• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.6
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• pp.363-375
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• 2001

Chromatography has been method of choice for the separation complex biologi-cal mixtures fro analytical purpose, particularly for the last fifty years. Its use has recently been extended to preparative separation where the productivity relative to the amount of resin and sol-vent used is a matter of concern. To overcome the inherent thermodynamic inefficiency of batch chromatography, as exemplified by the partial temporal usage of the resin and dilution of the product with the solvent, chromatography has been continually modified by separation engineers. Column switching and recycling represnet some of the process modifications that have brought high productivity to chromatography. Recently, the simulated moving bed (SMB) method, which claims a high separation efficiency based on counter-current moving bed chromatography. has be-come the mainstay of preparative separation, especially in chiral separation. Accordingly, this pa-per reviews the current status of SMB along with several chromatographic modification, which may be helpful in routine laboratory and industrial chromatographic practices.

• Membrane and Water Treatment
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• v.14 no.4
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• pp.181-189
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• 2023

The Covid-19 pandemic has increased demand for chlorine-based sanitizing solutions, most of which contain hypochlorous acid (HOCl) as an active agent. Free chlorine (HOCl) in these sanitizers is crucial for their efficacy. Disposable test strips are affordable and convenient tools for determining various qualitative and quantitative parameters. In this study, disposable opto-chemical test strips were developed by physically immobilizing 3,3',5,5'-tetramethylbenzidine (TMB) and o-dianisidine (o-D) reagents on chromatography and filter paper-based test strips for the visualization and detection of free chlorine in the form of HOCl. The reagents undergo a rapid color change upon reaction with chlorine through a redox reaction. The paper-based test strips showed rapid color change within a minute and a low sample volume requirement (1 ml). This portable, disposable paper-based test strip is a simple and cost-effective way to rapidly detect the presence of HOCl sanitizers for home and field applications. Both TMB and o-D successfully detected chlorine. Chromatography paper proved to be the more efficient option among the two papers used as substrates for the reagents (TMB and o-D). It exhibited high retention capacity and high performance in terms of color transformation when reacting with HOCl, even after two months of storage.

• Korean Chemical Engineering Research
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• v.45 no.1
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• pp.1-11
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• 2007

Using strong cation exchange simulated moving bed (SMB) chromatography, a nitrogen-phosphate-potassium (NPK) fertilizer is produced in a cost-effective manner. The SMB process operated in a non-traditional way is divided into production and regeneration sections for exclusion of undesirable ions, and composed of six zones including two wash-water zones. This paper addresses modeling and simulation studies on the ion-exchange SMB process, comparing simulation results with experimental data obtained both from a pilot plant and an industrial plant. The simulation results show a good agreement with in situ experimental data obtained in the two plants. The model equation validated by the experiments will be applicable for optimization problems to obtain optimum operating conditions of the process.

• Korean journal of applied entomology
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• v.7
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• pp.61-64
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• 1969

By way of paper chromatography, free sugars in pycnial drops of Gymnosporangium haraeanum Sydow were investigated in regard of their biochemical interrelation with free sugars of Chinese juniper and pear leaf. The free sugar in pycnial drops of Gynnosporangium haraeanum Sydow were identified to only Fructose spot. Free sugars in Chinese juniper leaf were identified to Glucose. Galactose and two unknown spots. Free sugars of another sample in pear leaf were identified to spots of Glucose, Furctose and Galactose. The Arbutin from pear leaf was crystalized and its structure was identified to Glucose and Hydroquinone. The acetone powder of Emulsin was incubated for 1 hour at $40^{\circ}C$ with 0.05 M Arbutin substrate in test tube and purified by general method with the purpose of analysis of its. metabolic products. And the paper chromatographic analysis showed it to be Glucose spot. From the above results, this Fructose in pycinal drops of Gymnosporangium haraeanum Sydow is presumed to be the exchangeable from free sugars in pear leaf or to be the hydrolyzed of $\beta-glycoside$ (Arbutin)-the metabolic isomerization of Glucose into Fructose by pycnia isomerase.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.2
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• pp.67-75
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• 2002

The human complement receptor type 1 (CR 1, C3 b/C4b receptor) is a polymorphic membrane glycoprotein expressed on human erythrocytes, peripheral leukocytes, plasma and renal glomerular podocytes, which consists of transmembrane and cytoplasmic domains with 30 repeating homologous protein domains known as short consensus repeats (SCR). CR1 has been used as an inhibitor for inflammatory and immune system for the past several years. Recently; it is reported that CRl was found to suppress the hyper-acute rejection in xeno-transplantation and can be used to cure autoimmune diseases. A soluble form of CRl, called sCRl, is a recombinant CRl by cleaving the transmembrane domain at C-terminus and has been expressed in Chinese Hamster Ovary (CHO) cells. Several purification methods for sCR1 from CHO cells have been reported, but most of them require complicated steps at high cost. Moreover, such methods are mostly performed under the pH condition apt to denaturing sCR1 and causes sCRl losing its activity. We here report a rapid and efficient method to purify sCR1 from CHO cell. The new method consists of a two-stage of cell culture by cultivating cells in serum medium followed by serum-free medium, and a two-stage of column purification by means of heparin and gel filtration column chromatography. By using this novel method, sCR1 can be purified in a simple and effective way with high yield and purity, furthermore, the purified sCR1 was confirmed to retain its activity to suppress the complement activation in vivo and ex vivo.

• Environmental Engineering Research
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• v.23 no.3
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• pp.309-315
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• 2018

Chlortetracycline (CTC) is one of the most important compounds in antibiotic production, and its distribution has been widely investigated due to health and ecological concerns. This study presents systematic approach to optimize the high-performance liquid chromatography-tandem mass spectrometry for analyzing CTC in a multiple reaction monitoring mode ($479{\rightarrow}462m/z$). One-factor-at-a-time (OFAT) test with response surface analysis (RSA) was used as optimization strategy. In OFAT tests, the fragmentor voltage, collision energy, and ratio of acetonitrile in the mobile phase were selected as major factors for RSA. The experimental conditions were determined using a composite in cube design (CCD) to maximize the peak area. As a result, the partial cubic model precisely predicted the peak area response with high statistical significance. In the model, the (solvent composition) and (collision $energy^2$) terms were statistically significant at the 0.1 ${\alpha}$-level, while the two-way interactions of the independent variables were negligible. By analyzing the model equation, the optimum conditions were derived as 114.9 V, 15.7 eV, and 70.9% for the fragmentor voltage, collision energy, and solvent composition, respectively. The RSA, coupled with the CCD, offered a comprehensive understanding of the peak area that responds to changes in experimental conditions.

• Journal of the Korean Society of Clothing and Textiles
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• v.47 no.1
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• pp.52-72
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• 2023

This study examined the effect of Jojoba oil on the protection of virgin black hair and hair damaged by bleaching. Both hair types were treated for 35 days with 100% Jojoba oil or one of two types of hair conditioner, one formulated with 3% of Jojoba oil and the other formulated without Jojoba oil. The effect of protection was examined in terms of the change in the color, tensile stress, weight, and amount of protein leak compared to untreated black hair or bleached hair. The composition of fatty acids in the Jojoba oil was analyzed using the Gas chromatography mass spectrometry. The differences among the three treatments were statistically tested by one-way analysis of variance test and the Duncan post-hoc test at α = .05. The main fatty acid contained in the Jojoba oil was 11-eicosenoic acid (75.14%). Based on the statistical test it was found that 100% Jojoba oil was the most effective in increasing the tensile stress of black hair and the weight of bleached hair after 35 days of treatment.

• Journal of Pharmaceutical Investigation
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• v.38 no.1
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• pp.73-78
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• 2008

To evaluate the bioequivalence of two ramipril formulations, a standard 2-way randomized cross-over study was conducted in twenty-six healthy male Korean volunteers. A single oral dose of 10 mg of test formulation $Ramiprin^{(R)}$ (tablet) or reference formulation Tritace $Protect^{(R)}$ (tablet) was administered with one-week washout period. Plasma concentrations of ramipril were assayed over a period of 12 hr with a well validated method using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The values of area under the plasma concentration-time curve, from time zero to last sampling time $(AUC_t)$ and from time zero to time infinity $(AUC_{inf})$ were $77.45{\pm}44.78\;and\;78.96{\pm}45.64$ for test, and $70.30{\pm}42.27\;and\;71.99{\pm}43.55ng\;hr/mL$ for reference formulation, respectively. Similarly, maximum concentration $(C_{max})$ and elimination half-life $(t_{1/2})$ were $65.61{\pm}19.96ng/mL$ and $2.15{\pm}0.75hr$ for test, and $63.63{\pm}25.50ng/mL$ and $2.16{\pm}0.73hr$ for reference formulations, respectively. Time to reach maximum concentration $(T_{max})$ for the test and the reference, were $0.51{\pm}0.22hr\;and\;0.52{\pm}0.18hr$, respectively. The parametric 90% confidence intervals on the mean of the differences between the two formulations (test-reference) of the log-transformed values of $AUC_t\;and\;C_{max}$ were 1.03 to 1.19 and 0.98 to 1.17, respectively. The overall results indicate that the two formulations are bioequivalent and can be prescribed interchangeably.

• Archives of Pharmacal Research
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• v.18 no.5
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• pp.340-345
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• 1995

A nebumetone tablet in development $(Navuton^R)$ was tested for its bioequivalence to the erference tablet $(Uniton^R)$. Seventeen healthy Korean male subjects participated in this study. Each subject received a 1-g dose of nabumetone (2tables each) in an unbalanced, randomized, two-way crossover investigation. Serum concentrations of 6-methoxy-2-na-phthylacetic acid (6-MNA), a major metabolite of nebumetone, were measured over 120 hr interval by a high-performance liquid chromatography. The maximum serum concentration $(C_{max})$ and time to reach the maximum concentration$(T_{max})$ were read directly, but area under the serum concentration time curve from time 0 to 120 hr (AUC) and mean residence time serum curves showed multiple peaks of 6-MNA in most subjects, and the $C_{max}$ and $T_{max}$ were read from the highest serum peaks. calculated bioavailability parameters for test and reference tablets were 148.6 : 1377.9 $\mug \cdot hr/ml$ for AUC; 25.2:23.1 $\mu/ml$ for $C_{max}$; 11.8:16.4 hr for $T_{max}$, and 42.6 : 43.8 hr for MRT, respectively. The paired t-test revealed no significant differences in all the parameters between the two tablets. Analysis ofl variance (ANOVA) revealed no significant differences between groups and formulations in all the parameters ($C_{max}$ and $T_{max}$, AUC and MRT) indicating the crossover design of the experiment was properly performed. But significant differences (p<0.05) between subject/groups and periods were found for all the parameters indicating substantial intersubject and interperiodic variations for these parameters.

• Entomological Research
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• v.48 no.6
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• pp.490-498
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• 2018

Ruspolia differens (Serville) (Orthoptera: Tettigoniidae) is a highly valued edible grasshopper species in Africa. However, the effects of plant diets on lipid content and fatty acid composition of R. differens are not well understood. We tested the effects of four diets on the total lipid content and fatty acid composition of R. differens. Sixth instar nymphs of R. differens were reared on one, and mixtures of two, three, and six natural plant inflorescences. Individuals collected from the field constituted a control treatment. We extracted lipids and analyzed the fatty acid methyl esters using gas chromatography-mass spectrometry. We analyzed if the total lipid content, body weight, and fatty acid composition differed among diets and between the sexes using two-way ANOVAs and a PERMANOVA model, respectively. The total lipid content and weight of R. differens did not differ among the diets. The nine common fatty acids were palmitic (mean across treatments, 26%), oleic (22%), palmitoleic (18%), linoleic (13%), stearic (7%), myristic (6%), myristoleic (4%), ${\alpha}$-linolenic (2%) and arachidic acid (1%). The composition of fatty acids and the proportion of essential fatty acids significantly differed among the diets. The proportion of essential fatty acids was highest in the control treatment (21%) but low in less diversified (one to three feed) diets (12-13%). This study demonstrates that the fatty acid composition in R. differens can be influenced through diet. Thus, with dietary manipulations, using local plants in Africa, it is possible to produce R. differens with preferred high quality essential fatty acids for human consumption.