• Environmental Analysis Health and Toxicology
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• 제26권
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• pp.12.1-12.7
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• 2011

Objectives: Perchlorate is an emerging contaminant that is found everywhere, including various foods. Perchlorate is known to disturb the production of thyroid hormones and leads to mental disorders in fetuses and infants, as well as metabolic problems in adults. In this study, we attempted to establish an LC-MS/MS method for measuring perchlorate in dairy products and used this developed method to investigate perchlorate levels in Korean milk and yogurt samples. Methods: The developed method of perchlorate analysis requires a shaker and 1% acetic acid/acetonitrile as the extracting solvent. Briefly, the samples were extracted and then centrifuged (4000 rpm, 1hour), and the supernatant was then passed through a $Envi^{TM}$ Carb SPE cartridge that had been prewashed sequentially with 6 mL of acetonitrile and 6 mL of 1% acetic acid in water. The final volume of the sample extract was adjusted to 40 mL with reagent water and the final sample was filtered through a 0.20-${\mu}m$ pore size PTFE (Polytetrafluoroethylene) syringe filter prior to LC-MS/MS. Results: The average levels of perchlorate in milk and yogurt samples were $5.63{\pm}3.49\;{\mu}g/L$ and $3.65{\pm}2.42\;{\mu}g/L$, respectively. The perchlorate levels observed in milk samples in this study were similar to those reported from China, Japan, and the United States. Conclusions: The exposure of Koreans to perchlorate through the consumption of dairy products was calculated based on the results of this study. For all age groups, the calculated exposure to perchlorate was below the reference of dose (0.7 ${\mu}g/kg$-day) proposed by the National Academy of Science, USA, but the perchlorate exposure of children was higher than that of adults. Therefore, further investigation of perchlorate in other food samples is needed to enable a more exact assessment of exposure of children to perchlorate.

• 한국건설순환자원학회논문집
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• 제11권1호
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• pp.48-54
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• 2023

본 연구에서는 금속성분을 다량 함유한 전기로산화슬래그(EOS)를 골재로 활용한 콘크리트에 도전성이 높은 카본계 재료를 혼입하여 현장적용이 가능한 EMP 차폐 콘크리트의 최적배합을 도출하고자 기초적인 물성과 두께별 EMP 차폐성능을 평가하였다. 평가결과 슬럼프는 카본섬유(CF)의 혼입량이 증가할수록 저하, 밀드카본(MCF) 혼입시 증가하는 것을 확인할 수 있었다. 압축강도는 EOS가 NA에 비해 강도를 증진시키는 것을 확인할 수 있었으며, CF 및 MCF 혼입시 강도가 저하되는 것을 확인할 수 있었다. EMP 차폐 측정결과 두께가 증가할수록 차폐율이 증가하였으며, 도전성 재료의 첨가량보다 도전성 재료의 종류 및 시험체의 두께가 차폐율 증가에 영향력이 더 큰 것을 확인할 수 있었다. 종합적으로 비교평가를 진행한 결과 EMP 차폐 콘크리트 배합으로 EOS CF 0.2가 적합한 것으로 사료된다.

• Journal of Applied Biological Chemistry
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• 제59권2호
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• pp.165-169
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• 2016

The quantitative analytical method for the bioactive substance, 3-cyano-4-methoxy-N-methyl-2-pyridone (ricinine) and an index compound, ricinoleic acid in castor plant (Ricinus communis) extract or oil was developed. For the determination of a pyridone alkaloid compound, ricinine, successive cartridge cleanup method combined with ultra-performance liquid chromatography was set up with $ENVI-Carb^{TM}$ (0.5 g) and $C_{18}$ SPE cartridges. Accuracy and precision were evaluated through fortification studies of one biopesticide (PE) at 10 and $100mg\;kg^{-1}$. Mean recoveries of ricinine were 98.7 and 96.0 % associated with less than 10 % RSD, respectively. For the determination of ricinoleic acid in castor extract and oil, saponification and methylation were optimized using gas chromatography-time of flight mass spectrometry. Recovery was more than 84.8 % associated with 6.2 % RSD after derivatization procedure. Both methodologies developed were applied to analyze real samples including three castor oil products and six commercially available biopesticides containing R. communis, collected at Korean market. The contents of ricinine and ricinoleic acid in most commercial biopesticides were less than the oil or extract contents indicated by label.

• 한국식품영양과학회지
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• 제36권8호
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• pp.1022-1030
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• 2007

붉은 대게 가공부산물로 이용도가 낮은 자숙액을 이용하여 효소 가수분해물의 제조를 시도하였고, 아울러 이의 맛, 영양 및 건강기능에 대한 특성을 조사하였다. 붉은 대게 자숙액은 일반성분 및 안전성면에서 식품가공소재로 이용하여도 아무런 문제가 없었다. 1단 가수분해물의 경우 TCA soluble index(TSI), ACE 저해능 및 항산화능을 고려하는 경우 Alcalase로 2.0시간 반응시켜 제조하는 것이 가장 적절하였다. 붉은 대게 자숙액 유래 Alcalase 1단 가수분해물을 기질로 하여 Flavourzyme, Neutrase 및 Protamex로 각각 2시간씩 연속적으로 가수분해시킨 2단 가수분해물의 ACE 저해능 및 항산화능은 1단 가수분해물에 비하여 유사하거나 약간 우수하여 2단 가수분해의 필요성이 인정되지 않았다. 붉은 대게 자숙액에 비하여 이를 Alcalase 처리한 가수분해물의 경우 일반성분 및 색조는 차이가 없었으나, glutamic acid 및 aspartic acid와 같은 맛에 관여하는 유리아미노산의 경우 증가하였다. 붉은 대게 유래 Alcalase 처리 가수분해물의 아미노산 함량은 11,859.6 mg/100 mL이었고, 주요 아미노산으로는 glutamic acid(10.2%), proline(10.1%) 및 glycine (10.7%) 등이었다.