• 생약학회지
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• 제20권1호
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• pp.21-24
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• 1989

A new method for quantitative determination of icariin in Epimedii Herba by high performance liquid chromatography was established. A reversed-phase system with $a\;{\mu}Bondapak\;C_{18}$ column using methanol in water(15% to 70%, gradient elution) as a mobile phase was developed. Icariin and spinosin as an internal reference were detected at 350 nm and the analysis was successfully carried out within 30 min.

• 생약학회지
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• 제16권3호
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• pp.175-179
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• 1985

The optimal condition for the determination of saikosaponin a and d, the major pharmacologically active saponins of the roots of Bupleurum falcatum, was studied with the conversion of these saponins into diene saponins $(saikosaponin\;b_1\;and\;b_2)$. The complete separation and quantitative analysis of these saponins were performed by the method of high performance liquid chromatography using $NH_2$ column. The conversion of saikosaponin a and d into diene saponins under gastric pH was calculated. Thirty-three percent of saikosaponin a was converted to saikosaponin $b_1$ and 63 percent of saikosaponin d was converted to saikosaponin $b_2$.

• Natural Product Sciences
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• 제16권3호
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• pp.180-184
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• 2010

The simple and accurate method was established for the simultaneous determination of (-)-menthone and (-)-menthol in Menthae herba obtained from Korea and China. A quantitative analysis was performed with a gas chromatography-flame ionization detector and reference compounds were separated on a capillary HP-Innowax column (30 m $\times$ 0.23 mm, 0.50 ${\mu}m$, Agilent, MA, USA). The correlation coefficients of the compounds showed good linearity ($r^2$ > 0.9997) over the linear range. The precision, repeatability and stability showed less than 1.7% of relative standard deviation (RSD) values for two compounds. Recovery rates were within the range of 95.72 - 103.76%. The method was applied successfully to analyze 15 samples of Menthae herba and achieved sufficient and specific separation of reference compounds. The principal component analysis (PCA) exhibited the classification of 15 samples according to their locations of origin.

• 대한화학회지
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• 제7권2호
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• pp.186-188
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• 1963

An attempt to improve the method of volumetric determination of tungsten developed by Luke has been made successfully. Using amalgam coated lead instead of pure metallic lead in the reduction procedure. W(VI)-W(III) reduction has been found to be quantitative in rather concentrated hydrochloric acid. Since there was no excessive dissolution of lead via reduction of hydrogen ion, lead surface was totally accessible for the reduction of tungsten and no trouble was caused by dereposition of $PbCl_2$ crystals at the nozzle of Jones reductor. Furthermore, it has been confirmed that almost 100 mg. of $WO_3$ can be handled easily if the chloride concentration of the HCl is increased by adding solid $NH_4Cl$.

• 대한화학회지
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• 제15권1호
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• pp.5-9
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• 1971

모나자이트 시료중의 토륨만을 신속히 정량하기 위하여 양이온 교환수지법을 사용한 분리법을 고안하였다. 희토류 원소를 포함한 모든 공존 이온을 3N 염산으로 용출제거하고 남아있는 토륨을 5N 황산으로 용출한 다음 토린을 착색제로 사용하여 광도 법을 써서 정량하였다. 방사성 동위원소 및 출광 분광법을 써서 용출된 토륨의 정량적인 회수 및 그의 화학적 순도를 확인하였다.

• Archives of Pharmacal Research
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• 제4권2호
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• pp.85-90
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• 1981

A quantitative GC-MS spectrometric assay was used for the determination of residual N, N-dimethylaniline as a contaminant in commercial penicillin derivatives from various sources. The assay utilizes selective ion focusing to monitor in a GC effluent the molecular ions of DMA generated by electron impact ionization. This method includes dissolution of the sample in alkaline solution, extraction of organic base with cyclohexane and injection into GC-MS with a 3% OV-17 column. Levels of 50 ppb of DMA were easily measured with a coeffecient of varation less than 5 % and recoveries from spiked samples exceeded 97 %. The results of the determinations of DMA in various commercial penicillins were relatively free of this contaminant.

• Journal of Pharmaceutical Investigation
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• 제16권2호
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• pp.72-75
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• 1986

A convenient high performance liquid chromatographic method was established for the quantitative determination and content uniformity test of aclatonium napadisilate preparation. This method was more simple to make the sample solution for injection, and easy to determine the content in the preparation. Aclatonium napadisilate was chromatographed using a $Lichrosorb-NH_2$ column $(4mm\;{\times}\;25\;cm$, and acetonitrile-water mixture (83:17) as an eluent at a flow rate of 1.8 ml/min. RI-detector response was linear over a range of $0.5{\sim}2.0%$ aclatonium napadisilate under above conditions. Reproducibility studies gave relative standard deviation of 1.29%.

• Journal of Pharmaceutical Investigation
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• 제13권2호
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• pp.59-65
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• 1983

A convenient high performance liquid chromatographic method for the quantitative determination and content uniformity of prednisolone in tablets is described. The prednisolone was chromatographed using a ${\mu}-Bondapak\;C_{18}$ column and the eluent 70% MeOH at a flow rate 1. 0ml/min. Diethylstilbestrol was used as an internal standard. The UV detector response at 254nm was linear over a range of $10{\sim}60{\mu}g/ml$ under conditions of the analysis. Reproducibility studies gave relative standard deviations of $0.3{\sim}0.5%$.

• Bulletin of the Korean Chemical Society
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• 제15권1호
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• pp.74-77
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• 1994

Rare earth elements (REE) were individual separated by applying the gradient elution via HPLC using ${\alpha}-hydroxyisobutyric$ acid (HIBA) as an eluent. However, the overlap of Y and Dy peaks was too severe to obtain the resolution of these two peaks. The target transformation factor analysis (TTFA) was applied to resolve the elution peaks of Y and Dy. [A]$_{raw}$ formed from the absorbances of mixed solution was factor analyzed. The abstract factor analysis(AFA) was used to determine the number of components that contributed to the poorly resolved peaks. The error theory in the AFA showed that the number of components was 2. The test vectors which correspond to pure component were selected from the standard solutions of Y and Dy. TTFA was accomplished by target testing. The results showed that the resolution of two peaks as well as the determination of Y and Dy were possible by the factor analysis.

• 약학회지
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• 제5권1호
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• pp.16-19
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• 1960

Quantitative determination of Arsenic acid by precipitation of Arsenic acid as ZnNH$_{4}$AsO$_{4}$ and titration of Zn in the precipitate by EDTA has been investigated. Conclusion are as follows; 1) ZnNH$_{4}$AsO$_{4}$ was Soluble in NH$_{4}$Cl-NH$_{4}$OH buffer solution of pH lo and back-titration was unnecessary as in the case of MGNH$_{4}$AsO$_{4}$. 2) The end point was clear whether AsO$_{4}$$^{-3}$ present or not. 3) More simple and rapid method than that of Gravi metric method. 4) Could be determined within 0.3% error.