• Journal of Nutrition and Health
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• 제17권1호
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• pp.31-40
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• 1984

혐기적 조건밑에서 $FeCl_{3}$에 의해 촉진된 TBA 반응을 이용하여 혈청중 과산화물 측정을 위한 새로운미량 분석법을 설정하였다. 즉. 혈청단백침전물이 현탁된 TBA반응흔합액에 혈청 $10{\mu}l$당 $1.0{\mu}mole$의 $FeCl_{3}$를 첨가한 다음 질소기류밑에서 50분간 끊는 물에 중탕한다. 이 분석법의 반응 예민도는 현행 일반 TBA법보다 40여배나 증대되었으며 따라서 미량의 시료$(10{\sim}20{\mu}l)$로도 TBA반응생성물의 농도 측정이 비색법으로도 가능하였다. 그리고 TBA반응생성물의 butanol 추출액을 $(NH_{4})_{2}SO_{4}$염석으로 부분말수시킴으로써 예민성 및 재현성이 개선될 수 있었다. 이 분석법을 이용하여 측정한 건강인들의 혈청 TBA같은 높은 연령군일수록 증가하는 경향을 보였다.

• Preventive Nutrition and Food Science
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• 제1권2호
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• pp.174-178
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• 1996

The content of anserine, taurine, and L-histidine was measured by HPNC in the muscle of mature(670~690g) and juvenile(80~120g) rainbow trout fatmed in Chungsun, Korea. The concentration of anserine and taurine was higher in mature rainbow trout than in juvenile, but that of L-histidine was lower in mature than in juvenile. When measured with the chemiluminescence(CL) assay, anserine and taurine showed very powerful antioxidative activity above physiological concentration rainbow trout. Taurine still showed antioxidative activity below physiological concentration, while anserine showed prooxidative activity below that. L-Histidine was prooxidative dose-dependently. In TBA method, while taurine showed very week antioxidative effect, anserine appeared very powerful antioxidant and L-histidine prooxidant at physiological concentration. There was no synergism between anserine and taurine and anserine inhibited prooxidative effect of L-histidine.

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1693-1698
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• 2012

A headspace gas chromatographic mass spectrometric (GC-MS) assay method was developed for the simultaneous determination of methyl tertiary butyl ether (MTBE), $tert$-butyl alcohol (TBA) and benzene, toluene, ethyl benzene and xylene (BTEX) in soil contaminated with gasoline. 2 g of soil sample were placed in a 10 mL headspace vial filled with 5 mL of phosphoric acid solution (pH 3) saturated with NaCl, and the solution was spiked with fluorobenzene as an internal standard and sealed with a cap. The vial was heated in a heating block for 40 min at $80^{\circ}C$. The detection limits of the assay were 0.08-0.12 ${\mu}g$/kg for the analytes. For five independent determinations at 10 and 50 ${\mu}g$/kg, the relative standard deviations were less than 10%. The method was used to analyze fifty six soil samples collected from various regions contaminated with gasoline in Korea. The developed method may be valuable for the monitoring of the analytes in soil.

• Bulletin of the Korean Chemical Society
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• 제30권12호
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• pp.3049-3052
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• 2009

Methyl tert-butyl ether (MTBE) is added to gasoline to enhance the octane number of gasoline, tert-butyl alcohol (TBA) is major degradation intermediate of MTBE in environment, and benzene, toluene, ethyl benzene and xylene (BTEX) are also major constituents of gasoline. In this study, a simplified headspace analysis method was adapted for simultaneous determination of MTBE, TBA and BTEX in ground water samples. The sample 5.0 mL and 2 g NaCl were placed in a 10 mL vial and the solution was spiked with fluorobenzene as an internal standard and sealed with a cap. The vial was placed in a heating block at 85 $^{\circ}C$ for 30 min. The detection limits of the assay were 0.01 ${\mu}$g/L for MTBE and BTEX, and 0.02 ${\mu}$g/L for TBA. The method was used to analyze 110 ground water samples from various regions in Korea, and to survey the their background concentration in ground water in Korea. The samples revealed MTBE concentrations in the range of 0.01 - 0.45 ${\mu}$g/L (detection frequency of 57.3%), TBA concentrations in the range of 0.02 - 0.08 ${\mu}$g/L (detection frequency of 5.5%), and total BTEX concentrations in the range of 0.01 - 2.09 ${\mu}$g/L (detection frequency of 87.3%). The developed method may be used when simultaneously determining the amount of MTBE, TBA and BTEX in water.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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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.