• Bulletin of the Korean Chemical Society
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• 제17권6호
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• pp.496-498
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• 1996

Fatty alcohol ethers, nonionic surfactants which are used as general purpose emulsifiers were separated by use of water-modified carbon dioxide mobile phase in capillary supercritical fluid chromatography. Much greater peak intensities and improved separation were observed in the chromatogram with on-line modified mobile phase than with pure CO2. A simple method for the preparation of on-line modified mobile phase is also introduced.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.423.1-423.1
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• 2002

A simple. specific and sensitive method for the determination of cyclosporine A (CsA) in human serum has been developed by a high performance liquid chromatography/diode array detector (DAD) and applied to pharmacokinetic study of CsA. This method involves the use of solid phase extraction procedure following rapid protein precipitation with zinc sulphate from 1 $m\ell$ of human serum, using a disposable $C_{18}$ extraction cartridge. (omitted)

• 분석과학
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• 제18권2호
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• pp.147-153
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• 2005

본 연구는 GC/MS를 이용하여 수질, 토양 및 저질 시료 중의 benzophenone (BP)을 분석하는 방법을 확립하고자 하였다. BP는 수질 시료 (100 mL)에서 n-hexane으로 추출하였으며, 토양 및 저질 시료 (10 g)에서는 먼저 메탄올로 추출한 후 hexane으로 다시 추출하여 농축시켜 분석하였다. 수질 시료 중의 BP 회수율은 71.4% 이상이었으며 토양에서의 회수율은 86.5-94.7%를 보였고 재현성은 19.8% 이하였다. 검정곡선은 상관계수 ($r^2$) 값이 수질과 토양 모두에서 0.998이상의 좋은 직선성을 보여주었다. 수질 시료의 경우 43지역 중 3지역의 수질에서 30-200 ng/L 농도 범위로 BP가 검출되었으며 토양과 저질 시료에서는 모든 지역에서 검출되지 않았다. 이 분석방법은 환경 중에 미량으로 존재하는 BP의 분석과 모니터링에 유용하게 사용할 수 있는 적합한 방법이라 사료된다.

• 한국식품위생안전성학회지
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• 제5권3호
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• pp.131-138
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• 1990

Aflatoxins is a chemically diverse group of toxic secondary metabolites that are produced by fungi and often occur in agricultural commodities. Because of their wide range of toxic effects, Aflatoxins cause severe economic losses to farmers and livestock producers and pose a health to human consuming contaminated foods. Long term prospects for biotechnological control of Aflatoxins require elucidation of the specific steps and regulation of their biosynthetic pathways . Aflatoxin determinations can be approached many ways. It is essential to safely handle all experimental materials associated with aflatoxin analysis or aflatoxigenic fungi Visual screening of suspect samples, base on the presence of conidial head of the aspergillus flavus group, and screening samples for the presence of bright greenish yellow flourescence are not chemical tests and such screening techniques may allow aflactoxin contaminated lots into commerce. Microcolumn screening procedures should always be used in conjunction with a quantitative method. Several thin layer chromatography(TLC) and high performance liquid chromatography(HPLC) methods are suitable for quantitation and are in general use. Immunochemical Methods such as the ELISA or affinity column chromatography methods are being rapidly developed. The chemical and immunochemical methods can be reliable if care is taken, using suitable controls and personnel that are well trained . All analytical laboratories should stress safety and include suitable analytical validation procedure. Especially a worldwide enquiry was undertaken in recent to obtain up-to-date information about aflatoxin legislation in as many countries of the world as possible. The information concerns aflatoxin in foodstuffs. aflatoxin MI in dairy products, aflatoxins in animal feedstuffs. Limits and regulations for aflatoxin have been expended in recent with more countries having legislation on subject, more products, and more aflatoxins covered by this legislation.

• 분석과학
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• 제5권4호
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• pp.465-469
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• 1992

유당분해효소의 활성도를 정량하기 위하여 고속액체크로마토그래피(HPLC)를 사용하는 방법을 확립하였다. Aminex HPX-87C 컬럼 및 RI 검출기를 사용하여 유당, 글루코스 및 갈락토스를 12분 이내에 정량적으로 분석할 수 있었다. 컬럼 온도는 $85^{\circ}C$로 고정하였으며 이동상으로는 탈이온화된 증류수를 사용하였다. ONPG(ortho-nitrophenol-${\beta}$-D-galactopyranoside)를 이용하는 발색법의 결과와 비교하여, 고속액체크로마토그래피에 의한 유당분해효소 활성도 측정법의 타당성을 고찰하였으며, 그 결과 ONPG 방법과 고속액체크로마토그래피 방법에 의한 효소활성도 측정의 실험결과에는 큰 차이가 없었으며, 고속액체크로마토그래피를 사용하는 경우에는 420 nm에 대한 방해 작용이 있는 기질에서도 유당분해효소의 활성도를 측정할 수 있는 장점을 가짐을 확인하였다.

• 분석과학
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• 제28권5호
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• pp.317-322
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• 2015

토양 중 음이온 바이오사이드인 chlorite, chlorate, cyanuric acid와 sodium dodecylbenzenesulfonate (Na-DBS)의 liquid chromatography-tandem mass spectrometry (LC-MS/MS) 동시 분석방법을 개발하였다. Chlorite와 chlorate는 물로 추출하였으며, cyanuric acid와 Na-DBS는 0.25 mM ammonium formate를 함유한 20 mM formic acid와 acetonitrile (1:1) 이동상을 이용하여 추출하였다. 추출물은 필터 후 직접 LC-MS/MS로 주입하였다. 분석물질이 검출되지 않는 토양에 각 성분들을 첨가한 후 정도관리를 실시한 결과 검출한계는 chlorite 0.04 mg/kg, chlorate 0.04 mg/kg, cyanuric acid 0.27 mg/kg 그리고 Na-DBS의 경우는 0.05 mg/kg 이었다. 이 방법을 사용하여 우리나라 AI로 소독제를 많이 사용한 장소 40개 지역과 사용하지 않은 지역 10개 대조 지역의 토양을 분석한 결과 대조지역을 포함한 모든 조사지역에서 네 가지 음이온 모두 검출되지 않았다.

• 분석과학
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• 제15권5호
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• pp.410-416
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• 2002

본 연구에서는 LC - MS/MS를 이용해 혈장과 뇨중에서 반코마이신을 신속하게 정량분석하는 방법을 개발하였다. 크로마토그래피는 $C_{18}$ XTerra MS 컬럼 ($2.1{\times}30mm$, $3.5{\mu}m$)을 사용하여 분석하였다. 이동상으로는 0.25% 초산이 섞인 10% 아세토니트릴 용액을 사용하였으며, 유속은 $250{\mu}L/min$이다. 반코마이신과 카페인 (내부표준물질)은 multiple reaction monitoring (MRM) 방법을 사용하여 검출하였으며 반코마이신은 precursor ion m/z 725.0 ( $[M+2H]^{2+}$)와 product ion m/z 100.0을 사용하였다. 혈장에서 반코마이신의 검출한계는 1 nM이며 좋은 정확성과 정밀성을 보여주었다. 또한 혈장중에서 반코마이신의 정량범위는 $0.01{\mu}M$ - $100{\mu}M$이다. 혈장과 뇨중에서 반코마이신을 정량하는 이 분석방법은 약물동력학연구 및 관련연구에 성공적으로 적용되었다.

• 분석과학
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• 제31권3호
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• pp.134-142
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• 2018

The uranium isotopic ratio in environmental samples around nuclear facilities is important because it reveals information regarding illegal activities or anthropogenic pollution. Determination of uranium isotopes, however, is a challenging task requiring much labor and time because of the complex separation procedures and lengthy process. In this study, a rapid determination method for uranium isotopes in environmental samples was developed using. The sample was completely decomposed using the alkali fusion method. The separation procedure using extraction chromatography (UTEVA) was simplified in a single step without any further removal process for Si and major matrix elements. The established method can be completed within 3 h from sample dissolution to ICP-MS measurement. Most matrix elements and uranium isotopes in the soil samples were well separated and purified. Five types of were used to assess the method's accuracy and precision for a rapid uranium analysis method. The analytical accuracy for all CRM samples ranged from 95.1 % to 97.8 %, and the relative standard deviation was below 3.9 %. From the analytical results, one may draw conclusions that the evaluated method for uranium isotopes using alkali-fusion, the extraction chromatography process, and ICP-MS measurements is fast and fairly reliable owing to its recovering efficiencies. Thus, it is expected that the evaluated method can contribute to the improvement of environmental monitoring ability.

• 분석과학
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• 제13권5호
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• pp.666-674
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• 2000

본 연구는 기체크로마토그래피-질량분석법을 이용한 생물시료 중 polybrominated biphenyls(PBBs)의 분석법을 설명하였다. 생물 시료 중 PBB류는 40mL 아세톤과 80mL의 헥산 혼합용매에서 초음파추출기 20분간 교반하여 추출하였다. 추출액 중 존재하는 지질성분은 농축 황산용액으로 분해한 후 PBB류는 Florisil 컬럼으로 정제하였다. PBB류를 정량분석하기 위하여 정제액은 GC/MS-selected ion monitoring 방법에 의해 분석하였다. 본 실험 조건하에서 전반적인 PBB류의 추출율은 77-111%로 나타났다.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2006년도 추계학술대회
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• pp.65-74
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• 2006

Modem drug discovery requires rapid pharmacokinetic evaluation of chemically diverse compounds for early candidate selection. This demands the development of analytical methods that offer high-throughput of samples. Naturally, liquid chromatography / tandem mass spectrometry (LC-MS/MS) is choice of the analytical method because of its superior sensitivity and selectivity. As a result of the short analysis time(typically 3-5min) by LC-MS/MS, sample preparation has become the rate- determining step in the whole analytical cycle. Consequently tremendous efforts are being made to speed up and automate this step. In a typical automated 96-well SPE(solid-phase extraction) procedure, plasma samples are transferred to the 96-well SPE plate, internal standard and aqueous buffer solutions are added and then vacuum is applied using the robotic liquid handling system. It takes only 20-90 min to process 96 samples by automated SPE and the analyst is physically occupied for only approximately 10 min. Recently, the ultra-high flow rate liquid chromatography (turbulent-flow chromatography)has sparked a huge interest for rapid and direct quantitation of drugs in plasma. There is no sample preparation except for sample aliquotting, internal standard addition and centrifugation. This type of analysis is achieved by using a small diameter column with a large particle size(30-5O ${\mu}$m) and a high flow rate, typically between 3-5 ml/min. Silica-based monolithic HPLC columns contain a novel chromatographic support in which the traditional particulate packing has been replaced with a single, continuous network (monolith) of pcrous silica. The main advantage of such a network is decreased backpressure due to macropores (2 ${\mu}$m) throughout the network. This allows high flow rates, and hence fast analyses that are unattainable with traditional particulate columns. The reduction of particle diameter in HPLC results in increased column efficiency. use of small particles (<2 urn), however, requires p.essu.es beyond the traditional 6,000 psi of conventional pumping devices. Instrumental development in recent years has resulted in pumping devices capable of handling the requirements of columns packed with small particles. The staggered parallel HPLC system consists of four fully independent binary HPLC pumps, a modified auto sampler, and a series of switching and selector valves all controlled by a single computer program. The system improves sample throughput without sacrificing chromatographic separation or data quality. Sample throughput can be increased nearly four-fold without requiring significant changes in current analytical procedures. The process of Bioanalytical Method Validation is required by the FDA to assess and verify the performance of a chronlatographic method prior to its application in sample analysis. The validation should address the selectivity, linearity, accuracy, precision and stability of the method. This presentation will provide all overview of the work required to accomplish a full validation and show how a chromatographic method is suitable for toxirokinetic sample analysis. A liquid chromatography/tandem mass spectrometry (LC-MS/MS) method developed to quantitate drug levels in dog plasma will be used as an example of tile process.