• Journal of the Optical Society of Korea
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• v.7 no.3
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• pp.174-179
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• 2003

We construct a four-level system where a metastable state is included in an $Er^{3＋}$ Doped Yttrium aluminum garnet (YAG) crystal. Because of the action of the coherent field, the traditional light amplification with inversion can be exhibited with remarkable variation. As a result, we propose a method to achieve the gain equalization by atomic coherence. At the same time, we find that the high index of refraction accompanied by vanishing absorption can also be reached in this model. We also find that a higher index of refraction with zero absorption can be easily obtained when the coherent field is off resonance.

• YAKHAK HOEJI
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• v.23 no.3_4
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• pp.141-146
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• 1979

Germanium in various botanical drugs was determined by flameless atomic absorption spectro-photometry with a graphite tube atomizer. The amounts of Ge in Zingiberis Rhizoma and Angelicae Radix were $169{\mu}g/g$ and $146{\mu}g/g$, respectively. The amounts of Ge in some other drugs ranged from $70{\mu}g/g$ to $130{\mu}g/g$. There is much more Ge in botanical drugs than in foods.

• Journal of Environmental Health Sciences
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• v.19 no.2
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• pp.40-45
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• 1993

A solvent extraction system of copper-thiocyanate complex into various types of alkylamines such as secondary, tertiary and quaternary ammonium salt for the determination of trace copper by atomic absorption spectrometry is presented. The maximum extraction of copper shows at 0.1 M-thiocyanate and single extraction with 10 ml of 1% amine-MIBK from 50 ml of aqueous solution is enough to be quantitative for micro amounts of copper. The effect of amine diluents and of diverse ions are also examined.

• Journal of the Korean Ceramic Society
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• v.13 no.4
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• pp.15-19
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• 1976

Mutual interferences of alkali and alkali-earth metals in atomic absorption were examined. For determination of Na or K interfering elements increase the absorbancy, and for Ca or Mg decrease. Since influences of coexisting elements become nearly constant by addition of large amount of same coexisting element, could be use mixed standard solution for alkali or alkali-earth metal determination in the presence of other alkali and alkali-earth metals. The metals can be readily incorporated into scheme of rapid silicate analysis. Precision and accuracy are good.

• YAKHAK HOEJI
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• v.29 no.4
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• pp.220-222
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• 1985

Rifampicin reacts with cupric ion to produce rifampicin-Cu(II) chelate (2:1) at pH 6.5, which can be extracted with methylisobutylketone (MIBK). Therefore, rifampicin can be quantitatively, determined by measuring the quantity of Cu(II) in the organic phase by atomic absorption spectrophotometry. Because higher absorbance ratio was obtained in pH 6.0~7.0, buffer solution at pH 6.5 was used in this measurement. Linear relationship was found between absorbance and concentration in the range of 1.0~4.0${\times}10^{-4}M$. This method might be applicable to the determination of rifampicin in the preparations.

• Proceedings of the Korean Society of Potoscience Conference
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• spring
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• pp.89-90
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• 1999

• Journal of Soil and Groundwater Environment
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• v.22 no.6
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• pp.22-28
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• 2017

The accuracy of analytical results in response to the use of different additives ($NH_4Cl$, KCl, $LaCl_3$) and oxidant gases was evaluated and compared by using Atomic Absorption Spectrometry (AAS). Identification of spectroscopic interferences and possible improvements in Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) analysis were also discussed. The average accuracies of total chromium using Certified Reference Materials (CRMs) were found to be 72.1~94.2% in air/acetylene flame condition by AAS, and they were improved to 100.5~110.5% when the oxidants was changed to nitrous oxide rather than adding the additives. The field samples showed similar trends to CRMs, but chromium concentrations were highly variable depending on analytical conditions. The average accuracies using CRMs were estimated to be 89.3~166.1% by ICP-AES, and improved to below 121.7% after eliminating iron interference. Field samples with low chromium and high iron concentration were measured to be > 30% lower in total chromium concentrations by ICP-AES than AAS in nitrous oxide/acetylene flame. Total chromium concentrations in soil could be analyzed with better accuracy under nitrous oxide/acetylene flame by AAS because it was more effective to increase the temperature of the flame than to eliminate the chemical interference for maximizing atomization of chromium. When using ICP-AES, interference substances, total chromium levels, and analytical conditions should be also considered.

• Polymer(Korea)
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• v.32 no.6
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• pp.598-602
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• 2008

In this study we prepared crosslinked separators with the improved thermal stability by irradiating a commercial polyethylene (PE) separator for lithium secondary battery with an electron beam, and the thermal and mechanical properties of the prepared separators were evaluated as a function of the absorption dose. The thermal shrinkage of electron beam irradiated separator was decreased with increasing absorption dose. As a result of the shutdown behavior using an AC impedance, it was observed that the irradiated separator had the better shutdown function than the unirradiated separator. The modulus of the irradiated separator was enhanced as the absorption dose was increased, while the tensile strength and the break elongation of the irradiated separator were decreased.

• Analytical Science and Technology
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• v.10 no.3
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• pp.179-186
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• 1997

This study was carried out to improve the analytical method for determination of germanium in plants by atomic absorption spectrometry with graphite furnace. For the decomposition of plant samples, the mixed acid of $HNO_3+HClO_4+H_2SO_4$(10 : 4 : 1, v/v) was used. Under this condition, time requirement for the decomposition was 4~5 days and recovery rate was more than 98%. Solution for filling up to constant volume after decomposition was 0.1M acetic acid-sodium acetate. Detection limit for determination of germanium was 0.02 ppm by atomic absorption spectrometry with graphite furnace and argon gas. These results were corresponded with the above-mentioned research projects for improving the determination method of germanium in plants.

• Journal of Preventive Medicine and Public Health
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• v.7 no.2
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• pp.377-381
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• 1974

Determination of lead in urine is important in industrial hygiene and toxicology. Dithizone method has been principally used for the determination of lead in urine, which gives accurate results in skilful hands but is usually complex and time-consuming. Atomic absorption spectrophotometry is a new simple method and several procedures have been described. However, the influences of pH and the presence of chelating agents during treatment of lead poisoning are not clear. The purpose of this study was to find out the effect of pH and chelating agents on the determination of lead using Shimadzu atomic absorption/flame spectrophotometer, model AA-610. The results obtained were as follows: 1. The atomic absorption spectrophotometry(AAS) could be applied without prior acid digestion to specimens in the absence of chelating agents. The absorbance at $2,170\;{\AA}$, though more sensitive, was more noisy electronically. Therefore, we selected the wavelength of $2,833\;{\AA}$ plus scale expansion. 2. The optimal pH was in the range from 2 to 3. 3. The sensitivity was $0.075{\mu}g/ml/%$ and detection limit was about $0.2{\mu}g/ml$. 4. In the presence of EDTA, lead could not be completely determined without prior acid digestion. 5. On specimens from patients receiving penicillamine therapy, a comparison was made between the values obtained with dithizone method and AAS method with prior acid digestion. The results of comparison showed a very good agreement.