• Title/Summary/Keyword: Spectrophotometric method

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Optimum Concentration of the Cd(II)-Quercetin Complexation Reaction (Quercetin의 카드뮴 착물반응에 대한 최적농도)

  • Lee, Jeong-Ho;Shin, Sun-Woo;Baek, Seung-Hwa
    • YAKHAK HOEJI
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    • v.53 no.5
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    • pp.235-240
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    • 2009
  • The interaction of cadmium (II) ion with quercetin was investigated in aqueous solution at different pH. The quercetin/cadmium stochiometries for cadmium (II) binding have been determined by UV-vis spectrophotometric method. The complexation of Cd(II) ion with 54.72 ${\mu}M$ quercetin (A=1.00793) was formed in 0.2 M $NH_3-0.2$ M $NH_4Cl$ (pH 8.0) buffer solution. 1:1 Cd(II)-complex had a maximum absorbance and showed the bathochromic shift of the long-wavelength band of the UV-vis spectra in the alkaline pH when interacted with quercetin in buffer solution. These results suggest that Cd(II)-quercetin complex has the optimal condition of chelation in basic buffer solution.

Study of 8-Hydroxyquinoline Derivatives. The Acid Dissociation Constants of 5-Acetyl-8-Hydroxyquinoline (8-Hydroxyquinoline 誘導體에 關한 硏究 5-Acetyl-8-Hydroxyquinoline의 酸解離定數)

  • Lee, Dong-Hyung
    • Journal of the Korean Chemical Society
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    • v.9 no.1
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    • pp.33-36
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    • 1965
  • Acid dissociation constants of 5-acetyl-8-hydroxyquinoline have been determined by spectrophotometric and potentiometric methods at $25^{\circ}C$. $pK_1$, $pK_2$ values obtained by potentiometric method were 4.56, 8.20 respectively and $pK_1$ obtained by spectrophotometric method was 4.21. pK values were lower than those of 8-hydroxyquinoline. The lower basicity of 5-acetyl-8-hydroxyquinoline compared with 8-hydroxyquinoline was considered as the result of the electronic attraction of the acetyl group with aromatic ring.

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Spectrophotometric Determination of Nitrate with Brucine (Brucine에 依한 窒酸이온의 吸光光度定量法)

  • Bo shik Han
    • Journal of the Korean Chemical Society
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    • v.18 no.6
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    • pp.415-420
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    • 1974
  • A simple and rapid spectrophotometric method has been found for the determination of nitrate content in natural water according to brucine method by means of neither particular apparatus nor troublesome procedures. Brucine reacted with nitrate in the presence of 30 N sulfuric acid to develop stable color with good reproducibility after 30 minutes reaction at $60^{\circ}C$<\TEX>. An essentially linear relationship to the nitrate concentration was observed in the range of 0.07~0.6 ppm at 410 nm, and it was established that the number of absorbing species in the reaction system was only one between 400 and 490 nm. Among the interferences, nitrite could be removed by the addition of methanol.

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Spectrophotometric Determination of Amantadine Sulfate after Ion-Pairing with Methyl Orange

  • Choi, Kyong;Choi, Jung-Kap;Yoo, Gyurng-Soo
    • Archives of Pharmacal Research
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    • v.14 no.4
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    • pp.285-289
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    • 1991
  • A convenient spectrophotometric method was examined for the determination of amantadine sulfate (AMTS) which has no UV-VIS chromopohores. AMTS was ion-paired quantitatively with methyl orange (MO) at $70^{\circ}C$ for 30 min. The ion-paired complex was extracted with dichloromethane and the absorbance was measured at 421.5 nm. A linear relationship was observed in the range of $2.5{\times}10^{-7}\;M$ to $3.75{\times}10^{-6}\;M$ and the correlation coefficient was 0.999 (n=3). This assay method was applied to the quantification of AMTS in commercial tablet form with good recovery and high precision.

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Analysis of Germanium in the Ore Samples by UV-Visible Spectroscopy

  • Reddy, K. Raghava;Lee, Kwang-Pill;Gopalan, Anantha Iyengar;Showkat, Ali Md;Kim, Sang-Ho;Paek, U-Hyon
    • Analytical Science and Technology
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    • v.17 no.6
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    • pp.476-480
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    • 2004
  • A simple, rapid, reproducible and selective UV-Visible spectrophotometric method has been developed for determination of germanium in a week acid medium (pH = 3.0) in the presence of mandelic acid (MA) and malachite green (MG). A single extraction in chlorobenzene was used for the analysis. The germanium-MA ion association complex exhibits an absorption maximum at ${\lambda}_{max}=618nm$ with MG as counter ion and has an apparent molar absorptivtity of $1.313{\times}10^5L\;mol^{-1}\;cm^{-1}$. The values obtained by this UV-Visible spectrophotometric method are in good agreement with the values from inductively coupled plasma-mass spectrometer analysis.

Spectrophotometric Determination of Reducing Drugs (Ascorbic Acid, Potassium Antimonyl Tartrate, Isonicotinic Acid Hydrazide) with $Bis(2,4-diaminophenyl)phosphonate-KIO_3$ ($Bis(2,4-diaminophenyl)phosphonate-KIO_3$에 의한 환원성의약품(Ascorbic Acid, Potassium Antimonyl Tartrate, Isonicotinic Acid Hydrazide)의 분광광도정량)

  • Suh, Jung-Hyun;Kam, Sang-Kyu
    • YAKHAK HOEJI
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    • v.34 no.1
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    • pp.22-33
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    • 1990
  • Aqueous solution of bis(2,4-diaminophenyl)phosphonate(APP) was very stable, especially below pH 2.0 and the red-color compound formed by the reaction of APP and $IO_3-$ was stable at room temperature. A simple and rapid spectrophotometric method for the determination of ascorbic acid, potassium antimonyl tartrate (PAT), and isonicotinic acid hydrazide (INAH) was established by the reaction of $IO_3-$ and these reducing drugs, and the absorbance measurements were made at 500 nm. In the reaction of $IO_3-$ and each of the reducing drugs, the conditions of pH were suitable below 2.5 for ascorbic acid, below 2.0 for PAT, and below 1.5 for INAH. Beer's law did hold in the range of $17.6{\sim}1549.9\;ug$ for ascorbic acid, $33.4{\sim}2871.8{\mu}g$ for PAT,and $6.9{\sim}548.6\;{\mu}g$ for INAH. Many common ingredients present in pharmaceutical dosage forms did not interfere. The average recoveries for ascorbic acid and INAH in pharmaceutical formulations were 99.8 $-100.3\;{\pm}\;0.2{\sim}0.4%$, $99.8\;{\pm}\;0.3%$, respectively.

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Studies on the Spectrophotometric Determination and Electrochemical Behavior of Heavy Lanthanide Ions in Nonaqueous System and Heavy Metal Chelate Complexes with Bidentate Legands: (Part I) Flow Injection Spectrophotometric Determination of Heavy Lanthanide Ions with Xylenol Orange

  • Sam-Woo Kang;Chong-Min Park;Kwang-Hee Cho;Hong-Seock Han
    • Bulletin of the Korean Chemical Society
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    • v.14 no.1
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    • pp.59-62
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    • 1993
  • Spectrophotometric determination of some heavy lanthanide ions by flow injection method is described. Xylenol Orange forms water soluble chelates with lanthanide ions in a tris[hydroxymethyl]-aminomethane-buffered medium having pH 8.3 and containing cetyltrimethylammonium bromide. The molar absorptivities of Ln(III)-XO complexes were increased by the ternary system with cetyltrimethylammonium bromide with the concomitant bathochromic shift of absorption maxium compared to those of the binary system without cetyltrimethylammonium bromide. The calibration curves are linear in the range 0.25-1.00 ppm for Gd(III), Dy(III), Er(III), Tm(III) and Yb(III) and the dynamic range are very wide. The detection limits (S/N=2) are from 2 ppb for Gd(III) to 30 ppb for Yb(III) and the relative standard deviations are from 1.2% for 0.5 ppm Gd(III) to 1.8% for 0.5 ppm Yb(III). The sample throughput was ca. 50 $h^{-1}$.

Spectrophotometric Determination of Soil Chemical Properties Using Soiltek® KA-P Spectrophotometer (Soiltek KA-P 분광광도계률 사용한 토양 화학적 성질의 분광학적 분석)

  • Hyun, Hae-Nam;Oh, Sang-Sil;Koo, Bon-Jun;Kang, Ho-Jun
    • Korean Journal of Soil Science and Fertilizer
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    • v.33 no.2
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    • pp.127-138
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    • 2000
  • To enable rapid and convenient soil test, new soil analytical methods, which require only one instrument, UV/Vis spectrophotometer, were developed and named "Soiltek KA-P spectrophotometric methods". The Soiltek$^{(R)}$ KA-P spectrophotometric method was compared with standard method of RDA in analytical capability for soil chemical properties. Using the 78 soils collected from upland, paddy, orchard, and vinyl house soils, soil organic matter, exchangeable K, Ca, and Mg. CEC, available $SiO_2$, and nitrate were analyzed by the two methods. The color stability(ratio of the absorbance at elapsed time t to the absorbance at time t=0) of organic matter. Ca, Mg, and available $SiO_2$ decreased to about 2% within one hour. However, that of exchangeable K, CEC, and nitrate remained constant. The results obtained with Soiltek$^{(R)}$ KA-P spectrophotometric method showed highly significant correlation with those measured by the standard method of RDA($R^2$ >0.9501), in which the slopes were near unity of $1.0{\pm}0.05$. The standard deviation values of organic matter, exchangeable K, Ca, and Mg, CEC, available $SiO_2$, and nitrate were apparently lower than ${\pm}1.8gkg^{-1}$, ${\pm}0.05cmol^+kg^{-1}$, ${\pm}0.18cmol^+kg^{-1}$, and ${\pm}0.13cmol^+kg^{-1}$, ${\pm}1.0cmol^+kg^{-1}$, ${\pm}5.0mgkg^{-1}$, and ${\pm}10.0mgkg^{-1}$, respectively. All the measurements showed coefficients of variation of less than 7~17% and were within the confidence level of 95%, which means both the methods are precise. Considering the relative simplicity, low cost, precision and accuracy, the proposed Soiltek$^{(R)}$ KA-P spectrophotometric methods could be recommended as an alternative to standard method.

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Extraction-Spectrophotometric Determination of Cimetidine in Pharmaceutical Samples as an Ion Pair with Bromothymol Blue (티몰블루와 함께 이온쌍으로서 약제 샘플에서 시메티딘의 추출-분광광도 측정)

  • Zargar, B.;Pourreza, N.;Shahrouz, M.
    • Journal of the Korean Chemical Society
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    • v.55 no.1
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    • pp.46-49
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    • 2011
  • A highly sensitive and selective extraction-spectrophotometric method has been developed for determination of trace amounts of cimetidine. This method is based on the extraction of cimetidine as an ion pair with bromothymol blue (BTB) into chloroform and measuring its absorbance at 417 nm. The effect of different variables such as pH, concentration of BTB, volume of chloroform and shaking time was investigated. The effect of interfering ions on the extraction was also studied. The calibration curve was linear in the range of 0.25-8 ${\mu}gmL^{-1}$ with correlation coefficient of 0.9997. The detection limit based on 3Sb was 0.14 ${\mu}gmL^{-1}$ and relative standard deviation for 10 replicated measurements of 1.0 and 4.0 ${\mu}gmL^{-1}$ of cimetidine was 3.2 and 1.49%, respectively. The proposed method was applied to the determination of cimetidine in pharmaceutical samples with good recoveries.