• Natural Product Sciences
• /
• 제17권4호
• /
• pp.328-336
• /
• 2011

A high-performance liquid chromatography (HPLC) with diode array detector (DAD) method was established for the discrimination of a folk medicine Forsythia suspensa and Forsythia viridissima. Five and three representative metabolites of the lignan and phenolic glycoside classes were selected for the analysis from F. suspensa and F. viridissima, respectively. The optimal chromatographic conditions were obtained on an ODS column (5 ${\mu}m$, $4.6{\times}250$ mm) with the column temperature at $40^{\circ}C$. The mobile phase was composed of methanol and 0.3% acetic acid using an isocratic elution with the flow rate 1 mL/min. Detection wavelength was set at 280 nm. All calibration curves showed good linear regression ($r^2$ > 0.996) within test ranges. Limits of detection (LOD) and limits of quantitation (LOQ) values were lower than 0.096 and 0.291 ${\mu}g/mL$, respectively. The developed method provided satisfactory precision and accuracy with overall intra-day and inter-day variations of 0.07-0.63% and 0.14-0.62%, respectively, and the overall recoveries of 97.79-102.46% for all of the compounds analyzed. In addition, effectiveness of diverse extraction methods was compared to each other for the development of standard analytical method. The verified method was successfully applied to the quantitative determination of representative metabolites in fifty-three commercial F. suspensa samples and fifteen commercial F. viridissima samples from diverse sources. The overall analytical results showed the unequivocal differences in bioactive constituents between F. suspensa and F. viridissima.

• 분석과학
• /
• 제17권4호
• /
• pp.302-307
• /
• 2004

환경시료중의 극미량의 악티늄계 동위원소들을 분석하기는 무척 어렵다. 이들 원소들은 개별 분리하는 작업이 필요하며, 알파분광법으로 분석한 어떤 핵종들은 검출감도도 높은 편이다. 이런 극미량의 악티늄계 동위원소들을 분석하기 위해 용매추출법이 결합된 TRU-Spec 이온교환수지와 음이온 교환수지를 사용하여 악티늄계 원소들을 분리한 후 알파분광법으로 검출하였다. 그리고 U과 Th의 검출한계를 낮추기 위해 중성자방사화분석법을 적용하였다. 중성자방사화분석법을 적용하기 위한 바탕물질로 고순도 V foil을 사용하여 검출감도를 10배 향상시킬 수 있었으며, 이 분석법을 표준시료인 NIST-4354, IAEA-368 퇴적물 시료에 적용한 결과 표준값과 10% 이내에서 잘 일치하였다.

• 분석과학
• /
• 제14권2호
• /
• pp.115-122
• /
• 2001

우리나라 해안에 인접한 "K"지역 병원에서 구한 44명의 혈액에서 유기주석화합물인 mono-butyltin(MBT), dibutyltin(DBT) 그리고 tributyltin(TBT)을 불꽃광도검출기가 부착한 가스크로마토그라프로 분석하였다. 본 연구의 목적은 일부 주민의 혈액을 대상으로 MBT, DBT, TBT에 대한 분석방법과 농도를 고찰하는 것이다. 본 연구에서 이용한 분석방법에 대한 검출한계(method detection limit, MDL)는 MBT 3.67, DBT 0.91, TBT는 1.09ng Sn/g 습중량 기준으로 나타났다. 또한 일본 국립환경연구소가 제조한 농어중의 $1.3{\mu}g/g$ TBT as chloride의 농도가 가진 표준물질(standard reference material)을 분석한 결과 공인값과 잘 일치하였다. 혈액 중에서 검출된 농도의 범위는 MBT가 3.69-7.93ng Sn/g, DBT 1.15-5.41ng Sn/g이었고, TBT는 검출한계 미만 및 미검출이었다. 혈액중에서 검출된 MBT 및 DBT의 흡수와 축적은 사람들이 유기주석화합물이 생체축적된 수산물의 섭취, 각종 플라스틱류 사용 등에 원인이 있을 것으로 사료된다. 혈액중 유기주석화합물이 인체로 흡수되는 내재용량(internal dose)을 평가할 수 있는 지표서의 신뢰성에 관한 연구가 계속해서 진행되어야 할 것으로 판단된다.

• Bulletin of the Korean Chemical Society
• /
• 제20권10호
• /
• pp.1165-1171
• /
• 1999

The analysis of trace herbicides using the on-line SPE-HPLC system and a photochemical reaction was studied. 18 compounds of herbicides including eight triazines, six phenoxy acids and esters, and four other herbicides were examined. The on-line SPE-HPLC system developed for selection of eluting solvent improved chromatographic efficiency. The recoveries of herbicides were higher than 77%. With 100 mL tap water samples, the detection limits for all analytes were in the 0.1-2.3×10-10 M range. Detection was done by a UV or fluorescence spectrometer after photochemical reaction at the end of the column with 2W or 450W mercury lamp. Without a photochemical reaction, all compounds responded to 230 nm UV detector, but phenoxy acids and esters were weakly detected. However, with a photochemical reaction, these compounds were selectively detected at 320 nm wavelength of UV absorption and 400 nm emission of the fluorescence detectors. This method can be used for the analysis of environmental water containing herbicides at trace levels.

• Journal of Positioning, Navigation, and Timing
• /
• 제9권3호
• /
• pp.215-220
• /
• 2020

This paper deal with estimating the direction of arrival (DOA) of GNSS signal using two antennae for spoofing detection. A technique for estimating the azimuth angle of a received signal by applying the interferometer method to the GPS carrier signal is proposed. The experiment assumes two antennas placed on the earth's surface and estimates the azimuth angle when only GPS signal are received without spoofing signal. The proposed method confirmed the availability through GPS satellite placement simulation and experiments using a dual antenna GPS receiver. In this case of using dual antenna, an azimuth angle ambiguity of the received signal occurs with respect to the baseline between two antennas. For this reason, the accurate azimuth angle estimation is limits, but it can be used for deception by cross-validating the ambiguity.

• 한국임상약학회지
• /
• 제5권2호
• /
• pp.71-74
• /
• 1995

A high performance liquid chromatographic method has been developed for the simultaneous analysis of non-steroidal anti-inflammatory drugs in plasma. The simultaneous determination of ibuprofen, fenoprofen and ketoprofen is performed by RP-HPLC with UV detection. The chromatographic system consisted of Spherisorb octyl column$(5{\mu}m)$ ; the mobile phase was $acetonitrile\;-\;0.5\%$ phosphoric acid(55 : 45, v/v) and the detection wavelength was 230nm. Tolmetin was employed as an internal standard. The method described is rapid and simple with sensitivity limits of $2.0{\mu}g/ml$ ibuprofen, $0.5{\mu}g/ml$ fenoprofen and $0.3{\mu}g/ml$ ketoprofen and is suitable for routine clinical and pharmacokinetic studies.

• 분석과학
• /
• 제12권4호
• /
• pp.341-345
• /
• 1999

The separation and determination of inorganic cations by a capillary zone electrophoresis was studied. Cations were separated by the capillary column and detected by indirect UV method. The running buffer of 0.03 M creatinine and 0.02 M-hydroxy isobutylic acid solution (pH 4.8) was used to improve the mobility of ions in the column. A potential of 18 kV was applied at anode. A complete separation of cations ranged within 15 min and detection limits were between 0.1 and 1.0 ppm. The applicability of the method for real samples was demonstrated.

• 대한화학회지
• /
• 제38권6호
• /
• pp.418-426
• /
• 1994

미국 환경청이 지정한 129종의 priority polluatants 중 40종의 비휘발성 염기/중성 유기화합물을 대상물질로 선정하였다. 분석방법으로 초음파 추출법(sonication extraction)과 Soxhlet 추출법(Soxhlet extraction)을 이용하여 토양에 있는 유기물을 추출 및 농축하여 기체크로마토그래프/질량분석기-SIM(selected ion monitoring)법으로 검출하였다. 표준물질이 첨가된 토양시료에 두 추출법을 적용하여 회수율을 구하고 정확도, 정밀도 및 검출한계를 측정하여 미량 분석의 가능성을 조사하였다.

• Journal of Ginseng Research
• /
• 제19권2호
• /
• pp.134-137
• /
• 1995

Ginseng saponins were analyzed by thermospray (TSP) LCMS method using ODS column and with acetonitrile/ammonium acetate solution. Optimal condition for TSP Lchfs was found as follows: capillary temperature: 33$0^{\circ}C$ repelled voltage: 200 V, and concentration of ammonium acetate: 0. 05 M. Panaxadiol and panaxatriol type saponins showed characteristic fragment ions. The calibration curve of ginseng saponin showed good linearity with a correlation coefficient of 0.99. Detection limits using selected ion monitoring (SIM) technique were improved by 10~200 times compared to conventional HPLCnnr detection method.

• Food Science and Biotechnology
• /
• 제18권5호
• /
• pp.1118-1123
• /
• 2009

Event-specific real-time polymerase chain reaction (PCR) detection method for genetically modified (GM) maize MIR604 was developed based on integration junction sequences between the host plant genome and the integrated transgene. In this study, 2 primer pairs and probes were designed for specific amplification of 100 and 111 bp DNA fragments from the zSSIIb gene (the maize endogenous reference gene) and MIR604. The quantitative method was validated using 3 certified reference materials (CRMs) with levels of 0.1, 1, and 10% MIR604. The method was also assayed with 14 different plants and other GM maize. No amplification signal was observed in real-time PCR assays with any of the species tested other than MIR604 maize. As a result, the bias from the true value and the relative deviation for MIR604 was within the range from 0 to 9%. Precision, expressed as relative standard deviation (RSD), varied from 2.7 to 10% for MIR604. Limits of detections (LODs) of qualitative and quantitative methods were all 0.1%. These results indicated that the event-specific quantitative PCR detection system for MIR604 is accurate and useful.