• Food Science and Biotechnology
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• v.14 no.4
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• pp.466-469
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• 2005

Chinese cabbage (Brassica campestris L. Pekinensis) is Brassica vegetable that contains high amounts of glucosinolates. Glucosinolates and their breakdown products are thought to contribute to health promotion by preventing some cancers. Chinese cabbage is the most commonly consumed vegetable in Asian countries including Korea. In this study, qualitative and quantitative analyses of 3-butenyl glucosinolate (Gluconapin) from different cultivars and different parts of the cabbage were performed. Gluconapin of Chinese cabbage was extracted by hot ethanol ($80^{\circ}C$), isolated by an anion exchange column and identified by GC/MS and LC/MS. The levels of glucosinolates in Chinese cabbage varied according to the different parts, cultivars, and blanching time. In general, the concentrations of 3-butenyl isothiocyanate (ITC) were higher in the leaf than in the midribs parts. The cultivar 'Bulam no. 3' had a much greater content of 3-butenyl ITC than the cultivar 'Garak no. 1,' and the levels of butenyl ITC were highest after two weeks of storage. Blanching treatment decreased the concentration of 3-butenyl ITC. The ITC concentration varied extensively among different crops of the same species, and according to the different parts on the cabbage, the storage duration and the boiling time.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.337-340
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• 2005

Ethylene oxide is a genotoxic carcinogen with widespread uses as industrial chemical intermediate and gaseous sterilant. 2-hydroxyethylated N-terminal valine in Hb is a good biomarker for biological monitoring of ethylene oxide exposure, because of its stability. We studied the determination method of (N-2-hydroxy-ethyl)valine in hemoglobin adduct by using GC/MS. PFPITC and TBMS were used as appropriate derivatives. Ethylene oxide formed Hb adducts as (N-2-hydroxy-ethyl)valine(HEV) in mouse with ethylene oxide inhalation exposure. Standard HEV can be synthesized with 2-amino-ethanol and 2-bromo-3-methylbutyric acid. GC/MS can measured them after derivatization with pentafluorophenylisothiocianate(PFPITC) and N-(tertiary butyl dimethylsiiyl)-N-methyl-trifluoroacetamide(TBDMS-TFA) by using Edman procedure. Concentrations of Hb adduct were proportionally increased with exposure levels. They were 230${\pm}$35(nmol g$^{-1}$ globin) and 410${\pm}$72(nmol $g^{-1}$ globin) at 200ppm and 400ppm ethylene oxide inhalation exposure, respectively.

• Korean Journal of Food Science and Technology
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• v.13 no.2
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• pp.142-145
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• 1981

A modified hydroxamate method was developed for determination of fat content in milk. Fat globules in milk were destroyed by adding ethanol and diethyl ether, and a homogeneous reaction system was obtained. The homogenate was reacted with hydroxylamine, milk fat formed ferric hydroxamate chelates which had red-purple color, and the ferric hydroxamate chelates was analyzed colorimetrically. This method was simpler than original hydroxamate method and comparable with the Babcock method in accuracy.

• YAKHAK HOEJI
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• v.43 no.3
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• pp.300-305
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• 1999

A sensitive and efficient assay method was applied to determine the level of glutamic acid (GA) and ${\gamma}-aminobutyric$ acid (GABA) in frontal cortex and hippocampus of rat administrated with ethanol and drugs. The compounds were derivatized with ο-phthalaldehyde (OPA) and 2-mercaptoethanof for precolunm analysis. The condition for the simultaneous determination of GA, GABA and $\beta-aminobutyric$ acid (BABA) by high performance liquid chromatography with electrochemical detection was reverse phase $C_{18}$ column as stationary phase, 0.1 M phosphate buffer containing 0.1 mM $Na_4EDTA$ : methanol = 55:45 (v+v) pH 3.8 as mobile phase and 0.7V electrode voltage. The stability of reaction product of GA, GABA and BABA with OPA could be increased by adding the same volume of polyethylene glycol 400 to reaction mixture. The GABA level in frotal cortex of rat was significantly decreased by the administration of picrotoxin and diazepam, but it was significantly increased by the administration of red ginseng total saponin, N-methyl-D-glucamine and (-)-deprenyl.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2229-2237
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• 2012

The two chelates based on calix[4]arene and thiacalix[4]arene have been synthesized and used as neutral ionophores for preparing PVC based membrane sensor selective to $Ho^{3+}$ ion. The addition of potassium tetrakis(4-chlorophenyl)borate (KTpClPB) and various plasticizers, viz., NDPE, o-NPOE, DOP, TEP and DOS have been found to improve significantly the performance of the sensors. The best performance was obtained with the sensor no. 6 having membrane of $L_2$ with composition (w/w) ionophore (2%): KTpClPB (4%): PVC (37%): NDPE (57%). This sensor exhibits Nernatian response with slope $21.10{\pm}0.3mV/decade$ of activity in the concentration range $3.0{\times}10^{-8}-1.0{\times}10^{-2}M\;Ho^{3+}\;ion$, with a detection limit of $1.0{\times}10^{-8}M$. The proposed sensor performs satisfactorily over a wide pH range of 2.8-10, with a fast response time (5 s). The sensor was also found to work successfully in partially non-aqueous media up to 25% (v/v) content of methanol, ethanol and acetonitrile, and can be used for a period of 4 months without any significant drift in potential. The electrode was also used for the determination of $Ho^{3+}$ ions in synthetic mixtures of different ions and the determination of the arsenate ion in different water samples.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2813-2818
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• 2010

A novel method was developed for the speciation of chromium in natural water samples based on homogeneous liquid-liquid extraction and determination by flame atomic absorption spectrometry (FAAS). In this method, Cr(III) reacts with a new Schiff's base ligand to form the hydrophobic complex, which is subsequently entrapped in the sediment phase, whereas Cr(VI) remained in aqueous phase. The Cr(VI) assay is based on its reduction to Cr(III) by the addition of sodium sulfite to the sample solution. Thus, separation of Cr(III) and Cr(VI) could be realized. Homogeneous liquid-liquid extraction based on the pH-independent phase-separation process was investigated using a ternary solvent system (water-tetrabutylammonium ion ($TBA^+$)-chloroform) for the preconcentration of chromium. The phase separation phenomenon occurred by an ion-pair formation of TBA and perchlorate ion. Then sedimented phase was separated using a $100\;{\mu}L$ micro-syringe and diluted to 1.0 mL with ethanol. The sample was introduced into the flame by conventional aspiration. After the optimization of complexation and extraction conditions such as pH = 9.5, [ligand] = $1.0{\times}10^{-4}\;M$, [$TBA^+$] = $2.0{\times}10^{-2}\;M$, [$CHCl_3$] = $100.0\;{\mu}L$ and [$ClO_4$] = $2.0{\times}10{-2}\;M$, a preconcentration factor (Va/Vs) of 100 was obtained for only 10 mL of the sample. The relative standard deviation was 2.8% (n = 10). The limit of detection was sufficiently low and lie at ppb level. The proposed method was applied for the extraction and determination of chromium in natural water samples with satisfactory results.

• YAKHAK HOEJI
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• v.37 no.3
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• pp.209-215
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• 1993

Basic drugs could be extracted as ion-paired complexes with Lumogallion, Superchrome Garnet Y and their alkyl derivatives from aqueous acid solution, and then determined fluoro-metrically after addition of aluminum ion. The analysis was carried out as follows; To a 1 ml portion of basic drugs (10$^{-9}$~2$\times$0$^{-8}$mole/ml), 1ml of 0.01w/v% fluorescent reagent solution, and 10ml of dichloroethane are added. The mixture is stirred for 1 minute. After standing for a few minutes, the dichloroethane layer is transfered to 1 ml of 0.1w/v% Al(NO$_{3}$)$_{3}$ ethanol solution. After mixing, and standing for 30 minutes at room temperature, the fluorescence intensity is measured with each maximum excitation and emission wavelength. The reagent blank is run through the whole procedure. From the degree of enhancement of fluorescence intensity, hexyl and dodecyl lumogallion and Superchrome Garnet Y were judged to be the useful one of fluorescent reagent for basic drugs analysis.

• Analytical Science and Technology
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• v.8 no.4
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• pp.457-460
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• 1995

A new hollow fiber filled with the lower refractive index liquid as core constructs a liquid core optical fiber(LCOF). The LCOF have been used as colorimetric cell to determine elements Cr and Cu in the presence of 70%- 50% ethanol or 50% dioxane aqueous solution, based on colored complex of Chromium(VI) with Diphenycarbazid(DPC) and copper with Chromaurd S(CAS) respectively. The sensitivity (1/ng/ml) of calibration curve of Cr and Cu are 0.052, 0.017 over the range 0 - 25, 0 - 24(ng/ml) respectively. The Cr in the animal gum and Nation Standard of China are determined with recoveries of 94 - 102%.

• Korean Journal of Food Science and Technology
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• v.51 no.2
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• pp.133-140
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• 2019

Antioxidant activities of Ulmus davidiana root and bark extracts were evaluated by various antioxidant tests, including DPPH radical-scavenging, nitric oxide-scavenging, superoxide anion radical-scavenging, and ABTS radical-scavenging assays, and superoxide dismutase (SOD)-like activity and reducing power analysis, along with the determination of total phenolic and flavonoid contents. Both the extracts showed strong antioxidant activities by these testing methods. Ulmus davidiana root extract possessed strong reducing power and nitric oxide-scavenging activity, and high scavenging activities against free radicals including the superoxide anion, and the ABTS and DPPH radicals, but a weaker scavenging activity of SOD. In contrast, the Ulmus davidiana bark extract exhibited a strong SOD-like activity, but all the other activities were weak. It was observed that the total phenolic and flavonoid contents of the Ulmus davidiana root extract were higher than those of the Ulmus davidiana bark extract.

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.13-17
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• 2021

Qantitative analysis of six compounds: (+)-catechin, benzoic acid, gallic acid methyl ester, paeonol, paeoniflorin, and albiflorin from Paeonia lactiflora extracts was performed using high-performance liquid chromatography and an ultraviolet (UV) detector, following different extraction methods. A reverse-phase column was used in a gradient elution system, and UV detection was performed at 280 nm. The results showed that the quantity of paeoniflorin was the highest in ethanol and water extracts (73.89 and 57.87 mg/g, respectively) among the six compounds. This study contributes a good analysis method for the contents of P. lactiflora and would be propitious for developing medicines and functional foods.