• Applied Biological Chemistry
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• 제17권1호
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• pp.49-53
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• 1974

Mohan's aniline procedure for the quantitative determination of niacin in feed additives containing various vitamines and minerals was compared with microbiological procedure utilizing growth rate of Lactobacillus arabinosus 17-5. Microbioassay was more sensitive than chemical procedure to the detection of standard niacin and was applicable to the determination of minute amounts of niacin. while both microbioassay and chemical proce dure were discovered to be unsatisfactory by the recovery test for the determination of niacin in feed additives containing much interfering substances. But the possibility of the determination of niacin in feed additives on chemical prccedure together with microbioassay was proved.

• Bulletin of the Korean Chemical Society
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• 제23권11호
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• pp.1590-1594
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• 2002

Liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) has been used for the determination of sulfonamides in meat. Five typical sulfonamides were selected as target compounds, and beef meat was selected as a matrix sample. As internal standards, sulfapyridine and isotope labeled sulfamethazine (${13}^C_6$-SMZ) were used. Compared to the results of recent reports, our result have shown improved precision to a RSD of 1.8% for the determination of sulfamethazine spiked with 75 ng/g level in meat.

• Bulletin of the Korean Chemical Society
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• 제22권1호
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• pp.84-86
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• 2001

• Bulletin of the Korean Chemical Society
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• 제22권1호
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• pp.123-126
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• 2001

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.171-176
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• 2012

A novel chemiluminescence (CL) system was established for the determination of cytosine arabinoside (Ara-C) in pharmaceutical preparations. It was showed that a clear CL signal was observed when Eosin Y mixed with Fenton reagent. The CL intensity was decreased significantly when Ara-C was added to the reaction system and partially scavenged the hydroxyl radicals in the solution. The extent of decrease in the CL intensity had a good stoichiometrical relationship with the Ara-C concentration. Based on this, we developed a new method for the determination of Ara-C using a flow injection analysis (FIA) technique with CL detection. Under the optimal conditions, the linear range of Ara-C concentration was $6.0{\times}10^{-9}\sim1.0{\times}10^{-7}mol/L$ (R = 0.9982) with a detection limit of $7.6{\times}10^{-10}mol/L$ (S/N=3), the RSD was 5.6% for $6.0{\times}10^{-8}mol/L$ Ara-C (n = 11). The method was successfully applied to the determination of Ara-C in injection samples. The possible chemiluminescence reaction mechanism was discussed.

• Bulletin of the Korean Chemical Society
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• 제29권5호
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• pp.988-992
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• 2008

A poly(methyl red) film-modified glassy carbon electrode (PMRE) was fabricated for determination of norfloxacin (NFX). The electrochemical behavior of NFX was investigated and a well-defined oxidation peak with high sensitivity was observed at the film electrode. PMRE greatly enhanced the oxidation peak current of NFX owing to the extraordinary properties of poly(methyl red) film. Based on this, a sensitive and simple voltammetric method was developed for measurement of NFX. A sensitive linear voltammetric response for NFX was obtained in the concentration range of $1\;{\times}\;10^{-6}\;-\;1\;{\times}\;10^{-4}$ mol/L and the detection limit was $1\;{\times}\;10^{-7}$ mol/L using linear sweep voltammetry (LSV). The proposed method possessed advantages such as low detection limit, fast response, low cost and simplicity. The practical application of this new analytical method was demonstrated with NFX pharmaceuticals.

• 대한화학회지
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• 제37권6호
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• pp.585-589
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• 1993

N,N'-oxalylbis(2-pyridyl-3'-sulphobenzoyl hydrazone)(OPSH)를 발광시약으로 사용하여 형광광도법으로 Fe(Ⅲ)을 정량하는 방법을 개발하였다. pH 3인 수용액에서 290 nm를 들뜸 파장으로 하여 367 nm에서 Fe(Ⅲ) 착물의 형광세기를 측정하여 정량하였다. Fe(Ⅲ)의 농도가 2000~10ng/ml인 범위에서 정량이 가능하였으며 이 방법을 합성시료 및 수도물의 분석에 적용하였다.

• 분석과학
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• 제15권2호
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• pp.180-183
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• 2002

The new useful method for the direct determination of trace boron in iron matrix was studied by applying the precipitation of $Fe(OH)_3$ and ICP-AES. Optimum pH range was 11 ~ 12.5. Linear concentration range of boron was $0.01{\sim}1.0{\mu}g/m{\ell}$ in $5000 {\mu}g/m{\ell}$ solution as iron.

• 대한화학회지
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• 제59권5호
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• pp.407-412
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• 2015

A preconcentration procedure for determination of palladium by laser thermal lens spectrometry (TLS) is proposed. It is based on cloud point extraction of palladium(II) ions as 2-(3,5-dichloro-2-pyridylazo)-5-dimethylaminoaniline (3,5-diCl-PADMA) complexes using octylphenoxypolyethoxyethanol (Triton X-114) as surfactant. The effects of various experimental conditions such as pH, concentration of ligand and surfactant, equilibration temperature and time on cloud point extraction were studied. Under the optimized conditions, the calibration graph was linear in the range of 0.15~6 ng mL⁻¹, and the detection limit was 0.04 ng mL⁻¹ with an enrichment factor of 22. The sensitivity was enhanced by 846 times when compared with the conventional spectrophotometric method. The recovery of palladium was in the range of 96.6%~104.0%. The proposed method was applied to the determination of palladium in water samples.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.204-208
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• 2012

A novel chemiluminescence (CL) flow injection method for the determination of balofloxacin is described. The method is based on the weak CL signal arising from the reaction of $KBrO_3$ with $Na_2S_2O_4$ in acidic medium being significantly enhanced by balofloxacin in the presence of europium (III) ion and sodium dodecyl benzene sulfonate (SDBS). The experimental conditions that affected CL intensity were carefully optimized and the CL reaction mechanism was briefly discussed. Under the optimum conditions, the relative CL intensity was proportional to the concentration of balofloxacin in the range of $7.0{\times}10^{-11}$ to $3.0{\times}10^{-7}g\;mL^{-1}$. The detection limit was $2.7{\times}10^{-11}g\;mL^{-1}$ and the relative standard deviation was 2.1% for $7.0{\times}10^{-10}g\;mL^{-1}$ balofloxacin (n = 13). The proposed method was successfully applied to the determination of balofloxacin in pharmaceutical formulations and biological fluids.