• Journal of the Korean Chemical Society
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• v.31 no.3
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• pp.271-279
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• 1987

A nitrate ion-selective PVC membrane electrode based on ammonia modified bakelite A-Ni$(NO_3)_2$ complex as ion exchanger was prepared. The electrode gave a linear response with a Nernstian slope of 60mV per decade within the concentration range $1{\sim}10^{-4}$ M $KNO_3$ but nonresponse to hydrogen ion and multivalent anions. The selectivity, response time and life time of the electrode were investigated and it was found that the electrode exhibited good selectivity for four univalent anions ($Cl^-,\;Br^-,\;I^-,\;{ClO_4}^-$). Analytical application to the determination of nitrate were also studied.

• YAKHAK HOEJI
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• v.39 no.2
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• pp.113-117
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• 1995

Garlic tissue cells are employed for the conversion of L-asparagine into ammonia. An ammonia gas electrode is used as a detector. The effect of pH, buffer solution, temperature and life time of electrode to have used were investigated in order to optimize the electrode response. The combination of L-asparaginase in garlic tissue cells and the gas electrode response linearly to Lasparagine over the concentration range 1.0$\times$10$^{-4}$~1.0$\times$10$^{-1}$ M with a slope of 72.0 mV/decade and is selective with respect to other L-amino acids.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.2
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• pp.231-237
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• 1998

This study was carried out to investigate the effects of curing methods on the concentration of ammonia during curing in burley tobacco leaves. The air-cured tobacco(KB108; Nicotiana tabacum L.) was grown at Chonju Tobacco Experiment Station in 1998 and the tenth leaves from the top on the stalk were harvested. Half of the harvested leaves were cured in normal air curing facility and the other leaves were cured in excessive curing facility. Stalk cut tobaccos were cured in horizontal curing facility. The leaves were sampled every five days from harvesting time to the end of curing(25 days). Ammonia concentration of leaves increased during curing period with a remarkable increase at yellowing stage. The concentration of ammonia was high in the primed cured leaves, while that of the excessive cured leaves was low. It is considered that the lower increase of ammonia in stalk cured leaves may be caused by the translocation from the leaves to the stalk during curing, while that of excessive cured leaves may be caused by the poor decomposition of protein and amino acid during curing by excessive moisture loss and high temperature condition.

• Environmental Engineering Research
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• v.11 no.6
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• pp.311-317
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• 2006

Feasibility of destroying synthetic and actual leachate containing humic acids and ammonia compounds by supercritical water oxidation (SCWO) was evaluated. In this study, destruction efficiencies of humic acids and ammonia respectively were investigated at various reaction temperatures and residence times under pressure a supercritical pressure (280 atm). To lower reaction temperature, chemical oxidants were used. The experiment was carried out in a cylindrical batch reactor made of Hastelloy C-276 that can withstand high temperature and pressure. Concentrations of humic acids and ammonia were measured using a $COD_{Cr}$ method and an ammonia selective electrode, respectively. The optimal destructive condition of humic acids in the presence of stoichiometric oxygen(air) was 3 min at $380^{\circ}C$, but the temperature could be lowered to subcritical region ($360^{\circ}C$) along with $H_2O_2$ as an oxidant. For ammonia, the optimal destructive condition with air was 5 min at $660^{\circ}C$, but it was possible to operate the process for 3 minutes at $550^{\circ}C$ or 2 min at $600^{\circ}C$ along with $H_2O_2$ as an oxidant. At 2 min and $550^{\circ}C$ along with $H_2O_2$ as an oxidant, humic and ammonia compounds in the actual leachate were easily destructed and the effluent quality met the Korea Standard Leachate Quality.