• The Journal of Korean Medicine
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• v.32 no.3
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• pp.25-34
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• 2011

Objectives: We performed simultaneous determination of five constituents by HPLC in Samul-tang (SMT). Additionally, we investigated the immune-stimulatory potential of SMT on specific cellular and humoral immune responses in ovalbumin (OVA)-immunized mice. Methods: Reverse-phase chromatography using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array (PDA) detection at 190-400 nm, were used for quantification of the five components of SMT. Mobile phase using a gradient flow consisted of two solvent systems. Solvent A was 1.0% (v/v) aqueous acetic acid and solvent B was acetonitrile with 1.0% (v/v) acetic acid. C57BL/6 mice were immunized intraperitoneally with OVA/alum ($100{\mu}g/200{\mu}g$) on days 1, 8, and 15. The extract of SMT (1000 mg/kg) was given to mice orally for 21 days (from day 1 to day 21). At day 22, OVA-, lipopolysaccharide (LPS)- and concanavalin A (Con A)-stimulated splenocyte proliferation and OVA-specific and total antibodies were measured in plasma. Results: Calibration curves were acquired with $r^2$>0.9999, and the relative standard deviation (RSD, %) for intra- and inter-day precision were both less than 3.5%. The recovery was in the range of 95.69-115.12%, with an RSD less than 6.0%. The contents of five components in SMT were 1.08-15.30 mg/g. SMT significantly enhanced Con A-induced splenocyte proliferation in OVA-immunized mice (p<0.01). Also, SMT significantly enhanced OVAspecific IgG, IgG1 and total IgM levels in plasma compared with the OVA-immunized group. Conclusions: The established method will be applied for the quantification of major components and immunestimulating activity in OVA-immunized mouse model of SMT.

• Applied Chemistry for Engineering
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• v.26 no.6
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• pp.631-639
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• 2015

Extraction/separation of cobalt by solvent extraction is reviewed. Separation of cobalt using various reagents and also cobalt recovery from scrap using commercial extractant were analyzed. The separation ability for cobalt followed the order of phosphinic > phosphonic > phosphoric acid due to the increasing stabilization of tetrahedral coordination of cobalt complexes with the extractant in the organic phase. Depending upon the solution composition, commercial extractants like Cyanex 272, D2EPHA and PC 88A should primarily be used for commercial extraction processes and also the efficient management of their combination could address various separation issues associated with cobalt bearing scrap.

• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.74-79
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• 1998

This study was conducted to evaluate the surfactant solutions which influence solvent extraction from light hydrocarbon contaminated soils. Nine characteristic compounds were studied: benzene, toluene, ethylbenzene, o-xylene, mxylene, p-xylene, n-propylbenzene, 1,2,4-trimethylbenzene, and n-butylbenzene which were found in gasoline. Adsee-799 and Witbreak DRA-22 showed some extractive capacity for light hydrocarbons from soil. There was no added advantage obtained by using other surfactants in this study. No removal of contaminants from soil was observed when the surfactant concentration was 0.5 percent or below. When the surfactant concentration was 4 percent, the average recovery for some hydrocarbons was 10.8 percent, which was the best obtained at these levels. There was 10 percent surfactant contribution for methanol extraction from soil with the Witbreak DPG-482 and Witbreak DRA-22. This study provided a useful screening technique for procedures that can be used to remediate soils contaminated with light hydrocarbons.

• Korean Journal of Organic Agriculture
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• v.20 no.1
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• pp.91-99
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• 2012

This study was conducted to develop a functional feed additive for pig with spent $Lycium$ $chinense$ Mill fruit. We investigated the optimum conditions for the extraction of polyphenol from spent $Lycium$ $chinense$ Mill using methanol. Methanol concentration as a solvent for extraction, extraction time and the volume of solvent per a gram of solid (ground spent Lyceum chinense Mill) were selected as parameters. Three levels of parameters were configured according to Box Behnken experiment design, a fractional factorial design, and total 15 trials were employed. Total polyphenol concentration from each trial was used as response from experiment system and effects of parameters on total polyphenol extraction efficiency were determined using response surface model. As a result, all terms in analysis of variance, regression ($p$ = 0.001), linear ($p$ = 0.002), square ($p$ = 0.017) and interaction ($p$ = 0.047) was significant and adjusted determination coefficient ($R^2$) was 94.7%. Total polyphenol extraction efficiency was elevated along increased methanol content and decreased solvent to solid ratio. However extraction time did not affect the efficiency. This study provides a primary information for the optimum extraction conditions to maximize total polyphenol recovery from spent Lycium chinens Mill fruit and this result could be applied to re-use of argo-industrial by-products and to develop of functional feed additives in organic farming.

• Resources Recycling
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• v.29 no.5
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• pp.73-80
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• 2020

In order to develop a process for the recovery of valuable metals from spent LiBs, solvent extraction experiments were performed to separate Cu(II) and/or Co(II) from synthetic hydrochloric acid solutions containing Li(I), Mn(II), and Ni(II). Commercial amines (Alamine 336 and Aliquat 336) were employed and the extraction behavior of the metals was investigated as a function of the concentration of HCl and extractants. The results indicate that HCl concentration affected remarkably the extraction efficiency of the metals. Only Cu(II) was selectively at 1 M HCl concentration, while both Co(II) and Cu(II) was extracted by the amines when HCl concentration was higher than 5 M, leaving the other metal ions in the raffinate. Therefore, it was possible to selectively extract either Cu(II) or Co(II)/Cu(II) by adjusting the HCl concentration.

• Journal of Soil and Groundwater Environment
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• v.17 no.1
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• pp.42-46
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• 2012

The ISO document of ISO/TC/190/SC3/WG11/N11 is a working draft of international standard (WD) dealing with analytical method for the determination of explosives and related compounds using high performance liquid chromatography. The scope of this WD covers the storage of samples, preparing test portion, extraction and instrumentation. The main purpose of this study was to improve the extraction conditions which were already adopted in the WD. For this purpose, mechanical shaking method could be corresponded up to 18 hours of ultrasonic bath extraction in the WD was tested. Methanol was also tested with the intention of being added as an extracting solvent other than acetonitrile in the WD. According to the results, 16 hours of mechanical shaking method showed statistically the same effectiveness as that of 18 hours of ultrasonic bath extraction. In case of extracting solvent, methanol also showed statistically the same extraction capability as acetonitrile for DNB, TNT, 2-A-DNT and 2,4-DNT. However, the recovery rate of TNB with methanol extraction was 40% higher than that of acetonitrile extraction. Through adding mechanical shaking method into committee draft (cf. the next stage draft of the WD during the process for making international standard), ISO standard of analyzing explosives and related compounds in soil would become more useful in dealing with huge number of field samples in the laboratory. In other aspect, adopting methanol as an alternative extracting solvent would be very effective in the terms of exchangeability with GC-ECD/MS method which is being developed by German experts.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.1
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• pp.40-46
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• 2024

A novel approach is presented to address issues associated with the use of strong acidic solutions for the leaching of magnesium oxide (MgO) from spent magnesia-carbon refractories. An ultrasonic flotation and separation process is employed, with a mildly acidic solvent, acetic acid, used to selectively chelate MgO from the spent refractories. When using 2 M acetic acid as a solvent, the recovery of the graphite exhibited 99.7 % with high purity of 72.7 %, showing a significant improvement compared to using water as the solvent. Furthermore, the technology presented in this study offers a method for producing magnesium acetate through the reaction of MgO in spent refractory with acetic acid, providing a means for the purification and separation of graphite.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1165-1170
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• 2010

A method for the determination of four pesticide compounds, urea (isoproturon), bis-carbamate (phenmedipham), thiocarbamate (pyridate) and vinyllidenediamine (nitenpyram) were examined and analyzed by HPLC with C-18 column ($250\;mm{\times}4.6\;mm$, $5\;{\mu}m$ diameter particle size). Mobile phase consisted of deionized water, acetonitrile and 50 mM $KH_2PO_4$ (pH 2.5). Isoproturon and phenmedipham analytical condition was isocratic elution of the column with 50% solvent A (acetonitrile) and 50% solvent B (deionized water); pyridate was 85% solvent A (acetonitrile) and 15% solvent B (deionized water) at a flow rate of 1 mL/min; and nitenpyram analytical condition was 90% solvent A (50 mM $KH_2PO_4$, pH 2.5) and 10% solvent B (acetonitrile) at a flow rate of 1 mL/min. In results, retention times were 6.12, 8.63, 9.40 and 12.76 min for isoproturon, phenmedipham, pyridate and nitenpyram, respectively. All injection volumes were $10\;{\mu}L$ and the limit of quantitation was 0.05 mg/kg for four pesticide compounds, respectively. Recovery rate test was performed with three farm products, rice, apple and soybean. Four pesticide compounds were spiked at concentrations of 0.05, 0.1 and 0.5 mg/kg. The recovery rates were ranged from 70.18% to 118.08% and the standard deviations of all experiments were within 10%.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.473-477
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• 2022

In this study, candidate technologies for lithium recovery from the process waste liquid generated in the waste battery recycling process were reviewed, and technologies applicable to the process from the commercialization point of view were reviewed from a qualitative point of view. The evaporation method is difficult to apply because it requires a large-scale land and shows a low recovery rate due to the loss of Li during the concentration process. In the case of precipitation, a commercially available technology shows a high recovery rate due to the high Li/Na selectivity of phosphoric acid, but there are disadvantages in that the process is complicated due to the use of expensive phosphoric acid, requiring a recovery step, and continuous operation is impossible because solids are handled in the Li concentration process. In the case of solvent extraction, if we find an inexpensive extractant with high Li/Na selectivity, continuous operation is possible with the method used in extraction of other metals in the previous step, and when Li is concentrated, continuous operation is possible because it is in a liquid state. If it shows a similar recovery rate compared to precipitation technology, commercialization will be the most likely.

• Analytical Science and Technology
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• v.15 no.5
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• pp.466-474
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• 2002

The analytical method of 14 kinds of coplanar - PCBs was established and applied the soil sample. The three kinds of extraction solvents (toluene, acetone: n-hexane, dichloromethane) were selected to apply the soil sample. The silica gel, florisil and alumina column cleanup also performed to compare the elution recovery. The average recovery of selected solvents in soil A, B and C was surveyed the 84.25%, 56.09% and 44.69% for toluene, 52.56%, 81.42% and 58.53% for acetone : n - hexane and 55.94%, 71.33% and 61.05% for dichloromethane. The average recovery is represented 49.99% for silica gel (n - hexane 100 mL), 69.65% for florisil (6% ether/n - hexane 100 mL), and 65.23% for alumina (2% DCM : n - hexane 100 mL, 50% DCM: n-hexane 150 mL). In silica gel (n - hexane) and florisil (6% ether : n - hexane) cleanup, the 14 kinds of coplanar PCBs eluted until 40 mL. In the silica gel and florisil columns cleanup, the amounts of elution solvent can be reduced from these results, but the researcher has to confirm the elution amounts before performing the experiments. In alumina cleanup process, the result was obtained to the 100 mL of elution solvents (2% DCM: n-hexane 100 mL and 50% DCM: n-hexane 40 mL), therefore the change of elution solvent is necessary to develop the simple procedure.