• Applied Chemistry for Engineering
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• v.33 no.5
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• pp.451-458
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• 2022

Semiconductor quantum dots (QDs) are optical probes with excellent fluorescence properties. Therefore, they have been applied to various bio-medical imaging techniques and biosensors. Due to the unique optical characteristics of wide absorption and narrow fluorescence energy bands, multiple types of signals can be generated by the combination of fluorescence wavelengths from different QDs, which enables the simultaneous detection of more than two biomarkers. In this review, the advantages and applications of QDs and QD nanobeads (QBs) in multiple biomarker assays were described, and new developments or improvements in multiplexed biomarker detection techniques were summarized. In particular, recent reports were summarized, focusing on the design strategies in immunoassay construction and signal transducing materials for fluorescence-linked immunosorbent assays using QDs and immunochromatographic assays using QBs. New detection platforms will be developed for early diagnosis of diseases and other fields if multiplexed detection technologies of excellent accuracy and sensitivity are combined with artificial intelligence algorithms.

• Journal of Environmental Impact Assessment
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• v.30 no.3
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• pp.155-163
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• 2021

The number of trees to be removed trees (ART) in the environmental impact assessment is an environmental indicator used in various parts such as greenhouse gas emissions and waste of forest trees calculation. Until now, the ART has depended on the forest tree density of the vegetation survey, and the uncertainty of estimating the amount of removed trees has increased due to the sampling bias. A full-scale survey can be offered as an alternative to improve the accuracy of ART, but the reality is that it is impossible. As an alternative, there is an individual tree detection using aerial image (ITD), and in this study, we compared the ARTs estimated by full-scale survey, sample survey, and ITD. According to the research results, compared to the result of full-scale survey, the result of ITD was overestimated by 25. While 58 were overestimated by the sample survey (average). However, as the sample survey is an estimate based on random samples, ART will be overestimated or underestimated depending on the number and size of quadrats.

• Proceedings of the Costume Culture Conference
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• 2004.04a
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• pp.44-46
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• 2004

심하게 퇴색된 출토 복식유물의 경우 유물의 고유색을 알지 못함은 물론 사용된 염료의 종류를 알지 못함으로 인하여 유물의 보존처리 및 장기간 보관과 전시에 큰 어려움을 지닌다. 이화학 분야에서는 미지시료의 기초 성분분석 방법으로서 thin layer chromatography(TLC)법이 오래 전부터 사용되었는데, 퇴색된 복식유물의 염료분석을 다룬 일부 선행연구에서는 이를 활용하여 유물의 염료를 판정하였다(Kharbade ＆ Agrawal, 1985; Schweppe, 1989). (중략)

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.11.2-11.2
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• 2005

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.916-921
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• 1996

This study was conducted to measure fat contents of potatochips by near infrared spectroscopy (NIRS). Both potatochip powder and potatochips were used to find correlations between the absorbance at certain wavelengths find the fat contents. Based on the correlation analysis, linear regression models predicting the fat contents were developed to predict the fat contents. Artificial neural network (ANN) models were also developed. Predicted values were compared to the measured ones. The regression and the ANN model predicting the fat contents of potatochip powder had determination coefficients of 0.93 and 0.92, and standard errors of prediction (SEP) of 1.29% and 1.17%, respectively. The correlation analysis of potatochips showed that the determination coefficients were low. Therefore, the fat contents of not potatochips but potatochip powder could be measured by NIRS.

• Analytical Science and Technology
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• v.24 no.3
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• pp.200-211
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• 2011

In this study, 13 compounds including four volatile fatty acids (VFA) and nine volatile organic compounds (VOC) were analyzed by cryogenic trapping-thermal desorption technique. In order to evaluate the analytical method for VFA, calibration experiments were performed using five different sorbent materials. When the calibration results are compared between different sorbents, sampling tube filled with Carbopack X showed the highest response factor (RF) for both VFA and VOC. To validate this new analytical method for VFA using cryogenic trapping-thermal desorption technique, this method was compared with alkali absorption method recommended by the odor prevention law of the Korea Ministry of Environment (KMOE). For this purpose, unknown samples were analyzed by two different methods, i.e., cryogenic trapping-thermal desorption (TD) and alkali absorption with solid phase microextraction (SPME). When the results of two different methods were compared, ratios of concentrations determined by the two analytical methods (TD/SPME) was found as 0.46 (valeric acid) ~ 0.71 (isovaleric acid). Therefore, additional study is required to properly establish and find stable analytical conditions for VFA analysis. Furthermore, comparison between two different methods should be made with more reliable calibration approaches.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1791-1795
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• 2014

The objective of this study was to compare two extraction methods for determination of vitamin K1 (phylloquinone) in vegetables. In addition, analytical method validation parameters such as accuracy, precision, limit of detection (LOD), limit of quantification (LOQ), and linearity were calculated to ensure the method's validity. Vitamin K1 was quantified by reversed-phase HPLC using post-column derivatization and fluorescence detection ($Ex{\lambda}=243nm$, $Ex{\lambda}=430nm$). Higher analytical values were observed using solvent extraction compared to those from the enzyme extraction method. The results from the method validation showed high linearity in the calibration curve with a coefficient of correlation ($R^2$) of 0.9994. The LOD and LOQ were 0.1335 and 0.2784 ng/injection volume ($50{\mu}L$), respectively. The inter-day precision and inter-day precision were 2.0% and 2.1%, respectively. Overall recovery was close to 100% (n=5). The phylloquinone contents ranged from 9.42 to $1,212.57{\mu}g/100g$. Our study provides reliable data on the phylloquinone contents in commonly consumed vegetables in Korea.

• The Korean Journal of Pesticide Science
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• v.20 no.3
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• pp.236-246
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• 2016

The aim of this study was to develop an analytical method for the determination of pyribencarb and its metabolite KIE-9749 in agricultural commodities. The experiment was performed with a range of concentrations $0.05{\sim}2.5{\mu}g/g$ in apple, green pepper, potato, hulled rice, soybean, pear, peach, grape and cucumber. Each samples were extracted with acetone and cleaned by dichloromethane/saline water partition and purified with Florisil solid phase extraction (SPE) cartridge and aminopropyl SPE cartridge. Pyribencarb and KIE-9749 were separated and quantified by HPLC/UVD at 265nm using acetonitrile and water as mobile phase. The recoveries of pyribencarb and KIE-9749 were within 78.3~108.4% and 73.9~113.7% with RSD below 12.2% and 15.0%, respectively. The limits of quantification (LOQ) were both $0.05{\mu}g/g$. LC/ESI-MS/MS was optimized for confirmation of residue identity.

• Journal of Food Hygiene and Safety
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• v.31 no.1
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• pp.21-27
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• 2016

The objectives of this study are to produce monoclonal antibodies (MAbs) against Vibrio parahaemolyticus and to develop an immuno-selective filtration (ISF) method for the rapid and sensitive detection of V. parahaemolyticus. The characterization of the MAb produced from HKVP 4H9-9 hybridoma cell was validated by enzyme-linked immunosorbent assay (ELISA) and western blot. The produced MAb was specific to V. parahaemolyticus and showed weak cross-reaction to V. alginolyticus, V. vulnificus and Staphylococcus aureus. After optimization of the method, $5{\times}10^1cell/mL$ of V. parahaemolyticus in a pure culture could be detectable. Although weak cross-reactivity to V. vulnificus, V. alginolyticus and Staphylococcus aureus was observed, the ISF was confirmed to be highly specific to V. parahaemolyticus. Especially, the ISF showed the most sensitivity compared to the immunoassays currently reported is easier to perform and quicker than ID-ELISA.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.309-317
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• 2015

BACKGROUND: An analytical method was developed using GC-ECD/MS to precisely determine the residue of fipronil, a phenylpyrazole insecticide used to control a wide range of foliar and soil-borne pests.METHOD AND RESULTS: Fipronil residue was extracted with acetone from representative samples of five raw products which comprised hulled rice, soybean, Kimchi cabbage, green pepper, and apple. The extract was diluted with saline water, and fipronil was partitioned into n-hexane/dichloromethane (20/80, v/v) to remove polar co-extractives in the aqueous phase. Florisil column chromatography was additionally employed for final purification of the extract. Fipronil was separated and quantitated by GC-ECD using a DB-17 capillary column. Accuracy of the proposed method was validated by the recovery from crop samples fortified with fipronil at 3 levels per crop in each triplication.CONCLUSION: Mean recoveries ranged from 86.6% to 106.0% in five representative agricultural commodities. The coefficients of variation were less than 10%. Limit of quantitation of fipronil was 0.004 mg/kg as verified by the recovery experiment. A confirmatory technique using GC/MS with selected-ion monitoring was also provided to clearly identify the suspected residue. Therefore, this analytical method was reproducible and sensitive enough to determine the residue of fipronil in agricultural commodities.