• 한국식품영양학회지
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• 제12권4호
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• pp.358-363
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• 1999

This study was conducted to evaluate the extraction methods for the determination of antioxidants in soybean oil. Recovery rates of various antioxidants in soybean oil showed similar rates as 80.4~102.1% by solvent/solvent extraction method and 89.9~106.4% by sweep co-distillation method except 46.6~61.2% of PG at corresponding spiked concentractions. The maximun recovery rates of antioxidnts were obtained when extraction time and extraction temperature used in UNITREX were 20min and 21$0^{\circ}C$ respectively. In the recovery rates with the activation of florisil when 2% ofwater was added to florisil the highest recovery rates for TBHQ, BHA, BHT were obtained by sweep co-distillation met-hod. Therefore sweep co-distillation method showed less solvent simple operation and high recovery rate compared with solvent/solvent extraction method.

• Applied Biological Chemistry
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• 제47권2호
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• pp.228-237
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• 2004

농약성분 분석에 있어서 시료 전처리시간을 단축할 수 있는 분석방법을 개발하기 위해 농산물 중에 잔류하고 있는 잔류농약성분을 대상으로 ASE(accelerated solvent extraction) 방법을 활용한 자동화된 전처리 방법을 검토하였다. ASE 추출조건은 preheat 1 min, heat 5 min, static 1 min, solvent flush% 60 vol, nitrogen purge 60 sec, cycle 4, pressure 1500 psi, temperature $100^{\circ}C$를 선택하였다. 이 분석조건과 n-hexane:acetone(4 : 1, v/v)를 추출용매로 사용하였을 때, ASE 추출과 정제능력은 solvent extraction 방법과 유의적인 차이를 보이지 않았고, 추출 용매의 감소는 추출산물의 재현성에 큰 영향을 미치지 않았다. ASE 방법은 잔류농약 분석 시 소요되는 유기용매의 양을 감소하고 추출과 정제를 동시에 수행함으로써 동결건조 시간을 제외한 전처리 시간이 단축되어 분석비용 또한 solvent extraction에 비해 감소시킬 수 있었다.

• Mass Spectrometry Letters
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• 제14권2호
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• pp.36-41
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• 2023

A simple method was developed to determine residual p-arsanilic acid (ASA), an organo-arsenic compound used as a feed additive, in aquatic products (eel, halibut, and shrimp) using EDTA-assisted solvent extraction and LC-MRM. The method was successfully validated in terms of specificity, linearity (coefficient of determination ≥ 0.995), accuracy (recovery or R, 72.72-78.73%), precision (the relative standard deviation of R, 2.08-6.98%), and sensitivity (the lower limit of quantitation, 5 ppb) according to CODEX guidelines (CAC-GL 71-2009). The use of EDTA in the extraction solvent and water with a suitable pH modifier as the reconstitution solvent may be the key factors for successful results. This is the first method that can be used for monitoring residual ASA in aquatic products using LC-MRM and could contribute to establishing a better aquatic product safety management system.

• Elastomers and Composites
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• 제54권3호
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• pp.188-200
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• 2019

Rubber articles contain various organic additives such as antidegradants, curing agents, and processing aids. It is important to extract and analyze these organic additives. In this paper, various extraction methods of organic additives present in rubber composites were introduced (solvent extraction, Soxhlet extraction, headspace extraction, and solid-phase microextraction), and the extracts were characterized using gas chromatography/mass spectrometry (GC/MS). Solvent and Soxhlet extractions are easy-to-perform and commonly used methods. Efficiency of solvent extraction varies according to the type of solvent used and the extraction conditions. Soxhlet extraction requires a large volume of solvent. Headspace sampling is suitable for extracting volatile organic compounds, while solid-phase extraction is suitable for extracting specific chemicals. GC/MS is generally used for characterizing the extract of a rubber composite because most components of the extract are volatile and have low molecular weights. Identification methods of chemical structures of the components separated by GC column were also introduced.

• 펄프종이기술
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• 제44권6호
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• pp.50-57
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• 2012

In this study, the beeswax extraction methods using organic solvents were examined to develop a optimal dewaxing technology for beeswax-treated Hanji. Thermally-aged beeswax-treated Hanji was dewaxed using four types of extraction methods including dipping, Soxhlet extraction, ultrasonic washing and shaking methods. Then, the aging stability of the dewaxed Hanji was evaluated in terms of variations in paper strength and in the color of the printed area with muk. The experimental results suggested that the dewaxing methods allowing solvent to flow during extraction showed superior extraction efficiency. The dipping method in which the organic solvent does not flow showed the slowest extraction rate of beeswax compared to three other methods. In terms of variations in tensile strength and folding endurance, however, no obvious differences in the aging stability were observed amongst these four extraction methods. Regarding the aging stability in terms of the color of the printed area with muk, Soxhlet extraction method showed the best performance of dewaxing.

• 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)

• KSBB Journal
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• 제28권4호
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• pp.238-243
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• 2013

Astaxanthin is one of the carotenoid with strong antioxidant. The conditions of extraction of astaxanthin from Portunus trituberculatus were optimized in this work. Six factors of conditions such as, extraction method, extraction solvent, ratio of solvent to raw material, temperature, and time, were investigated. For the increase of the extraction yield, ionic liquids were used as additives in the extraction solvent. The optimum extraction conditions were found: heat reflux extraction, Dichloromethane/methanol (25:75, v/v) as solvent, 1:30 of the ratio of solvent raw material, $80^{\circ}C$, 90 min, and ionic liquid as additive. As a result, 45.81 ${\mu}g/g$ of astaxanthin was extracted from waste.

• Bulletin of the Korean Chemical Society
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• 제20권6호
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• pp.689-695
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• 1999

Supercritical fluid extraction (SFE), ultrasonic extraction (USE), and accelerated solvent extraction (ASE) were compared with the well known Soxhlet extraction for the extraction of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins(PCDDs) from the XAD-2 resin which was used to adsorb PCDDs in the atmosphere. XAD-2 resin spiked with five PCDDs was chosen as a sample. The optimum conditions for the extraction of PCDDs by SFE were turned out to be the use of CO2 modified with 10% toluene at 100 ℃ and 350 atm, with 5 min static extraction followed by 20 min dynamic extraction. SFE gave a good extraction rate with good reproducibility for PCDDs ranging from 68 to 98%. The ultrasonic extraction of PCDDs from XAD-2 was investigated and compared with other extractions. A probe type method was compared with a bath type. Two extraction solvents, toluene and acetone were compared with their mixture. The use of their mixture in probe type, with 9 minutes of extraction time, was found to be the optimum condition. The average recovery of the five PCDDs for USE was 82-93%. Accelerated solvent extraction (ASE) with a liquid solvent, a new technique for sample preparation, was performed under elevated temperatures and pressures. The effect of tem-perature on the efficiency of ASE was investigated. The extraction time for a 10 g sample was less than 15 min, when the organic solvent was n-hexaneacetone mixture (1 : 1, v/v). Using ASE, the average recoveries of five PCDDs ranged from 90 to 103%. SFE, USE, and ASE were faster and less laborious than Soxhlet extraction. The former three methods required less solvent than Soxhlet extraction. SFE required no concentration of the solvent extracts. SFE and ASE failed to perform simultaneous parallel extractions because of instrumental limitations.

• Bulletin of the Korean Chemical Society
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• 제31권9호
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• pp.2488-2492
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• 2010

A method is described for the determination of the Po nuclides in a water sample. After the Po nuclides were purified from interfering elements in a water sample using a manganese dioxide precipitation followed by a solvent extraction method, the Po nuclides were deposited onto the silver plate. A large volume of the water sample was effectively pretreated with manganese dioxide precipitation method. To determine the optimum conditions for plating Po, the effects of the pH, volume, temperature and time on the Po deposition were investigated in hydrochloric acid solution. The investigated determination method of Po nuclides with solvent extraction was applied to a tap water sample.

• 대한금속재료학회지
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• 제46권4호
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• pp.227-232
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• 2008

Solvent extraction reaction of cobalt by Alamine336 from strong hydrochloric acid solution was identified by analyzing the solvent extraction data reported in the literature. Analysis of the data by graphical method revealed that Alamine336 took part in the solvent extraction reaction as a monomer in the concentration ranges, [Co(II)] : 0.0169 - 0.102 M, [Alamine336] ; 0.02- 1.75 M, and [HCl ] : 5 - 10 M. The following solvent extraction reaction and equilibrium constant was obtained from the experimental data by considering the activity coefficients of chemical species present in the aqueous phase. $Co^{2+}+2Cl^{-}+R_3NHCl_{org}=CoCl_3\;R_3NH_{org}$, $K_{ex}=2.21$ The distribution coefficients of cobalt predicted in this study agreed well with those reported in the literature.