• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.482-488
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• 2001

Platinum group metals (pgm) are useful to many industries such as chemical, dental and medical, petroleum, refining, electrical and electronic, and automotive. Researchers at the South Dakota School of Mines and Technology and PGM Recovery Ltd. have developed jointly an environmentally sound and metallurgically efficient process for extracting these metals from secondary sources. Once these metals have been dissolved in the leach liquor, the individual metals mainly platinum, palladium, and rhodium, should be separated in order to recover the individual metals with high purity. During this investigation, solvent extraction has been chosen as the method used to achieve the separation and extraction of platinum, palladium, and rhodium from the leach liquor. There were three solutions used throughout this procedure: 1) Synthetic solution (200 ppm Pt 80 ppm Pd 20 ppm Rh; 300 ppm Pt, 180 ppm Pd 50 ppm Rh), and 2) Auto catalyst leach liquors (100 ppm Pt, 30 ppm Pd, 20 ppm Rh). The solvents investigated included Lix 84(2-hydroxy-5-nonylacetonphenone oxime in a mixture with 5-dodecylsalicyloxime), Lix 84-I, ACORGA CLX-50 (diester of pyridine 3,5 dicarboxylic acid), and di-hexyl sulfide. The extraction values achieved using ACORGA CLX-50, Lix 84, and Lix 84-I were respectively Pt (25%, 0% 0%), Pd (100%, 99.8%, 95.3%), and Rh (99.1%, 35.5%, 4.25%). The stripping processes for the Lix 84, and Lix 84-I were proven to be more involved than others. The solutions were required to be simultaneously heated and stirred. The percentages acquired through these processes yielded unsatisfactory results. The stripping procedure for the ACORGA CLX-50 was easier to execute, yet the percentage recovered from this process was also unsatisfactory. Overall the di-hexyl sulfide has proved to be the most successful organic for this procedure. The average percent extracted for palladium was excellent with 99.9% - 100% with very little Platinum and rhodium extracted. The ability of stripping palladium in ammonia solution was also found to be excellent.

• Journal of Environmental Health Sciences
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• v.31 no.6
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• pp.498-503
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• 2005

Stability of soybean isoflavone isomers according to extraction conditions such as temperature, pH, and extracting solvents was investigated. Heating induced three chemical reactions to occur for malony1 derivatives of isoflavones, namely decarboxylation of malony1 groups into acety1 derivatives, deesterification of malony1 residues, and hydrolysis of $\beta$-glycosidic bonds. Among the twelve isoflavone isomers, change in concentrations of acety1glycosides were most pronounced: Acety1 derivatives were present only in trace amounts in unheated hypocotyls, but the content increased dramatically during heating. As for the glycosides, concentrations of daidzin and glycitin increased due to heat treatment, though that of genistin remained almost unchanged. Heat decomposition rates and the patterns differed among the three malony1 derivatives. After 120 min at $80^{circ}C$, the relative concentrations of daidzin, glycitin and genistin were increased from $9.2\%$, $12.4\%$ and $3.3\%$ to $19.3\%$, $21.9\%$ and $6.2\%$, respectively. When crude isoflavones were solubilized in glycine buffer (pH 10.0) and incubated at $80^{circ}C$, deesterification occurred faster than at pH 7.0. When the pH of isoflavone solution was increased, the malony1glycosides were hydrolyzed to their respective glycosides at increased rate. Both acetyl and aglycone forms were unchanged and only de-esterification reactions occurred. At the acidic pH, malonylglycosides were much stable both at 60 and $80^{circ}C$. However at pH 10, $80^{circ}C$ and 1 hr, $75-80\%$ of malonylglycosides were transformed to their deesterified glycosides. When isoflavones were extracted with $60\%$ aqueous ethanol at $60^{circ}C$, isoflavone isomers were stable and the deesterification reactions did not occur in these conditions. However, at $80^{circ}C$ deesterification of malonyiglycosides occurred significantly with $15-20\%$ of malonylglycosides being hydrolyzed into their respective glycosides. This experiment showed that malonylglycosides undergo decomposition when heated or exposed to alkaline conditions. Also, aqueous ethanol was preferred to aqueous methanol as solubilizing media for obtaining extract with minimum degradation of malonylglycosides.

• Journal of Korean Medicine Rehabilitation
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• v.30 no.2
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• pp.67-75
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• 2020

Objectives SJ004 is a natural herbal medicine that contains Acyranthes japonica Nakai and Eucommia ulmoides Oliver traditionally used for joint and spinal diseases. This study aimed to establish an efficient method of extracting SJ004 to standardize using the yield, high-performance liquid chromatography (HPLC), and antioxidant assay. Methods SJ004 was extracted with distilled water, 70% and 100% of ethyl alcohol (EtOH). The method validation of 20-hydroxyecdysone and pinoresinol diglucoside was determined by HPLC-photo diode array and the content of SJ004 was calculated. The antioxidant activity of each extract was compared and measured using total flavonoids, total phenolic compounds, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and ferric reducing antioxidant power according to the standard protocol. Results The yield was highest in pure water extract and lowest in 100% EtOH. But, the content of marker compounds indicating 20-hydroxyecdysone and pinoresinol diglucoside was highest in 100% EtOH extract. In the physiological activity measurement using antioxidant activity, 100% ethanol extract was highest. The limit of detection indicating 20-hydroxyecdysone and pinoresinol diglucoside were analyzed 0.33 ㎍/mL, 0.1616 ㎍/mL, and the limit of quantification were analyzed 1.01 ㎍/mL and 0.49 ㎍/mL respectively. Conclusions The experimental results showed that the extraction conditions have a significant effect on content of marker compounds and antioxidant activity. As a result of method validation, SJ004 was standardized by 20-hydroxyecdysone and pinoresinol diglucoside.

• Food Science and Preservation
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• v.14 no.6
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• pp.633-638
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• 2007

Changes in organic acid, mineral, color, curcumin and bitter taste of Curcuma longa L. (autumn woolgeom in Korean) and Curcuma atomatica Salib (spring woolgeom) were investigated according to picking time. Oxalic and lactic acid were gradually increased, and then malic acid and malonic acid were decreased by extending the picking time. Total organic acid was increased by extending the picking time and then decreased after January of the coming year. Minerals were increased by extending the picking time and decreased slightly after the coming year. Hunter color index, L, a and b, was increased by extending the picking time. Contents of curcumin in spring woolgeom was slowly increased by extending the picking time and autumn woolgeom was $1.8{\sim}2.5$ times higher than spring woolgeom. Intensity of bitter taste in two woolgeoms were not different by picking time and extracting solvents. Bitterness of spring woolgeom was strong as compared to autumn woolgeom.

• Clean Technology
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• v.22 no.4
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• pp.241-249
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• 2016

In this study, comparative work has been performed between two-columns and three-columns configurations for an extractive distillation process to produce highly purified ethanol with not less than 99.7 wt% using dimethyl sulfoxide (DMSO) and ethylene glycol (EG) as extracting agents. Optimal ethanol concentration at a concentrator top stream which minimized the total reboiler heat duties was determined for a three-columns configuration for two different solvents. For the thermodynamic model, NRTL liquid activity coefficient model was used and PRO/II with PROVISION 9.4 at Schneider electric company was utilized. DMSO was proved to be a better solvent than EG and three-columns configuration is better than two- columns configuration in the total utility consumptions since some of the liquid water contained in the feed stream was removed at a concentrator bottom liquid stream.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.42-49
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• 2000

A new method for the quantitative determination of capsaicinoids in microcapsule has been developed. Among seventeen solvents tested for solubilizing wall material (gum arabic and modified starch) of microcapsule, dimethyl sulfoxide (DMSO) was selected as an optimal solvent. The most appropriate mixing ratio of microcapsule to DMSO for solubilizing wall material was 1 to 10(w/v). Appropriate carriersolubilizing temperature and time were $55^{\circ}C$ and 30 min, respectively. Also conditions for extracting oleoresin from the solubilized microcapsule were studied. The mixing ratio of ethanol to DMSO was optimal at 8 to 1(v/v). Optimized vortexing time was 5 min at 40㎐. Pecipitant was obtained by centrifugation at 21000 rpm for 15 min. The precipitant was reextracted with ethanol. The extracted supernatants were combined and adjusted to final volume of 25 ml. Extracted solutions were analyzed for quantitation of total capsaicinoids by employing HPLC and for quantitation of total carotenoids by spectrophotometric method. This method can be used to monitor changes of capsacinoid during manufacturing or storage of red pepper oleoresin microcapsule powder.

• International Journal of Industrial Entomology and Biomaterials
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• v.35 no.2
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• pp.89-96
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• 2017

Various health promoting effects of steamed and freeze-dried mature silkworm powder (SMSP) have been reported. However, it is not still clear which substances in SMSP are responsible for those health promoting effects yet. In this study, we examined and compared the quantities of phytochemicals in SMSP and freeze-dried mulberry leave powder (FMLP). To investigate the optimal solvent for extracting phytochemicals from SMSP and FMLP, we used four different solvents. Among them, 80% ethanol extracts from SMSP and FMLP contained the highest amount of five flavonoids examined. In addition, FMLP had high contents of flavonoids compared with those of SMSP. The amounts of rutin, isoquercetin, astragalin, quercetin, and kaempferol in FMLP were $5.078{\pm}0.187mg/g$, $5.162{\pm}0.083mg/g$, $2.989{\pm}0.061mg/g$, $3.317{\pm}0.236mg/g$, and $2.243{\pm}0.237mg/g$, respectively, while the amounts of rutin, isoquercetin, astragalin, quercetin, and kaempferol in SMSP were $0.171{\pm}0.024mg/g$, $0.252{\pm}0.032mg/g$, $0.374{\pm}0.031mg/g$, $0.645{\pm}0.063mg/g$, and $0.0512{\pm}0.047mg/g$, respectively. Taken together, SMSP could be a source for providing various and readily absorbable flavonoids.

• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.329-333
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• 2021

Subcritical water extraction (SWE) is an eco-friendly extraction method that uses only purified water as a solvent under high temperature and high pressure conditions. In this study, total phenolics, and antioxidant activity were evaluated in Ziziphus jujuba Mill extracts from subcritical water obtained by varying the extraction temperature (110-190℃) and extraction time (1-20 min). Total phenolics was maximized with extraction at 190℃ for 15 min (67.79±3.45 mg gallic acid equivalent/g jujube). The 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (48.84±4.74%) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) free radical scavenging activity (84.75±1.15%) were maximal at extraction conditions of 190℃, for 20 min. All jujube extracts prepared using SWE had higher total phenolics and antioxidant activities than extracts prepared using organic solvent extraction (60℃, 120 min), including methanol and ethanol. SWE could be an excellent alternative to organic solvents for extracting phenolics and antioxidant compounds.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.1
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• pp.9-16
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• 2023

In this study, we tried to verify the value of the use of Mucuna pruriens (M. pruriens) extract as an antioxidant functional cosmetic material based on natural materials. After extracting, concentrating, and freeze-drying M. pruriens with water, 70% ethanol, and 70% acetone as solvents, samples of powdered hydrothermal extract (MW), 70% ethanol extract (ME), and 70% acetone extract (MA) were prepared. As a result of analyzing antioxidant activity through DPPH radical scavenging activity, ABTS⁺ radical scavenging activity, SOD-like activity, reduction ability, total phenol and flavonoid content analysis using MW, ME, and MA, all showed excellent antioxidant effects. Therefore, it is believed that M. pruriens extract is highly likely to be used as a natural material for antioxidant-related functional cosmetics.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.231-237
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• 2009

This paper aimed to develop a solvent extraction and purification process to recover high-purified ${\beta}$-carotene from recombinant Escherichia coli. Cells harvested from the culture broth were treated through numerous steps: dehydration, solvent extraction, crystal formation and separation. To optimize the extracting condition, experiments were carried out to investigate the effect of cell disruption, temperature, organic solvents, solvent-biomass ratio on the yield of ${\beta}$-carotene extracted from cells. The result indicated that no significant differences of extraction yield were observed from cells with or without step of cell disruption. Among different extracting solvents, the highest extraction yield of ${\beta}$-carotene, 30.3 mg-${\beta}$-carotene/g-dry cells, was obtained with isobutyl acetate at solvent-biomass ratio 25 mL/g-dry cells at $50^{\circ}C$. Notably, in case of acetone, the extraction yield was quite low when using acetone itself, but increased almost up to the highest value when combining this solvent and olive oil. The purity of ${\beta}$-carotene crystals obtained from crystallization and separation was 89%. The purity degree was further improved up to 98.5% by treating crude crystals with additional ethanol washing.