• Mass Spectrometry Letters
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• v.4 no.4
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• pp.75-78
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• 2013

A gas chromatography/mass spectrometric (GC/MS) method was developed as a candidate reference method for the accurate determination of essential fatty acids (linoleic acid, ${\alpha}$- and ${\gamma}$-linolenic acids) in food supplemental oil products. Samples were spiked with three internal standards (stearic acid-$d_{35}$, $^{13}C_{18}$-linoleic acid, and $^{13}C_{18}$-${\alpha}$-linolenic acid). Samples were then subject to saponification, derivatization for methylation, and extraction by organic solvent. For GC/MS measurement, an Agilent HP-88 column, designed for the separation of fatty acid methyl esters, was selected after comparing with other columns as it provided better separation for target analytes. Target analytes and internal standards were detected by selected ion monitoring of molecular ions of their methyl ester forms. The GC/MS method was applied for the measurement of three botanical oils in NIST SRM 3274 (borage oil, evening primrose oil, and flax oil), and measurement results agreed with the certified values. Measurement results for target analytes which have corresponding isotope-labeled analogues as internal standard were calculated based on isotope dilution mass spectrometry (IDMS) approach, and compared with results calculated by using the other two internal standards. Results from the IDMS approach and the typical internal standard approach were in good agreement within their measurement uncertainties. It proves that the developed GC/MS method can provide similar metrological quality with IDMS methods for the measurement of fatty acids in natural oil samples if a proper fatty acid is used as an internal standard.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.5
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• pp.712-718
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• 2004

This study was carried out to separate the calcium-binding protein derived from enzymatic hydrolysates of cheese whey protein. CWPs (cheese whey protein) heated for 10 min at $100^{\circ}C$ were hydrolyzed by trypsin, papain W-40, protease S, neutrase 1.5 and pepsin, and then properties of hydrolysates, separation of calcium-binding protein and analysis of calcium-binding ability were investigated. The DH (degree of hydrolysis) and NPN (non protein nitrogen) of heated-CWP hydrolysates by commercial enzymes were higher in trypsin than those of other commercial enzymes. In the result of SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis), $\beta$-LG and $\alpha$-LA in trypsin hydrolysates were almost eliminated and the molecular weight of peptides derived from trypsin hydrolysates were smaller than 7 kDa. In the RP-HPLC (reverse phase HPLC) analysis, $\alpha$-LA was mostly eliminated, but $\beta$-LG was not affected by heat treatment and the RP-HPLC patterns of trypsin hydrolysates were similar to those of SDS-PAGE. In ion exchange chromatography, trypsin hydrolysates were shown to peak from 0.25 M NaCl and 0.5 M NaCl, and calcium-binding ability is associated with the large peak, which was eluted at a 0.25 M NaCl gradient concentration. Based on the results of this experiment, heated-CWP hydrolysates by trypsin were shown to have calcium-binding ability.

• Polymer(Korea)
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• v.24 no.1
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• pp.29-37
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• 2000

Polyaniline (PANi)/Poly(ethylene of oxide) (PEO) in-situ blends were prepared by inducing phase separation through solvent evaporation after casting from solutions containing aniline monomer, oxidant (initiator), dopant and PEO in methanol/water mixed solvent. It was observed that the electrical conductivity first increases rapidly as PANi amount in the PANi/PEO blend increases and then slowly increases as the weight percentages of polyaniline become above 11 wt% in the blend. We also noted that the morphology of PANi/PEO blends changes when the holding time in a stirrer at constant temperature is varied and eventually affects the electrical conductivity. As the length of alkyl group in dopants increases, the electrical conductivity of doped blends increases. The PANi/PEO blend prepared with a high molecular weight of PEO yields higher electrical conductivity.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.378-383
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• 1996

Dietary fibers (DF) have been used as functional food components due to the various health promoting activities. Dietary fibers have been separated from the peels of Korean tangerine by employing ultrafiltration (UF) membranes. Optimum conditions in a batch type ultrafiltration unit using YM100 (molecular weight cut-off, MWCO=100,000), YM 10 (MWCO=10,000) and YM1 (MWCO=1,000) membranes were : transmembrane pressure 7.5 psi, temperature of the peel extracts $35^{\circ}C$, and pH of the peel extract 3.0, respectively. The flux in YM 10 membrane unit was higher than that in YM 10 or YM 1 membrane unit. However, YM 100 membrane was superior to YM 10 or YM 1 membrane with respect to the recovery of the retentate and the contents of DF The contents of DF in the tangerine peel extract, in the 170 mesh retentate, and in the YM 100 retentate were shown to be 33.4%, 18.5% and 8.4% based on dry matter, respectively. Most dietary fibers were recovered at the separation stages of 170 mesh and YM 100.

• Journal of the Korean Chemical Society
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• v.17 no.6
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• pp.434-438
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• 1973

Distribution coefficients (C) of some transition metal ions such as Ni(II), Cu(II), Cd(II), Zn(II), and Hg(II) have been determined in methanol-, ethanol-, isopropanol-, acetone-, and dimethylsulfoxide-water mixtures by using Rexyn 101 (Na-form) resin and 0.2 M sodium chloride solution. The log C values of the metallic ions decrease almost straightly with the increase in reciprocal values of the dielectric constants of the mixed solvents. In the solvents having the same dielectric constants, the distribution coefficients of the metallic ions decrease with the increase in the basicity of the aprotic organic molecule and with the decrease in the molecular size of the protic organic molecule. The separation of the metallic ions has been accomplished with the eluting agent suggested by the C values.

• Journal of the Korean Chemical Society
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• v.20 no.4
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• pp.309-315
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• 1976

An efficient separation method and the utilization of sericin are searched. Sericin was extracted with hot water from cocoons under atmospheric pressure. The separated sericin was gel-filtrated with Sephadex G-75 and G-150 at room temperature and at $70^{\circ}C$. The results indicated that sericin is consisted of only one fraction in elution diagram. In the graft copolymerization of acrylonitrile to sericin ceric ammonium nitrate was chosen as an initiatior. A maximum yield was obtained at certain concentration of the initiator confirming our previous experiments. Viscosity measurement of alkali-hydrolyzed graft copolymers indicated that the polyacrylonitrile graft had the molecular weight in the range of 7,000.

• Journal of The Korea Institute of Healthcare Architecture
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• v.26 no.1
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• pp.73-84
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• 2020

Purpose: Though Korean healthcare services have been upgraded, infection and fire had been broken out in general hospitals. And higher concerns about quality assessment made it to clinical laboratory design guideline studies. So, this study investigates the facilities, equipment and personnel of laboratory medicine focusing on more than five hundred fifty bed hospital, and contributes to make guidelines for safety and efficiency in lab. Methods: Questionnaires to supervisor technologist and field surveys to medical laboratories in korean hospitals have been conducted for the data collection. 16 answers have been analysed statistically by MS Excel program. Results: Most of the sample tests such as hematology, clinical chemistry, immunology, transfusion, urinalysis, microbiology and molecular diagnosis are performed by more than 80% in large sized general hospital laboratory. In the test methods, automatic analyzers are used up to 80%, total laboratory automation up to 43% in clinical chemistry and immunology, and manual tests in all sorts of the test. There are placed in single lab or two and three labs above the ground, which are all in semi-open lab. There is some correlation with the number of specimens and the number of lab people depending on the number of hospital beds. Laboratory environment shows that work distance is good, but evacuation path width, visibility, separation of staff area from automatic analyzer, and equipment installations are needed to have more spaces and gears. Most of the infection controls are equipped with mechanical ventilation, air-conditioning, washbasin and wastewater separation, BSC installation and negative pressure lab room. Implications: Although the laboratory space area is calculated considering the number of hospital beds, type of tests and number of staff, hospital's expertise and the samples numbers per year should be taken into account in the planning of the hospital.

• Membrane Journal
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• v.7 no.3
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• pp.131-135
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• 1997

Polymeric micellar enhanced ultrafiltration method using a new type of polyrmer, $\alpha$-allyl-$\omega$-methoxy polyoxyethlene and maleic anhydride copolymer (AKM-0531, Mw 15, 000), has been proposed to separate 1-naphthylamine as a weak cationic toxic organic solubilizate. Enhancement effect of polymeric micelle was identified by the ultrafiltration runs using polyacryronitrile(PAN) holow fiber membrane with molecular weight cut off 6, 000. The linear dependance of flux on the pressure difference is shown to be valid up to 0.6kg/${cm}^2$ and the rate of flux increase in response to change in the pressure is gradually reduced under the pressure difference. Rejection of 0.96 was observed for f mM of 1-naphthylamine with 2 wt.% polymer solution at the conditions of 0.4kg/${cm}^2$, natural pH. and $25^{\circ}C$ Solubilization of 1-naphthylamine into the polymeric micelle enhanced the separation efficiency.

• Membrane Journal
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• v.29 no.2
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• pp.67-79
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• 2019

High purity propylene (propene) is an octane-enhancing chemical and also feedstock to industrially important chemicals. Purification of propylene from propane mixture is technologically and financially challenging because of their close boiling points. ZIF-8 membrane has been increasingly researched due to its great potential to separate propylene from propane effectively by molecular sieving. The increasing interest in ZIF-8 membranes lies in the so called "gate opening" effect. The gate opening effect enlarges the membrane pores and preferentially allows propylene to permeate through the membrane pores, while retaining the larger and heavier propane molecules in the feed stream in order to effect high propylene separation from propylene/propane mixture. In this paper, the widely accepted methods of ZIF-8 membrane preparation and parameters affecting propylene permeation and selectivity in ZIF-8 membrane are identified and reviewed.

• Membrane Journal
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• v.29 no.3
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• pp.130-139
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• 2019

Various two-dimensional nano materials such as graphene, zeolite, and metal-organic framework have been utilized to develop an ultra-thin high-performance membrane for water purification, gas separation, and so on. Particularly, in the case of graphene oxide, synthesis methods and thin film coating techniques have been accumulated and established since early 2000s, therefore graphene oxide has been rapidly applied to membrane field. The multi-layered graphene oxide thin film can filter molecules separately by the molecular sieving of interlayer spacing between adjacent layers, and it is also possible to separate various materials depending on the surface functional groups or the degree of interaction to intercalated materials. This review mainly focuses on the nanofiltration application of graphene oxide. The major factors affecting the separation performance of graphene oxide membrane in solvent are summarized and other technical elements required for the commercialization of graphene oxide membranes will be discussed including stability issue and fabrication method.