• Journal of the Korean Society of Food Science and Nutrition
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• v.1 no.1
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• pp.25-31
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• 1972

The Undaria pinnatifida collected in the waters of Dongbaek Island were grouped into young and adult ones and calcium and iron contents of each were analyzed by parts, i.e., separately for blade, stripe, and sporophyll by potassium permanganate titration method and spectrophotometric method respectively (O-phenanthrolin used). The results showed that the blades contain higher percentage of calcium than other parts both in young and adult seaweeds and that proportionately twice as much iron is contained in the blades than in the stripes.

• Journal of Food Hygiene and Safety
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• v.20 no.1
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• pp.64-68
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• 2005

An analytical method of nine synthetic foods colors in Korea, Japan, Joint FAO/WHO Expert Committee of Food Additives (JECFA), and USA were compared. Contents of water insoluble matter in synthetic food colors tested were not different by general test methods of various organs. Contents of chloride and sulfate salts in Food Green No.3, Food Red No.3, Food Blue No.2, and Food Yellow No.4 slightly differed in various methods, and but up to the standard, and general test methods of JECFA and USA needed far more time. For the measurement of arsenic contents in food colors, colorimetric method in Korea and Japan, and silver diethyldithiocarbamate colorimetric method in USA and JECFA were used, but the standards of them were different. Content of heavy metals was up to the standard, but the methods were used colorimetric method in Korea, atomic absorption method in Japan, and both methods in JECFA and USA.

• Journal of Food Hygiene and Safety
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• v.19 no.4
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• pp.171-175
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• 2004

An analytical method of nine synthetic food colors in Korea, Japan, Joint FAO/WHO Expert Committee of Food Additives (JECFA), and USA were compared. Contents of water insoluble matter in synthetic food colors tested were not different by general test methods of various organs. Contents of chloride and sulfate salts in Food Green No.3, Food Red No.3, Food Blue No.2, and Food Yellow No.4 slightly differed in various methods, and but up to the standard, and general test methods of JECFA and USA needed far more time. For the measurement of arsenic contents in food colors, colorimetric method in Korea and Japan, and silver diethyldithiocarbamate colorimetric method in USA and JECFA were used, but the standards of them were different. Content of heavy metals was up to the standard, but the methods were used colorimetric method in Korea, atomic absorption method in Japan, and both methods in JECFA and USA.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.918-921
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• 2005

Quantitative analysis of flavonoids in commercial propolis extract products were compared by three colorimetric methods; aluminum chloride method, dinitrophenylhydrazine method and aluminum nitrate method, Aluminum nitrate method in Korea Health Supplement Food Code was proved to be specific only for flavones and flavonols same as aluminum chloride method, while dinitrophenylhydrazine method was specific for flavanones and dihydroflavonols. Therefore, the sum of flavonoid contents determined by 2,4-Dinitrophenylhydrazine method and aluminum nitrate method may represent the real content of total flavonoids. As for the 25 commercial propolis extract products examined, the contents of flavonoid varied from 2.15% to 9.53% except for one product.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.3-6
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• 2012

Purpose : Samsung medical ceter shall find a cause of the interference factor and suggest a solution for it. Materials and Methods : A sample of $^{18}F$-FDG, radioactive pharmaceuticals produced by TRACERlab MX and FASTlab synthesizer. Gel-clot method uses Positive control tube and single test tube. Kinetic chromogenic method uses ENDOSAFE-PTS produced by Charles River. Results : According to Gel clot method of Endotoxin Tests at FASTlab, both turbidity and viscosity increased at 40-fold dilution and Gel clot was detected. In case of TRACERlab MX, Gel clot was detected in most of samples but intermittently not in a few of them. When using ENDOSAFE-PTS, sample CV (Coefficient of Variation) of FASTlab is 0% at all dilution rates whereas spike CV is 0% at 1-fold dilution, 0~35% at 10-fold, 3.6~12.9% at 20-fold, 5.2~7.1% at 30-fold, 1.1~17.4% at 40-fold, spike recovery; 0% at one-fold, 25 ~ 58% at 10-fold, 50 ~ 86% at 20-fold, 70~92% at 30-fold, and 75~120% at 40-fold. Sample CV of TRACERlab MX, is 0% at all dilution rates whereas spike CV is 1.4~4.8% at one-fold dilution, 0.6~19.9% at 10-fold, spike recovery; 35~72% at one-fold dilution and 77~107% at 10-fold. Conclusion : Gel clot does not seem to occur probably to H3PO4 which engages in bonding with Mg2+ion contributing gelation inside PCT. Dilution which is identical to reducing the amount of H3PO4, could remove interfering effects accordingly. Spike recovery was obtained within 70~150% - recommended values of supplier - at 40-fold dilution even in kinetic chromogenic method.

• Analytical Science and Technology
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• v.18 no.5
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• pp.425-430
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• 2005

In this study, we investigated the performance of a portable colorimeter used for the measurements of atmospheric ammonia against the more reliable method like UV/VIS spectrophotometer. For the purpose of this study, we tested a portable colorimeter and UV/VIS spectrophotometer for such basic analytical parameters as detectibility, reproducibility, linearity, and accuracy. According to our study, the performance of the colorimeter was fairly good to show a good agreement with the UV/VIS system. However, the performance of colorimeter suffered from both low and high concentration ranges: it was found to have very poor reproducibility at lower concentration (below $10\mu}g$), while its linear dynamic range was limited at the upper end (e.g., near $100{\mu}g$). If we assume that air samples are collected up to 30 liter, it implies that the colorimeter can be used to measure samples containing NH3 in the range of 500 ppb to 5 ppm (without the aid of diluting technique). Consequently, we recommend the use of such instrument with the awareness of its basic properties pertaining to the fundamental performance (such as its detectable range).

• Journal of Food Hygiene and Safety
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• v.3 no.3
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• pp.99-103
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• 1988

For the purpose of discussing two colorimetric methods modified from the Standard Methods of Sanitary Inspection. Guide issued by the Ministry of Health and Social Affaires of Korea (1985), the Standard Methods of Analysis of Hygienic Chemists authorized by the Pharmaceutical Society of Japan.(1980) and HPLC (high performance liquid chromatography) method were studied. Two kinds of ham, sausage samples and four kinds of roe samples were analyzed by the HPLC method and the results agreed well with those obtained by the diazotization-coupling colorimetric method prescribed in the Standard Methods of Analysis for Hygienic Chemists authorized by the Pharmaceutical Society of Japan (1980) and two modified methods.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.266-271
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• 2007

Bisphenol A (BPA) has been widely used as a monomer for production of epoxy resins and polycarbonate plastics. The annual production of BPA exceeds 640,000 metric tons in worldwide. BPA, a suspected phenolic endocrine disrupter, is moderately soluble and frequently detected in industrial wastewater. To date, HPLC and GC has been used for BPA analysis. However, HPLC and GC-analysis need high operation lost, experts, and an elaborate pre-treatment of samples, and is difficult to apply on-time and mass analysis. Therefore, simple, mass and rapid detection of BPA in environments is necessary. In the present study, spectrophotometric method of BPA quantification was developed. Based on blue-color product formation with BPA and ferric chloride/ferricyanide under the optimized conditions, the standard curve was acquired $({\lambda}_{750}=0.061\;BPA\;[{\mu}M]+0.07155,\;R^2=0.992)$. Using an established method, the BPA contents in the soil extract, and different water samples and living products, including disposable syringe, cup and plastic tube, were analyzed. The results suggested that the method is useful for BPA determination from different massive samples. Since the BPA metabolites, nontoxic 4-hydroxyacetophenone or 4-hydroxybenzaldehyde, did not form blue-color product, this method is also useful to screen a microorganism for BPA bioremediation.

• Nuclear Engineering and Technology
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• v.15 no.2
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• pp.142-148
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• 1983

Distribution coefficients between cation exchange resin (Dowex 50W$\times$8) and $\alpha$-hydroxyisobutric acid ($\alpha$-HIBA) are measured in order to separate traces of Sm, Eu, Gd and Dy from nuclear material. Individual separations are performed by pH gradient technique with 0.40M $\alpha$-HIBA from 3.40 to 3.60 in cation exchange resin after a group separation. Each of separated elements is determined with a fluorometric method except Gd by colorimetry. The results are applied to analyze Sm, Eu, Gd and Dy in magnesium diuranate (yellow cake).

• Journal of Life Science
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• v.14 no.2
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• pp.221-224
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• 2004

Comparisons of enzymatic method, gas chromatographic method, and the Iatroscan method for the determination of cholesterol in each parts of Korean squid were undertaken. The Iatroscan method was the most suitable procedure for the rapid and simple determination of net cholesterol concentration in parts of Korean squid. 5$\alpha$-cholestane is used as a good internal standard. The cholesterol contents in body, leg, viscera, eye, skin, and liver part of Korean squid, Todarodes pacificus STEEN STRUP by Iatroscan method were 178.9, 321.4, 168.9, 159.5, 608.8 and 634.2 mg%, respectively.