• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.2
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• pp.25-30
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• 2021

This study investigated how the indicators of quality control are improved by proficiency in the measurement of phosphate concentration. In addition, analysis equipments were to be compared to see if there were any differences in measurements depending on the type of analysis device. In order to find out the effect of the proficiency of the analyst on the analysis results, three analysts measured phosphate concentration seven times in accordance with the Korean water pollution test standards, and met the quality control indices if repeated more than five times. The limit of quantification for phosphate was calculated at 0.02 mg/L. If the analysis devices are different, the absorbance and concentration of the samples near the limit of quantification are statistically significant difference.

• Journal of Science and Technology Studies
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• v.7 no.2
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• pp.125-154
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• 2007

1997년부터 2002년까지 수돗물의 바이러스 오염 여부에 관한 논쟁이 있었다. 서울대의 K 교수는 학회에서 수돗물을 분석한 결과 질병을 일으키는 바이러스가 검출되었다고 보고했고, 이 내용이 언론을 통해 보도되면서 수돗물의 안정성에 대한 논쟁이 일어났다. 이 논쟁은 바이러스 검출방법론의 신뢰성을 둘러싼 과학적 논쟁과 검출된 바이러스가 위험한지에 대한 위험논쟁이 함께 공존하며 진행되었다. 필자는 정책의 변화를 요구하는 과학적 사실을 둘러싼 논쟁을 분석하기 위해 과학전문가와 정부를 분석의 대상으로 삼고 있으며, 아래의 세 가지를 주장하고 있다. 첫째, 논쟁을 제기한 과학자(K 교수)와 정부(환경부, 서울시)가 바이러스의 확인부터, 승인, 정책 결정에 이르는 전 과정에서 검출방법론에 차이를 보이고 있으며, 이러한 방법의 차이는 민감성과 정확성을 추구하는 과학계와 법적기준을 위한 정량적 가치를 중시하는 정부의 특징이 반영된 것임을 주장한다. 둘째, 과학논쟁에서 K 교수팀이 PCR 방법을 통해 바이러스의 실재(reality)를 확인하면서 과학적 정당성을 확보했음을 보인다. 셋째 바이러스의 검출 방법에서 PCR 방법이 과학적 실재를 결정했지만, 위험의 실재를 규정하는 데에는 한계가 있었음을 지적한다. 마지막으로 본 논문은 논쟁분석을 통해 정책입안을 둘러싼 과학 위험논쟁에서 과학전문가의 역할을 고찰하고 있다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.273-273
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• 2002

대기 중 기체상 알데히드와 케톤류 등의 자동분석을 개발하고 이를 실제 대기 분석에 응용하였다. 본 분석장치는 분석 기체를 흡수 농축하는 확산 스크러버와 홉수액을 분석하는 고성능 액체크로마토 그래피로 구성되어 있다. 분석기체는 스크러버 속에서 기체와 반대방향으로 흐르는 DNPH 흡수액에 흡수되어 하이드라존을 형성하고 HPLC에서 분리 검출된다. 표준편차 3배로 정의한 본 방법의 검출한계는 수ppt로 매우 낮아 환경대기의 분석이 가능하다. (중략)

• Analytical Science and Technology
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• v.31 no.1
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• pp.23-30
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• 2018

Twenty-two allergy-induced aromatics in children were analyzed using a gas chromatography flame ionization detector (GC-FID) and gas chromatography mass spectrometer (GC-MSD). Analytes were extracted using an automatic Soxhlet extractor and centrifuged for 10 min in a fast freezing centrifuge, and the supernatant was transferred into a 2 mL vial and injected in split mode. Under the established conditions, the calibration curve showed linearity with a correlation coefficient of 0.996 or more. A wide range of sensitivity of 6.7 to 1,859,839 depending on the device characteristics and detector used was shown. The detection limit of the device was 0.0032 to $0.0335{\mu}g/mL$, and the maximum detection limit was less than $0.1{\mu}g/mL$. The detection limit of the method ranged from 0.0033 to $0.1161{\mu}g/mL$. In addition, the limit of quantification ranged from 0.0100 to $0.5422{\mu}g/mL$, with a level of precision ranging from 0.21 % to 4.89 % and a degree of accuracy ranging from 89 % to 111 %. The analytical method developed in this study was applied to commercial products.

• Journal of the Korean Chemical Society
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• v.35 no.6
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• pp.699-706
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• 1991

The moderate power (500 W) Microwave Induced Plasma was generated with helium gas and was used for the direct analysis of aqueous samples. Usually, the helium plasma obtained with a modified Beenakker type cavity forms a cylindrical one. Though, by the careful controls of gas flows, a "toroidal" shape plasma could be made but its analytical performances were found to be worse. Using the glass frit nebuliser, the detection limits for metal ions obtained were around 10~100 ppb and that for chloride was about 50ppm.

• Journal of the Korea Convergence Society
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• v.9 no.3
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• pp.165-171
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• 2018

In this study, to analyze the detection of limit for sensitivity of the influenza rapid antigen test kit, the positive detection of limits were analyzed by serial dilution of influenza virus A and B type for five influenza rapid antigen test kits in Korea. As a result of analysis, visual measurement of type A were up to 1:8192 for the Wellsbio product and up to 1:4096 for the II product, up to 1:512 for the I and III products, and only 1:128 for the IV product, and type B were positive for up to 1:8192 for the Wellsbio product, up to 1: 4096 for the II product and up to 1:1024 for the I, III and IV products. For instrument readings with the same specimen, both A and B types were found to be positive for up to 1:8192 for the Wellsbio product, up to 1: 4096 for the II product, and up to 1:2048 for the I product. The sensitivity of the rapid antigen test for influenza differs greatly depending on the sampling area of the patient, infection period, specimen volume, etc. Therefore, it is necessary to observe exactly the collection timing and method of the specimen. And it is necessary further study to improve the sensitivity for influenza rapid antigen test.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.289-295
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• 2018

The aim of this study was to develop and validate an analytical method for determining the presence of wogonin, quercetin, and quercetin-3-O-glucuronide in extracts of Nelumbo nucifera, Morus alba L., and Raphanus sativus mixtures. We evaluated the specificity, linearity, precision, accuracy, limit of detection (LOD), and limit of quantification (LOQ) of analytical methods for wogonin, quercetin, and quercetin-3-O-glucuronide using high performance liquid chromatography. Our result showed that the correlation coefficients of the calibration curve for wogonin, quercetin, and quercetin-3-O-glucuronide were 0.9999. The LOD for wogonin, quercetin, and quercetin-3-O-glucuronide ranged from 0.09 to 0.16 and those for the LOQ ranged from 0.26 to $0.48{\mu}g/mL$. The inter-day and intra-day precision values of wogonin, quercetin, and quercetin-3-O-glucuronide ranged from 0.74 to 1.87 and from 0.28 to 1.12%, respectively. The inter-day and intra-day accuracies were 99.96~115.88% and 99.73~114.81%, respectively. Therefore, the analytical method was validated for the detection of wogonin, quercetin, and quercetin-3-O-glucuronide in extracts of Nelumbo nucifera, Morus alba L., and Raphanus sativus mixtures.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.4
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• pp.333-340
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• 2019

This study attempted to eatablish a high performance liquid chromatography (HPLC) analysis method for the determination of avicularin, quercitrin as a part of the quality control for the development of functional cosmetic materials from Astilbe chinensis extract. HPLC was performed on a Capcell Pak C₁₈ MGII column with a gradient elution of 0.05% (v/v) trifluoroacetic acid (TFA) and acetonitrile at a flow rate of 1.0 mL/min at 30 ℃. The analyte was detected at 254 nm. The HPLC method was performed in accordance with the international conference on harmonization (ICH) guideline (version 4, 2005) of analytical procedures with respect to specificity, precision, accuracy, and linearity. The limits of detection and quantitation of avicularin and quercitrin were 0.094 and 0.285 mg/mL, 0.031 and 0.095 mg/mL respectively. Calibration curves showed good linearity r² > 0.99990 for avicularin and r² > 0.99994 for quercitrin. Precision of analysis was satisfied with less than 0.59% for avicularin and 0.63% for quercitrin. Recoveries of quantified compounds ranged from 100.97 to 101.77% for avicularin and 100.18 to 100.32% for quercitrin. These result indicated that the established HPLC method is very useful for the determination of marker compounds in A. chinensis extracts.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.1
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• pp.57-63
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• 2021

In this study, isoscoparin was selected as an indicator component to develop Silene seoulensis extract as a functional cosmetic material, and we developed an analysis method using high performance liquid chromatography (HPLC) for quality control. HPLC was performed on a Unison US-C18 with a gradient elution of 0.05% (v/v) trifluoroacetic acid (TFA) and methanol at a flow rate of 1.0 mL/min at 35 ℃, and the detection wavelength was 330 nm. The HPLC method was performed in accordance with the international conference on harmonization (ICH) guideline (version 4, 2005) of analytical procedures with respect to specificity, precision, accuracy, and linearity. The limits of detection and quantitation were 0.02 and 0.07 mg/mL respectively. Calibration curves showed good linearity (R2 > 0.99988), and the precision of analysis was satisfied (less than 0.46%). In addition, the recovery rate was in the range of 99.10 to 101.61%, it was shown to be accurate. This result indicated that the established HPLC method is very useful for the determination of marker compounds in Silene seoulensis extracts.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.1
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• pp.87-93
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• 2019

This study attempted to eatablish a High Performance Liquid Chromatography (HPLC) analysis method for the determination of (-)-epicatechin gallate as a part of the quality control for the development of functional cosmetic materials from Penthorum chinense Pursh. HPLC was performed on a Unison $US-C_{18}$ column ($4.6{\times}250mm$, $5{\mu}m$) with a gradient elution of 0.05% (v/v) trifluoroacetic acid (TFA) and methyl alcohol at a flow rate of 1.0 mL/min at $30^{\circ}C$. The analyte was detected at 280 nm. The HPLC method was performed in accordance with the International Conference on Harmonization (ICH) guideline (version 4, 2005) of analytical procedures with respect to specificity, precision, accuracy, and linearity. The limits of detection and quantitation were 0.11 and 0.33 mg/mL, respectively. Calibration curves showed good linearity ($r^2$ > 0.9999), and the precision of analysis was satisfied (less than 0.6%). Recoveries of quantified compounds ranged from 99.51 to 101.92%. This result indicates that the established HPLC method is very useful for the determination of marker compound in P. chinense Pursh extracts.