인증기관·개인회원 무료
        Proteomics may help to detect subtle pollution-related changes, such as responses to mixture pollution at low concentrations, where clear signs of toxicity are absent. Also proteomics provide potential in the discovery of new sensitive biomarkers for environmental pollution. We utilized SELDI-TOF MS (surface enhanced laser desorption. / ionization time-of-flight mass spectrometry) to analyze the proteomic profile of Heterocypris incongruens exposed to several heavy metals (lead, mercury, copper, cadmium and chromium) and pesticides (emamectin benzoate, endosulfan, cypermethrin, mancozeb and paraquat dichloride). Several highly significant biomarkers were selected to make a model of classification analysis. data sets obtained from H. incongruens exposed to pollutants were investigated for differential protein expression by SELDI-TOF MS and decision tree classification. Decision tree model was developed with training set, and then validated with test set from profiling data of H. incongruens. Machine learning techniques provide a promising approach to process the information from mass spectrometry data. Even thought the identification of protein would be ideal, class discrimination does not need it. In the future, this decision tree model would be validated with various levels of pollutants to apply field samples.
        42.
        2011.05 구독 인증기관·개인회원 무료
        This study was conducted to examine the potential of surface enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) to screen Tetranychus urticae resistance to pyridaben and dicofol. T. urticae is one of the most important pests in greenhouse and orchard, and huge expense is needed to control because of its strong resistance to acaricides. Consequently speedy and accurate monitoring of acaricidal resistance is the key factor of IPM for T. urticae. SELDI-TOF MS is a novel approach to biomarker discovery that combines two powerful techniques: chromatography and mass spectrometry. It can provide a rapid protein expression profile of acaricidal sensitive and resistant T. urticae. In this study we had different protein and peptide patterns between sensitive and resistant strains to pyridaben and dicofol. In the future this results could be a useful data to develop a good monitoring tool of site and host specific mite resistance to various acaricides.
        43.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A reversed-phase high-performance liquid chromatography with tandem mass-spectrometric detection was developed and validated for the simultaneous analysis of 13 quinolones (orbifloxacin, sarafloxacin, marbofloxacin, ofloxacin, enrofloxacin, danofloxacin, pefloxacin, ciprofloxacin, norfloxacin, difloxacin, oxolinic acid, flumequine, nalidixic acid) in pork. The drugs were extracted from homogenized sample using acidic buffer (2% trichloracetic acid) and acetonitrile with ethyl acetate. Analysis was performed by liquid chromatograph with tandem mass spectrometry (LC-MS/MS) in positive mode for all quinolones. Mass spectral acquisition was performed in the multi reaction monitoring mode (MRM), selecting two structurally significant transitions per compound. Good linear relationship (R2=0.999) was observed at 6 concentrations of 2.5~100 ng/g. Satisfied recoveries (73.3~105.4%) of all quinolones were demonstrated in spiked pork at three levels from 5 to 20 ng/g. The limits of quantitation (LOQs) for quinolones ranged from 0.25 to 5.0 ng/g.
        4,000원
        44.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        LC-DAD-ESI/MS를 이용하여 국내 자색벼 품종에 대해 개별 안토시아닌 조성 및 함량을 평가한 결과는 다음과 같다. 1. 자색벼 품종에서 분리된 모든 개별 안토시아닌의 화학구조는 MS fragment 패턴을 확인하여 cyanidin을 base로 한 unknown 화합물 1종을 포함, cyanidin 3,5-diglucoside, cyanidin 3-glucoside, peonidin 3-glucoside의 총 4가지 개별성분이 분리 및 동정되었다. 2. Cyanidin 3-glucoside 및 peonidin 3-glucoside이 주요성분으로 cyanidin 3-glucoside의 경우 90% 이상의 가장 높은 함량 비중을 나타냈으며, 개별성분별 평균 함량은 cyanidin 3-glucoside > peonidin 3-glucoside > cyanidin 3,5-diglucoside > unknown(cyanidin based)의 순으로 나타났다. 3. 흑진주벼의 총 안토시아닌 함량은 408 mg/100 g으로 흑남벼보다 약 6배 정도 높은 함량을 나타내었다.
        4,000원
        45.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A simple, selective and sensitive procedure for the confirmation of 14 sulfonamide antibacterials in milk was developed. The milk samples were homogenized, extracted and deproteinized by acetonitrile and defatted by n-hexane. Analysis was performed by liquid chromatography with tandem mass spectrometry (LC-MS/MS) in positive mode for all 14 analytes. Mass spectral acquisition was performed in the multi reaction monitoring mode (MRM), selecting two structurally significant transitions per compound. The calibrations were performed in sample matrixes and the interference effect of sample matrixes on the ionization was effectively eliminated. Good linear relationship (R2=0.992~ 0.999) were observed at 6 concentrations of 2.5~100 ng/g. Satisfied recoveries (86.3~110.2%) of all sulfonamides were demonstrated in spiked milk at three levels from 5 to 20 ng/g. The limits of quantitation (LOQs) for sulfonamides ranged from 0.25~2.1 ng/g.
        4,000원
        46.
        2010.05 구독 인증기관·개인회원 무료
        Bacillus thuringiensis (B. t.) strains are important microorganism because they produced a large amount of δ-endotoxin protein per bacterial cell and their toxins are highly toxic to Lepidoptera, Coleoptera, and Diptera depending on B. t. To date, more than a hundred Cry proteins have been identified and classified into 195 holotypes, based on the amino acid sequence identity. The Cry proteins or cry genes from the Korean native B. t. isolates in this study were not identified yet. The electrospray ionization of quadrupole time of flight mass spectrometry (ESI Q-TOF MS) was used to get the internal amino acid sequences of the endotoxin-spore culture mixtures of B. t. isolates, for which polymerase chain reaction (PCR) techniques were unable to detect the cognate genes. Most of Cry proteins seperated, excized, and extracted from the one dimensional - polyacrylamide gel electrophoresis (1D-PAGE), instead of 2D-PAGE, were matched with protein databases using MS-MASCOT search program. The internal amino acid sequences which were submitted to protein BLAST (basic local alignment search tool) had partially homology with the Cry protein databases. Hence, present data strongly suggest that the de novo amino acid sequencing and ESI Q-TOF/MS analysis along with MASCOT search could be used as a simple and rapid method for detection of novel Cry toxins from B. t. isolates and identification of B. t. isolates.
        47.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The pomegranate (Punica granatum), especially its fruit, possesses a vast ethnomedical history and represents a phytochemical reservoir of heuristic medical value. The tree and fruit can be divided into several anatomical compartments, and the fruit juice, peel and oil are known to be weakly estrogenic and heuristically of interest for treatment of menopausal symptoms and sequellae. In this study, analysis of estrogen in pomegranate extract was carried out with LC/MS/MS. Three batches of pomegranate extract samples were used to analysis the target compounds (estrogen). The contents of estrogen derivatives in the samples were 38.6 ppb of estriol, 83.5 ppb of estrone,and 10.9 ppb of estradiol. This result suggests that the pomegranate extract can used for treatment of menopause symptoms in the woman.
        3,000원
        53.
        2006.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Benzoxazolo carbocyanine compounds were synthesized by condensation of a suitable ortho-ester with an appropriately substituted 2-methylbenzoxazole in the presence of triethylamine. This compounds used as green sensitizing dyes in photographic emulsions. The compounds are characterized by fast atom bombardment mass spectrometry. The values(m/z) of structurally significant ions observed in FAB spectra. It was showed tentative fragmentation pattern in FAB spectroscopy of HN(C2H5)3 cations in glycerol/trifluoroacetic acid matrix.
        4,000원
        55.
        2005.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        다수의 잠재적인 내분비계장애물질이 환경에 방출됨으로써 새로운 환경문제로 세계적 관심이 모아지고 있다. 이러한 물질들을 측정하고 감시하기 위한 고감도이며 신뢰성 있는 분석방법의 개발이 필수적이다. 이 연구에서는 기체크 로마토그래피 질량분석법과 액체크로마토그래피 질량분석법이 내분비계장애물질들의 분석을 위해 이용되었으며 두 가지 분석방법들이 DEHP, BBP, PCP, BPA에 대해 비교 및 평가되었다 그 결과 액체크로마토그래피 질량분석법이 더 낮은 검출 한계를 나타내는 것으로 조사되었다. 또한 액체크로마토그래피 질량분석법은 대부분의 순수한 분자들로서 내분비계장애물질들을 측정 가능함이 판명되었다. 이 연구에서는 음용수에서 내분비계장애물질들을 제거하는 방법으로 유기막과 세라믹막을 제시하였으며 십자류 나노여과 방식이 내분비계장애물질들을 100% 제거하는 것으로 조사되었고 분획분자량 250 나노여과는 내분비계장애물질을 제거함에 있어 효과적인 것으로 판명되었다. 나노여과, 고속한외여과, 저속한외여과의 투과플럭스와 물질전달계수와의 비는 0.67, 3.4, 그리고 0.44였으며 나노여과와 저속한외여과는 확산이 주요한 조건에서 운전되며 고속한외여과는 대류가 주요한 조건에서 운전된다. 더욱이, 확산이 주요한 나노여과와 저속한외여과에서 내분비계장애물질의 제거율이 높은 것으로 측정되었다. 한외여과에 의한 제거는 내분비계장애물질들의 분자량에 의존하는 것으로 조사되었으며 내분비계장애물질들은 확산이 주요한 수리동역학적 조건에서 제거됨이 판명되었다.
        4,500원
        56.
        2001.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        CTA ester bonds in TG molecules were not attacked by pancreatic lipase and lipases produced by microbes such as Candida cylindracea, Chromobacterium viscosum, Geotricum candidium, Pseudomonas fluorescens, Rhizophus delemar, R. arrhizus and Mucor miehei. An aliquot of total TG of all the seed oils and each TG fraction of the oils collected from HPLC runs were deuterated prior to partial hydrolysis with Grignard reagent, because CTA molecule was destroyed with treatment of Grignard reagent. Deuterated TG (dTG) was hydrolyzed partially to a mixture of deuterated diacylglycerols (dDG), which were subsequently reacted with (S)-(+)-1-(1-naphthyl)ethyl isocyanate to derivatize into dDG-NEUs. Purified dDG-NEUs were resolved into 1, 3-, 1, 2- and 2, 3-dDG-NEU on silica columns in tandem of HPLC using a solvent of 0.4% propan-1-o1 (containing 2% water)-hexane. An aliquot of each dDG-NEU fraction was hydrolyzed and (fatty acid-PFB ester). These derivatives showed a diagnostic carboxylate ion, (M-1)-, as parent peak and a minor peak at m/z 196 (PFB-CH3)- on NICI mass spectra. In the mass spectra of the fatty acid-PFB esters of dTGs derived from the seed oils of T. kilirowii and M. charantia, peaks at m/z 285, 287, 289 and 317 were observed, which corresponded to (M-1)- of deuterized oleic acid (d2-C18:0), linoleic acid (d4-C18:0), punicic acid (d6-C18:0) and eicosamonoenoic acid (d2-C20:0), respectively. Fatty acid compositions of deuterized total TG of each oil measured by relative intensities of (M-1)- ion peaks were similar with those of intact TG of the oils by GLC. The composition of fatty acid-PFB esters of total dTG derived from the seed oils of T. kilirowii are as follows; C16:0, 4.6 mole % (4.8 mole %, intact TG by GLC), C18:0, 3.0 mole % (3.1 mole %), d2C18:0, 11.9 mole % (12.5 mole %, sum of C18:1Ω9 and C18:1Ω7), d4-C18:0, 39.3 mole % (38.9 mole %, sum of C18:2Ω6 and its isomer), d6-C18:0, 41.1 mole % (40.5 mole %, sum of C18:3 9c,11t,13c, C18:3 9c,11t,13r and C18:3 9t,11t,13c), d2-C20:0, 0.1 mole % (0.2 mole % of C20:1Ω9). In total dTG derived from the seed oils of M. charantia, the fatty acid components are C16:0, 1.5 mole % (1.8 mole %, intact TG by GLC), C18:0, 12.0 mole % (12.3 mole %), d2-C18:0, 16.9 mole % (17.4 mole %, sum of C18:1Ω9), d4-C18:0, 11.0 mole % (10.6 mole %, sum of C18:2Ω6), d6-C18:0, 58.6 mole % (57.5 mole %, sum of C18:3 9c,11t,13t and C18:3 9c,11t,13c). In the case of Aleurites fordii, C16:0; 2.2 mole % (2.4 mole %, intact TG by GLC), C18:0; 1.7 mole % (1.7 mole %), d2-C18:0; 5.5 mole % (5.4 mole %, sum of C18:1Ω9), d4-C18:0 ; 8.3 mole % (8.5 mole %, sum of C18:2Ω6), d6-C18:0; 82.0 mole % (81.2 mole %, sum of C18:3 9c,11t,13t and C18:3 9c,11t,13c). In the stereospecific analysis of fatty acid distribution in the TG species of the seed oils of T. kilirowii, C18:3 9c,11t,13r and C18:2Ω6 were mainly located at sn-2 and sn-3 position, while saturated acids were usually present at sn-1 position. And the major molecular species of (C18:2Ω6)(C18:3 9c,11t,13c)2 and (C18:1Ω9)(C18:2Ω6)(C18:3 9c,11t,13c) were predominantly composed of the stereoisomer of sn-1-C18:2Ω6, <..
        5,400원
        57.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Analytical method for preservatives in food was developed using gas chromatography/mass spectrometry (GC/MS). Propionic acid, sorbic acid, benzoic acid, ethyl salicylate, ethyl p-hydroxy benzoate, iso-propyl p-hydro benzoate, n-propyl p-hydroxy benzoate, iso-butyl phydroxy benzoate, n-butyl p-hydroxy benzoate, p-hydroxy benzoic acid and dehydro acetic acid were extracted from cooling beverage with diethyl ether. The polar hydroxyl and carboryl groups of food preservatives were derivatized with N-methyl-N-tent-butyldimethylsilyl-trifluoroacetamide (MTBSTFA) to form the corresponding tert-butyldimethyl-silylated derivatives, and submitted to GC/MS analysis. The mass spectra of the derivatives were investigated for the selection of monitoring ions for multi-residue analysis of 11 preservatives by GC/MS. The macro program was also developed for the qualitative analysis of these preservatives in food.
        4,000원
        58.
        1997.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The prevention of oxidative degradation in fats and oils is largely controlled by the use of synthetic phenolic antioxidants. Antioxidants, BHA: 2-&3-tert-butyl-4-hydroxyanisol, BHT: 3,5-di-tert-butyl-4-hydroxytoluene, TBHQ: tert-butylhydroquinone, PG: propyl gallate, PTG: pentyl gallate, OG: octyl gallate, were extracted from fatty foods with hexane and from hexane layer to presaturated acetonitrile with hexane. The polar phenolic hydroxyl groups of antioxidants were silylated with MSTFA and injected to Gas Chromatography/Mass Spectrometry. The calibration plots were linear in the investigated range, 0.1-10.0 ug/g. The limit of detection for 6 phenolic antioxidants was 0.1 ug/g. Recoveries and reproducibilities from samples fortified at 1.0 ug/g were in the range of 70-90% and 0.5-13%, respectively. The simultaneous determination of phenolic antioxidants in fatty foods using GC/MS-SIM mode and macro program was described.
        4,000원
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