• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.4
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• pp.253-259
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• 1996

Ammonia microdiffusion method and colorimetric measurement are described for the nitrogen determination. The diffusion of ammonia could be successfully induced by using a microdiffusion cell. It is a simple and rapid technique, which is suitable for transforming the nitrogen in digests into $NH_4CI$ for the colorimetric N determination with ammonia color reagent. Above 99% of N recovery were obtained with microdiffusion up to 15 hours. The coloration method of collected $NH_4CI$ for the colorimetric N determination was also estabilshed with a scanning in U.V. spectrophotometer. Under the proposed coloration method (0.5 mL of sample digest, 4.0 mL of $H_2O$ and 0.5 mL of ammonia color reagent), a maximal absorbance was observed at 410 nm. The kinetic measurement of absorbance showed a high stability from 5 to 45 minutes after color development. Absorbance was directly proportional to the amount of $NH_4^+-N$ present. The microdiffusion-ammonia coloration method was successfully applied to the nitrogen determination in the forms of protein-N or total -N in plant tissue. Comparing with Kjeldahl distillation method, the values obtained with described method were slightly higher and more reliable.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.1
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• pp.135-137
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• 2005

A PC-based automatic system was developed for automatic titration in volatile basic nitrogen analysis by the microdiffusion method. The system used a CCD-type PC camera for the automatic detection of the titration end point. The camera checked whether the green value of a pixel on the red image of titrated solution became greater than the red value. The data from the automatic titration using the system were not significantly different (p>0.05) from those taken by manual titration. The agreement between means of data from manual titration and those from automatic titration was good.

• Toxicological Research
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• v.3 no.2
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• pp.89-96
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• 1987

To test the efficacies of thiosulfate in cyanide poisoning with or without oxygen, after the administration of sublethal dose of potassium cyanide, serial arterial blood samples were collected during 60 minutes in 15 rabbits. Cyanide ion concentrations were measured by Conway cell microdiffusion method, and arterial oxygen tensions were also observed. Comparison of elimination constants showed that arterial blood cyanide ion concentration decreased most rapidly in the thiosulfate with oxygen-administered group. The elimination of cyanide ion by the action of thiosulfate in acutely poisoned rabbit accelerated probably due to oxygen and elimination pattern seems to occur by first-order elimination kinetics.

• YAKHAK HOEJI
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• v.4 no.1
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• pp.47-49
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• 1959

Another application of the new quantitative analytical method of prussic acid by "Microdiffusion analysis" for the determination of prussic acid in human blood was studied. The blood containing potassium cyanide was dropped in outer room of unit, and then N-sulfuric acid was added. The liberated HCN gas was absorbed into nickel sulfate solution of inner room, afterward, absorbed prussic acid was determined with EDTA by residual titration. The result was coincided with the result of Liebig Denigs' method at ordinary temperature.

• YAKHAK HOEJI
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• v.4 no.1
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• pp.43-46
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• 1959

A new quantitiative analytical method of prussic acid by "Microdiffusion analysis" was studied. HCN-Glucoside of ARMENIACA was hydrolysed with KOH in out-room of unit, and then concentrated sulfuric acid was poured in order to liberate the HCN gas. The liberated gas was absorbed into nickel sulfate solution of inner room of unit quantitatively. The excess of nickel sulfate was determined by EDTA Reagent using MX-indicator. By this method, the following results were obtained: (1) It was needed more than 4 hours, in order to hydrolyse completely at $50^{\circ}C$, but could be shortened to 3 hrs. at $^60{\circ}C$. (2) It was completely absorbed into nickel sulfate solution after 30min.

• Journal of Environmental Health Sciences
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• v.9 no.2
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• pp.67-74
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• 1983

An experimental study was carried out to determine the degree of contamination of cyanide and metals in each stork's (Ciconia c. boyciana) organ. The samples used for this experiment were gullet, respiratory tract, stomach content, rectum, lung, liver, heart, pancreas, gall, kidney, and muscles. Those samples were isolated by Conway microdiffusion method and determined by UV spectrophotometry for the cyanide, on the other hand, the samples for metals were dissolved by mercury digestion apparatus and analyzed by atomic absorption spectrophotometry. The results are as follows: 1) The quantities of cyanide accumulated in each organ were from 0.05 to 2.57 ppm and concentration of those in tissues was in order of 2.57 ppm in stomach content, 2.13 ppm in lung, 1.58 ppm in kidney, 1.22 ppm in gall, 0.52 ppm in pancreas, 0.32 ppm in heart, 0.25 ppm in rectum, 0.20 ppm in gullet, 0.19 ppm in liver, 0.07 ppm in muscles and 0.05 ppm in respiratory tract. 2) The calcium content is in a range of 10.89-105.74 ppm, iron is 2.47-557.70 ppm, zinc is 2.37-23.62 ppm, cupper is < 0.1- 1.76 ppm and cadmium, nickel, cobalt and lead is beyond 0.5 ppm, respectively.

• Korean Journal of Food Science and Technology
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• v.8 no.2
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• pp.90-94
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• 1976

The amounts of volatile fatty acid and carbon dioxide of different salt Kimchis (1.02% NaCl, 3.16% NaCl) and Kimchis fermented at different temperature were determined. After the extraction of the acids with 80% ethanol it was steam-distillated. Identification and quantitative determination of individual acids were performed by gas chromatography and paper chromatography. Carbon dioxide contents were measured by microdiffusion method. Formic and acetic acid were found in four Kimchis. The acetic acid content of 1.02% NaCl Kimchi and Kimchi fermented at $4-5^{\circ}C$ were very high and their carbon dioxide contents were also high. Fifteen taste panels scored 1.02% NaCl Kimchi higher than 3.16% NaCl Kimchi and Kimchi fermented at $4-5^{\circ}C$ higher than Kimchi fermented at $20-22^{\circ}C$. It is assumed that large amounts of acetic acid and carbon dioxide make Kimchi flavorful.