• Analytical Science and Technology
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• v.13 no.5
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• pp.592-600
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• 2000

The concentration of free fatty acids and fatty acid composition as well as cholesterol supersaturation in bile may be an important factor in the gallstone formation. Therefore, we simultaneously determinded 23 fatty acids in bile by selected ion monitoring (SIM) method of gas chromatography-mass spectrometry (GC-MS). Biliary fatty acids were extracted by aminopropyl column and the extracts with (phospholipid fraction) or without (free fatty acid fraction) alkaline hydrolysis of phospholipid were derivatized with MSTFA/TMCS (N-methyl-N-trimethylsilyl-trifluoroacetamide/trimethylsilylchloride) mixture in order to be detected on the GC-MS. The recovery range of this method was 61.1-99.0% and the RSD value of within-a-day and day-to-day test were 3.1-25.6% and 3.8-27.0%, respectively. Using this method, biliary profile was investigated in the bile of normal controls and patients with gallstones. The amounts and their distribution of free and phospholipid fatty acids showed different pattern between normal subjects and patients.

• Analytical Science and Technology
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• v.12 no.4
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• pp.265-272
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• 1999

A simultaneous profile analysis of 19 environmental estrogens, which act like estrogen and may effect the endocrine system by binding to hormone receptors or influencing cell signaling pathways, was attempted. The present method was based on the selected ion monitoring (SIM) mode of gas chromatography/mass spectrometry (GC/MS). It involves solid-liquid extraction, enzyme hydrolysis, liquid-liquid extraction and quantitative conversion into trimethylsilyl (TMS)-ether derivatives. Analytical recovery range was 47.6 ~ 99.5% and the RSD values of within-a-day and day-to-day test were 0.66 ~ 9.33%, 1.66 ~ 16.14%, respectively. The Korean reference values for the evaluation of environmental estrogen effects were established by this method.

• Bulletin of the Korean Chemical Society
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• v.28 no.6
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• pp.929-935
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• 2007

The objective of this study was to develop a rapid, simple, and qualitative acetylcholinesterase (AChE)- detection kit, based on a modification of the Ellman and ELISA methods, for the detection of organophosphorus (OP) and carbamate (CB) pesticide. The developed kits were used to screen a large number of agricultural samples (spiked and real) for OP and CB pesticide residues. AChE was extracted from the heads of honeybees (Apis mellifera L.) using Triton X-100, and was purified through 3 steps: diethylaminoethylcellulose chromatography (DEAE), affinity chromatography and membrane filtering, and Mono-Q column chromatography. Epoxy-activated Sepharose 6B affinity chromatography was used for large-scale purification. The presence of OP and CB pesticide residues in agricultural samples was assayed on the basis of AchE inhibition value. The presence (6 bands) or absence of some colored bands on the test line indicated a negative or positive result, respectively. The limits of detection for measured organophosphorus (OP) and carbamates (CB) pesticide residues in standard pesticide solutions and fortified samples were ranged from 0.50 to 2.50 ppm and 0.50 to 4.75 ppm, respectively.

• Applied Biological Chemistry
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• v.17 no.4
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• pp.257-274
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• 1974

The studies on the carotenoids in the viscera of abalone (Haliotis discus hannai) have been-carried out. The pigments were extracted with acetone-methanol mixture (4 : 1) from the viscera of abalones which were caught around the coastal water of Korea from March to August. The individual carotenoid in the extracts was separated and purified by the silica gel TLC, $Mg(OH)_2$ impregnated paper chromatography and $Mg_2(OH)_2CO_3$ TLC. The isolated eleven carotenoids were investigated and identified by epoxide test, partition test, reduction with sodium borohydride, alkaline hydrolysis, co-chromatography and comparative test with reference carotenoids and electronic and IR absorption spectrophotometry. ${\alpha}$-Carotene, ${\beta}$-carotene. lutein, zeaxanthin, siponaxanthin, siponein, fucoxanthin, loroxan-thin-like and fucoxanthinol-like have been identified among the eleven carotenoids isolated. It has been found that fucoxanthin, on alkaline treatment, was transformed to the product of which chromophore was the same one as fucochrome and semifucoxanthol. Among the identified nein carotenoids siphonaxanthin, siponein, fucoxanthin, loroxanthin-like and fucoxanthinol-like have not been reported previously to be contained in the shellfish.

• Journal of Aquaculture
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• v.21 no.4
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• pp.285-293
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• 2008

Vitellogenin (Vg) is the precursor of vitellin (Vn), the major yolk protein of teleost fishes. In this study, Vg and Vn proteins of the Korean bullhead Pseudobagrus fulvidraco were isolated using gel-filtration chromatography (Sephadex-G 200 column) and anion-exchange chromatography (Mono Q HR 5/5 column), respectively. Purified Vn with an estimated molecular mass of 360 kDa by gel filtration chromatography was obtained from ovarian egg, and it was composited to one major subunit with an estimated molecular mass of 107 kDa by SDS-PAGE. In the result of western blotting, one major band was detected using antiserum against Vn (anti-Vn). These results suggested that Vn was composed of three subunits having the same molecular weight in Pseudobagrus fulvidraco. Vg was induced by estradiol-$17{\beta}$ ($E_2$) and purified from $E_2$ treated male serum. The molecular weight of whole Vg was estimated to be 450 kDa by gel filtration chromatography, and it is composed of three subunits with estimated molecular masses of 110 kDa, 125 kDa and 147 kDa as determined by SDS-PAGE. In the Ouchterlony's immunodiffusion test using anti-Vn and antiserum against female and male serum, purified Vg was detected in matured female and Ez treated male serum but not in untreated male. These results can be used in detecting estrogenic contamination of the aquatic environment.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.258-264
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• 1988

Phenolic compounds present in upland weeds (Artemisia asiatica Nakai, Capsella bursa-pastoris (L.) Medik, Portulaca orleracea L. and Trifolium repens L.) which have shown allelopathic activity were determined using paper chromatography (PC) and high performance liquid chromatography (HPLC). Effect of the determined phenolic compounds on germination and post-germination growth of test plants was also investigated. Kinds of phenolic compounds determined by PC in the four weed species were greater in the aqueous extract than in the methanol extract. Ferulic acid was found in both extracts of the weeds studied, whereas benzoic acid was that the weeds commonly contained hydroquinone, p-hydroxybenzoic, ferulic and cinnamic acids. Out of the phenolic compounds determined by PC and HPLC p-hydroxybenzoic, cinnamic and ferulic acids inhibited germination and post-germination growth of radish and sesame. Inhibition of the phenolic compounds on the radicle growth was greater than on the germination of the test plants.

• Analytical Science and Technology
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• v.37 no.3
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• pp.143-154
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• 2024

In this study, we improved the vitamin C test method and reviewed data on the adjustable range of chromatography conditions for quantification. First, we adjusted the mobile phase conditions such as solvent composition, salt concentration, pH and column temperature and in particular, it was confirmed through an improved test method that the peak derived from the buffer solution could be clearly separated from the target component, vitamin C by adjusting the pH. The retention time of vitamin C was partially changed by adjusting the column diameter, length and particle size but the number of theoretical plates indicated similar values and did not affect the separation and quantitative analysis of the target component. The flow rate according to the column specifications was derived from the equation proposed by the U.S. FDA (Food and Drug administration) and the Korean MFDS (Ministry of Food and Drug Safety), and evaluation of the applicability to vitamin complexes showed high selectivity for vitamin C even with altered stationary phase conditions and flow rates. In conclusion, vitamin C can be optimally separated and detected by changing the chromatographic method conditions and it was confirmed that the mobile and stationary phase conditions of liquid chromatography can be slightly adjusted in case the assay method uses an isocratic elution.

• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.320-325
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• 1992

For natural antioxidant test, the Rhus javanica $Linn\'{e}$ was extracted by 75% ethyl alcohol and fractionated it by chloroform and ethyl acetate using separatory funnel and column chromatography. In the Rhus javanica L. extract, the effective material was disolved easily in ethyl acetate and chloroform. When 600 ppm of ethyl acetate fraction of the extract was added to palm oil and lard, AI(antioxidant index) of each oil was 1.60 and 3.90 respectively. The $CHCl_3$ and EtOAc fractions were more effective than whole extract of Rhus javanica L. The palm oil, lard and soybean oil containing different levels of the Rhus javanica L. extract were stored at $60^{\circ}C$ to compare their antioxidative activity. Peroxide value, acid value and TBA value of each oil were monitored. The Rhus javanica L. extract was very effective to retard oxidation of palm oil and lard. This result coincided with Ranimat test.

• Analytical Science and Technology
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• v.33 no.1
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• pp.1-10
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• 2020

Alpha lipoic acid, an antioxidant, is widely used for treatment of various diseases. It is a racemic mixture, with R-(+)-α lipoic acid exhibiting greater potency, bioavailability, and effectiveness than those of the S-form. Thus, selective R-(+)-α lipoic acid has been recently used in various applications, necessitating the development of a method to test the enantiomeric impurity in R-(+)-α lipoic acid. We developed a simple and fast high-performance liquid chromatography method using a new immobilized amylose-based chiral column (Chiralpak IA-3). Design of experiment was applied to accurately predict the effects and interactions among various factors affecting the analytical parameters and to optimize the chromatographic conditions. This optimized method could completely separate the two enantiomer peaks with a resolution > 1.8 within a short running time (9 min). Then, the optimized method was validated according to the guidelines of the International Conference on Harmonization and applied for quantification of S-(-)-α lipoic acid in some commercial R-(+)-α lipoic acid tromethamine raw material. Our results suggested that the developed method could be used for routine quality control of R-(+)-α lipoic acid products.

• Journal of Animal Science and Technology
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• v.45 no.3
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• pp.491-498
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• 2003

The purpose of this study is to observe purification and properties of osteopontin(OPN) from bovine milk. The purification of osteopontin from bovine milk was performed by using ion-exchange and hydrophobic chromatography. SDS-PAGE analysis revealed that the protein migrated at Mw. 60,000. NH2-terminal sequence analysis of the first seven amio acids revealed the protein to be identical to that previously reported for bovine OPN. 35-wk-old chickens, including 3 Single Comb White Leghorn (SCWL), were used to produce egg yolk antibody(IgY) against OPNas a antigen. However, the anti-OPN antibody activities determined by ELISA. Immunological assy of OPN in milk was performed using radial immunodiffusion test based on the standard curve of pure OPN. The radial precipitation lines of four different milk samples indicated that the concentrations of OPN in the milk samples were within the range of 31.7 to 39.7${\mu}g$/ml. On inhibition with OPN on precipitation of calcium phosphate, OPN was slightly higher than casein phosphopeptide(CPP) and poly-glutamic acid.