• Title/Summary/Keyword: Colorimetric method

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Use of HPLC for the Determination of Provitamin A Carotenoids in Red Peppers (HPLC를 이용한 고추 및 고추 가공품의 비타민 A 함량 측정)

  • 김영남
    • Journal of Nutrition and Health
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    • v.25 no.5
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    • pp.389-396
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    • 1992
  • Provitamin A carotenoids($\alpha$- $\beta$-carotene lutein capsanthin) cintents in various red pepper and red pepper products were analyzed by HPLC and UV/VIS spectroscopy. The amounts of $\beta$-carotene and capsanthin were at its highest in powdered red pepper and lutein in red pepper leaves. There are little $\alpha$-carotene present in all samples analyzed. So vitamin A activity was calculated only from $\beta$-carotene content. Capsanthin and $\beta$-carotene contents of red pepper were higher than those of green pepper whereas lutein content of red pepper was lower than that of green pepper. whereas lutein content of red pepper was lower than that of green pepper. Vitamin A activity from colorimetric analysis was higher than that from chromatographic method and results were not generally in accordance with the vitamin A data presented in current food composition tables. Vitamin A activities in retinol equivalent(R. E. ) of green pepper red pepper powdered red pepper fermented red pepper paste and red pepper leaves were 70, 570, 1, 340, 140, 980 R. E respectively.

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Development of Portable Colorimeter and Size Analyzer by Using Smartphone (스마트폰을 이용한 휴대용 색차계와 입도계 개발)

  • Yoo, Sanggyu;Park, Hyunmin;Kim, Hyungu;Kim, Sayeom;Song, Simon
    • Journal of the Korean Society of Visualization
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    • v.17 no.3
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    • pp.19-23
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    • 2019
  • The purpose of this research is to develop a facile measurement system for colorimetric analysis for zinc powder and size analyzer for zeolite particles in order to reduce the process time for their characteristic analysis. We present facile smartphone-based analysis methods to measure and estimate the size of zinc power by using colorimeteric method and the size of zeolite particles by using ImageJ program which is an open-source program. The results show a possibility of our methods to replace the previous professional analysis processes with them.

Diagnosis of Potato Leafroll Virus with Digoxigenin-labeled cRNA Probes (Digoxigenin으로 표지된 cRNA 프로브를 이용한 감자잎말림바이러스(PLRV)의 짐단)

  • 서효원;함영일;오승은;신관용;최장경
    • Korean Journal Plant Pathology
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    • v.14 no.6
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    • pp.636-641
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    • 1998
  • Digoxigenin (DIG) was used to prepare nucleic acid probe for the detection of RNA of potato leafroll virus (PLRV) in the potato leaf extracts. The 0.6 kb coat protein (CP) gene cDNA of PLRV in plasmid pSPT 18 vector was labeled with digoxigenin by in vitro run-off transcription and then used for cRNA probe. In the several buffers tested for increase the total RNA extraction efficiency AMES buffer was the most suitable for this detection method. The RNA extracts from potato leaves shown symptoms of PLRV were dot blotted onto nylon membrane and hybridized with labeled RNA probes. After hybridization, labeled RNA bound to PLRV RNA on membrane was detected with anti-digoxigenin alkaline phosphatase. 5-bromo-4-chloro-3-indolyl-phosphate/nitroblue tetrazolium (NBT) salt and CSPD were used as substrate for colorimetric and film exposure detection, respectively. These detection methods were very sensitive allowing for detection of 1/32 diluted total RNA extract from 100 mg leaf tissue.

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Calibration of Scanner at Color Inspection of printed Texture (직물의 색상검사에서 스캐너의 편차 보정)

  • 정병묵;조지승;박무진
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.383-386
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    • 2002
  • It is very important to inspect color of printed texture in the textile process. To distinguish the color of the printed texture, RGB color values obtained from a scanner must be transformed to the standard colorimetric system used in the textile industry. It is XYZ color system that is defined by CIE(Commission Internationale do 1Eclairage). The mapping from RGB to XYZ color values is not simple and the scanner has even a positional deviation of RGB colors. In this paper an automatic color inspection method using a general scanning machine is presented. We used a U(neural network) model to map RGB to XYZ and compensate the positional error. In the real experiments, this inspection system shows to get very exact XYZ values from the traditional scanner regardless of the measuring position.

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A Study on the Isolative Determination of 4-Morpholine Carboximidoylguanidine Hydrochloride in Ophthalmic Solutions (점안제중(點眼劑中) 4-Morpholine Carboximidoylguanidine Hydrochloride의 분리정량(分離定量))

  • Lah, Woon-Lyong
    • Journal of Pharmaceutical Investigation
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    • v.4 no.1_2
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    • pp.7-12
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    • 1974
  • The isolative determination of 4-Morpholine carboximidoylguanidine Hydrochloride in the ophthalmic solutions was examined by means of colorimetric method using oxidized nitroprusside and sodium hypobromite. According to the results, the following could be summerzied. 1) The wave length of maximun absorption in $650\;m{\mu}$. 2) Beer's Lew is obeyed for $20{\sim}80\;mcg/ml$ in colored solutions. 3) Absorptions of colored solutions must be measured 5 minutes after the addition of oxidized and 5 minutes after the completion of sodium hypobromite. 4) 4-Morpholine carboximidoylguanidine hydrochloride can be determined within standard deviation 2.0%.

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Cytotoxicity of water extract of Dangkwieumja ka Sumsoo on A43l Cells (當歸飮子加蟾수가 皮膚癌細胞(A431)의 細胞毒性에 미치는 影響)

  • Choi, Jeong-Hwa
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.9 no.1
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    • pp.1-15
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    • 1996
  • The purpose of this research was to investigate effect of water extract of DangKwi-Eum-Ja ka Sumsoo(DESE) on the cytotoxicity of human epidemloid cell, A431 cells. The effects of DESE on the proliferation of A431 cells, Balb/c 3T3 cells, mouse thymocytes and splenocnes were estimated by MTT colorimetric assay, and nitric oxide production from mouse peritoneal macrophage was estimated by Griess method. DESE inhibited the proliferation of A431 cells at $10{\mu}g/ml$, and did not affect the proliferation of Balb/c 3T3 cells. DESE decreased the cytotoxicity of mitomycin C or cisplatin on A431 cells, increased the cytotoxicity of mitomycin C or cisplatin on Balb/c 3T3 cells. DESE inhibited the proliferation of mouse thymocytes and splenocytes at $100{\mu}g/ml$. DESE did not affect the nitric oxide production from mouse peritoneal macrophage in vitro, but decreased the nitric oxide production from DESE-treated mouse peritoneal macrophage.

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Studies on the pretense produced by Penicillium species (Penicillium속(屬)이 생산(生産)하는 alkaline pretease에 관(關)하여)

  • Kim, Kyung-Soon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.6 no.1
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    • pp.27-33
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    • 1977
  • The alkaline protease was isolated from the culture of Penicillium species (P-46) grown in the wheat bran media. The crude purification of this enzyme was carried out by extraction with distilled water and precipitated with 0.7-saturated ammonium sulfate, then dialysis for 3days. The activity of this enzyme was determined by Folin's colorimetric method. The results were as follows; 1. The optimum pH and temperature of this enzyme were pH 8.4 and $45^{\circ}C$. 2. This enzyme was stable at pH $7.0{\sim}9.0$. 3. This enzyme was not inactivated by treatment in lower temperature than $30^{\circ}C$. 4. The activity of this enzyme was strongly inhibited by $Hg^{++}$ and $Cu^{++}$, but slightly by $Ag^+$ 5. This enzyme was not inhibited by cystein, thiourea, ${\varepsilon}-aminocaproic$ acid, 2, 4-DNP, EDTA but strongly inhibited by PCMB.

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Studies on Chemical Components in the Korean Panax Ginsevh (1) Identification and Quantitative Determination of ${\beta}$-Sitosterol in Crude Sterol Fraction of the Panax Ginseng (한국인삼의 화학 성분 연구(제1보) 인삼의 Crude sterol fraction 에서의 ${\beta}$-sitosterol 분리 및 정량)

  • Ahn, Young-Pil;Chung, Chong-Cheun
    • Journal of the Korean Chemical Society
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    • v.14 no.4
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    • pp.281-286
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    • 1970
  • A experiment was performed to investigate the stigmasterol and campesterol in the Panax ginseng. Crude sterol fraction obtained from the ginseng was analysed by TLC and quantitative determination of ${\beta}$-sitosterol was performed with colorimetric method. The results were summarized as follwer, 1. It was observed with ethyl ether-petroleum ether extract of the ginseng that there was no evidence of showing the presence of both free capesterol and stigmasterol but that only ${\beta}$-sitosterol was presence in an significant amount. 2. Average amount of the ${\beta}$-sitosterol was 0.20-0.35mg per gram of the sample.

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Mechanochemistry on Self-Assembled Monolayer(SAM) /Electrodes after Contacting with Polymeric Stamp (고분자물질과 접촉한 자기조립단분자막 전극 물질의 기계화학 현상 분광학적 연구)

  • Yun, Changsuk
    • Journal of the Korean institute of surface engineering
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    • v.53 no.5
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    • pp.265-270
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    • 2020
  • We investigated mechanochemical radical, which is concomitant with chemical lift-off lithography(CLL), on the self-assembled monolayer(SAM)/electrodes and a polydimethylsiloxane(PDMS) using a colorimetric and a spectroscopic method. The 11-mercaptoundecanol(MUO)/Au or the 11-hydroxyundecylphosphonic acid (HUPA)/ITO were contacted with bare or activated PDMS. After contact, the each of SAM/substrates and the PDMS were immersed in a 2,2 Diphenyl-1-picrylhydrazyl(DPPH) radical scavenger. The color of the DPPH exposed to the PDMS was changed from purple to yellow and the absorbance decreased definitely at 515 nm wavelength. The SAM/substrates, however, have caused small changes in spectroscopic property, indicating no existence of radical species. We concluded that mechanochemical radicals were formed by homolytic cleavage of PDMS molecules upon external force and hardly transferred on the SAM/substrates.

Synthesis of Platinum-Reduced Graphene Oxide (Pt-rGO) Nanocomposite for Selective Detection of Hydrogen Peroxide as a Peroxidase-Mimic Catalyst

  • Doyun Park;Min Young Cho;Kuan Soo Shin
    • Journal of the Korean Chemical Society
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    • v.67 no.6
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    • pp.415-419
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    • 2023
  • In this study, we report the one-pot synthesis of reduced graphene oxide (rGO) containing platinum nanoparticles with catalytic activity to break down hydrogen peroxide as a peroxidase-mimicking catalyst. A single reducing agent was used to reduce graphene oxide and a platinum precursor at a moderately low temperature of 70℃. The rGO was homogeneously decorated with platinum nanoparticles. The catalytic activity of Pt-rGO was investigated for the oxidation of 3,3',5,5'- tetramethylbenzidine (TMB), a peroxidase substrate, in the presence of hydrogen peroxide. The Pt-rGO coupled with glucose oxidase was also able to detect glucose at millimolar concentrations (up to 1 mM). Our results show that the Pt-rGO composite is a promising catalyst for the detection of hydrogen peroxide. This method was also applied for the detection of glucose.