• Journal of Veterinary Science
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• 제21권2호
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• pp.24.1-24.11
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• 2020

The pandemic of avian influenza viruses (AIVs) in Asia has caused enormous economic loss in poultry industry and human health threat, especially clade 2.3.4.4 H5 and H7 subtypes in recent years. The endemic chicken H6 virus in Taiwan has also brought about human and dog infections. Since wild waterfowls is the major AIV reservoir, it is important to monitor the diversified subtypes in wildfowl flocks in early stage to prevent viral reassortment and transmission. To develop a more efficient and sensitive approach is a key issue in epidemic control. In this study, we integrate multiplex reverse transcription recombinase polymerase amplification (RT-RPA) and capillary electrophoresis (CE) for high-throughput detection and differentiation of AIVs in wild waterfowls in Taiwan. Four viral genes were detected simultaneously, including nucleoprotein (NP) gene of all AIVs, hemagglutinin (HA) gene of clade 2.3.4.4 H5, H6 and H7 subtypes. The detection limit of the developed detection system could achieve as low as one copy number for each of the four viral gene targets. Sixty wild waterfowl field samples were tested and all of the four gene signals were unambiguously identified within 6 h, including the initial sample processing and the final CE data analysis. The results indicated that multiplex RT-RPA combined with CE was an excellent alternative for instant simultaneous AIV detection and subtype differentiation. The high efficiency and sensitivity of the proposed method could greatly assist in wild bird monitoring and epidemic control of poultry.

• 생명과학회지
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• 제16권2호
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• pp.323-327
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• 2006

아크릴아마이드의 형성과정에서 가열조건이 아크릴아마이드의 생성량과 아크릴아마이드 형성에 관여 또는 동반 생성하는 화합물을 조사하기 위하여, 아스파라긴과 포도당의 등량 혼합물을 125, 150, 175 및 $200^{\circ}C$에서 각각 10, 20 및 30 분간 가열하는 모델반응을 이용하였다. 가열한 반응물을 ethyl acetate 및 methanol 2종의 용매로 달리 추출하고 FFAP capillary column과 HP-5MS 5% phenyl methyl siloxane column으로 GC/MS에서 분석한 결과, 아크릴아마이드는 methanol추출물을 FFAP capillary column으로 분석한 결과에서 retention time 23.53분에서 검출되었고 최저검출한계는 4 ng 이었다. 아크릴아마이드 생성량은 $175^{\circ}C$보다. 낮은 125 및 $150^{\circ}C$에서는 온도와 가열시간을 증가시킬수록 점차 증가하여, $175^{\circ}C$에서 10분간 처리하였을 때 최대량인 $116{\mu}g/g$을 생성하였지만 175 및 $200^{\circ}C$에서는 온도 및 가열시간을 증가시킬수록 감소하는 결과를 나타내었다. 아크릴아마이드이외 반응생성물들로서, 1,3-dihydroxypropanone, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyrane-4-one 및 5-hydroxymethylfurfural이 다량으로 검출되었으며, 또 다른 화합물인 5-methylfurfural, 2-acetylpyrrole 및 N,N-dimethylcyclohexamine 등은 소량 생성되었음을 확인하였다.

• 대한화학회지
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• 제47권6호
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• pp.547-552
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• 2003

코발트와 니켈 이온을 4-(2-피리딜아조)레조루신올(PAR) 리간드와 킬레이트를 만들고 이 금속-PAR 킬레이트들을 역상 모세관 고성능 액체 크로마토그래피(RP-CpHPLC)로 분리와 정량을 하였다. 컬럼은 주로 Vydac C4 모세관 컬럼을, 이동상은 아세토니트릴(MeCN) 수용액을 사용하였다. 머무름 인자, k와 봉우리 높이에 대한 이동상의 pH와 MeCN 농도의 영향을 검토하여 분리와 정량의 최적 조건을 얻었다. 결과, 분리의 최적 이동상은 22.5% MeCN, pH 5.6이었고, Co(II) 이온의 정량은 이 조건에서 할 수 있었다. 그러나 Ni(II) 이온의 정량은 분리와 봉우리의 높이로부타 22.5% MeCN, pH 7.20이 보다 적합함을 확인하였다. 각각의 조건에서 Co(II)와 Ni(II) 이온의 검출한계(D.L., S/N=3)는 각각 $2.0{\times}10{-7}$ M(14.9 ppb)와 $1.0{\times}10{-6}$ M(59.2 ppb)였다.

• 한국식품과학회지
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• 제37권4호
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• pp.513-518
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• 2005

포도종실추출물에 함유되어 강력한 항산화 작용을 나타내는 성분인 proanthocyanin의 구성 성분이면서 에피머인 (+)-catechin과 (-)-epicatechin을 CE법을 이용하여 분석하였다. CE법을 이용한 catechin류 분석의 최적 조건은 fused silica capillary$(20cm{\times}50{\mu}m)$, current $56{\mu}A$, voltage 10 kV, phosphate/borate buffer(pH 6.0), 온도 $20^{\circ}C$로서 (+)-catechin과 (-)-epicatechin을 6분 이내에 매트릭스의 방해없이 분석할 수 있었다. 비색법, HPLC법과 CE분석법의 특징을 비교해 보면 비색법은 (+)-catechin과 (-)-epicatechin합한 총 함량은 알 수 있으나 두성분의 분리는 할 수 없었다. 또한 HPLC방법은 표준품은 두 성분이 잘 분리되었으나 시료 분석 시 proanthocyanin을 가수분해하기 위해 첨가한 산으로 인해 시료가 강산성을 띠어 컬럼 손상되는 문제가 있어 직접 분석이 불가능하여 시료를 희석해야 했으며, 희석을 하여 분석할 경우에도 많은 잡 피크들로 정량적인 결과를 얻기에 용이하지 않았다. 한편 CE법의 경우 산 가수분해한 시료를 별다른 처리 없이도 다른 성분의 방해 없이 분석할 수 있었다. 분석소요시간의 경우 비색법은 실험단계가 복잡하여 많은 시간이 걸렸으며 HPLC는 15분 그리고 CE는 6분 이내에 분석이 가능하였다. 재현성과 직선성을 보면 HPLC와 CE의 방법이 모두 양호하였고 검출한계에 있어서는 CE법이 0.035mg/L로서 검출감도가 매우 우수하였다. 이와 같이 CE법은 포도종실에 존재하는 (+)-catechin과 (-)-epicatechln을 분석하는데 방법의 용이성, 분석결과의 정확성에 있어서 기존 방법인 비색법과 HPLC 방법보다 우수한 결과를 나타내었다.

• KSBB Journal
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• 제30권4호
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• pp.141-147
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• 2015

The convenient determination of methylsulfonylmethane (MSM) for a commercially available dietary supplement was developed using gas chromatography (GC)-flame ionization detector (FID). Chromatography was performed on a capillary column ($0.32mm\;I.D{\times}30m$, $0.25{\mu}m$) coated with dimethylpolysiloxane using diethylene glycol methyl ether as an internal standard. The performance characteristics of GC were evaluated in terms of selectivity, linearity, precision, accuracy, recovery, limit of detection (LOD) and limit of quantification (LOQ). The calibration curve was highly linear (the coefficient of determination: 0.9979) within the concentration range of $10.0{\sim}800.0{\mu}g/mL$ for MSM. The recoveries for three fortified concentrations were 96.7~97.1%, 96.6~97.3% and 96.8~97.2%, respectively. The LOD and LOQ of the method were $0.29{\mu}g/mL$ and $0.97{\mu}g/mL$, respectively. All obtained results were acceptable according to the guidelines of the Association of Official Analytical Chemists for dietary supplements. Thus, the validated analytical method using the GC-FID system is suitable for the determination of MSM in dietary supplement formulations for quality control.

• Archives of Pharmacal Research
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• 제15권4호
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• pp.328-332
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• 1992

A new high performance liquid chromatographic procedure is described for the analysis of ginseng saponins. Ginseng saponins were separated on Lichrosorb $NH_2$ column and anthraquinone-2, 6-disulfonate (AQDS) solution was added to the column effluent. The effluent was passed through 1.5m-PTFE capillary coiled around 10 W-UV lamp to reduce AQDS to highly fluorescent 9. 10-dihydroxyanthracene-2, 6-disulfonate which was detected by fluorescence detector. The detection limit for the ginsenoside $Rg_1$ by this method was found to be about 350 ng, the dynamic linear range was $10^2$ and the correlation coefficient of the calibration curve was 0.9999.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.195-198
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• 2005

A solid-phase microextraction and gas chromatography-mass spectrometry for the extraction and analysis of methyl-tert-butyl ether has been described. methyl-tert-butyl ether was extracted from aqueous solution using SPME fiber coated polydimethylsiloxane and analysed by GC-MS with capillary column. Extraction parameters and chromatographic separation conditions were optimized. The applied method represented good analytical performance in terms of precision (3-8%, RSD) and accuracy(93-102%, mean recovery) with a method detection limit of 0.03 ppb.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권10호
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• pp.449-452
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• 2005

We fabricated an electrochemical detector (ECD) to catalyze redox reaction efficiently by electrodepositing Prussian blue (PB) on the indium tin oxide (ITO) electrode. Capillary electrophoresis (CE) and amperometric method were used. We investigated the PB surface properties by topography from atomic force microscopy (AFM). Also PB film thickness calibration with respect to deposition time and voltage was used to get better PB surFace. The PB thin film of dense and smooth surface could catalyze redox reaction efficiently. Comparing with CE-ECD microchip using bare-lTO electrode, proposed CE-ECD microchip using PB deposited electrode has shown better sensitivity by determining the detected peak current from the electropherograms while the concentration of tested analyzes was maintained the same. It is verified that detection limit can be lowered for 0.01 mM of dopamine and catechol respectively.

• 태양에너지
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• 제18권3호
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• pp.205-215
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• 1998

Entrainment in thermosyphons and heat pipes was characterized in view of the interfacial stability associated with the critical Weber number and the entrainment limit at the onset of liquid entrainment from the liquid or wicked interface. Both literature review and theoretical analysis on the entrainment models were peformed in order to evaluate accuracy of the predicted value. For this purpose, the models were categorized in two groups according to their entrainment mechanism and interfacial configurations, i.e., the wave-induced entrainment and the shear-induced entrainment, respectively. Thus, the twelve models(five models for the wave-induced entrainment and seven for the shear induced entrainment) were examined to obtain individual trends and their discrepancies from the general tendency of the overall models. As a result, the critical Weber numbers and entrainment limits were calculated and represented as a function of vapor temperature for the chosen characteristic dimensions of the interface.

• 한국해양환경ㆍ에너지학회지
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• 제10권2호
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• pp.107-111
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• 2007

경계를 가지는 비점성 2유체 유동을 해석할 수 있는 수치해법을 개발하고 이를 이용하여 초기에 정지되어 있는 액체판의 끝단에서 일어나는 수축현상을 분석하였다. 경계면은 보오텍스 쉬트로 모델하였고 유동장은 와도격자법과 경계면추적법을 적용하여 계산하였다. 액체판의 끝단은 표면장력에 의해 수축되고 뭉툭한 형상을 취하게 되고, 이러한 끝단은 잘룩한 형상의 통로에 의하여 액체판에 연결되어 안쪽으로 끌려들게 된다. 이러한 현상을 비점성 조건에서 운동에너지 변화를 포함한 무차원 수의 함수로 분석하였다. 끝단의 수축속도는 로 파악되었고 표면장력파의 전파특성이 엄밀하게 조사되어야 함을 밝혔다.