• 한국식품과학회지
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• 제17권2호
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• pp.95-100
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• 1985

콩우유 가공중 부산물로 생산되는 비지를 acetone과 ethanol로 세척한뒤 저온에서 건조하였을때 세척회수가 건조비지의 건조시간(乾燥時間)과 이화학적(理化學的) 성질(性質)에 미치는 영향을 조사하였으며 건조비지가 밀가루와 혼합(混合)될 때 수분과 기름의 흡수능력(吸收能力)의 변화를 측정하였다. 비지와 용매의 비율을 1:1.5로 하여 세척회수(1-5회)가 증가함에 따라 건조속도와 단백질 함량의 증가 그리고 지방과 총당의 감소가 있었으며 수분과 기름의 흡수능력도 증가하였다. 전반적으로 acetone은 3회(回), ethanol은 2회(回) 세척후 이들 성질의 변화가 완만해 졌으며 acetone 세척이 ethanol보다 건조속도나 색상 그리고 지방함량의 감소에서 유리함이 밝혀졌다. 한편, 건조비지를 밀가루와 혼합할때 비지의 혼합비율이 증가하면서 거의 직선적으로 수분과 기름의 흡수능력이 증가됨을 보여 주었다.

• 공업화학
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• 제4권3호
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• pp.515-521
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• 1993

석유 잔사유 중 고부가가치를 가진 윤활기유와 같은 중질 탄화수소를 얻기 위하여 펜탄 용매를 이용하여 상압 잔사유로부터 탈아스팔트오일을 분리하였다. 분리실험결과 상압 잔사유의 펜탄 용매의 밀도에 좌우됨을 보였으며, 임계영역에서 증가되었다. 또한 분리오일 중 금속성분은 시료인 상압 잔사유와 비교할 때 많은 양이 제거되었으나, 황성분의 제거율은 상대적으로 낮았다.

• 한국동물위생학회지
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• 제28권3호
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• pp.285-294
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• 2005

This study was conducted to investigate the extraction method for the determination of organochlorine, organophosphorus and synthetic pyrethroid pesticide residues in beef fat by gas chromatography-mass selective detector(GC-MSD). Twenty one pesticide residues in fat were determined using a simple and rapid procedure based on solid- phase extraction(SPE) clean-up cartridges with octadecyl $(C_{18})-bonded$ porous silica, florisil, $10\%$ deactivated florisil. a tandem $C_{18}$ and florisil and a tandem $C_{18}$ and $10\%$ deactivated florisil. Solvent-solvent extraction using acetonitrile was not satisfied to eliminate fat interference for pesticide residue analysis by GC-MSD, and the recoveries of the method in fat ranged from 16.2 to $57.3\%$ except DDT$(83.2\%)$. The recoveries of SPE methods using a tandem $C_{18}$ and Florisil was $59.6\~123.8\%$ except fenitrothion $(135.2\%)$. the SPE method was verified the satisfactory performance of pre-treatment for pesticide residues analysis in fat by GC-MSD. The efficiency of florisil deactivated with $10\%$ water has been not proved significantly on recoveries of pesticide residues in fat.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2687-2690
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• 2009

Due to the importance of isoflavone content in soybean extracts, the microwave-assisted process (MAP) was compared to the conventional extraction methods. For comparison of the three methods, all extraction parameters (solvent, sample to solvent ratio, temperature, etc.) were kept the same; the microwave extractor was operated at 187.5 W with an emission frequency of 2450 MHz under atmospheric pressure conditions and the extractions were carried out at 75 ${^{\circ}C}$ for 3 min while the conventional reflux was at 75 ${^{\circ}C}$ for 3 h. Total yield and crude isoflavone content were determined by ultraviolet spectrophotometric and compared with the three methods. Results indicated that the MAP was comparable to the conventional method in its capability to extract target compounds without causing any degradation; in addition it dramatically reduced the extraction time from 3 h to a few minutes, suggesting that it can be an alternative technique to the time-consuming conventional reflux method.

• 농약과학회지
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• 제9권3호
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• pp.237-242
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• 2005

SFSI (Solvent free solid injector)를 이용하여 추출과 정제과정이 필요없는 신속한 농약잔류분석법을 개발하고, 이 분석법의 실효성 여부를 확인하고자 내분비계장애추정농약으로 알려진 endosulfan, metribuzin, trifluralin, 그리고 vinclozolin의 작물 중 잔류양상을 분석하였다. SFSI에 주입된 시료는 동결건조 후 사용하였으며, SFSI에서 시료의 충분한 기화를 위한 pre-heating time을 조사한 결과 endosulfan과 trifluralin은 1 분, metribuzin은 10 분, vinclozolin은 5 분이었다. 또한 농약들의 최소검출량은 endosulfan, metribuzin, trifluralin 그리고 vinclozolin에서 각각 0.05, 0.1, 0.05, 0.05 ng이었다. 분석대상농약의 작물별 회수율은 배추 중 endosulfan은 74%, 상추 중 metribuzin은 $98{\sim}107%$, 시금치 중 trifluralin은 $86{\sim}95%$, 그리고 고추 중 vinclozolin은 $94{\sim}95%$이었다. 현장시료에 적용해 본 결과 상추에서 metribuzin이 0.6 ng/mg 수준으로 검출되었다.

• 한국환경농학회지
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• 제32권2호
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• pp.128-135
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• 2013

BACKGROUND: This study was performed to develop a single residue analytical method for new herbicide metazosulfuron in crops. METHODS AND RESULTS: Brown rice, apple, mandarin, Kimchi cabbage and soybean were selected as representative crops, and clean-up system, partition solvent and extraction solvent were optimized. Instrumental limit of quantitation (ILOQ), linearity of calibration curve and method limit of quantitation (MLOQ) were determined based on the chromatography and whole procedures. For recovery tests, brown rice, apple, mandarin, Kimchi cabbage and soybean samples were macerated and fortified with metazosulfuron standard solution at three levels (MLOQ, 10 MLOQ and 100 MLOQ). And then those were extracted with acetonitrile, concentrated, and partitioned with ethyl acetate. Then the extracts were concentrated again and cleaned-up through $NH_2$ (aminopropyl) SPE cartridge with acetone : dichloromethane (1% acetic acid) (20 : 80, v/v) before concentration and analysis with HPLC. CONCLUSION(S): ILOQ of metazosulfuron was 2 ng (S/N${\geq}$10) and good linearity was achieved between 0.05 and 12.5 mg/Kg of metazosulfuron standard solutions, with coefficients of determination of 0.9999. MLOQ was 0.02 mg/Kg. Good recoveries from 74.1 to 116.9% with coefficients of variation (C.V.) of less than 10% were obtained, regardless of sample type, which satisfies the criteria of Korea Food and Drug Administration (KFDA). Those results were reconfirmed with LC-MS (SIM). The method established in this study is simple, economic and efficient to be applied to most of crops as an official and general method for residue analysis of metazosulfuron.

• Journal of Applied Biological Chemistry
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• 제60권2호
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• pp.95-100
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• 2017

오미자를 착즙하고 남은 착즙박을 이용하여 추출조건에 따른 이화학적 변화를 알아보았다. 즉, 착즙박을 열수, 50% 에탄올, 70% 에탄올 및 95% 에탄올을 추출 용매로 사용하였으며, 추출시간은 1시간에서 10시간까지 1시간 간격으로 $60^{\circ}C$에서 정치 추출하여 여과한 후, 감압 농축하여 제조된 용매별 농축액을 분석시료로 이용하였다. 오미자에 함유된 유효성분 중 하나인 schizandrin 함량은 추출 용매에 따라서 열수: 0.52 g/100 g, 50% 에탄올: 1.79 g/100 g, 70% 에탄올: 2.01 g/100 g 및 95% 에탄올은 2.37 g/100을 나타내었으며, 열수를 이용하여 추출한 경우보다 에탄올 농도가 증가할수록 schizandrin 함량이 증가하는 경향을 나타내었다. 총 폴리페놀 함량은 50% 에탄올 용매 추출물에서 16.70 mg/mL로 가장 높게 나타났으며, 2,2-diphenyl-1-picrylhydrazyl 전자공여소거능에 대한 효과는 분석 시료의 200 mg/mL 농도에서 측정하였을 때, 50% 에탄올 용매 추출물에서 86.16%로 가장 높게 나타내었다. 또한, 안토시아닌 함량은 모든 용매 추출물이 추출 시간이 증가할수록 감소하는 경향을 보였다.

• 한국초지조사료학회지
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• 제38권3호
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• pp.156-164
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• 2018

Pesticide application in agriculture provides significant benefits such as protection from disease, prevention of harmful insects, and increased crop yields. However, accurate toxicological tests and risk assessments are necessary because of many related adverse effects associated with pesticide use. In this review, we discuss and analyze residual pesticides contained in livestock feed in Korea. A pesticide residue tolerance standard for livestock feed has not been precisely established; so, risk assessments are required to ensure safety. Standards and approaches for animal criteria and appropriate methods for evaluating residual pesticides are discussed and analyzed based on technology related to animal product safety in Korea. The safety of livestock feed containing pesticides is assessed to establish maximum residue limits relative to pesticides. Analysis of residual pesticides in milk, muscle, brain, and fat was performed with a livestock residue test and safety evaluation of the detected pesticide was performed. Efficacy of organic solvent extraction and clean-up of feed was verified, and suitability of the instrument was examined to establish if they are effective, rapid, and safe. This review discussed extensively how pesticide residue tolerance in livestock feed and hazard evaluation may be applied in future studies.

• 한국도로학회논문집
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• 제18권6호
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• pp.97-104
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• 2016

OBJECTIVES : The objective of this research is to develop additives for the modification of Solvent DeAsphalting Residue (SDAR) to be used as pavement materials, and evaluate the performance of asphalt mixture manufactured using the SDAR modified by developed additives. METHODS : The SDAR generally consists of more asphaltenes and less oil components compared to the conventional asphalt binder, and hence, the chemical/physical properties of SDAR are different from that of conventional asphalt binder. In this research, the additives are developed using the low molecular oil-based plasticizer to improve the properties of SDAR. First, the chemical property of two SDARs is analyzed using SARA (saturate, aromatic, resin, and asphaltene) method. The physical/rheological properties of SDARs and SDARs containing additives are also evaluated based on PG-grade method and dynamic shear-modulus master curve. Second, various laboratory tests are conducted for the asphalt mixture manufactured using the SDAR modified with additives. The laboratory tests conducted in this study include the mix design, compactibility analysis, indirect tensile test for moisture susceptibility, dynamic modulus test for rheological property, wheel-tracking test for rutting performance, and direct tension fatigue test for cracking performance. RESULTS : The PG-grade of SDARs is higher than PG 76 in high temperature grades and immeasurable in low temperature grades. The dynamic shear modulus of SDARs is much higher than that of conventional asphalt, but the modified SDARs with additives show similar modulus compared to that of conventional asphalt. The moisture susceptibility of asphalt mixture with modified SDARs is good if, the anti-stripping agent is included. The performance (dynamic modulus, rutting resistance, and fatigue resistance) of asphalt mixture with modified SDARs is comparable to that of conventional asphalt mixture when appropriate amount of additives is added. CONCLUSIONS : The saturate component of SDARs is much less than that of conventional asphalt, and hence, it is too hard and brittle to be used as pavement materials. However, the modified SDARs with developed additives show comparable or better rheological/physical properties compared to that of conventional asphalt depending on the type of SDAR and the amount of additives used.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.259-263
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• 2001

There are several steps such as slicing, lapping, chemical etching and mechanical polishing in the silicon wafer production process. The chemical etching step is necessary to remove damaged layer caused In the slicing and lapping steps. The typical etching liquor is the acid mixture comprising nitric acid, acetic acid and hydrofluoric acid. At present, the waste acid is treated by a neutralization method with a high alkali cost and balky solid residue. A solvent extraction method is applicable to separate and recover each acid. Acetic acid is first separated from the waste liquor using 2-ethlyhexyl alcohols as an extractant. Then, nitric acid is recovered using TBP(Tri-butyl phosphate) as an extractant. Finally hydrofluoric acid is separated with the TBP solvent extraction. The expected recovered acids in this process are 2㏖/l acetic acid, 6㏖/1 nitric acid and 6㏖/l hydrofluoric acid. The yields of this process are almost 100% for acetic acid and nitric acid. On the other hand, it is important to recover and reuse the metal values contained in various industrial wastes in a viewpoint of environmental preservation. Most of industrial products are made through the processes to separate impurities in raw materials, solid and liquid wastes being necessarily discharged as industrial wastes. Chemical methods such as solvent extraction, ion exchange and membrane, and physical methods such as heavy media separation, magnetic separation and electrostatic separation are considered as the methods for separation and recovery of the metal values from the wastes. Some examples of the application of solvent extraction to the treatment of wastes such as Ni-Co alloy scrap, Sm-Co alloy scrap, fly ash and flue dust, and liquid wastes such as plating solution, the rinse solution, etching solution and pickling solution are introduced.