• KSBB Journal
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• v.16 no.3
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• pp.233-236
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• 2001

Because of casehardenign effect of amorphous paclitaxel, residual solvents, methylene chloride and emthanol could not be reduced to the maximum value allowed, 600 ppm and 3,000 ppm, in accord with the guidelines issued by the International Conference on Harmonization (ICH, 1997), using rotary evaporation and successive drying in a vacuum oven. However, methylene chloride and methanol were reduced to 486 ppm and 403 ppm, respectively using supercritical $CO_2$ on purified paclitaxel. The optimum pressure and operating time were 80 bar and 30 min at fixed operating temperature ($40^{circ}C$). This approach serves as a novel application of supercritical fluid extraction to remove residual solvents from active pharmaceutical ingredients.

• KSBB Journal
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• v.24 no.2
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• pp.212-215
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• 2009

In this study, the process parameters of liquid-liquid extraction were optimized to obtain a high purity and yield of paclitaxel in a pre-purification step. The optimal solvent ratio (methylene chloride/concentrated methanol extract ratio), extraction times, mixing time, and standing time for liquid-liquid extraction were 0.28 (v/v), 3(times), 30 min, and 40 min, respectively. The polar impurities from the biomass extraction were efficiently removed by liquid-liquid extraction. The complete concentration of liquid-liquid extract by rotary evaporator was reliable enough to obtain a high purity and yield of paclitaxel for subsequent purification steps.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.80-85
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• 1995

After solvent extraction of 28 domestic cultivated medicinal plants using methylene chloride, 1000ppm of extracts were added to linoleic acid to compare antioxidative activities. Although their magnitude was somewhat different, all extracts showed the antioxidative activities. Antioxidative activity of Scutellariae baicalensis extract was similar to that of BHA. Antioxidative activity of Paeonia moutan and Liriope platyphylla extracts was lower than that of Scutellariae baicalensis. When Scutellariae baicalensis was extracted with 9 solvents which have a different polarity, the extraction yield and antioxidative activity generally increased with increasing polarity. The nitrite-scavenging effects, electron donating abilities(EDA) and anti-complementary activities were determined.

• Journal of the Korean Chemical Society
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• v.30 no.5
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• pp.465-474
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• 1986

The solvent extraction and cleanup processes for the simultaneous gas-liquid chromatographic determination of 11 kinds of organophosphorous pesticide residues in crops were investigated. The extracts dissolved with acetone were partitioned with petroleum ether after adding saturated NaCl solution. Evaporated the partitioning solvent, the residue was dissolved in methylene chloride and eluted through mixed adsorbent (1 : 2 : 4 of activated carbon, magnesia and diatomaceous earth) with methylene chloride as an eluent. The pesticides recovered were 82∼105% and the impurities were effectively removed.

• Bulletin of the Korean Chemical Society
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• v.25 no.10
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• pp.1489-1494
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• 2004

A gas chromatography/mass spectrometric assay method was developed for the determination of persistent organochlorine pollutants (POPs) in hair. For the exact extraction study was used hair of rat exposed with POPs. Sonication of the hair matrix with 3 M HCl solution in methylene chloride of the extraction methods studied was the most efficient and rapid sample preparation method. After sonication of rat hair was achieved clean up with a solid phase extraction procedure using silica gel-florisil. Elution was performed with 8 mL of methylene chloride. The eluate was concentrated to approximately 100 ${\mu}L$ and analyzed by gas chromatography-mass spectrometry (GC-MS). Detection limits of POPs were in the concentration range of 0.6-1.2 ng/g in rat hair. Aldrin, dieldrin, p,p-DDT and mirex were dosed rat for 4 weeks at concentration of 0.01 mg/L in drinking water and detected in rat hair at concentration of 2.8, 11.3, 7.9 and 15.6 ng/g, respectively. Aldrin and p,p-DDT were metabolized to dieldrin and p,p-DDE, which were detected in concentration of 9.7 and 2.9 ng/g in rat hair, respectively. The developed method may be valuable to be used to analyze POPs in human hair.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1163-1168
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• 1998

Fish tissues were spiked with organophosphorus pesticides (OPPs), mixed with a celite as a drying agent, and dynamically extracted with pure $CO_2$ or modified $CO_2$ for 10 min at different extraction temperatures, pressures and $CO_2$ flow rates. Recoveries of OPPs spiked in jacopever increased with the decrease of extraction temperature and pressure, and decreased with the increase of $CO_2$ flow rates. Modified $CO_2$ extractions with 10% methylene chloride showed a slight increase in the recoveries over pure $CO_2$ extraction. Quantity of fish tissues had great effect on their extraction efficiencies. Recoveries of OPPs were $66.7{\sim}86.3%$ for jacopever, $56.2{\sim}79.2%$ for yellow tail, $57.6{\sim}77.8%$ for blanquillo, $84.2{\sim}96.3%$ for sardine, $74.6{\sim}83.6%$ for mackerel. Application of supercritical carbon dioxide extraction offers an attractive alternative to the use of organic solvents for extraction of pesticide residues from fish tissues.

• Bulletin of the Korean Chemical Society
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• v.21 no.11
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• pp.1101-1105
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• 2000

A simultaneous determination method of BTEX (benzene, toluene, ethylbenzene, o,m.p-xylene) and TPH (kerosene, diesel, jet fuel and bunker C) in soil with gas chromatography/flame ionization detection (GC-FID) was described. The effects of extracti on method, extraction solvent, solvent volume and extraction time on the extraction performance were studied. A sonication method was simpler and more efficient than Soxhlet or shaking methods. Sonication with 10 mL of acetone/methylene chloride (1 : 1, v/v) for 10 min was found to be optimal extraction conditions for 20 g of soil. Peak shapes and quantification of BTEX and TPH were excellent, with linear calibration curves over a wide range of 1-500 mg/L for BTEX and 10-5000 mg/L for TPH. Good reproducibilities by sonication were obtained, with the RSD values below 10%. By using about 20 g of soil, detection limits were 0.8 mg/L for BTEX and 10 mg/L for TPH. The advantages of this procedure are the use of simple and common equipment, reduced volumes of organic solvents, rapid extraction periods of less than 20 min, and simultaneous analysis of volatile and semivolatile compounds.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.305.1-305.1
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• 2003

A simple, specific and sensitive method for the determination of levofloaxcin (LFX) in human serum was developed by a high performance liquid chromatography/diode array detector and applied to pharmacokinetic study of LFX in human volunteers. This method involves several steps such as precipitation with acetonitrile, extraction with methylene chloride, evaporation, and concentration, using 0.5ml of the serum. (omitted)

• The Korean Journal of Food And Nutrition
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• v.31 no.6
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• pp.775-782
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• 2018

The purpose of this study was to investigate effects of Crataegus pinnatifida var. psilosa extracts obtained from 95% methanol and water. Methylene chloride, ethyl acetate, and methanol were used to fractionate the 95% methanol extract and each fraction was testified total polyphenol contents, electron donating abilities, the scavenging abilities of superoxide anion radical, as well as hydrogen peroxide. Extraction yields of 95% methanol and water from Crataegus pinnatifida var. psilosa were 25.40%, 23.12% respectively. Total polyphenol contents were $28,708.0{\pm}1,755.05{\mu}g\;GAE/mL$ in 95% methanol, revealing the highest among them, $12,726.67{\pm}479.33{\mu}g\;GAE/mL$ in water extract, $15,854.67{\pm}498.38{\mu}g\;GAE/mL$ in methanol fraction, $11,810.67{\pm}584.48{\mu}g\;GAE/mL$ in ethyl acetate fraction, and $5294.67{\pm}190.36{\mu}g\;GAE/mL$ in methylene chloride fraction. Total polyphenol contents revealed significant differences (p<0.05) between the solvents. In the experiment of the electron donating ability, water extract revealed $84.33{\pm}0.1%$ scavenging ability, the highest. Other extracts and fractions were $81.8{\pm}1.11%$ for water, $79.73{\pm}1.32%$ for ethyl acetate fraction, $75.73{\pm}2.17%$ for methylene chloride fraction, and $42.1{\pm}5.01%$ for methanol fraction, the lowest electron donating ability. Electron donating abilities revealed significant difference (p<0.05) between the solvents. In the experiment of superoxide anion radical scavenging ability, ethyl acetate fraction($0.0026{\pm}0.0002$) had the highest scavenging ability, and the others revealed slight increase rather than decrease in scavenging ability. Hydrogen peroxide scavenging ability revealed the highest in methanol fraction ($-0.00206{\pm}0.00165$) and the others were as follow; water extract ($0.00157{\pm}0.00249$), 95.0% methanol extract ($0.005{\pm}0.0036$), methylene chloride fraction ($0.0039{\pm}0.00364$), and ethyl acetate fraction ($0.0002{\pm}0.00059$).

• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.229-233
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• 2016

In this study, an efficient ultrasound-assisted liquid-liquid extraction process was developed for recovering of paclitaxel from plant cell cultures. The optimal ultrasonic power and operating time were 250 W and 15 min at fixed ratio of bottom phase, methylene chloride to top phase, MeOH (25%, v/v). Under the optimal conditions developed in the present method, most of the paclitaxel (~92%) was recovered from crude extract by a single extraction step. Due to the synergistic effect of ultrasound by the addition of inorganic salt, an appropriate inorganic salt concentration and the ultrasonic power were found to be required for the effective recovery of paclitaxel using ultrasound-assisted liquid-liquid extraction.