• ETRI Journal
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• 제27권4호
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• pp.446-448
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• 2005

Using tightly focused femtosecond laser pulses, we produce an optical waveguide and devices in transparent materials. This technique has the potential to generate not only channel waveguides, but also three-dimensional optical devices. In this paper, an optical splitter and U-grooves, which are used for fiber alignment, are simultaneously fabricated in a fused silica glass using near-IR femtosecond laser pulses. The fiber- aligned optical splitter has a low insertion loss, less than 4 dB, including an intrinsic splitting loss of 3 dB and excess loss due to the passive alignment of a single-mode fiber. Finally, we present an output field pattern, demonstrating that the splitting ratio of the optical splitter becomes approximately 1:1.

• 한국광학회지
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• 제11권1호
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• pp.43-46
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• 2000

Kerr 렌즈 모드록킹된 티타늄 사파이어 레이저에서 상용화된 광학부품만을 이용하여 9 fs의 펄스를 생성하였다. 공진기 내부와 출령경을 지나면서 발생하는 군속도 분산을 각각 용융 프리즘 쌍을 이용하여 보상하였고, 넓은 스펙트럼을 얻기 위하여 광대역 거울을 사용하였다. 이전에 사용했던 광대역 거울과 반사율을 비교해 봄으로서 10fs 미만의 극초단 펄스를 생성하기 위해서는 180nm 이상의 넓은 반사대역을 갖는 거울을 선택하는 것이 필수적임을 확인하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권1호
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• pp.11-15
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• 2006

We propose an optical and an electrical detection methods for detecting various bio-molecules effectively with microcantilevers. The microcantilevers were fabricated employing surface micromachining technique that has attractive advantages in terms of cost efficiency, simplicity and ability of fabricating in array. The fluid cell system for injection of bio-molecular solution is fabricated using polydimethylsiloxane (PDMS) and a fused silica glass. The microcantilever is deflected with respect to the difference of the surface stress caused by the formation of self-assembled bio-molecules on the gold coated side of the microcantilever. It detected cystamine dihydrochloride and glutaraldehyde molecules and analyzed individual concentrations of the cystamine dihydrochloride solution. We confirm that the deflections of bending-up or bending-down are occurred by the bio-molecule adsorption and microcantilever can be widely used to a ${\mu}-TAS$ and a lab-on-a-chip for a potential detection of various bio-molecules.

• 분석과학
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• 제17권2호
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• pp.192-197
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• 2004

The discrimination of bracken (Korean vs. Chinese) has been attempted using capillary electrophoresis (CE). Bracken (Pteridium aquilinum) was extracted with 30% methanol and separated on a uncoated fused-silica ($50{\mu}m{\times}27cm$) capillary. Conditions for optimal analysis include: temperature, $40^{\circ}C$; voltage, 8 kV; and pressure injection time, 5 sec. The optimal separation buffer was 0.3 M borate buffer (pH 8.5) containing 40 mM CHAPS with 30% ethylene glycol. Under the optimal conditions established for CE, the ratio of specific peak area (peak PA-1) to other peak area (peak PA-2) was effective in discrimination of Korean and Chinese bracken. The mean accuracy for discrimination of Korean and Chinese brackens were 80% and 86%, respectively.

• Bulletin of the Korean Chemical Society
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• 제12권1호
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• pp.87-92
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• 1991

A dual capillary column system is described for the simultaneous measurement of retention index (RI) and area ratio (AR) values of each peak on two capillary columns of different polarity, DB-5 & DB-1701. Both capillary columns were connected to a common splitless injector via a deactivated fused-silica capillary tubing of 1 m length and a 'Y' splitter, the dead volume effect of which was found to be negligible. RI and AR were measured with high reproducibility(${\leq}$0.05% RSD) and with high accuracy (<10% RE), respectively. When applied to the test samples of the organic acid mixture, each acid was positively identified by the combined computer RI library search-AR comparison.

• Bulletin of the Korean Chemical Society
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• 제15권11호
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• pp.945-949
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• 1994

Mixtures of cyano complexes of palladium(II) and platinum(II) were separated by capillary electrophoresis using a fused silica capillary as a separation column and 30 mM phosphate buffer (pH 7) containing 15 wt. % acetonitrile as a running buffer. By virtue of the high ionic mobilities of the negatively charged cyano complexes of Pd(II) and Pt(II), they were separated using a cathodic injection and anodic detection scheme. The metal complexes eluted through the capillary were detected by direct UV absorption at 214 nm. A linear relationship between peak area and concentration was obtained for both ions and the detection limit was lower than $10^{-14}$ mole. The proposed method was applied to real sample, e.g., anode slime obtained from an electrolytic copper refinary, as a method for the simultaneous determination of palladium and platinum.

• Bulletin of the Korean Chemical Society
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• 제20권12호
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• pp.1483-1486
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• 1999

The contents of pentachlorophenol (PCP) and 2,3,5,6-tetrachlorophenol (TeCP) in textile products are regulated for safety. Since an organic solvent such as 2-methoxyethanol is needed to extract chlorinated phenols from textile samples, nonaqueous capillary electrophoresis has been applied to achieve the separation of PCP and isomers of TeCP. The run buffer was 100 mM Tris/acetate in methanol whose pH was adjusted to 8.0. All of the analytes were negatively charged at pH 8.0 and their electrophoretic velocities were higher than the electroosmotic flow of the methanol buffer. A reverse voltage of -20 kV was applied along a 27-cm fused silica capillary with ID of 50 μm, and PCP and 3 TeCP isomers were separated based on the difference in $pK_a$ values in less than 4 min. The limits of detection (S/N = 3) were about 0.02 μM. By varying pH of the methanol run buffer, $pK_a$ values of the 4 chlorinated phenols were also estimated.

• Bulletin of the Korean Chemical Society
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• 제14권2호
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• pp.250-255
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• 1993

A dual capillary column system is described for the simultaneous analysis of a given sample and measurement of retention index (RI) and area ratio (AR) values of each peak on two capillary columns of different polarity, DB-5 & DB-1701 from a single injection. Both capillary columns were connected to either a splitless injector or an on-column injector via a deactivated fused-silica capillary tubing of 1 m length and a 'Y' splitter. Both injection modes allowed to measure RI and AR values with high reproducibility (<0.01% RSD) and high accuracy (<10% RE), respectively with the exception that the trace and high boiling solutes required the on-column mode for the accurate quantification and AR comparison. When the dual capillary column system in on-column injection mode was applied to the blind samples containing organic acids, each acid was positively indentified by the combined computer RI library search-AR comparison.

• Applied Biological Chemistry
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• 제32권4호
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• pp.350-356
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• 1989

무주산 오미자로부터 lignan 화합물인 deoxyschizandrin, gomisin N, schizandrin, gomisin A, wuweizisu C, angeloygomisin H 및 tigloylgomisin H를 분리 동정하고 capillary-GC (FID)를 이용하여 이들 화합물의 정량성을 조사하였다. 이 때 lignan 화합물의 동정에는 GC/MS (Finigan MAT 212; El, 70eV), 1H-NMR (Bruker FT; 300MHz) 및 IR (Perkin Elmer 599B)을 이용하였으며, lignan 화합물의 정량에는 FID 및 integrator(Hewlett-Packard 3393A)가 부착된 GC (Hewlett-Packard 5890A)를 이용하였다. 한편, GC column은 SPB-1 fused silica capillary$(0.25mm\;ID{\times}30m,\;Supelco)$를 사용하였고 column oven의 온도는 $200^{\circ}C$부터 $300^{\circ}C$까지 분당 $4^{\circ}C$씩 승온하였으며, carrier gas는 $N_2$, 1.0ml/min(split ratio=40 : 1)을 사용하였다. 각 lignan 화합물의 정량 가능농도범위는 deoxyschizandrin과 wuweizisu C가 $2{\sim}500ppm$이었고 gomisin N, schizandrin, gomisin A, angeloylgomisin H 및 tigloygomisin H 가 $5{\sim}500ppm$이었으며 무주산 오미자의 lignan성분 함량은 schizandrin이 6.50mg/g으로 가장 높았고 gomisin N, gomisin A, wuweizisu C, angeloylgomisin H, deoxyschizandrin, tigloylgomisin H의 순으로 낮은 경향이었다.

• Applied Biological Chemistry
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• 제46권4호
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• pp.380-384
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• 2003

최근 수입자유화 이후 중국산 한약재의 수입이 증가하면서 수입산과 국산의 명확한 판별이 요구되고 있는 가운데 수입이 급증한 품목 중 하나인 천궁을 선택, CE를 이용한 분석조건을 확립하고 원산지판별에의 적용가능성을 검토하였다. 분석을 위한 지표물질의 추출에는 30% ethanol 을 사용하였고, $50\;{\mu}m\;I.D.{\times}27\;cm$ 길이의 uncoated fused-silica capillary를 이용하여 $40^{\circ}C$, 10 kV로 200 nm에서 분석하였다. 0.1 M phosphate buffer(pH 2.5)에 40% methanol과 15 mM IDA를 첨가하여 분석 buffer로 사용하였고, 국산시료는 5초, 수입산은 2초 동안 pressure injection하였다. 분석 시 시료 injection 전에 증류수로 4분간 흘려주고 분석 buffer로 10분간 평형화시켰으며 분석이 끝난 후 0.1M phosphoric acid와 1N sodium hydroxide를 각각 4분씩 흘려 분석의 재현성을 높이고자 하였다. 이상의 조건으로 시중에 유통되는 국내산(62점)과 수입산(51점) 천궁을 분석한 결과 전체 peak에 대한 구성비율이 서로 차이를 나타내는 peak LW-1과 peak LW-5(용출시간 약 11분, 14분)를 원산지 판별에 적용할 수 있는 peak로 도출하였으며, 이 peak를 이용한 국산 및 수입산 천궁의 원산지 판별율은 국산이 약 65%(총 62점 중 40점을 바르게 판별), 수입산은 약 63%(총 51점 중 32점을 바르게 판별)로 나타났다.