• Analytical Science and Technology
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• v.24 no.6
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• pp.443-450
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• 2011

Quantitative analytical condition for nickel in ceramic, metal and plastic materials using complexation and solvent extraction followed by inductively coupled plasma-atomic emission spectrometry (ICP-AES) and atomic absorption spectrophotometry (AAS) was studied. Ceramic, metal and plastic samples were dissolved by acid digestion. Nickel was determined by ICP-AES and AAS after extraction of Ni $(DMG)_2$ in $CHCl_3$. Recovery efficiency of nickel was satisfactory, and most of matrix elements causing interference could be effectively eliminated by the separation. Nickel in the certified reference materials (BAM-376 and PACS-2) were quantitatively determined without influence of sample matrix.

• Korean Journal of Clinical Laboratory Science
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• v.40 no.2
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• pp.113-117
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• 2008

It designed a study to examine the efficiency of DNA and RNA extraction from archival formalin-fixed, paraffin-embedded tissues using an non-heating and heating method. Archival paraffin blocks of liver, kidney, colon were randomly selected. Each paraffin block was prepared in 20 microtubes. For each paraffin blocks were tested non-heating DNA extraction to 10 microtubes and heating protocol under pH 7.0 and $100^{\circ}C$ to 10 microtubes. Evaluation of the results of DNA extraction was carried out by measuring concentration by UV spectrophotometry and then PCR amplification. DNA extraction content that non-heating method was liver $5{\pm}0.7{\mu}g/mL$, kidney $2{\pm}0.3{\mu}g/mL$, colon $6{\pm}0.4{\mu}g/mL$ and heating method was liver $12{\pm}0.6{\mu}g/mL$, kidney $7{\pm}0.5{\mu}g/mL$, colon $10.{\pm}0.3{\mu}g/mL$. Successful RNA extraction was observed, by ${\beta}$-actin amplification, in 46.7% sections for samples treated by the heating method versus 30.0% using non-heating DNA extraction. The extracted nucleic acid showed better values for samples heated at $100^{\circ}C$. Therefore heating extraction of nucleic acid is reliable, quick and efficiency.

• Korean Journal of Veterinary Research
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• v.33 no.1
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• pp.61-69
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• 1993

In order to search for new antibiotics from anaerobic bacteria, a large number of samples from domestic soil were collected and processed by apropriate methods. A potential strain, Streptococcus sp. An-21-1, was found to produce antimicrobial compounds. The Results were as follows; 1. During fermentation, the bacteria grew rapidly up to 20hr, thereafter entered the death phase. The optimal temperature and pH for the bacterial growth were $37^{\circ}C$ and pH 7.0, respectively. 2. Antibiotics were purified from culture broth by solvent extraction, silica gel column chromatography and Sepadex L.H 20 column. 3. Physicochemical properties of Ap-1 and Ap-2 were similar ; Their melting points were between $234-237^{\circ}C$. Color reactions of ninhydrin, 2,7-dichlorofluorescein, 4-dimethylaminobenzaldehyde, Dragendroffs reagent and 20% $H_2SO_4$, were positive. Therefore, we assumed that these antibiotics have amine group, immine group, alkaloid, and lipid components. These were stable to heat. UV spectrophotometry showed two peaks at 210 nm and 260 nm. From above results, we assumed these antibiotics are belong to the peptide antibiotic family.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.5
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• pp.59-65
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• 2009

Adsorption of an oil-proof agent (OPA）onto cellulose fibers during the papermaking process was investigated using UV-Vis spectrophotometry by measuring the OPA concentration decrease in the solution. From the calibration curve, the spectrum were converted to chemical concentrations in solution, from which the amount adsorbed onto the fiber surface could be determined. Thus, it was possible to determine the total amount adsorbed onto the fibers and in solution. Using this approach, we studied the adsorption behavior of the OPA onto the fiber surface and derived its, ${\Gamma}^s_t={\Gamma}^s_{\infty}(1-e^{-k_{\alpha}t})$. The values of the parameters kaand ${\Gamma}^s_{\infty}$ were determined using a mathematic model based on a mass transfer equation. Ultimately, a complete was derived: $Q={\alpha}{\cdot}\sum\limits_{i-1}^m{\pi}d_il_i{\cdot}M_A{\cdot}(1-e^{-k_{\alpha}t})/A_N$.

• The Korean Journal of Mycology
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• v.13 no.4
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• pp.243-247
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• 1985

Experiments were conducted to study effects of steroidal carbamate derivatives upon mycelial growth and aflatoxin production by Aspergillus flavus ATCC 15517. The basal medium was supplemented with various concentrations of these compounds and inoculated with spores. The developing cultures were incubated for 11 days at $28^{\circ}C$ without agitation. Aflatoxins were extracted with chloroform, separated by thin layer chromatography, and quantitated by ultraviolet spectrophotometry. At a concentration of 50 mg per 30 ml of medium., stigmasteryl-N-(2-chloroethyl) carbamate, cholesteryl- N - (2-chloroethyl) carbamate, $5{\alpha}-cholestan-3-one-oximino-N-(2-chloroethyl)$ carbamate and ${\beta}-sitosteryl-N-(2-chloroethyl)$ carbamate were the most effective in reducing aflatoxin production by Aspergillus flavus. However, cholest-4-ene-3-one-oximino-N-(2-chloroethyl) carbamate, at a concentration of 100 mg per 30 ml, significantly decreased aflatoxin production. There was no significant inhibition of mycelial growth by the addition of the various concentrations of these compounds.

• Journal of the Korean Ceramic Society
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• v.48 no.4
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• pp.282-287
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• 2011

ACF and $WO_3$ modified $TiO_2$ composites (ACF/$WO_3$/$TiO_2$) were prepared using a sol-gel method. The composites were characterized by Brunauer.Emmett.Teller (BET) surface area measurements, X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis and scanning electron microscope (SEM) analysis. A methyl orange (MO) solution under visible light irradiation was used to determine the photocatalytic activity. The degradation of the MO was determined using UV/Vis spectrophotometry. An increase in photocatalytic activity was observed and attributed to an increase of the photo-absorption effect by the $WO_3$ and the cooperative effect of the ACF.

• Journal of Food Hygiene and Safety
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• v.1 no.1
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• pp.31-38
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• 1986

In order to investigate the harmful trace elements in Korean common vegetable, the contents of Lead, Cadmium, Copper, Zinc and Manganese are studied in this paper. As shown in the Table 1, the following vegetable samples collected from the agriculture-marine products market I Seoul were used; root vegetables-potato, sweet potato, carrot, radish, onion and garlic, fruit vegetables-cucumber, pumpkin, green pepper, egg plant, tomato and melon. The contents of the harmful trace elements were determinded by means of atomic absorption spectrophotometry. These elements were extracted from the vegetables with the DDTC-MIBK extraction method. The results were as follows; 1. The average contents of the harmful trace elements in the vegetables were as follows; Root vegetables-Lead, 0.387 ppm; Cadmium, 0.030 ppm; Copper, 1.267 ppm; Zinc, 7.395 ppm; Manganese, 5.380 ppm. Fruit vegetables-Lead, 0.259 ppm; Cadmium, 0.028 ppm; Copper, 1.155 ppm; Zinc, 3.732 ppm; Manganese, 3.532 ppm. 2. The contents of harmful trace elements in vegetables were significantly low compared with foreign standards. This means that vegetables contamination with those harmful trace elements is not significant at present.

• Journal of Preventive Medicine and Public Health
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• v.12 no.1
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• pp.49-55
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• 1979

In order to investigate air pollution by heavy metals in Seoul city, the suspended particulates in the atmosphere were sampled with high volume air sampler in industrial area(Ku Ro Dong), commerical(Kwang Hwa Moon) and residential(Shin Chon Dong) from January to November, 1977. The sampled suspended particulates were digested and extracted from suspended particulates with the acidic solution by reflux-extraction technique, and were measured by atomic absorption spectrophotometry. And mercury was measured by mercury analyzer applying the reducing sublimation technique. Among heavy metals analyzed, the iron was identified at the highest level in the suspended particulates and the chromium was the least. Through the surveyed area, the concentration of heavy metals of the industrial area was comparatively high among others and the commercial was the second. It was detected that lead was the most concentrated in the suspended particulate of the commercial area, that might be caused of the traffic emissions. The seasonal variations were analyzed and the correlations among heavy metals and total suspended particulate were also calculated. Especially, the iron was highly correlated with total suspended particulate in all the surveyed areas.

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.899-902
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• 2005

Peptide assimilation by Helicobacter pylori was investigated using L-phenylalanyl-3-thia-phenylalanine (PSP) as a detector peptide; the release of thiophenol upon enzymatic hydrolysis of PSP was spectrophotometrically detected with the aid of 5,5'-dithiobis[2-nitrobenzoic acid] (DTNB). By adding PSP to whole-cell suspension, thiophenol was produced progressively, resembling that found in Esherichia coli or Staphylococcus aureus. Interestingly, the rate of thiophenol production by H pylori in particular was markedly reduced when cells were pretreated with trypsin, indicating surface exhibition of peptidase. According to the competitive spectrophotometry using alanyl-peptides, H pylori did not appear to assimilate PSP through the peptide transport system. No discernible PSP assimilation could be ascertained in H pylori cells, unless provided with some additives necessary for peptidase activity, such as $Ni^{2+}\;or\;Mg^{2+}$ and an appropriate concentration of potassium or ammonium salts. These observations strongly suggest that, regardless of a presumptive peptide transport system, peptide assimilation of H. plori appears to be highly dependent upon milieu conditions, due to unique peptidase exhibition on the cell surface.

• Journal of Pharmaceutical Investigation
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• v.40 no.3
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• pp.187-192
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• 2010

We aimed to evaluate the effect of temperature, pH, and light conditions on the stability of porcine placental extract (PPE)-loaded liposomes with different surface charges. The size distribution profiles and in vitro release patterns were investigated by dynamic light scattering method and spectrophotometry. The stability of PPE-loaded liposomes was affected by the surface charges of the liposomes. As compared to neutral and anionic liposomes, cationic liposome formulations showed significantly lower physical stability. At the test storage conditions of different temperatures and pHs, the mean sizes of cationic PPE-loaded liposomes substantially increased. In contrast, neutral and anionic liposomes did not reveal significant changes in mean sizes upon various storage conditions. The neutral and anionic liposomes showed no significant differences in the release profiles of PPE after storage at various temperatures and pHs. Our results indicate that anionic and neutral liposome compositions might be more suitable for the formulations of PPE providing the higher stability.