• 분석과학
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• 제15권3호
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• pp.300-316
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• 2002

수질 및 토양 시료 중의 PBBs의 분석방법 확립을 위해 표준물질이 준비된 PBBs 22종을 대상으로 추출 및 정제 등의 전처리 회수율 및 검출한계를 환경시료로부터 얻었다. PBBs의 시료 추출법으로 액/액, 속실렛, 초음파 추출법을 적용하였고, 실리카겔, 플로리실 정제컬럼의 적용성 검토 후 GC/MS로 분석하였다. 수질 시료의 경우 검출한계는 브롬화된 정도에 따라 약간의 차이를 보였고 5~10 ng/L이었으며, n-hexane, dichloromethane 및 toluene 등의 단일 용매의 평균회수율은 96~107%, n-hexane:acetone (1:1) 및 (9:1)의 혼합용매의 평균 회수율은 60~80%로 나타났다. 또한, 토양 시료의 경우 검출한계는 0.5~3.5 ng/g이었으며, 선정 용매의 평균 회수율은 속실렛 추출이 67~97% 및 초음파 추출이 64~76%로 나타났다.

• 대한화학회지
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• 제33권1호
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• pp.46-54
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• 1989

식품 및 비타민 제제중에 존재하는 지용성 비타민의 추출 및 동시 정량법을 검토하였다. 역상 액체크로마토그래피에 의한 지용성 비타민의 동시 분리 및 정량은 메탄올 : 물 = 95 : 5 이동상으로 Novapak $C_{18}$ 컬럼하에서 이루어졌다. 비타민의 검출에는 UV검출기를 사용하였으며 검출감도를 증가시키기 위하여 분석중 UV 검출파장을 각각의 비타민 용리시간에 따라 최대흡수 파장인 330, 265, 285 및 290nm로 변경하였다. 지용성 비타민의 분리 및 분석은 40분안에 완료되었다. 시료의 전처리에는 알카리 가수분해법과 효소가수분해법을 이용하였으며, 비타민의 추출은 액체-액체추출법과 액체-고체추출법을 이용하였다. 비타민 A,D, E 분석에는 알카리 가수분해법 및 효소가수분해법이 비타민 K 분석에는 효소가수분해법만이 좋은 결과를 나타냈으며, 비타민 추출에는 액체-액체 추출시 diethyl ether, pentane 및 n-hexane이, 액체-고체 추출시 silica 카트리지가 좋은 추출효과를 나타냈다.

• Korean Chemical Engineering Research
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• 제50권4호
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• pp.684-689
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• 2012

Poly(acrylic acid) (PAA) 구형 입자는 바이오 분야의 소재에서부터 전자 재료에 이르기까지 다양한 분야에 사용되는 고분자 물질이다. 이를 생산하기 위해서는, 분산제(surfactant)를 이용한 중합 방법으로 합성을 한 후, 사용한 분산제를 제거하기 위한 별도의 Purification 과정을 거치게 된다. 일반 유기 용매를 사용하면 막대한 폐수 발생, 별도의 분리 공정 추가, 잔류 용매의 가능성 등의 문제점이 발생한다. 이에 이러한 문제를 해결하고자, 액체 이산화탄소를 용매로 하여, high-pressure Soxhlet extraction 방법을 개발하였다. 본 연구에서는 compressed liquid dimethyl ether (DME) 상에서 PAA 분산 중합에 사용된 pyrrolidene carboxylic acid-g-poly (siloxane) 계열의 분산제, Monasil PCA 제거하는 연구를 진행하였다. 추출된 PAA 입자의 모양은 field emission scanning electron microscopy (FE-SEM)으로 확인을 하였고, Monasil PCA의 농도는 Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES)로 분석하였다. 용매의 효과를 비교하기 위해서, 액체 이산화탄소와 n-hexane과 liquid DME를 대상으로 추출 실험을 하였다. 그 결과 n-hexane의 경우 일부 정제된 PAA 구형 입자를 얻을 수 있었지만, 일부는 n-hexane 증기의 높은 열에 의해서 변형된 형태의 입자를 얻었다. Liquid DME의 경우엔, 추출이 잘 되지 않았다. 액체 $CO_2$를 이용하는 경우에 구형의 형태는 유지하면서 분산제가 제거된 입자를 얻을 수 있었다. 그리고 최적 운전 조건을 알기 위해서 8시간 동안 재비기와 응축기의 온도를 달리하면서 실험을 실시하였다. 그 결과 추출기의 온도가 $19.6{\pm}0.2^{\circ}C$, 압력이 $51.5{\pm}0.5$ bar일 때, 가장 좋은 제거 효율을 보였다.

• 한국환경보건학회지
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• 제25권3호
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• pp.103-107
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• 1999

Even if odorous compounds remain very low concentration in water, it cause strong odor. Because Geosmin and most of odorous compound had very low vaporization, those were difficult to analyze with GC/MSD and Purge & Trap. So, we needed pre-treatment method for decreasing amounts of extracting solvents, improving recovery efficiencies and increasing analytical efficiencies. This study developed efficient technology for analyzing odorous compounds, using various adsorbents and extracting solvents. The optimum adsorbent was XAD resins. Especially, XAD-2, XAD-7 and XAD-2010 were superior, but XAD-2 of these and the optimum extraction solvent is MTBE. Other extraction solvents' efficiency is in order of MTBE>Dichloromethane>n-Hexane>Diethylether. The optimum NaCl dosage for increasing efficiency is 5 g in liquid-liquid extraction method. The shaking time(0~24hr) has no concern with adsorption efficiency. The optimum adsorbent is XAD-2 resin and extraction solvent is MTBE. Dosing NaCl, adsorption efficiency is increased in liquid-liquid extraction method, but NaCl has no effect on liquid-solid extraction method. In this experimental results, this algae toxins(Mycrocystin, Anatoxin etc.).

• 생명과학회지
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• 제9권5호
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• pp.575-580
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• 1999

Even if odorous compounds remained very low concentration in water, it caused strong odor. Because Geosmin and most of odorous compound had very vaporization, those were difficult to analyze with GC/MSD and Purge & Trap. So, we needed pre-treatment method for decreasing amounts of extracting solvents, improving recovery efficiencies and increasing analytical efficiencies. This study developed efficient technology for analyzing odorous compounds, using various adsorbents and extracting solvents. The optimum adsorbent was XAD resins. Especially, XAD-2, XAD-7 and XAD-2010 were superior, but XAD-2 of these and MTBE was the optimum extraction solvent. Other extraction solvent's efficiency was in order of MTBE>Dichloromethane>n-Hexane>Diethylether. The optimum NaCl dosage for increasing efficiency was 5g in liquid-liquid extraction method. The shaking time(0∼24hr) had no concern with adsorption efficiency. The optimum adsorbent was XAD-2 resin and extraction solvent was MTBE. Dosing NaCl, adsorption efficiency was increased in liquid-liquid extraction method, but NaCl has no effect on liquid-solid extraction method. In this experimental results, this method will apply to not only Geosmin but other well-known odorous compounds (2-MIB, IBMP, IPMP, TCA) and algae toxins (Mycrocystin, Anatoxin etc)

• Preventive Nutrition and Food Science
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• 제1권2호
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• pp.179-185
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• 1996

Extraction yields of thiosulfinates from garlic were studied by using gas-in-liquis-dispersion(GLD) system to maxmize the thiosulfinate extraction. Extracted thiosulfinates were spectrophotometically quantified using synthesized dially1 thiosulfinate. The conditions for maximum extraction were optimized by response surface methodology. The volatile components extracted by various methods, such as hexane extraction, simultaneous steam distillation and GLD system, were compared by using gas chromatography. The results indicated that the thiosulfinate yield was increased by incresaing temperature and nitrogen gas flow rate, while the effects of bubble sizes on thiosulfinate extraction were not significant at the ranges tested. Application of GLD system resulted in extraction of more volatile components than other extraction methods, Therfore, it was suggested that GLD system was one of the efficient extraction methods among the ever introduced ones, for thiosulfinate extraciton.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권1호
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• pp.47-51
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• 2004

Ceramide III was prepared by the cultivation of Saccharomyces cerevisiae. Ceramide III was partitioned from the cell extracts by solvent extraction and analyzed by Normal Phase High Performance Liquid Chromatography (NP-HPLC) using Evaporative Light Scattering Detector (ELSD). We experimentally determined the mobile phase composition to separate ceramide III with NP-HPLC. Three binary mobile phases of n-hexane/ethanol, n-hexane/lsoprophyl Alcohol(IPA) and n-hexane/n-butanol and one ternary mobile phase of n-hexane/IPA/methanol were demonstrated. For the binary mobile phase of n-hexane/ethanol, the first mobile phase composition, 95/5(v/v), was step-increased to 72/23(v/v) at 3 min. In the binary mobile phase, the retention time of ceramide III was 7.87min, while it was 4.11 min respectively in the ternary system, where the mobile phase composition of n-hexane/IPA/methanol, 85/7/8(v/v/v), was step-increased to 75/10/15(v/v/v) at 3 min. However, in the ternary mobile phase, the more peak area of ceramide III was observed.

• 분석과학
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• 제13권5호
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• pp.636-645
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• 2000

본 연구에서는 GC/MS를 이용하여 수질시료로부터 7종의 유기주석화합물을 분석하는 방법을 연구하였다. Hydrogenation과 ethylation의 반응시의 pH, 반응시간, 반응시약의 농도 등을 변화시켜 최적 반응조건을 조사하였다. n-Hexane을 용매로 사용한 액체-액체 추출 후 hydrogenation에 의한 유기주석염화물의 추출 회수율은 61-112% 범위로 나타났다. 물시료에서 ethylation한 후 n-hexane으로 추출한 경우의 추출 회수율이 74-113% 범위로 나타나 hydrogenation의 경우보다 높은 추출율을 보였다. 또한 ethylation후 styrene-divinylbenzene (SDB) 재질의 disk형의 고체상을 사용하고 추출 용매로 methylene chloride를 사용한 경우 61-97% 범위의 회수율을 나타냈다. Hydrogenation과 ethylation에 의한 검출한계는 각각 0.05-0.5 ng/ml와 0.02-0.05 ng/ml로 나타났다.

• Environmental Analysis Health and Toxicology
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• 제16권3호
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• pp.121-126
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• 2001

Analytical method of benzophenone (BP) in sediment and soil was developed by gas chromatography/mass selective detector/selected ion monitoring (GC/MSD/SIM). The ultrasonic extraction of US EPA (method 3550B) method and liquid-liquid extraction for sediment and soil samples were used for the analysis of BP from sediment and soil. BP was extracted with n-hexane. Organic layer was washed with 5% sodium chloride solution. 1∼2 l of the concentrated solution of organic layer was applied to GC/MSD. The retention time of BP peak was 11.10 min. Recovery (％) of BP by ultrasonication from sediment and soil samples was 96.0∼100.6％ and 40.0∼83.0％, respectively. Recovery of BP by liquid-liquid extraction was 51∼59％ in soil samples. The detection limit of BP in sediment and soil samples were determined to 0.1 ng/g.

• 한국환경과학회지
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• 제19권3호
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• pp.379-387
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• 2010

Sediments of Little Scioto (LS) River in Ohio was contaminated by poor disposal of creosote from Baker Wood Creosoting Facility. Among the primary compounds of creosote, Polycyclic Aromatic Hydrocarbons (PAHs) are the most common ingredient PAHs are known for toxic, carcinogenic and mutagenic compounds. There are many difficulties to remove the PAHs in nature environment because their characteristics are having a less water-solubility, volatile and low mobility properties as increasing the molecular weight. The generation of hydroxyl radicals (${\cdot}OH$) and hydrogen peroxide ($H_2O_2$) forms as well as high temperature (5000 K) and pressure (1000 atm) by a physico-chemical effects of ultrasound during a cavitation collapse can promote the degradation and desorption of PAHs in sediment And it can also produces shock wave and microjets which are able to change the size and surface of particle in solid-liquid system as one of physical effects. Therefore, we explored to understand the role of particle size, the effect of elimination for PAHs concentration by ultrasound and optimize the conditions for ultrasonic treatment. The condition of various size of particles (> $150{\mu}m$, < $150{\mu}m$) and solid-liquid ratio (12.5g/L, 25g/L) for the treatment was considered and ultrasonic power (430 W/L) with liquid - hexane extraction and microwave extraction method were applied after ultrasound treatment.