• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.943-946
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• 2005

An effective spectrophotometric determination of palladium with 4-(2-pyridylazo)-resorcinol (PAR) using molten naphthalene as a diluent has been studied. A red complex of palladium with PAR is formed at 90 ${^{\circ}C}$. In the range of pH 9.0-11.0, the complex is quantitatively extracted into molten naphthalene. The organic phase is anhydrously dissolved in $CHCl_3$ to be determined spectrophotometrically at 520 nm against the reagent blank. Beer’s law is obeyed over the concentration range of 0.1-2 ${\mu}g{\cdot}mL^{-1}$. The molar absorptivity and Sandell’s sensitivity are 8.0 ${\times}\;10^5\;L{\cdot}mol^{-1}{\cdot}cm^{-}1\;and\;0.49\;{\mu}g{\cdot}cm^{-2}$ respectively. From the results of tolerance limits, it was found that there was no interferences were observed for most of the ions examined and those somewhat high interferences by Co(II), Fe(II) and Bi(III) could be effectively masked by EDTA.

• Bulletin of the Korean Chemical Society
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• v.20 no.3
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• pp.352-354
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• 1999

The spectrophotometric determination of Cu(Ⅱ) with α-(2-benzimidazolyl)-α',α"-(N-5-nitro-2-pyridylhydrazone)-toluene has been investigated. The optimum conditions of pH, stability, concentration of ligand and surfactant were evaluated. This method is a simple and sensitive method for determination of Cu(Ⅱ) and offers a selective separation of Cu(Ⅱ) from sample solution containin- I ppm below amount of Ni(Ⅱ), Co(Ⅱ), Zn(Ⅱ) and Sn(Ⅱ). Copper was determined by measuring the absorbance of Cu(Ⅱ)-BINPHT complex extracted with benzene in Brij 58 surfactant at 410 nm. Beer's law is obeyed over the concentration range 0∼2.5 μgmL-1 and the detection limit (S/N=2) is 0.06 μgmL-1. The relative standard deviation at the 0.3 μgmL-1 is 2.4% (N=7). The method was applied for the determination of Cu(Ⅱ) in various milks.

• Analytical Science and Technology
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• v.9 no.3
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• pp.244-252
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• 1996

Spectrophotometric properties of lanthanide complexes with methylthymol blue(MTB) and cetyltrimethylammonium bromide(CTAB) were studied and also lanthanide(III) ions were determined by flow injection analysis on the base of the above results. The absorption maxima of lanthanide(III)-MTB complexes in the presence of CTAB are 635nm with molar absorptivity of $4.51{\sim}6.11{\times}10^4Lmol^{-1}cm^{-l}$ at pH 5.8. The mole ratio of lanthanide(III) complexes with MTB is 1:2 in the presence of CTAB. The calibration curves of lanthanide(III) ions obey the Beer's law in the range of 0.1 to 0.4ppm under the optimum condition. The samples throughput was ca. $60hr^{-1}$. The interfering effect of some cations and anions was investigated. The ligand anions such as tartrate and citrate, many transition and rare earth elements interfered severely and must be removed before the determination of lanthanide(III) ions.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.4
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• pp.71-77
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• 2008

This paper presents a methodology for recovering the industrial radiographic images from the effects of nonlinear distortion. Analytical approach based on the inverse square law and Beer's law is developed in order to improve a mathematic model of nonlinear type. The geometric effect due to dimensions of the radioactive source appeals on the digitized images. The relation that expresses parameters values(angle, position, absorption coefficient, length, width and pixel account) is defined in this model, matching with the sample image. To perform the search for image recovery most similar to the model, a correction procedure is designed. The application of this method on the radiographic images of steel tubes is shown and recovered results are discussed.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.155.1-155.1
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• 2015

Nowadays, Plasma has been used in biological, medical such as wound healing, plant grow, killing cancer. When plasma generated, UV light and ROS(Reactive oxygen species), RNS(Reactive nitrogen species) can generated and those things effect to biological material. So we made simple plasma device using needle type of electrode and generated plasma. We used three kinds of gas and measured applied voltage and current. Also we observed optical emission spectrum. Using deuterium ramp, we can observed absorption spectrum and calculated radical density by lambert-beer's law. It is around ~1016cm3. And we can see the time-resolved absorption spectrum from monochromator, PMT(photo multiply tube), IV-converter, oscilloscope.

• YAKHAK HOEJI
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• v.31 no.2
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• pp.45-51
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• 1987

Methyl orange(MO) and cetyltrimethylammonium bromide(CTA) were mixed and added to 10ml of the buffer solution and then the solution was shaken for 5 minutes. The maximum absorption wavelength of the reaction product was 419nm. Dichloromethane was the best extracting solvent among the several organic solvents and the most suitable pH range was 2~8. When the CTA-MO calibration curve was made in the best experimental condition, the Lambert-Beer's law was obeyed in the range of CTA concentration of $1.5\times$$10^{-5}$~1.0$\times$$10^{-4}M$ by UV spectrophotometer. This method was possible to determine quaternary ammonium salts in the pharmaceutical preparations.

• Journal of the Korean Chemical Society
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• v.9 no.1
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• pp.45-48
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• 1965

Stability constant, composition of copper (II)-oxamidoxime complex were determined by spectrophotometric method. The ratio of copper (II) and oxamidoxime in the above complex was 1 : 1, and its stability constant was calculated to be $2.4{\times}10^{22}$. The complex solution gave constant absorbancy between the pH range of 4.5 to 6 at 600 $m{\mu}$ in which Beer's law applicable in the concentration range of 0.3 to 2.0 ppm studied in this work. It was noted that some metals such as Fe(III), Ni(II), Co(II), U(VI) interfere copper determination by this method.

• Journal of the Korean Chemical Society
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• v.15 no.6
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• pp.378-384
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• 1971

A new analytical reagent 8-(p-ethylbenzenesulfonamido)quinoline(EBSQ) has been synthesized, and identified its structure. EBSQ forms copper chloroform-soluble complex in a basic solution (pH = 7.5∼10.5). The other optimum conditions for the spectrophotometric study of Cu-EBSQ have been established at 380 $m{\mu}$. Beer's law is followed in the concentration range of 0~44.5 ${\mu}g$ per 10 ml of chloroform. The composition of complex has been found to be $Cu(EBSQ-H)_2$and the over-all instability constant is calculated to be $1.22{\times}10^{-7}$. The absorption coefficient of the $Cu(EBSQ-H)_2$ complex is ${\varepsilon}$ = 15,800.

• YAKHAK HOEJI
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• v.35 no.1
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• pp.15-21
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• 1991

Quaternary amines which are widely used as medicines are nitrogen compounds. Metanil yellow(MY) and benzalkonium chloride(BKC) were mixed and added to 10ml of the buffer solution and then the solution was shaken for 5 minutes. The maximum absorption wavelength of the reaction product was 402 nm. Dichloromethane was the best extracting solvent among the several organic solvents and the most suitable pH range was 2~8. When the BKC-MY calibration curve was made in the best experimental condition, the Lambert-Beer's law was obeyed in the range of BKC concentration of 2$\times$$10^{-6}$~9$\times$$10^{-6}$M by UV spectrophotometer. This method was possible to determine quaternary ammonium salts in the pharmaceutical preparation.

• YAKHAK HOEJI
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• v.38 no.4
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• pp.366-371
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• 1994

To improve the identification power of TLC/HPTLC the in situ reflectance spectra obtained directly from plates with commercial scanner are used. The spectrum normalization should be carried out prior to comparing and searching the spectra from library for the identification of compounds. Because the reflectance does not obey the Lambert-Beer's law, there arise some problems in normalization. These problems could be solved to some extent by normalizing the spectra with regression methods. The spectra are manipulated with the regression function of a curve obtained from the correlation plot. When the parabola was used as the manipulating function, the spectra were identified with the accuracy of 97% and this result was better than that of conventionally used the point and area normalization method.