• Journal of Astronomy and Space Sciences
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• 제37권3호
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• pp.171-185
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• 2020

This paper presents a methodology for Initial Orbit Determination (IOD) based on a modification of the Laplace's geocentric method. The orbital elements for Near-Earth asteroids (1864) Daedalus, 2003 GW, 2019 JA8, a Hungaria-type asteroid (4690) Strasbourg, and the asteroids of the Main Belt (1738) Oosterhoff, (2717) Tellervo, (1568) Aisleen and (2235) Vittore were calculated. Input data observations from the Minor Planet Center MPC database and Astronomical Observatory of the Technological University of Pereira (OAUTP; MPC code W63) were used. These observations cover observation arcs of less than 22 days. The orbital errors, in terms of shape and orientation for the estimated orbits of the asteroids, were calculated. The shape error was less than 53 × 10^-3 AU, except for the asteroid 2019 JA8. On the other hand, errors in orientation were less than 0.1 rad, except for (4690) Strasbourg. Additionally, we estimated ephemerides for all bodies for up to two months. When compared with actual ephemerides, the errors found allowed us to conclude that these bodies can be recovered in a field of vision of 95' × 72' (OAUTP field). This shows that Laplace's method, though simple, may still be useful in the IOD study, especially for observatories that initiate programs of minor bodies observation.

• Bulletin of the Korean Chemical Society
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• 제28권3호
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• pp.373-378
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• 2007

A micro organism Agrobacterium tumifacient as an immobilized cell on a solid support was presented as a new biosorbent in a simple and sensitive spectrophotometry determination of Ni(II) in various samples using 4-hydroxy benzaldehyde-4-bromophenyl hydrazone as a color developing agent (λmax 497 nm) at pH 4.0 ± 0.2. Beer's law was obeyed over the range of 0.01-0.1 μg L-1. The molar absorptivity and Sandell's sensitivity were 1.285 × 105 L mol-1cm-1 and 0.007245 μg cm-2 respectively. Under these conditions, the preconcentration factor obtained was 82, and the detection limit achieved was 0.05 μg L-1. The detailed study of various interfering ions made the method more sensitive and selective. The recovery of Ni(II) from various samples range from 97.75 to 99.35%. The present method was successfully applied for the determination of Ni(II) in spiked, natural water and alloy samples. The proposed method was compared with reported methods in terms of Student's ‘t'-test and Variance ratio ‘f'-test which indicates that there is no significant difference between proposed and literature method at 95% confidence level.

• 약학회지
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• 제44권2호
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• pp.135-140
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• 2000

Determination of Aconitum alkaloids in processed Buza (Cho-0, Salted Buza, Moist-heating Buza, Limed Buza), which had been prepared from the raw tubers of Aconitum chiisanenseb(Ranunculaceae), was established using visible spectrophotometry and high-performance liquid chromatography (HPLC) method especially for Aconitine analysis. Aconitum alkloids were reacted with tetra- thiocy-anatocobalt[II] complex ion to form a stable ion pair. The reaction product was insoluble in water but freely soluble in several organic solvents. 1.2-Dichloroethane was the best extracting solvent among the examined solvents. Spectrophotometry of Aconitum alkaloids at nax. 625 was carried out. The HPLC method for aconitine was carried out using Radial PAK-CN column with gradient solvent system by solvent mixture of acetonitrile and phosphate buffer (pH 3.0) at 4$0^{\circ}C$ and 254 nm. Linear relationship was found between absorbance response and concentration of aconitine in range of 0.45 mM~0.9 mM ($r^2$=0.9949) by spectrophotometry and 0.3 mM~1.2mM($r^2$=0.9983) by HPLC method. These methods have been found to be suitable and reproducible for routine analysis of Aconitum alkaloids and its pharmaceutical preparations.

• Bulletin of the Korean Chemical Society
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• 제27권7호
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• pp.991-994
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• 2006

Herein, insoluble single-walled carbon nanotube (SWNT) was successfully dispersed into water in the presence of a special kind of surfactant-dicetyl phosphate (DCP), subsequently, a SWNT-DCP composite film coated glassy carbon electrode (GCE) was fabricated. The electrochemical behaviors of 6-benzylaminopurine (6-BAP) at the unmodified GCE and SWNT-DCP modified GCE were examined. It is found that the SWNT-DCP modified GCE remarkably enhances the oxidation peak current of 6-BAP, indicating great potential in the determination of trace level of 6-BAP. Finally, a sensitive and simple voltammetric method with a good linear relationship in the range of ${\times}5.0\;\;10^{-8}\sim 2.5\;{\times}\;10^{-6}$ mol/L, was developed for the determination of 6-BAP. The detection limit is as low as $2.0\;{\times}\;10^{-8}$ mol/L for 3-min accumulation. This newly-proposed method was successfully demonstrated with practical samples.

• Bulletin of the Korean Chemical Society
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• 제28권10호
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• pp.1729-1734
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• 2007

The electrochemical behaviors of estrone in the presence of various surfactants were examined with great details. It is found that a cationic surfactant, cetyltrimethylammonium bromide (CTAB), obviously facilitates the electro-oxidation of estrone at carbon paste electrode (CPE) from the significant peak current enhancement and the negative shift of peak potential. Additionally, chronocoulometry and electrochemical impedance spectroscopy (EIS) were also used for further investigation of the electrode process of estrone, indicating that low concentration of CTAB exhibits excellent enhancement effects on the electrochemical oxidation of estrone, greatly enhances the diffusion coefficient and the electron transfer rate. Based on this, an electrochemical method was proposed for the determination of estrone. The oxidation peak current is proportional to the concentration of estrone in the ranges over 9.0 × 10?8 - 8.0 × 10?6 mol/L, and a low detection limit of 4.0 × 10?8 mol/L was obtained for 180s accumulation at open circuit (S/N = 3). Finally, this proposed method was demonstrated using estrone tablets with good satisfaction.

• 약학회지
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• 제42권3호
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• pp.243-247
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• 1998

A method for the determination of basic drugs based on their reaction with picric acid to form an ion-association complex extractable into several plasticizers was developed. Ba sic drugs-picric acid complexes in acid medium could be extracted quantitatively into several plasticizers except phosphates. For example, the chlorpromazine-picric acid complex showed maximum absorbance at near 410nm and was applied to extraction spectrophotometric determination of chlorpromazine. The calibration curves are linear (r>0.998) within a range from $10^{-6}to\;5{\times}10^{-4}M$ and the precision of the method was acceptable because RSD was less than 2.6% (n=7). The factors affecting the extraction system was discussed.

• 한국환경보건학회지
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• 제2권1호
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• pp.49-51
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• 1975

The accidents, homicides and suicides of carbon monoxide poisoning to increase in number every year are required precize, accurate, and rapid method for the determination of carbon monoxide in the blood samples. Here is the basis of this method for the determination of percentage saturation of hemoglobin by carbon monoxide which have found out to be suitable in laboratory as follows: A 0.1ml of blood is mixed with 20ml of 0.1% ammonium hydroxide, and 20mg sodium hydrosulfite is added to convert oxyhemoglobin to reduction hemoglobin. The absorbance is measured at 538nm and 578nm, the measurement was carried out within ten minutes of addition of sodium hydrosulfate.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2727-2731
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• 2011

A new method for the determination of josamycin has been developed based on quenching of the fluorescence of 3-mercaptopropionic acid-capped CdTe quantum dots (MPA-CdTe QDs) by josamycin in ethanol. Reaction time, interfering substances on the fluorescence quenching, and mechanism of the interaction of CdTe QDs with josamycin were investigated. Under optimum conditions, the relative fluorescence intensity was linearly proportional to the concentration of josamycin between 12.0 and 120.0 ${\mu}g\;mL^{-1}$ with a correlation coefficient of 0.9956 and a detection limit of 2.5 ${\mu}g\;mL^{-1}$. The proposed method was successfully applied to commercial tablets, and the results were satisfactory, i.e. consistent with those of high-performance liquid chromatography (HPLC).

• 한국동물학회지
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• 제3권1호
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• pp.19-23
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• 1960

A method for determination of thyroid secretion rate in rabbit by means of radioactive iodine presented. After injection of radioactive iodine, in vivo determination so f radioactivity in thyroid gland were made during a 19 day-experimental period. In the same period blood samples were drawn and analyzed for protein-bound iodine (PBI) and for protein-bound radioactive iodine(PBI181). A rate constant for secretion of thyroid hormone was calculated from the disappearance rate of radioactive iodine in thyroid gland. The secretion rate of radioactive hormone iodine was calculated by multiplying this rate constant by the amount of radioactive iodine present in thyroid gland. Assuming that the specific radioactiveness of the circulating thyroid hormone and of the hormone just secreted were identical , thyroid secretion rate was calculated by the equation. {{{{ { Secreted hormone-iodine , gamma /hr} over { Secreted hormone-I^131, % dose/hr }= { PBI, ${\gamma}$/ml.Serum} over { PBI^131 , % dose/ml . Serum } }} The method presented consisted of measurements for series of independent criteria on thyroid function, and the resulting thyroid secretion rate was calculated by combination of those.

• 한국해양학회지
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• 제15권1호
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• pp.66-70
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• 1980

A method for the determination of dissolved species of Cd, Co, Cu, Ni, Pb and Zn in sea water by flame atomic absorption spectrophotometry (AAS) is described. Prior to analysis by AAS, these elements are concentrated by coprecipitation with iron pyrrolidinedithiocarbamate at pH 3 because of matrix effects and their low concentration levels in sea water. The detection limits are 0.01, 0.04, 0.02, 0.05, 0.08, and 0.03$\mu\textrm{g}$/l, and the relative standard deviations are 1.0, 2.4, 1.3, 2.9, 2.0 and 2.9% for Cd, Co, Cu, Ni, Pb and Zn, respectively. The method is shown to be satisfactory in terms of recovery and precision for the determination of these metals in sea water.