• Journal of the Korean Chemical Society
• /
• v.37 no.9
• /
• pp.793-799
• /
• 1993

Ion-pair model was predominated over ion-interaction model in the retention mechanism of analytes when tetramethylammonium bromide (TMAB) was used as a counter-ion in the investigation of aromatic sulfonic acids on the reversed-phase liquid chromatography by $C_{18}$ column as a stationary phase. The capacity factors of analytes were influenced by the type and concentration of counter-ions, concentrations of methanol and co-anion, types and position of functional group, and the pH mobile phase. Components of analyte mixture could be separated under the optimum conditions by this method.

• Journal of the Korean Chemical Society
• /
• v.45 no.2
• /
• pp.143-148
• /
• 2001

In this study, open tubular capillary columns for ion charomatography were developed to analyze trace amount of ions in samples. When small I,D. capillary column length is 1.0~5.0 m. The capillary columns were made using fused silica capillary(I.D:50㎛) and DMEOHA latex particles. The new conductivity cell and suppressor were also developed and made for capillary column ion chromatography. When several anions(fluoride, nitrite, nitale,chlorate,phosphte, sulfate) were analyzed using these capillary columns. reproducible and good chromatograms were obtained.

• Microbiology and Biotechnology Letters
• /
• v.23 no.4
• /
• pp.485-491
• /
• 1995

Protein ion exchange chromatography was studied experimentally in order to prove the theoretical prediction from the linear model of Yamamoto, S. et al (1). Adsorption isotherms were measured as a function of ionic strength in a batch experiment. The relationship between the characteristics of chromatogram and the operating conditions of ionic strength, flow rate, length of column, concentration and amount of protein sample were studied. At the higher ionic strength, the lower flow rate and the longer column conditions, the higher number of plate was obtained. Satisfactory agreement was observed between the experimental and the calculated chromatograms except for the case of high protein concentration.

• Bulletin of the Korean Chemical Society
• /
• v.24 no.12
• /
• pp.1805-1808
• /
• 2003

The simultaneous determination of As(III), As(V), and DMA has been performed by ion chromatography (IC) coupled with inductively coupled plasma-mass spectrometry (ICP-MS). The separation of the three arsenic species was achieved by an anionic separator column (AS 7) with an isocratic elution system. The separated species were directly detected by ICP-MS as an element-selective detection method. The IC-ICP-MS technique was applied for the determination of arsenic species in a NIST SRM 1643d water sample. An As(III) only was detected in the sample. The detection limits of As(III), As(V) and DMA were 0.31, 0.45, and 2.09 ng/mL, respectively. It was also applied for the determination of arsenic species in a human urine obtained by a volunteer, and three arsenic species were identified. The determination of total As in human urines that were obtained from 25 volunteers at the different age was also carried out by ICP-MS.

• Preventive Nutrition and Food Science
• /
• v.1 no.1
• /
• pp.1-5
• /
• 1996

Rapid analytical method was investigated to determine precursors of N-nitrosamine such an nitrite and nitrate in squid(Illex illecebrosus and Sepiell maindroni), codfish(Gadus marcrocephalus)and flatfish(Paralichthys olivaceus) by ion chromatography(IC) and colorimetric methods. Recoveries of nitrite and nitrate in fish tissues were 89~98.7% and 94.1~99.8% for IC, and 98.4~103.7% and 67.7~102.2% for colori-metric method, respectively. Using IC, nitrite was not detected and nitrate was 0.89~1.23mg/kg, while using colorimetric method, nitrite and nitrate were NO~0.08mg/kg and 0.3~0.42mg/kg, respectively. Therefore, the IC method showed better recoveries, and was applicable to extract nitrite and nitrate simultaneously, and is simpler compared with colorimetric method in analyzing nitrite and nitrate from fish tissues.

• Korean Journal of Pharmacognosy
• /
• v.33 no.2 s.129
• /
• pp.88-91
• /
• 2002

Liquid-chromatography coupled with electrospray-ion trap mass spectrometry was applied to the analysis of the eleutherosides B and E in the Eleutherococcus senticosus cortexes. The optimum ESI/MS results were obtained in the positive ion mode using extracted ion chromatogram targeting Na-adduct molecular ion of each compound. This method allowed rapid and simple gradient separation of underivatized eleutherosides B and E without pre-purification steps at very low concentration.

• Journal of Plant Biotechnology
• /
• v.31 no.4
• /
• pp.319-323
• /
• 2004

Soluble latex protein fraction excreted from Euporbia lathyris laticifer was resolved by 10% SDS-polyacrylamide gel electrophoresis to identify distinctively displayed latex major protein bands including ELp65, ELp55, ELp43, ELp32 and ELp23. Among them, ELp65 was purified by ammonium sulfate precipitation, gel permeation chromatography and ion exchange chromatography. Its N-terminal amino acid sequencing revealed its homology to the leading region of mature peptide of tomato p69a subtilisin-like protease, suggesting a certain role involved in plant defense system. In the analysis of Southern blot hybridization using PCR-amplified tomato p69a probe DNA, E. lathyris genome was suggested to have a gene family consisting of 3-5 gene members putatively encoding subtilisin-like proteases.

• BMB Reports
• /
• v.35 no.6
• /
• pp.576-582
• /
• 2002

Collagenase from the internal organs of a mackerel was purified using acetone precipitation, ion-exchange chromatography on a DEAE-Sephadex A-50, gel filtration chromatography on a Sephadex G-100, ion-exchange chromatography on DEAE-Sephacel, and gel filtration chromatography on a Sephadex G-75 column. The molecular mass of the purified enzyme was estimated to be 14.8 kDa by gel filtration and SDS-PAGE. The purification and yield were 39.5-fold and 0.1% when compared to those in the starting-crude extract. The optimum pH and temperature for the enzyme activity were around pH 7.5 and $55^{\circ}C$, respectively. The $K_m$ and $V_{max}$ of the enzyme for collagen Type I were approximately 1.1 mM and 2,343 U, respectively. The purified enzyme was strongly inhibited by $Hg^{2+}$, $Zn^{2+}$, PMSF, TLCK, and the soybean-trypsin inhibitor.

• Journal of Food Hygiene and Safety
• /
• v.14 no.3
• /
• pp.233-237
• /
• 1999

The bacteriocin produced by Lactobacillus sp. GM7311 was purified by sequential steps including n-propanol/acetone treatment, CM-cellulose chromatography, and gel filtration on Sephacryl HR-100. The relative activity of bacteriocin increased 493-fold after final purification step with a recovery of 8.3%. Two protein bands of ca. 8,200 and 2,500 were detected by SDSPAGE of bacteriocin purified through CM-cellulose and sephacryl HR-100 chromatography and both of them had bacteriocin activity.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.4
• /
• pp.587-593
• /
• 1995

Lectin was purified by using $(NH_4)_2SO_4$, DEAE-cellulose ion-exchange chromatography and Sephadex G-150 column chromatography from Alismatis Rhizoma(AR). The specific activity of AR lectin was 50, 441units/mg, and purification folds were 114. The AR lectin agglutinated human erythrocytes of all types(A, B, O, AB). The molecular weight of AR lectin was estimated about 90, 500 daltons by gel filtration and each subunits were 42,000, 27,000 and 22,500 daltons on SDS-PAGE respectively. The hemagglutinating activity of the lectin was inhibited by sialic acid, glucose, ribose, galactose, sucrose, and lactose. It was also inhibited by cations such as $Hg^{++},\;Fe^{++},\;Cu^{++}\;and\;Pb^{++}$.