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        검색결과 181

        84.
        1998.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The lipids from the seeds of Pinus koraiensis mostly composed of triacylglycerols (TGs), in which linoleic acid (46.2 mol%) and oleic acid (25.6 mol%) are present as main components in the fatty acid composition. Surprisingly, they also have unusual fatty acids with δ5-double bond systems such as δ5.9.12-C18:3 (16.0 mol%), δ5.9-C18:2 (2.3 mol%) and δ5.11.14-C20:3 (0.8 mol%). Saturated fatty acids of palmitic, stearic and arachidic acid were present in less than 8.0 mol%. TG was resolved into 17 fractions by reverse-phase HPLC according to so-called partition number (PN) suggested by Plattner, in which TG molecules with δ5-NMDB acyl chains eluted later than did those with δ9-MDB acyl radicals. Ag+-HPLC separated the TG into 14 fractions more clearly than did those with δ9-MDB acyl radicals. Ag+-HPLC separated the TG into 14 fractions more clearly than did reverse-phase HPLC, and the complexity of δ5.9.12-C18:3 moiety with silver ion impregnated in the column bed was in the level between δ9.12.15-C18:3 (C18:3Ω3) and C18:2Ω6 (δ9.12-C18:2). In the Ag+-HPLC, it was found that the molecular species having a given-numbered double bonds widely spreaded in the acyl chains eluted earlier than those concentrated in one acyl chain. The main molecular species are (C18:2Ω6)2/δ5.9.12-C18:3 (14.8 mol%), C18:1Ω9/C18:2Ω6)2 (12.8 mol%) and C18:1Ω9/C18:2Ω6/δ5.9.12-C18:3 (10.9 mol%).
        4,000원
        85.
        1998.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        발효식품이 유해곰팡이에 의한 발암물질(aflatoxin)생성에 미치는 억제효과에 관한 연구의 일환으로 유산균 및 유산균 발효유가 Aspergillus parasiticus ATCC 15517의 성장과 aflatoxin 생성에 미치는 영향을 실험하였다. 발효유를 일정 농도별로 첨가한 YES 배지에서 Asperigillus parasiticus를 배양하여 그 성장과 배양물의 변화를 관찰하고 HPLC에 의하여 aflatoxin을 분석하였다. 그 결과 배양말기에 대조군에 비하여 건조 균체량, 배양물의 PH, 그리고 aflatoxin 생성량 등이 낮게 나타났다(p<0.05). Aflatoxin B₁은 48.6~58.1%가 감소되었으며 G₁은 29.8~34.2%가 감소되었다. 이 발효유의 발효에 사용된 유산간균(Lactobacillus casei)과 A. parositicus를 변형 APT 배지에서 혼합배양한 결과 A. parasitious 단독배양의 경우에 비하여 균체량이 배양 5일째까지는 현저하게 억제되었으나 배양 말기에는 유의한 차이를 보이지 않았다. 또한 배양 말기에 단독배양의 경우보다 pH가 훨씬 감소되고(p<0.05) aflatoxin의 생성량도 감소되었다. 이로부터 발효유는 유해곰팡이인 A. parasiticus의 성장과 aflatoxin 생성을 억제시키는 효과를 가짐을 알 수 있으며, 이는 발효에 관여한 미생물의 경쟁뿐만 아니라 유산균의 대사산물에 의한 영향으로 보여진다.
        4,000원
        86.
        1998.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        HPLC에 의한 주요 aflatoxins(afatoxin B₁, B₂, G₁ 및 G₂)의 동시 분석에서 postcolumn 유도체화법을 시도하였다. Electrochemical cell(Kobra-cell)을 사용한 postcolumn 유도체화법은 기존의 precolumn 유도체화법보다 분석시간을 단축하였으며(약 1/2 단축), 더 안전하고, 향상된 분석능을 보였다. Aflatoxin B₁과 G₁의 경우 10~100 ppb에서, 그리고 B₂와 G₂의 경우 3~30 ppb에서 직선성을 나타내었다. Aflatoxin B₁과 G₁은 각각 88.9% 및 100.5%로 양호환 회수육을 보였다. Aflatoxin B₂와 G₂의 경우 분리도는 우수하였으나 회수율에 있어서 변이가 크게 나타났다.
        4,000원
        87.
        1997.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A simple, rapid and simultaneous analytical method is described for the detection of Sulfonamide and Tetracycline residues, i.e., Sulfamerazine (SMR), Sulfamethazine (SMT), Sulfamonomethoxine (SMM), Sulfadimethoxine (SDM), Sulfaquinoxaline (SQN), Oxytetracycline (OXY), Tetracycline (TC), Chlortetracycline (CTC). Blank control and sulfonamide and tetracycline fortified fish muscle samples (0.5 g) were blended with octadecylsilyl (C,e, 40 gm, 21% load, 60Å) derivatized silica packing material (2 g). Blended fish samples were washed with hexane, then, benzene and dichloromethane were used for the elution of tetracycline and sulfonamide, respectively, The eluants containg tetracycline and sulfonamide were analyzed by HPLC. Correlation coefficients of standard curves for individual sulfonamide and tetracycline isolated from fortified samples were linear (0.9993±0.0003-0.9997±0.0003, 0.9493±0.078-0.9753±0.036), respectively, The average percentage recoveries of sulfonamide and tetracycline ranged as 80.86-96.52% to 85.88-92.23%, and 30.01-37.12% to 65.89-73.40%, for the concentration range (0.1--1.0 ppm) examined, respectively. Limit of detection for sulfonamide was 0. 05 ug/g, then, tetracycline was 0.1 ug/g. Detection of quantitation of sulfonamide residue was 0.0012 ppm for SMR in Paralichthys Odiuacleus and 0.0020 ppm for SMR, 0.015 ppm for SMM in Cyprinus Carpio. The applicability of this procedure is demonstrated by separation and detection of incurred tetracycline and sulfonamide residues in fish muscle tissue.
        4,000원
        88.
        1997.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Triacylglycerols of the seeds of Ginkgo biloba have been resolved by high-performace liquid chromatography(HPLC in the silver-ion and reverse-phase modes. The fatty acids were identified by a combination of capillary gas chromatography and gas-chromatography /mass spectrometry as the methyl and /or picolinyl ester. The main components are C18:2Ω6(39.0mol%), C18:1Ω7(asclepic acid 21.5mol%), and C18:1Ω9(oleic acid, 13.8mol%). Considerable amounts of unusual acid such as C20:3δ5,11,14 (5.7mol%), C18:2δ5,9(2.8mol%), and C18:3δ5,9,12(1.6mol%), were checked. In addition, an anteiso-branched fatty acid, 14-methylhexadecanoic acid, was also present as a minor component(0.9 mol%). The triacylglycerols were separated into 17 fractions by reverse-phase HPLC, and the fractionation was achieved according to the partition numnber(PN) in which a δ5-non methylene interrupted double bond(5-NMDB) showed different behaviour from a methylene interrupted double bond in a molecule with a given cahinlength. Silver-ion HPLC exhibited excellent resolution in which fractions(23 fractions) were resolved on the basis of the number and configuration of double bonds. In this instance, the strength of interaction of a δ5-NMDB system with silver ions seemed to be weaker than a methylene interrupted double bond system. The principal triacylglycerol species are as follows ; (C18:2Ω6)2/C18:1Ω7, C18:1Ω9/C18:1Ω7/C18:2Ω6, (C18:1Ω7)2/C18:2Ω6, C16:1Ω7/C18:1Ω9/C20:3δ5,11,14, C16:1Ω7/C18:1Ω7/C20:3δ5,11,14, C18:1Ω9/C18:1Ω7/C18:2Ω6, C18:1Ω9/C18:2δ5,5/C20:3δ5,11,14, (C18:1Ω7)2/C18:2Ω6 and (C18:1Ω9)2/C18:2Ω6, while simple triacylglycerols without C18:2Ω6)3 were not present. Stereospecific analysis showed that fatty acids with δ5-NMDB system and saturated chains were predominantly located at the site of sn-3 carbon of glycerol backbones. It is evident that there is asymmetry in the distribution of fatty acids in the TG molecules of Ginkgo nut oils.
        4,900원
        89.
        1997.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sulfonamides, a therapeutically important group of antimicrobial drugs, are widely used to treat and prevent the acute systemic and skin infections in dairy cattle. They also pose an economic hazard through inhibition of growth of dairy starter cultures. This study was carried out to compare four screening methods for detection of sulfamethazine in milk and determine the positive milk sample by HPLC method. Sulfamethazine was used to spike at five levels of sulfamethazine. The Lac-Tek test and CharmII test were also consistent better than TTCII test and Delvo SP test in sulfamethazine detection. Analysis probabilities of obtaining a positive response with TTCII test and Delvo SP test assay at 50 ppb sulfamethazine level in milk samples were only 14%, 42% each. Whereas using the Lac-Tek test and CharmII test would have resulted in 100% identification of the five levels. Determination of sufamethazine using the HPLC method in the spiked milk were 10.64, 19.30, 30.76, 38.83 and 50.23 ppb, respectively.
        4,000원
        90.
        1996.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to determine and confirm of Dapsone in vegetables and fruits which were illegally used for freshness. We have developed a simple, rapid and precise method that Dapsone can be analyzed in the cabbages, grapes and strawberry by HPLC with photodiode array detector. Experimental subjects were included 15 cases of cabbages, 10 cases of grapes and 10 cases of strawberries purchased in Kangwon, Chungchong province and the Seoul area. The results were obtained that Dapaone in the experimental subject was separated completely within 10 min. Detection limit of Dapsone was 0.5 ng. Aberage recoveries from cabbages, grapes and strawberries were 93.3±0.26%, 92.5±0..37%, 91.4±0..65% respectively. 4 cases of cabbages were detected Dapsone and the amount was below the 0.3 ppm. There was not detected Dapsone in any grape and strawberry samples.
        4,000원
        95.
        1993.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Contents of vitamin D3 and 25-OH-vitamin D3 in marine animal products(20 species) were determined by HPLC. The isomers of vitamin D, D2 and D3, were not clearly separated on a reversed phase, μ Bonda Pak, with 20% methanol-acetonitrile, and on a normal phase, Zorbax SIL. with 0.4% isopropanol-hexane, but 25-OH-vitamin D2 and-D3 were separated on either μ Bonda Pak with 10% methanol-acetonitrile, or on Zorbax SIL with 2.2% isopropanol-hexane, respectively. Although levels of vitamin D3 and 25-OH-vitamin D3 varied remarkably according to species, their average value(fish : l,l87sim36,007 I.U/sample 100g, mussel : 58~1,706 I.U/sample 100g, pickle: 1,208~79,358 I.U/sample 100g) was greatly higher than that of meat(80~100 I.U/sample 100g) and dairy products(400~800 I.U/sample 100g). Fatty tissues of fish and pickled fish intestines contained high level of vitamin D3 and 25-OH-vitamin D3, while the clam and mussel known to have various kinds of sterol including δ7-sterol showed very low levels of vitamin D3 and its derivative.
        4,000원
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