• Analytical Science and Technology
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• v.28 no.2
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• pp.125-131
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• 2015

A method was developed and fully validated for the determination of terbutaline, a β₂-receptor agonist, in human plasma. Plasma samples were prepared by solid-phase extraction with Sep-Pak silica, followed by high-performance liquid chromatography (HPLC). The terbutaline was pre-separated from the interfering components in plasma on a Luna C18 (2) column, and terbutaline and salbutamol as an internal standard were resolved and determined on a Luna Silica column. The two columns were connected by a switching valve equipped with silica pre-column. The pre-column was used to concentrate the terbutaline in the eluent from the C18 column before back-flushing onto the silica column with fluorescence detection at an excitation/emission wavelength of 276/306 nm. The method was shown to be specific by testing six different human plasma sources. Linearity was established for a concentration range of 0.4-20.0 ng/mL with a correlation coefficient of 0.9999. The lower limit of quantitation was 0.4 ng/mL with a precision of 10.1% as C.V.%.

• Korean Journal of Food Science and Technology
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• v.18 no.5
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• pp.339-344
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• 1986

The specific reaction of trypsin inhibitors with trypsin to form stable complexes was successfully applied for detection of trypsin inhibitors in soybean. Soybean extract was treated with $Ca^{++}$ to remove globulin fraction, followed by digestion with trypsin and fractionated by chromatography on Sephadex G-50. The void volume fraction contained the trypsin-trypsin inhibitor complexes as well as trypsin. The trypsin inhibitors were then detected by their molecular weight differences on SDS-polyacrylamide gel electrophoresis, in which the complexes dissociate into trypsin and its inhibitors. With the method proposed, trypsin inhibitors were indentified by their ability forming the stable complexes with trypsin and their anti-tryptic moiety. The formation of the complexes with trypsin was further confirmed by two dimensional electrophoresis and DEAE-Sephadex A-25 chromatography. Employing the proposed method, it was found that soybean (Glycine max cv. Hill) contained 7 trypsin inhibitors.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.191-194
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• 2002

토양증기추출(Soil Vapor Extraction)법을 이용하여 대표적 휘발성 NAPL (Non-aqueous phase liquid)인 TCE (trichloroethylene)와 toluene을 토양으로부터 제거하는 칼럼 실험을 실시하였다. 토양특성 및 증기추출 조건들이 정화효율에 미치는 영향을 규명하는데, 균질한 Ottawa sand와 실제 오염지역의 토양들을 직경 2.5cm, 길이 30cm인 유리 칼럼이 충진시켰으며, 빨갛게 염색된 TCE 또는 toluene 4 g이 주입되었다 공기 유량계를 설치하여 0.03L/min의 일정한 속도로 공기가 주입되도록 하고, 퍼지장치를 설치하여 주입 공기의 습윤도를 99% 이상으로 유지하였다. 가스크로마토그래피로 유출 가스 농도를 분석하였다. Ottawa sand로 충진된 칼럼실험에서는 매질의 입자크기, 함수율, 토양 내 오염물 체류시간 등을 변화시켜 실험을 반복하였다. TCE로 오염된 세립질 Ottawa sand 칼럼실험에서 유출 공기의 최대 농도는 조립질 Ottawa sand 칼럼의 유출 농도보다 약 20% 정도 감소하였고, 오염지역의 실제토양 칼럼실험에서는 최대유출농도가 조립질 Ottawa sand 칼럼의 농도보다 약 50% 감소하였으나, 20 liter공기 주입 후부터는 모두 비슷한 농도감소 현상을 나타내었으며, 초기 주입량의 90 % 이상이 제거되었다. 함수율증가에 따른 유출공기의 농도 감소는 거의 나타나지 않았으며, TCE 주입 후 7일 동안 방치하였다가 SVE를 실시한 칼럼 실험에서도 잔류하는 TCE의 양이 약간 증가하였지만 20 liter 공기 추출 후에는 초기 주입량의 90% 가, 40 liter공기 추출 후에는 98% 이상이 제거되었다. Toluene으로 오염된 칼럼 실험에서도 TCE와 비슷한 제거 경향을 나타냈으며 200 liter 공기 추출 후에는 오염물 초기 주입량의 98% 이상이 제거되었다. 본 실험 결과로부터 증기추출법을 이용한 TCE, toluene 정화 효율성이 규명되었으며, 휘발성 NAPL로 오염된 실제 토양을 복원하기 위한 SVE법의 적용가능성을 확인할 수 있었다.

• Tribology and Lubricants
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• v.36 no.3
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• pp.161-167
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• 2020

Petroleum is the most used energy source in Korea with a usage rate of 39.5% among the available 1st energy source. The price of liquid petroleum products in Korea includes a lot of tax such as transportation·environment·energy tax. Thus, illegal production and distribution of liquid petroleum is widespread because of its huge price difference, including its tax-free nature, from that of the normal product. Generally, illegal petroleum product is produced by illegally mixing liquid petroleum with other similar petroleum alternatives. In such case, it is easy to distinguish whether the product is illegal by analyzing its physical properties and typical components. However, if one the components of original petroleum product is added to illegal petroleum, distinguishing between the two petroleum products will be difficult. In this research, we inspect illegally produced gasoline, which is mixed with methyl tertiary butyl ether (MTBE) as an octane booster. This illegal gasoline shows a high octane number and oxygen content. Further, we analyze the different types of green dyes used in illegal gasoline through high performance liquid chromatography (HPLC). We conduct component analyses on the simulated sample obtained from premium gasoline and MTBE. Finally, the illegal gasoline is defined as premium gasoline with 10% MTBE. The findings of this study suggest that illegal petroleum can be identified through an analytic method of components and simulated samples.

• Journal of the Korean Wood Science and Technology
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• v.34 no.6
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• pp.72-80
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• 2006

Fallen needle (8.5 kg) of Larix kaempferi were collected and extracted with 95% EtOH. The EtOH extracts were evaporated under reduced pressure, concentrated, and successively fractionated with a series of hexane, methylene chloride, ethylacetate and water on a separatory funnel to be freeze dried. A portion of ethylacetate and water soluble powder were chromatographed on a Sephadex LH-20 column eluting with aqueous MeOH and EtOH-hexane mixture. Spectrometric analyses such as NMR and FAB-MS, including TLC, were performed on the seven isolated compounds and were elucidated as (+)-catechin, (-)-epicatechin, 2"-O-rhamnosylvitexin, juglanin, afzelin, laricitrin-3-O-${\beta}$-D-glucopyranoside, isoquercitrin and cedrusin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.11
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• pp.1654-1659
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• 2010

In order to utilize squid liver by-products, which is normally discarded as industrial waste in the process of squid manufacturing, salt-fermented squid liver sauce was prepared experimentally and also tested for inhibitory activity against angiotensin converting enzyme (ACE). ACE inhibitory activity of squid liver sauce was increased with the elapse of fermentation days until 12 months, followed by a constant level of inhibitory activity thereafter. 15-month-old sauce ($IC_{50}=29.66\;{\mu}g$) was filtered through PM-10 membrane (M.W. cut-off 10,000 Da) to obtain the peptides fractions with ACE inhibition activity. Filtered fractions were applied to a Bio-gel P-2 column and three active fractions (A, B and C) were collected. Among them, fraction B applied to a SuperQ-Toyopearl 650S column chromatography lead to the isolation of active B-1 fraction. It has the ACE inhibitory activity ($IC_{50}=5.46\;{\mu}g$). The main composition of its amino acids is lysine, glycine and proline, which cover about 85% of the total amino acids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.177-181
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• 2009

The peptides from Aroase AP10 enzymatic hydrolysates of octopus proteins were isolated and tested for inhibitory activity against angiotensin converting enzyme (ACE). The Aroase AP10 hydrolysates were filtered through PM-10 membrane (M.W. cut-off 10,000) to obtain the peptides fractions with ACE inhibition activity. These fractions were applied to a Biogel P-2 column. Three active fractions (A, B, and C) were collected and applied to a SuperQ-Toyopearl 650S column chromatography, leading to the isolation of four active fractions (A-1, A-2, B-1, and C-1). Among the active fractions, C-1 had the highest ACE inhibitory activity ($IC_{50}=3.10{\mu}g$). The main composition of its amino acids is arginine, lysine, histidine and leucine, which cover about 60% of the total amino acids.

• Korean Journal of Pharmacognosy
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• v.40 no.4
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• pp.303-308
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• 2009

Essential oils of the musk from wild muskrat (Ondatra zibethicus) were analyzed by gas chromatography/mass spectrometry. Fifty-six chemical components were separated, and 14 volatile compounds (78% of composition of total essential oil) of macrocyclic musk, mainly cyclopentadecanone, 12-hydroxy-14-methyl-oxa-cyclotetradec-6-en-2-one, cycloheptadecanone and 9-cycloheptadecen-1-one, were identified by the comparison of Wiley/NBS Library from the results of GC-MS. However, l-muscone, a compound reported by earlier workers in the musk from muskrat, was not detected using the spike test in this study. Interestingly, cyclohexadecanone, which has the same molecular weight (Mw 238) as l-muscone, was identified. In addition, it is considered that because of possessing much higher amounts of macrocyclic components compared to the original musk, muskrat has higher economic values in perfume and pharmaceutical industries.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.900-903
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• 2012

Cadmium is known to be very toxic to human health and can be relative easily translocated from soils in plants. Therefore, a rapid method for screening Cd in soils and crops has become more and more important. For this reason, we examined a rapid immunochromatograpy (ICG) test kit which uses antigen-antibody reaction based on immunoassay and chromatography. Soils and rice grains collected from mine waste-contaminated sites were determined for their Cd contents using this kit. For comparison purposes, 0.1 M HCl and ICP-OES were employed as a conventional extraction and determination method. Cadmium contents in rice grains determined using ICG technique were $0.46{\sim}2.39mg\;kg^{-1}$ and Cd contents determined using 0.1 M HCl and ICP-OES were $0.52{\sim}1.97mg\;kg^{-1}$. The correlation between these two Cd contents were statistically significant ($r^2$=0.930). The results of Cd contents in soils also showed a statistically significant relationship between these two methods ($r^2$=0.975). On the basis of these results, ICG technique can be applied to rapidly quantify Cd in crops and soils. However, further research is necessary to apply ICG technique for the field screening.

• The Journal of the Korea Contents Association
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• v.14 no.3
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• pp.52-58
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• 2014

Point of care testing (POCT) is could be easily and economically performed and was widely used. In particular, the test items using immune chromatographic method has been conveniently used. But when an error occurs, we should reaffirmed the test results, but we could not reaffirm because the test line is disappeared as the time pass, and the test results are different between laboratory workers. Therefore, we developed multi-strip reader which can store images for the test results and can interpretate the test results automatically. Then we evaluated newly developed multi-strip reader for urine pregnancy test, the test results of the multi-strip reader was 100% matched with the previously results. Our newly developed multi-strip reader was convenient and economic, and will be widely used in many laboratories.