• Analytical Science and Technology
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• v.14 no.3
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• pp.244-252
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• 2001

A comprehensive analytical method of endocrine distruptors[i.e., nonylphenol(NP), octylphenol(OP), bis(2-ethylhexyl)phthalate(BEHP)] is fish samples was developed using two internal standards. This method employed closed culture tube extraction with dichloromethane and solvent exchange to iso-hexane and SPE(2g) aminopropyl column, followed by determination on gas chromatograph linked to mass spectrometer(GC/MS) operated in the single ion monitoring(SIM) mode. The recoveries of nonylphenol and octyphenol in the range of $0.2{\sim}20{\mu}g/g$ using 1-phenyl decanol as one internal standard were over 75%, and recovery of bis(2-ethylhexyl)phthalate in the range of $0.4{\sim}40{\mu}g/g$ using bis(2-ethylbutyl)phthalate(BEBP) as the other internal standards was showed over 102%. The present method was applied to fish samples from Korea and UK. The range of concentrations for nonylphnol(NP) and bis(2-ethylhexyl)phthalate in Korean fish were $0.02{\sim}0.06{\mu}g/g$ in 2 samples and $0.18{\sim}2.03{\mu}g/g$ in 9 samples respectively, but bis(2-ethylhexyl)phthalate(BEHP) in UK samples was found $2.99{\mu}g/g$ in just 1 sample. But octylphenol(OP) was not dected in any samples by this method. This two internal standard method provides a more precise analytical tool to investigate endocrine disruptors in a biological matrices of limited quantity.

• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.226-231
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• 2010

We aimed at the monitoring medroxyprogesterone acetate (MPA) residue amount in meats and confirmed the safety of its residue in meats. Optimized condition for analytical and instrumental methods was obtained by method validation. The limit of detection (LOD) and limit of quantification (LOQ) were validated at 1.5 and 5.0 ug/kg, respectively. The calibration curve showed good linearity ($r^2$ = 0.9968) within the concentration range of 5.0~50.0 ug/kg. We selected progesterone-d9 for internal standard, The recoveries in fortified meat ranged from 67.5 to 109.56% at the 3 spiking levels. As the regulation of MPA analysis method used by LC-MS/MS on other products have established. We selected 3 species of farm stock products (cattle, pig, chicken) and purchased at the markets of seven major cities. The total 196 of meat including 46 of domestic beef, 43 of import beef, 60 of domestic pork, 12 of import pork and 35 of domestic chicken. No residue of synthetic growth hormones were detected in cattle, pig and chicken samples tested.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2006.05a
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• pp.91-91
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• 2006

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.385-389
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• 2002

Analytical method for diethylstibestrol (DES) and zeranol, which are growth promoters, in muscle foods was studied. Through selected ion monitoring analysis by GC-MSD for hormones, $M^+$ 412, 420, 416, and 433 for DES, $D_8DES$, ${\beta}-estradiol$, and zeranol, respectively, were selected for quantitative analysis. Removal of interferences in meat was done by passing the meat through 1 cc of strong anion exchanges resin, Dowex $2{\times}8$, 400 mesh, whereby the recoveries of DES and zeranol were achieved. Recoveries of DES and zeranol were ranged from 85 to 110%, and 75 to 110%, respectively, in meat using $D_8DES$ as an internal standard, while were 82 to 105%, and 65 to 120%, respectively, using ${\beta}-estradiol$ as an internal standard. These results show that both $D_8DES$ and ${\beta}-estradiol$ can be adopted as the internal standard for the analysis of DES and zeranol in muscle foods. Limits of detection of DES and zeranol were 0.05 and 1.0 ng/g, and limits of quantitation were 0.5 and 1.0 ng/g, respectively. The results of this study revealed no DES and zeranol were present in 14 samples of beefs, porks, ducks, chickens, mutiplicated flat fish, and trout.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.3
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• pp.163-175
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• 2011

Though polycyclic aromatic hydrocarbon compounds (PAHs) in marine sediment has been produced by many colleges and institution in Korea, it is difficult to compare PAHs data in a study area with those in other areas due to the lack of confidence for the quality of data from the other organization. Therefore, we suggested the protocol for PAHs analysis in marine sediment through examining the method of PAHs analysis described in over twenty scientific papers and reports. When a known amount of 23 PAHs were spiked into a sediment and anlyzed following this new protocol, very good recoveries were obtained. In addition, for college and institution with their own method to analyze PAHs can keep producing PAHs data without exchanging to this new PAHs protocol, the method to get a full confidence through the QA/QC for the PAHs data produced by these organization is included to the protocol.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.360-365
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• 2007

The studies for the derivatization of 3-monochloropropane-1,2-diol (3-MCPD) were performed mainly as acylation with HFBI (heptafluorobutyrylimidazole), alkylation with PBA (phenylboric acid) and silylation with BSTFA (N,O-bis[trimethylsilyl]trifluoroacetamide). Also silylation with MTBSTFA(N-methyl-N-[tert.-butyldimethylsilyl] trifluoroacetamide) and acylation with MBTFA (N-Methyl-bis[trifluoro-acetamide]) were also considered. Except the TBDMS derivative of 3-MCPD, all the derivatives were detected well. The derivatives of 3-MCPD with HFBI, PBA and BSTFA showed below 10 ${\mu}g/kg$ which was sensitive enough to satisfy Korea maximum residue limit 0.3 mg/kg. Among the tested adsorbents, Extrelut20 and Florisil were evaluated as the proper adsorbents to eliminate the soy sauce matrix for 3-MCPD. Ethyl acetate was the most efficient eluent with good recovery rate. The desired surrogate compound and internal standard were 1,2-butanediol and 1,2-dibromo-3-chloropropane, respectively. The limit of detection for PB-MCPD and TMS-MCPD were 10.16 and 7.06 ${\mu}g/kg$ on GC/MSD, respectively. HFB-MCPD derivative showed the lowest detection limits 2.98 and 5.32 ${\mu}g/kg$ by GC/ECD and GC/MSD, respectively.

• Journal of Food Hygiene and Safety
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• v.7 no.1
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• pp.45-48
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• 1992

In Food revolution of Korea, colorimetries or a titration methods are introduced for the analysis of alcoholic liquors. But, these wet analyses have disadvantages such as individual errors, long process time, and sometimes tedious pretreatments. In the process of making alcoholic liquors, fusel oils are produced as by products. Five main fusel components that could be produced are 2-propanol, n-propanol, iso-butanol, n-butanol, and isoamyl alcohol. Also acetaldehyde and methanol could be produced as by-products of ethanol. With using capillary FFAP column in GC or GC/MSD, we analysed these five fusel components as well as internal standard (acetonitrile) including methanol, acetaldehyde and ethanol simultaneously. We obtained excellent mass spectra as qualitative data of all species. We also took excellent quantitative data with GC by using the internal standard method.

• Analytical Science and Technology
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• v.15 no.4
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• pp.335-340
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• 2002

An analytical method has been developed to determine multi-elements in human hair samples by inductively coupled plasma mass spectrometry (ICP-MS). 0.05 g of hair sample was added to the Teflon digestion bomb together with 1.5 mL of nitric acid and an appropriate amount of In as an internal standard. The sample was then decomposed in the microwave digestion system. The hair certified reference material, GBW 09101, was analyzed for the validation of the analytical method. The determined values were in good agreement with the certified values within the uncertainty range.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.3
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• pp.264-270
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• 2000

Quantitative analysis of iron ore sinter consisting of hematite, magnetite, calcium ferrite and slag was investigated by X-ray internal standard method. After selecting NaF and $SiO_2$as internal standard materials, the calibration curves were determined and were applied to quantitative analysis of the internal standard method. Calcium ferrite was identified as a solid solution of CaO.$2Fe_2$$O_3$with 7 wt% and 3 wt% solubility of $AI_2$$O_3$and $SiO_2$, respectively. The maximum deviation of quantitative analysis of synthetic iron ore was about $\pm$5 wt%. The contents of each mineral calculated in industrial sinter were 27~40 wt% of hematite, 20~30 wt% of magnetite, 22~33 wt% of calcium ferrite and 10~20 wt% of slag.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.44.2-44.2
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• 2014

우주론의 표준모형에서는 어느 정도 큰 규모에서 물질의 분포가 균일하고 등방하다고 가정한다. 본 연구는 어떤 규모에서 물질의 분포가 균일한지 은하의 관측 자료를 이용하여 조사하였다. 관측 자료로는 SDSS Data Release 7의 적색편이 값이 0.16에서 0.47사이에 있는 105,831개의 LRGs의 목록을 사용하였다. LRGs의 목록을 이용해서 일정한 적색편이 구간에 있는 은하들을 택하여, 이를 2차원 면으로 간주하고, 각 은하를 중심으로 원을 만들어 원의 면적에 대한 원 내부에 있는 은하들의 개수의 증감을 이용하여 균일성을 조사하였다. 정확한 비교를 위해 LRGs의 목록과 동일한 수의 은하를 무작위적으로 뿌린 Random catalog와 표준모형을 기반으로 만들어진 Horizon Run 3의 N-body simulation 의 결과로부터 얻어낸 halo mock catalog를 각각 비교하였다.