• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3275-3279
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• 2014

A mass balance method for purity assessment of thermolabile organic reference materials was established by combining several techniques, including liquid chromatography with UV/VIS detector (LC-UV), Karl-Fischer (K-F) Coulometry, and thermal gravimetric analysis (TGA). This method was applied to three fluoroquinolones like enrofloxacin, norfloxacin and ciprofloxacin. LC-UV was used to analyze structurally related organic impurities based on UV/VIS absorbance spectra obtained in combination with LC separation. For all three organic reference materials, the UV/VIS spectra of the separated impurities were similar to that of the major component of the corresponding materials. This indicates that the impurities are structurally related to the respective reference material sharing common chromophores. Impurities could be quantified by comparing their absorbances at the wavelength of maximum absorbance (${\lambda}_{max}$). The water contents of the reference materials were measured by K-F Coulometry by an oven-drying method. The total inorganic impurities contents were assayed from ash residues in TGA analysis with using air as a reagent gas. The final purities estimated from results of those analytical techniques were assigned as ($99.91{\pm}0.06$), ($97.09{\pm}0.17$) and ($91.85{\pm}0.17$)% (kg/kg) for enrofloxacin, norfloxacin and ciprofloxacin, respectively. The assigned final purities would be applied to the reference materials which will be used as calibrators for the certification of those compounds in matrix CRMs as starting points for the traceability of their certified values to SI units.

• 폴리머
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• 제26권2호
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• pp.209-217
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• 2002

편광 푸리에 변환 적외선 분광법과 자외선 분광법을 이용하여 액정 display (LCD)의 배향막으로 널리 사용되는 폴리이미드 (PI) 필름의 편광 자외선 (PUV) 조사에 따른 액정의 배향 메카니즘을 연구하였다. UV 측정 결과, PI 필름은 360 nm 이하 파장의 자외선을 주로 흡수하여 광화학 반응이 유도됨을 알 수 있었다. 또한, PUV가 조사된 PI의 경우, PI 분자들의 분해로 인해 FT-IR 흡수 피크들의 강도가 조사시간에 따라 감소하였고, $3244 cm^{-1}$ 부근에서 완만한 곡선 형태의 새로운 피크가 형성되었다. 또한 조사된 PUV의 극성 방향에 평행한 PI 분자들의 우선적인 광분해 반응으로 인하여 PUV 조사 후 남아 있는 PI 분자들은 조사된 PUV 극성 방향과 수직 배향을 나타내었다. 하지만 러빙 처리된 PI 필름은 러빙 방향과 평행하게 PI 분자들의 재배향이 유도됨을 확인하였다. 또한 러빙 처리 및 PUV가 조사된 PI 배향막을 차용하여 제조된 액정 셀에서는 액정이 러빙 방향에 대해서는 평행하게, 조사된 PUV의 극성방향과는 수직으로 배향함을 확인하였다.

• 한국물환경학회지
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• 제37권5호
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• pp.344-354
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• 2021

Optical methods such as UV and fluorescence spectrophotometers can be applied not only in the qualitative analysis of dissolved organic matter (DOM), but also in real-time quantitative DOM monitoring for wastewater and natural water. In this study, we measure the UV₂₅₄ and fluorescence excitation emission spectra for a sewage treatment plant influent and effluent, and river water before and after sewage effluent flows into the river to examine the composition and origin of DOM. In addition, a correlation analysis between quantified DOM characteristics and dissolved organic carbon (DOC) was conducted. Based on the fluorescence excitation emission spectra analysis, it was confirmed that the protein-type tryptophan-like DOM was the dominant substance in the influent, and that the organic matter exhibited relatively more humic properties after biological treatment. However, DOM in river water showed the fluorescence characteristics of terrestrial humic-like and algal tyrosine-like (protein-like) organic matter. In addition, a correlation analysis was conducted between the DOC and optical indices such as UV₂₅₄, the fluorescence intensity of protein-like and humic-like organic matter, then DOC prediction models were suggested for wastewater and river monitoring during non-rainfall and rainfall events. This study provides basic information that can improve the understanding of the contribution of DOC concentration by DOM components, and can be used for organic carbon concentration management in wastewater and natural water.

• 약학회지
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• 제38권4호
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• pp.366-371
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• 1994

To improve the identification power of TLC/HPTLC the in situ reflectance spectra obtained directly from plates with commercial scanner are used. The spectrum normalization should be carried out prior to comparing and searching the spectra from library for the identification of compounds. Because the reflectance does not obey the Lambert-Beer's law, there arise some problems in normalization. These problems could be solved to some extent by normalizing the spectra with regression methods. The spectra are manipulated with the regression function of a curve obtained from the correlation plot. When the parabola was used as the manipulating function, the spectra were identified with the accuracy of 97% and this result was better than that of conventionally used the point and area normalization method.

• 펄프종이기술
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• 제31권2호
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• pp.58-63
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• 1999

Three kinds of papers were prepared from different beating degree of pulps. Physical and optical properties were examined to elucidate the deterioration mechanism of paper according to beating degrees. Changes of double folds, elongation, water retention value, DP, K/S value and visible, UV region light absorption spectra of those papers treated by UV light were studied. Double folds and brightness were decreased more rapidly by UV treatment with increasing of beating degree. The light absorption rates of pulps in visible and UV region were also increased with change of beating level. The formation of new hydrogen bonds and higher light absorption rate of pulps according to beating induced to absorb and interact with much UV light. These phenomena maybe brought about to accelerate paper deteriortion by UV treatment both optical and physical properties.

• 한국염색가공학회지
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• 제26권1호
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• pp.53-62
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• 2014

This study examined the dyeability, color fastness and functionality of cotton fabrics dyed with residual parts of cultivated Pteridium aquilinum. UV-Vis absorption spectrum, TLC and FT-IR spectra analysis showed that colorants of Pteridium aquilinum are a mixture of pyrogallol tannin and catechol tannin. Optimum dyeing conditions was confirmed colorant concentration of 500% at $100^{\circ}C$ for 60 minutes. Color fastness followed to washing, rubbing, perspiration and light as 4-5, 5, 4-5(acidic), 3-4(alkaline) and 2, respectively. Deodorization rates of ammonia($NH_3$) and acetic acid ($CH_3COOH$) were analyzed 88.8% and 78.0%. UV protection rate was 94.2% of UV-A and 96.8% of UV-B. UV protection factor(UPF) was 27. Therefore residual parts of cultivated Pteridium aquilinum could be used for a new functional colorant.

• 한국식품과학회지
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• 제37권3호
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• pp.360-363
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• 2005

가시오가피에서 Polyacetylene 성분 중 falcarinol을 탐색하기 위해 TLC, HPLC/PDA, GC, GC/MS를 이용하여 falcarinol 표준품과 소분획물 사이의 비교 분석을 통하여 가시오가피에서 falcarinol을 동정하였다. 가시오가피 추출물을 silica gel column상에서 용매의 극성차이에 의해 6개의 분획물을 얻었고, 6개의 분획물과 falcarinol 표준품과의 TLC 상에서 전개시킨 결과 fraction 6 분획물에서 falcarinol과 동일 band의 물질을 분리하였다. Fraction 6의 분획물과 falcarinol 표준품을 HPLC/PDA로 분석한 결과 falcarinol 표준품의 peak와 동일 retention time의 peak를 fraction 6에서 분리하여 200-340nm 상에서 UV spectrum을 관찰한 결과 동일한 UV spectrum pattern을 보이는 것을 확인하였다. 이는 전형적인 polyacetylene 화합물의 UV spectrum pattern이었으며, 기존에 보고된 falcarinol의 UV spectrum과도 동일하였다. GC로 TMS 유도체화 전,후의 retention time을 확인한 결과 표준품과 fraction 6에서 동일한 결과를 보였다. TMS 유도체화 후에는 7.5분에서 8.5분으로 약 1분 정도 retention time이 증가하였고, detection 감도 또한 증가하였다. Falcarinol 표준품과 fiaction 6 분획물을 TMS 유도체화 후에 GC/MS로 mass fragment ion을 분석한 결과 표준품과 동일한 경향을 보였고 이는 기존의 보고와도 일치하였다(16). 본 실험결과들로 미루어 가시오가피에도 polyacetylene 성분인 falcarinol 존재하는 것으로 확인되었다.

• Archives of Pharmacal Research
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• 제12권4호
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• pp.289-294
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• 1989

A computer program which can differentiate compounds whose absorbance spectra are very similar was developed. The program. [SPECMAN PLUS], written in Pascal provides automated spectral comparison techniques, utilizing the values of Root Mean of Squares (RMS) of differences. This comparison routine of the program can deal with spectra of compounds different concentrations and different spectral recording resolutions. In addition, the program was designed applicable to any spectral data of digital form. The program was applied to the UV spectra of 13 pencillins and 5 cephalosporins, whose absorbance spectra are so similar. As a result, all compounds examined could be differentiated from each other.

• 분석과학
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• 제13권3호
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• pp.282-290
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• 2000

본 연구는 390nm 이하에서 자외선 흡수가 완벽한 폴리카보네이트(광학용)에 첨가된 각종 첨가제를 아세톤으로 추출하거나 용해-침전 방식으로 분리하여 분석하는 것이다. 분리된 첨가제를 정성적으로 분석하기 위해 자외선흡광광도계, FT-IR 및 HPLC로 분석하였다. 분리된 물질은 광안정제 및 산화방지제(1차 및 2차)등의 첨가제와 단량체 및 올리고머가 함유된 복잡한 혼합물로 추정할 수 있다. 분리된 첨가물을 Bondapak $C_{18}$ 칼럼, 메탄올 이동상, PDA (Photodiode Array) 검출기를 사용한 역상(reversed phase, RP) HPLC 분석을 통해 비스페놀 A, Irganox 1010, Cyasorb UV-5411 성분들을 확인할 수 있있다. 또한, 자외선 흡광도를 이용한 정량분석을 통해 폴리카보네이트에 광안정제인 Cyasorb UV-5411가 0.12중량% 함유된 것을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4093-4097
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• 2012

We introduced a new UV-cured resin polymer gel as an electrolyte for dye-sensitized solar cells (DSSCs) that is cured with UV irradiation to form a thin film of UV-cured resin polymer gel in the cells. The gel film was characterized and its potential for use as an electrolyte in DSSCs was investigated. This new UV-cured resin polymer gel was successfully applied as a gel polymer electrolyte in DSSCs overcoming the problems associated with the liquid electrolytes in typical DSSCs. The effect of ${\gamma}$-butylrolactone (GBL) on the long-term stability and photovoltaic performance in DSSCs using this UV-cured resin polymer gel electrolyte was also investigated. The results of the energy conversion efficiency, ionic conductivity and Raman spectra of the UV-cured resin polymer gel electrolyte with the addition of 6 wt % GBL to the UV-cured resin polymer electrolyte showed good long-term stability and photovoltaic performance for the DSSCs with the UV-cured polymer gel electrolyte.