• Korean Journal of Pharmacognosy
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• v.53 no.4
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• pp.202-206
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• 2022

Salidroside is a major phenolic glycoside of Acer tegmentosum (Aceraceae) and known to be a hepatoprotective compound. Extraction conditions are one of the most important factors to save time and cost from an economic point of view. For this reason, this study was conducted to optimize the extraction condition for maximum yield of salidroside. For optimization, three extraction factors such as ethanol concentration (%), extraction temperature (℃), and solvent to material ratio (mg/mL) were tested and optimized for maximum yield of salidroside using response surface methodology (RSM). The optimal condition was obtained as an ethanol concentration of 53.4%, an extraction temperature at 67.11℃ and a solvent to material ratio (mg/mL), 195.55 mg/ml. The salidroside yield under optimal conditions was found to be 1.59 mg/g dried samples, which were well-matched with the predicted value of 1.56 mg/g dried samples. These results will provide useful information about optimized extraction conditions for the development of salidroside as hepatoprotective therapeutics.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.4
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• pp.362-377
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• 2014

Polycyclic aromatic hydrocarbons (PAHs) have been of particular concern since they are present both in the vapor and particulate phases in ambient air. In this study, a simple method was applied to determine the vapor phase PAHs, and the performance of the new method was evaluated with a conventional method. The simple method was based on adsorption sampling and thermal desorption with GC/MS analysis, which is generally applied to the determination of volatile organic compounds (VOCs) in the air. A combination of Carbotrap (300 mg) and Carbotrap-C (100 mg) sorbents was used as the adsorbent. Target compounds included two rings PAHs such as naphthalene, acenaphthylene, and acenaphthene. Among them, naphthalene was listed as one of the main HAPs together with a number of VOCs in petroleum refining industries in the USA. For comparison purposes, a method based on adsorption sampling and solvent extraction with GC/MS analysis was adopted, which is in principle same as the NIOSH 5515 method. The performance of the adsorption sampling and thermal desorption method was evaluated with respect to repeatabilities, detection limits, linearities, and storage stabilities for target compounds. The analytical repeatabilities of standard samples are all within 20%. Lower detection limits was estimated to be less than 0.1 ppbv. In the results from comparison studies between two methods for real air samples. Although the correlation coefficients were more than 0.9, a systematic difference between the two groups was revealed by the paired t-test (${\alpha}$=0.05). Concentrations of two-rings PAHs determined by adsorption and thermal desorption method consistently higher than those by solvent extraction method. The difference was caused by not only the poor sampling efficiencies of XAD-2 for target PAHs and but also sample losses during the solvent extraction and concentration procedure. This implies that the levels of lower molecular PAHs tend to be underestimated when determined by a conventional PAH method utilizing XAD-2 (and/or PUF) sampling and solvent extraction method. The adsorption sampling and thermal desorption with GC analysis is very simple, rapid, and reliable for lower-molecular weight PAHs. In addition, the method can be used for the measurement of VOCs in the air simultaneously. Therefore, we recommend that the determination of naphthalene, the most volatile PAH, will be better when it is measured by a VOC method instead of a conventional PAH method from a viewpoint of accuracy.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.618-623
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• 2003

Solvent extraction experiments for separation of impurities from Ni-rich solution were carried out for manufacturing of high purity Ni compounds from acid leaching solution of spent Ni-Cd secondary battery. Artificial and leaching solutions were used as aqueous phases and PC88A saponified by sodium in kerosene were used as organic phase. The extraction order is Zn>Mn>Co>Ni and extraction percentage of metal ions was increased with increase of the concentration of extractant, initial pH of aqueous phase and ratio of O/A. The separation of cobalt, zinc and manganese from nickel was effectively accomplished at the condition of extraction stage=l, O/A=1 and initial pH 5.0 with 1.0 $mol/dm^3$ PC88A saponified to $50\%$ with NaOH.

• Resources Recycling
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• v.14 no.5 s.67
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• pp.18-23
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• 2005

Recovery of phosphoric acid from waste acid mixture of acetic, nitric and phosphoric acid has been attempted by using solvent extraction method. In this work, organic phosphate was used as an extraction agent. The effect of phosphate concentration, agitation speed and time on the solvent extraction of acetic and nitric acids has been investigated. The optimum concentration of phosphate for preferential extraction of acetic and nitric acids from waste acid was found to be about 50% irrespective of agitation speed and time. Purified phophoric acid was recovered from extraction residue at 1/3 of A/O ratio and 6th stage of extraction stage, which is well consistent with the value calculated by using McCabe-Thiele diagram.

• Journal of Environmental Science International
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• v.22 no.10
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• pp.1317-1325
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• 2013

Paulownia coreana is a medicinal, edible and industrial plant with the largest leaf, and is native to Korea. We evaluated the reducing power activities, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities (RSAs), nitrite scavenging activities (NSAs) and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation RSAs by solvent extraction of P. coreana bark by using $50^{\circ}C$ hot water and $25^{\circ}C$ methanol. The antioxidative effect of P. coreana bark extract on corn seed oil was evaluated using the Rancimat test. The extraction yields on dry weight basis with 15 folds of hot water and methanol were 23.88% and 5.30%, respectively; further the flavonoid content in the hot water extract was over 2.5 times more than that in the methanol extract. The DPPH RSA of the methanol extract was substantially higher than that of the water extract, whereas the NSA of the water extract was higher than that of the methanol extract at pH 1.2. The ABTS RSAs of the two extracts were almost the same as that of ascorbic acid and 2,6-ditertiarybutyl hydroxytoluene. The two extracts of P. coreana bark in this study were found to slightly improve the oxidation stability of corn seed oil.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.969-973
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• 2008

Solvent extraction using a Schiff-base, salen$(NEt_2)_2$, as a chelating agent has been conducted on several water samples to study the determination of trace Cu(II), Mn(II) and Zn(II). Experimental conditions for the formation and extraction of metal complexes were optimized with an aqueous solution similar in composition to the samples. The matrix difference between the sample and standard solutions was approximately matched, and the pH of each sample solution was adjusted to 9.5 with $NaHCO_3/NaOH$ buffer. The concentration of salen$(NEt_2)_2$ was $7.3\;{\times}\;10^{-3}$ mol/L, and the complexes were extracted into MIBK solvent followed by the measurement of AAS absorbance. The potential interference of concomitant ions was investigated, but no interference from alkaline and alkali earth ions was shown in this procedure. The given procedure is precise, as judged from the relative standard deviation of less than 5% for five measured data. The recovery of 93-103% shows that this method is quantitative for such trace metal analysis.

• Journal of Microbiology and Biotechnology
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• v.6 no.5
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• pp.358-360
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• 1996

Solvent extraction, soxhlet method, and supercritical fluid extracion were considered, respectively, as the method of choice for the recovery of DHA from lyophilized Thraustochitrium sp., and the results of corresponding extraction were compared. Supercritical fluid extraction seems to be the most appropriate process with respect to time, process simplicity, and extractant intoxicity.

• Korean Journal of Metals and Materials
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• v.47 no.6
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• pp.349-355
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• 2009

In the solvent extraction of Ru(IV) with Alamine336, it was found that Ru took part in the reaction as $RuCl_{6}_^{2-}$ in the HCl concentration range of 1 to 5 M. Interaction parameter between hydrogen ion and $RuCl_{6}_^{2-}$ was estimated by applying Bromley equation to the extraction data. From the mixed solutions of Pd(II) and Ru(IV), the distribution coefficients of Pd were found to be higher than those of Ru in the experimental ranges. Separation factor between Pd and Ru rapidly increased with the decrease of Alamine336 concentration. About 60% of the Ru from the mixed solutions was extracted by TBP at 8.3 M HCl, while Pd was not extracted in the HCl concentration range of 1.6 to 8.3 M.

• Journal of Food Hygiene and Safety
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• v.14 no.4
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• pp.365-371
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• 1999

Microwave-assisted extraction (MAE) is known as a more environmental-friendly process with economic advantages in terms of less time, less solvent, less energy and less waste than the current reflux method that is time-consuming. MAE was applied to extract three pesticides (quintozene, tolclofos-methyl and procymidone) from ginseng in a pesticide residue analysis and eliminate pesticide contaminants from ginseng prior to production of the ginseng extracts. The optimal conditions for pesticide extraction from ginseng were 50% in power (150 watts), 2 minutes, 20 mL hexane and 2.0 g sample. The results of optimal conditions were compared with those of Soxhlet method (7 hours, 150 mL hexane). The recoveries between two methods were almost same while time and amount of solvent used in MAE were significantly decreased in comparing with those in the Soxhlet methods. When the 45% ethyl alcohol as a extraction solvent was applied to eliminate pesticides from ginseng prior to the production of the ginseng extracts, it was found that 100% quintozene, 69％ tolclofos-methyl and 83% procymidone were eliminated from ginseng. The data showed that MAE may be used to eliminate pesticide contaminants in ginseng prior to making the ginseng extracts.

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.35-42
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• 2009

Headspace micro solid phase extraction using mulberry paper bag (HS-MPB-$\mu$-SPE) has been developed and validated for the analysis of volatile flavor compounds from five spice by gas chromatography-mass spectrometry (GC/MS). HS-MPB-$\mu$-SPE was performed with adsorbent particles enclosed inside a mulberry paper bag. Four different kinds of adsorbents such as Tenax TA, Porapack Q, dimethylpolysiloxane and polyethylene glycol were tested. The extraction solvents compared were petroleum ether, methylene chloride, and chloroform. Better results were obtained when Tenax TA and petroleum ether were used. The limit of detection (LOD) and the limit of quantitation (LOQ) were in the range of 1.3 ng/mL and 4.3 ng/mL, respectively, for o-cymene as a model compound of monoterpene. Proposed method showed good reproducibility (3.3%, RSD) and good recoveries (94.0%). The HS-MPB- μ-SPE is very simple to use, inexpensive, rapid, requires small sample amounts and solvent consumption. Because the solvent for extraction is reduced to only a very small volume (0.6 mL), there is minimal waste or exposure to toxic organic solvent and no further concentration step. This method allows successful characterization of the headspace in contact with the five spice sample. Strong trans-anethole from star anise or fennel is a characteristic flavor of five spice powders. HS-MPB-$\mu$-SPE combined with GC/MS can be a promising technique for the broad spectrum measurement of volatile aroma compounds from solid spices.