• Mass Spectrometry Letters
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• 제9권4호
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• pp.100-104
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• 2018

As a part of efforts to establish the positive list system (PLS) in South Korea, a method to determine residual emamectin benzoate (EB) in various aquatic products using QuEChERS-EDTA and LC-MRM was developed. The developed method was validated in the aspects of specificity, linearity (correlation coefficient of at least 0.996), sensitivity (the limit of detection and the lower limit of quantitation ${\leq}5ng/g$), recovery (the recovery range of 87.4 and 96.2), and precision (the relative standard deviation of recovery between 0.9 and 13.5). Additionally, the validated method was successfully applied for monitoring EB contamination in eel, halibut, and shrimp collected from local food markets. To our knowledge, the present method is the first one to determine residual EB in various aquatic products at the level satisfying the PLS and could contribute to the establishment of the PLS in South Korea.

• Journal of Applied Biological Chemistry
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• 제64권3호
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• pp.285-290
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• 2021

Salicornia herbacea is a type of salt marsh plant that has been used in traditional medicine to treat several diseases. Isorhamnetin-3-O-glucoside (I3G) and quercetin-3-O-glucoside (Q3G) are major flavonoids in S. herbacea that are known to exert various pharmacological activities. Therefore, our study sought to validate and optimize an HPLC/UV-based analytical method for I3G and Q3G yield quantification, as well as to determine its limit of detection, limit of quantification, linearity, precision, and accuracy. Upon testing a concentration range of 31.5-1.9 ㎍/mL the results exhibited good linearity (r² ≥0.9996 and r² ≥0.9999 for I3G and Q3G, respectively), and the procedure was deemed precise (relative standard deviation of ≤3.19 and ≤3.85%, respectively), and accurate (102.6-105.0 and 92.9-95.2%, respectively). The results showed that our proposed method could be used for rapid I3G and Q3G evaluation in S. herbacea.

• Journal of Microbiology and Biotechnology
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• 제32권8호
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• pp.976-981
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• 2022

Phenanthrenes are bioactive phenolic compounds found in genus Dioscorea, in which they are distributed more in peel than in flesh. Recent studies on phenanthrenes from Dioscorea sp. peels have revealed the potential for valuable biomaterials. Herein, an analytical method using high-performance liquid chromatography (HPLC) for quantitation of bioactive phenanthrenes was developed and validated. The calibration curves were obtained using the phenanthrenes (1-3) previously isolated from Dioscorea batatas concentrations in the range of 0.625-20.00 ㎍/ml with a satisfactory coefficient of determination (R²) of 0.999. The limit of detection (LOD) and the limit of quantification (LOQ) values of the isolated phenanthrenes ranged from 0.78-0.89 and 2.38-2.71 ㎍/ml, respectively. The intraday and interday precision ranged from 0.25-7.58%. The recoveries of the isolated phenanthrenes were from 95 to 100% at concentrations of 1.25, 2.5, and 5.0 ㎍/ml. Additionally, phenanthrenes (1-3) were found in all investigated peel extracts. Hence, the developed method was encouraging for the quantitative analysis of phenanthrenes in genus Dioscorea.

• 한국축산식품학회지
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• 제43권6호
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• pp.949-960
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• 2023

This research aimed to validate a high-performance liquid chromatography method for the quantitative determination of bixin and norbixin in various foods. The Diode Array Detector (495 nm) technique was used. Method was validated for specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy, and the measurement uncertainty was assessed. The calibration curve showed excellent linearity (r²≥0.9999) over the tested concentration range of 0.2-25 mg/L. The LOD and LOQ were 0.03-0.11 and 0.02-0.05 mg/L for bixin and norbixin, respectively. The intra-and inter-day accuracies and precisions were 88.0±1.3-97.0±0.5% and 0.2%-2.6% relative SD (RSD) for bixin and 88.2±0.8-105.8±0.8% and 0.3%-2.7% RSD for norbixin, respectively. Inter-laboratory validation for accuracy and precision was conducted in three laboratories, and these results all met the AOAC guidelines. In addition, the relative expanded uncertainty (<22%) satisfied the CODEX recommendation. Furthermore, products distributed in Korea were monitored for annatto extracts using the proposed method to demonstrate its application. The developed analytical method is reliable for quantifying bixin and norbixin in various foods.

• Mass Spectrometry Letters
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• 제2권1호
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• pp.12-15
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• 2011

The Korean government has regulated emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in waste water of manufacturing facilities producing chlorinated compounds since 2009. As this regulation is expected to be reinforced in 2013 to 50 pg I-TEQ/L, a large sample volume is required for the analysis of trace amounts of PCDD/Fs in waste water. Liquid-liquid extraction (LLE) is used to extract PCDD/Fs from aqueous samples; however, its low efficiency makes it inadequate for analyzing large sample volumes. Herein, we present a disk-type solid-phase extraction (SPE) method for the analysis of dioxin at a part per quadrillion level in waste water. This SPE system contains airtight glass covers with a decompression pump, which enables continuous semi-automated extraction. Small (0.5 L) and large (7 L) samples were extracted using LLE and SPE methods, respectively. The method detection limits (MDLs) were 0.001.0.25 and 0.015.4.1 pg I-TEQ/L for the SPE and LLE methods, respectively. The concentrations of detected congeners with both methods were similar. However, the concentrations of several congeners that were not detected with the LLE method were quantified using the SPE method.

• Food Science and Biotechnology
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• 제18권4호
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• pp.895-899
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• 2009

A new approach for the determination of acrylamide (AM) in foods by solid phase microextraction-gas chromatography (SPME-GC) was established. AM was bromized and transformed to 2-bromoacrylamide (2-BAM). 2-BAM was then extracted by a commercial SPME fiber, $75-{\mu}m$ Car/PDMS fiber, for GC detection. The influence of extraction and desorption parameters such as extraction temperature and time, stirring rate, desorption temperature, and time were studied and optimized. The mass concentration was proportional to the peak area of 2-BPA from 1.0 to 8,000 ${\mu}g/L$. The detection limit of the SPME-GC for 2-BAM was found to be 0.1 ${\mu}g/L$, and the recoveries and relative standard deviations for different food samples were 74.5 to 102.0%, and 4.2 to 9.1%, respectively. The presented method was applied to the determination of AM in fried foods.

• 한국멀티미디어학회논문지
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• 제25권3호
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• pp.546-557
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• 2022

Recently, the demand to interpret image data with artificial intelligence in various fields is rapidly increasing. Object recognition and detection techniques using deep learning are mainly used, and video integration analysis to determine unstructured object recognition is a particularly important problem. In the case of natural disasters or social disasters, there is a limit to the object recognition structure alone because it has an unstructured shape. In this paper, we propose intelligent video integration analysis system that can recognize unstructured objects based on video turning point and object detection. We also introduce a method to apply and evaluate object recognition using virtual augmented images from 2D to 3D through GAN.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.198-201
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• 2022

최근 신기술 대상 신종 사이버 위협이 증가하고 있으며, 해커의 공격 표적도 광범위해지고 지능화되고 있다. 이러한 공격에 대응하기 위해 주요 보안 기업들은 전통적인 EDR(Endpoint Detection and Response) 중심의 솔루션을 활용하고 있다. 하지만 종래 방식은 컨텍스트를 고려하지 않아서 지능형 공격에 대한 대응 정확도와 효율성에 한계가 있다. 이 문제를 개선하기 위해 최근 XDR(Extended Detection and Response) 중심의 보안 솔루션의 필요성이 대두되었다. 본 연구에서는 머신러닝 기반의 컨텍스트 분석을 활용한 XDR 동향과 발전 로드맵을 통해 변화하는 환경에 효율적인 위협탐지와 대응방안을 제시한다.

• 한국식품과학회지
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• 제42권4호
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• pp.377-382
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• 2010

ADC는 밀가루개량제로 사용기준이 설정되어 있는 식품첨가물이나 이의 사용량과 잔류량을 확인할 수 있는 시험분석법이 확립되어 있지 않은 상태임으로 사전 사후 안전관리를 위해서 ADC의 분해산물인 biurea를 밀가루 및 빵류에서 분석 가능한 방법을 확립하고자 하였다. 식품 중 ADC의 분해산물인 biurea 분석을 위하여 컬럼, 이동상 조건, 전처리 조건, 기기조건 등을 검토하여 LC/MS/MS를 이용한 분석법을 확립하였으며, 개발된 분석법의 회수율, 분석법의 유효성 검증 등을 검토하였다. 회수율은 94.3-112.5%로 양호하였으며, 검출한계(LOD)는 0.003 mg/L의 농도이었고, 정량한계(LOQ)는 0.01 mg/L의 농도이었다. 확립된 분석법에 의해 밀가루 등 51건, 빵 등의 가공식품 59건에 대하여 biurea 함량을 분석한 결과 밀가루 1건에서 2.76 mg/kg의 농도로 검출되었고(검출율: 2%), 빵 등 가공식품에서는 16건이 검출(검출율: 27%)되었으며 검출농도범위는 0.19-18.01 mg/kg(평균: 3.79 mg/kg)이었다. ADC의 사용기준인 밀가루 1 kg당 45mg에 비하여 매우 낮은 값을 나타내었다. 본 연구를 통하여 확립된 식품 중 biurea 분석법으로 밀가루, 빵류 등의 가공식품에 대한 ADC의 사후관리에 기여할 것으로 본다.

• 분석과학
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• 제11권3호
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• pp.161-166
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• 1998

정신질환 치료에 가장 폭넓게 사용되는 haloperidol(HAL)의 혈중농도 분석법이 개발되었다. 이 연구를 위하여 gas chromatography/nitrogen-phosphorus detection(GC/NPD)을 이용하였으며, bromoperidol을 내부표준물질로 사용하였고, 시료전처리 방법으로써 diethylether를 추출용매로 사용하는 3단계 추출법을 사용하였다. 이 과정에 있어서 추출효율은 15 ng/mL에서 $67.5{\pm}1.9%$이었고, 1~40 ng/mL 범위에서 상관계수 $r^2=0.999$인 좋은 직선성을 얻었으며, 혈청을 2 mL 사용했을 때 검출한계는 0.5 ng/mL이었다. 정신분열증 환자의 혈청내 HAL을 분석하기 위하여 이 방법을 적용하였다. Haloperidol decanoate(HD)를 정신분열증 환자에 근육주사한 후, 2주와 4주째의 HAL level을 조사한 결과 4주째에 HAL의 농도가 2주째보다 29.6% 낮게 나타났다. 제시된 방법은 낮은 검출한계와 높은 선택성을 나타냈다. 그러므로 본 연구 방법은 혈청내 HAL의 미량분석과 모니터링에 이용될 수 있을 것이다.