• Analytical Science and Technology
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• v.8 no.4
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• pp.843-848
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• 1995

A sensitive method for the determination of trace amounts of phosphate by fluorescence-quenching detection / FIA is proposed. The fluorescence of Rhodamine B(RB) was quenched with the formation of the ion associate of molybdophosphate with RB;${\lambda}_{ex}$ and ${\lambda}_{em}$ were 560nm and 580nm, respectively. A calibration graph was linear over the ranges from $10^{-8}$ to $3{\times}10^{-6}M$ of phosphate (~0.3~93ppb of phosphorus). The relative standard deviation was 1.2% with $8{\times}10^{-7}M$ phosphate solution and sampling rate was 15 samples / h. The proposed method was applied to the determination of phosphate in sea and river water samples.

• Bulletin of the Korean Chemical Society
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• v.27 no.7
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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.

• The Korean Journal of Zoology
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• v.7 no.2
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• pp.25-36
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• 1964

The present paper deals with the comparative study on phylogenic difference in the patterns of energy metabolism of brain slices of several vertebrate species by measuring oxygen consumptionwith glucose-6-phosphate, glucose-1-phosphate, glyceraldehyde-3-phosphate or glutamate as respiratory substrate employing Warburg's manometric method, by determination of the utilization rate of glucose using glucose-1-C14 by analyzing patterns of free amino acid distribution , and by histochemical determination using glucose-1-C14 by analyzing patterns of free amino acid distribution acid distribution , and by histochemical determination of glycogen contents. 1. Glucose enhances the oxygen consumption of brain slices of animals belinging to reptile, aves and mammalia while it shows a tendency to decrease that of animals belonging to pisces and amphibia. 2. Glucose-6--phosphate increase oxygen consumption more than glucose in every species examined, while glucose-1-phosphate and glyceraldehyde-3-phosphate increase that of Rana nigromaculata only . In general m, it appears that phosphosugars are more effective as a respiratory substrate to those species which have less endogenous respiration than to those having larger endogenous respiration. 3. Similar patterns of free amino acid distribution and the relative amount are found among the species and in every species examined glutamic acid is detected in the larges amount . ${\gamma}$-Amino butyric acid, glycine, alanine and aspartic acid are found in every species. 4. Ophicephalus showed less oxygen consumption than endogenous respiration when glutamate was added to the medium. When sodium fluoride was added, the oxygen consumption was some what increased . Such phenomenon wasnot found in the frog. 5. The result of histochemcial analysis of the brain showed that glycogen was abundantly present in the fish , amphibia , and especially in the reptile and that no distinctive grains of glycogen were found in the bird and mammal . From these facts, it may be supposed that anaerobic glycolysis as energy source dominates in fish and amphibia and aerobic respiration through the oxidation of glucose dominates in bird and mamal , the reptile occupying transitional position between these two categories. The way of obtaining energy for brain activity by the oxidation of glucose supplied from the circulating blood is seemed to be first acquired by reptile and the function is completed both in aves and mammal.

• Bulletin of the Korean Chemical Society
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• v.15 no.1
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• pp.9-12
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• 1994

The gravimetric determination of scandium by di-(2-ethylhexyl)phosphate(DEHPA) as a precipitant and the mole ratio of Sc-DEHPA arecipitation obtained in ethanol medium have been investigated. Scandium can be determined by gravimetric method of precipitation of Sc-DEHPA and the mole ratio of Sc-DEHPA is found as 1 :2 in ethanol medium.

• Journal of Veterinary Clinics
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• v.10 no.2
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• pp.185-192
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• 1993

Intraosseous phlebography was performed to determine the healing effect of the dosing treated with vitamin-D$_3$ and/or calcium phosphate on the fractured bone in male rabbits. Femoral shafts of 16 adult male rabbits were fractured and these animals were divided into 3 treated groups and 1 control group l. The 1st treated group of rabbits was dosed with vitamin-D$_3$(VD), the 2nd treated group of rabbits was given calcium phosphate(CP), and the 3.d treated group of rabbits received vitamin-D$_3$ and calcium phosphate. The control group of rabbits was dosed with saline alone. Radiographs were taken weekly in each rabbit over 6 weeks period and the results obtained were as follows. 1. Sinusoidal vein was visualized at 3rd week in eve animal received CP and VC, at 5 week in animals received VD and in control animals. 2. Main nutrient vein was observed more clearly in treated groups than in control group of animals. 3. These results indicate that venous reconstruction of the fractured bone in groups of rabbits received CP and VC was earlier and more complete than those of other groups of rabbits. 4. Therefore, intraosseous phlebography is suitable for determination of the bone healing effect of vitamin-D$_3$ and/or calcium phosphate in femoral fractured rabbits.

• Journal of the Korean Chemical Society
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• v.36 no.2
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• pp.338-341
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• 1992

• Journal of the Korean Chemical Society
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• v.12 no.4
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• pp.142-145
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• 1968

The relative activity of glucose-6-phosphate dehydrogenase in E. coli was measured at 340 $m\mu$ with a spectrophotometer. The synchronized E. coli cells in exponential phase were treated with Phage($T_2$) ghost, and used as a enzyme solution directly. This assay method supposed to be useful for the continuous determination of enzyme activity in E. coli.

• Archives of Pharmacal Research
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• v.20 no.6
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• pp.597-601
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• 1997

An oxidimetric titrant, 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone in anhydrous acetic acid is used for the semimicro-determination of hydrazine hydrate, phenylhydrazine hydrochloride, isoniazid and iproniazid phosphate in pure forms as well as in some pharmaceutical preparations containing isoniazid and iproniazid phosphate. The end point was detected potentiometrically using a platinum-calomel combination electrode. The results obtained are compared statistically with those obtained by the official methods and they are in good agreement.

• Analytical Science and Technology
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• v.5 no.4
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• pp.425-431
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• 1992

The concentration and determination of trace phosphate ion was studied by $La(OH)_3$ coprecipitaiton. Phosphate ions in 1.0L samples were coprecipitated with lanthanium hydroxide at pH 9.5 adjusted with ammonia solution. The precipitates were floated with the aid of mixed surfactant(1:8 sodium oleate/sodium dodecyl sulfate) and nitrogen gas bubbles. The floated precipitate was collected in suction flask from the solution. The precipitate were washed with dil. ammonia solution and dissolved in sulfuric acid. The phosphate ion in the concentrated solution was finally determinated by UV/VIS spectrophotometry using the molybdenium blue method. The proposed method could be applied to the determination of phosphate ion in tap water and river water.

• Microbiology and Biotechnology Letters
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• v.17 no.1
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• pp.46-50
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• 1989

A high concentration of inorganic phosphate (above 25 mM), which was suboptimal for vegetative growth in the minimal production medium, suppressed cephalosporin C (CPC) production in Cephalosporium acremonium. Results from the determination of intracellular concentrations of ATP, ADP and AMP with phosphate-starved resting cells indicated that phosphate exerted its effect indirectly by regulating the ratio of adenylated nucleotides, the so-called adenylated energy charge. It was also found that the type of phosphate regulation of CPC biosynthesis was not a repression effect but an inhibition effect.