• The Journal of Korean Medicine
• /
• v.31 no.6
• /
• pp.8-15
• /
• 2010

Objectives: We investigated to develop and validate HPLC-PDA methods for simultaneous determination of eight constituents in Galgeun-tang (GGT). Methods: Reverse-phase chromatography using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array (PDA) detection at 230 nm, 254 nm, and 280 nm, were used for quantification of the eight marker components of GGT. The 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. Results: Calibration curves were acquired with $r^2$ > 0.9999, and the relative standard deviation (RSD) values (%) for intra- and inter-day precision were less than 3.0%. The recovery rate of each component was in the range of 87.33-101.38%, with an RSD less than 7.0%. The contents of the eight components in GGT were 1.98-12.17 mg/g. Conclusions: The established method will be applied for the quantification of marker components in GGT.

• Herbal Formula Science
• /
• v.18 no.1
• /
• pp.95-103
• /
• 2010

Objectives : To develop and validate HPLC-PDA methods for simultaneous determination of seven constituents in Samsoeum(SSE). Methods : Reverse-phase chromatography using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array(PDA) detection at 254 and 280 nm, were used for quantification of the seven marker components of SSE. The 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. Results : Calibration curves were acquired with $r^2$>0.9997, and the relative standard deviation (RSD) values (%) for intra- and inter-day precision were less than 3.0%. The recovery rate of each compound was in the range of 100.07-112.65%, with an RSD less than 4.0%. The contents of seven compounds in SSE were 1.24-10.53 mg/g. Conclusions : The established method will be helpful to improve quality control of SSE.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.20 no.6
• /
• pp.307-313
• /
• 2010

Quantitative analytical condition for lead and cadmium in copper contained carbon materials using solvent extraction followed by inductively coupled plasma-atomic emission spectrometry was studied. Copper contained carbon samples were dissolved by nitric acid-perchloric acid digestion. Lead and cadmium were determined after separation with KCN masked copper by an dithizone-chloroform solvent extraction. Recovery efficiency of analyte elements was satisfactory, and most of matrix elements causing interference could be effectively eliminated by the separation. Lead and cadmium were quantitatively determined without influence of sample matrix, by applying it procedure to artifact sample.

• Clean Technology
• /
• v.23 no.4
• /
• pp.393-400
• /
• 2017

In this study, we have developed a process for separating and recovering Ni and Fe in solution through a new solvent instead of TBP and Alamine336, which are solvents used in the conventional solvent extraction method. Experimental conditions were optimized through lab test and a $10L\;h^{-1}$ pilot plant was constructed for commercialization. In addition, the process data for mass production were obtained through pilot experiment and it was confirmed that there is no problem in product quality that can be used through the corrosion test of ferric chloride.

• Membrane and Water Treatment
• /
• v.8 no.6
• /
• pp.575-590
• /
• 2017

PolyHIPEs membrane prepared with styrene (St), divinylbenzene (DVB), and ethylhexyl acrylate (EHA) can yield a unique pore structure provided by large voids highly interconnected by many small window throats. With the advantageous pore structure, PolyHIPE presents a potential as a support for carrier facilitated transport membrane. Tricaprylmethylammonium chloride (Aliquat 336) can be efficiently incorporated into the PolyHIPE membrane by a two-step solvent-nonsolvent method to obtain an Aliquat 336-immobilized PolyHIPE membrane with good stability. The study of Cr (VI) transport through Aliquat 336-immobilized PolyHIPE membrane indicates that the membrane has high initial flux and maxima stripping flux ($J_f^o=15.01({\mu}mol/m^2s)$, $J_s^{max}=6.15({\mu}mol/m^2s)$). The reusability study shows that the Aliquat 336-immobilized PolyHIPE membrane can maintain high Cr(VI) recovery efficiency even after 15 cycles of operations. The developed membrane was also used in the separation of Cr (VI) from other anions (i.e., $SO_4{^{2-}}$ and $NO_3{^-}$) and other cations (i.e., Ni (II), Mg (II) and Cu (II)) with good selectivity.

• Journal of the Korean Wood Science and Technology
• /
• v.19 no.4
• /
• pp.80-84
• /
• 1991

Lignocellulosic biomass including acetosolv ricestraw and spruce lignin were liquefied and converted into liquid hydrocarbons by catalytic hydroliquefaction reaction. These experimental works were carried out in 1-liter-capacity autoclave using 50% tetralin and m-cresol solution respectively as soluble solvent and Ni. Pd. Fe and red mud as catalyst. $H_2$ gas was supplied into the reactor for escaltion of deoxhydroenolysis reaction. Catalyst concentrations were 1 % of raw material based on weight. The ratio between raw materials and soluble solvent are 1g and 10cc. The reaction conditions are 400-$700^{\circ}C$ of reaction temperature, 10-50 atms of reaction pressure. The highest yield of hydrocarbon, so called "product oil" showed 32% and 5.5% of lowest char formation when red mud was used as catalyst. The product oil yields from those of other catalysts were in the range of 20-29%. The influence of different initial hydrogen pressures was examined in the range d 30-50 atms. A minimum pressure of 35 atms was necessary to obtain a complete recovery of souble solvent for recycling.

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

• Bulletin of the Korean Chemical Society
• /
• v.34 no.8
• /
• pp.2353-2357
• /
• 2013

The objective of this study was to develop a simple, less time-consuming and accurate sampling technique based on solid-phase sorption with activated carbon as the sorbents. The results from solid-phase sorption techniques were compared to that from a conventional solvent impinger-based technique to confirm the efficacy of the proposed method. The laboratory results indicated that the solid-phase sorption method was suitable for the determination of siloxanes as the measured concentrations were similar to that from a solvent impinge method. The data from solid-phase sorption method showed excellent recovery and reproducibility while the sampling was less labor intensive and less time consuming than the solvent impinge method. Following the laboratory tests, the solid-phase sorption technique was successfully applied to sampling biogas from a field site. This study shows that the activated carbon-based solid-phase sorption can be a reliable and less time-consuming option for the sampling and collection of siloxanes under various different landfill conditions.

• Korean Journal of Pharmacognosy
• /
• v.42 no.3
• /
• pp.240-245
• /
• 2011

A high-performance liquid chromatography (HPLC) method was developed for quantitative analysis of liquiritin and glycyrrhizin in Sagunja-tang (SGT, Sijunzi-tang in Chinese), a traditional Korean medicine. HPLC analysis was performed using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array (PDA) detection at 254 nm and 280 nm for quantification of the two components in SGT. The 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. Calibration curves were acquired with $r^2$ values > 0.9998, and the relative standard deviations (RSDs, %) for intra- and inter-day precision were not exceed 4.0%. The recovery of each component was in the range of 91.85 - 108.62%, with a RSD less than 4.0%. The contents of the two components in SGT were 7.94 - 13.83 mg/g.

• Korean Journal of Metals and Materials
• /
• v.48 no.5
• /
• pp.430-435
• /
• 2010

Solvent extraction experiments of Rh(III) and Ir(IV) were performed on the HCl solution by using Alamine336 and TBP. The extraction percentage of Rh and Ir by Alamine336 was much higher than that by TBP. For the solvent extraction with Alamine336, the extraction percentage of Rh and Ir decreased with a HCl concentration. However, the extraction percentage of both metals by TBP was below 12% in our experimental range and increased with an increasing HCl concentration of up to 8 M. From the mixed solution of Ir with an excess SnCl$_{2}$, most of the tin was extracted by Alamine336 and TBP. However, the extraction percentage of Ir by Alamine336 was reduced and no iridium was extracted by TBP. The extraction behavior of Ir and Sn was investigated by scrubbing experiments on the loaded Ir with a SnCl$_{2}$ solution.