• Analytical Science and Technology
• /
• v.11 no.3
• /
• pp.213-221
• /
• 1998

The determination of inorganic anions by capillary zone electrophoresis is reported. A ten component synthetic mixture of anions of bromide, chloride, fluoride, nitrite, nitrate, sulfite, sulfate, perchlorate, chlorate and chlorite was separated by the capillary column and detected by indirect UV method. The running buffer contained 5 mM ammonium dichromate, 10 mM ammonium acetate, 20 mM diethylenetriamine, 10% methanol solution at pH 9.3. A potential of 15 kV at the cathode (reversed polarity) was utilized for the separation of inorganic anions. A complete separation of anions was achieved in less then 10 min and the applicabilities of the method for the analysis of real samples was demonstrated. We compare the concentration of anions in toluene inhaled humen's urine and in postmortem bloods obtained by capillary zone electrophoresis and ion chromatograph.

• Membrane Journal
• /
• v.3 no.3
• /
• pp.126-135
• /
• 1993

Perchlorate ion-selective PVC membrane electrode responsive to $10^{-6}M$ was developed by incorporating the ion-pair complex of perchlorate with the quaternary ammonium salts as a active material. The effect of chemical structure, the content of active material, the kinds of plasticizers, and the membrane thickness on the electrode characteristics such as the linear response range and Nernstian slope of the electrode were studied. With the results, the useful pH range and the selectivity coefficients to various interfering anions were compared and investigated. It was obtained that the effect of the chemical structure of an active material on the electrode characteristics was improved with increasing the alkyl chain length of the quarternary ammonium salts in the ascending order of Aliquat 336P, TOAP, TDAP, and TDDAP. The electrode characteristics was improved with the decrease of the active material content below the optimum membrane composition, and DBP was the best as a plasticizer. The optimum membrane composition was 9.09wt% of TDDAP, 30.3wt% of PVC, and 60.6wt% of ptasticizer(DBP). And the optimum membrane thickness was0.45mm at this composition. Under the above condition, thelinear response ranger was $10^{-1}~1.2 {\times} 10^{-6}M$, and the detection limit was $5.1{\times}10^{-7}M$ with the Nernstian slope of 57mV/decade of activity of perchlorate ion. The electrode potential was stable within the pH range from 4 to 11. The selectivity coefficient was as shown below : $SCN^->I^->NO_3^->Br^->ClO_3^->F^->Cl^->SO_4^{2-}$

• Journal of the Korean Society of Propulsion Engineers
• /
• v.21 no.2
• /
• pp.26-31
• /
• 2017

Environmental problem of the solid propellants is an issue of growing importance in solid rocket. For examples, ammonium perchlorate (AP) as an solid propellants oxidizer could create a poisonous gas and atmospheric pollutions, such as HCl. Among the several oxidizers, N-guanylurea dinitramide (GuDN) is an effective candidate substance for eco-friendly oxidizer, which has high performance, pressure exponent, and eco-friendly smog during combustion for solid propellant of gas generator. In this paper, the theoretical analysis of characteristics as a gas generator propellant, propellant manufacturing processability, propellant hardness properties and combustion characteristics were studied.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.978-983
• /
• 2017

Ammonium dinitramide(ADN) is currently under inder investigation as a replacement for ammonium perchlorate, both for environmental and toxicological reasons. Another promising application is ADN-based liquid monopropellant as a replacement for hydarzine, which is highly toxic and carcinogenic. Production of ADN is today normally performed via guanylurea dinitramide(GUDN) by reaction with potassium hydroxide to yiela potassium dinitramide(KDN). In a second reaction step, KDN is reacted with ammonium sulfate to give ADN. In our new improved process, ADN is synthesized from GUDN in one single reaction step. The simplified process improves purity, reduces the amount of by-products and allows production of ADN at a potentially lower cost, which is crucial to favour the use of ADN.

• Korean Journal of Environmental Agriculture
• /
• v.32 no.3
• /
• pp.224-230
• /
• 2013

BACKGROUND: Perchlorate(${ClO_4}^-$) is an anion that is extremely water-soluble and environmentally stable. It mostly exists in the form of sodium perchlorate, ammonium perchlorate and potassium perchlorate which are used in rocket fuels, propellants, ignitable sources, air bag inflation systems and explosives. Perchlorate can be taken into the thyroid glands and interfere with iodide uptake. The determination of perchlorate in agricultural products is important due to its potential health impact on humans. The objective of this study was to determine the perchlorate concentrations in the samples of various agricultural products and soils. METHODS AND RESULTS: In this study, samples of cereal(Rice, Barley, Corn, Bean), vegetable(Spinach, Lettuce, Sesame, Chives, Chili, Pumpkin, Tomato), fruit(Apple, Pear, Tangerine, Grape) were analyzed for perchlorate contents. Perchlorate concentrations were analyzed by liquid chromatography-tandem mass spectrometry. The results showed that agricultural products respectively contained perchlorate concentrations in the range of : cereals N.D.~$7.46{\mu}g/kg$, vegetables $0.52{\sim}23.06{\mu}g/kg$, fruits $0.19{\sim}2.66{\mu}g/kg$. Bioconcentration factor was in the order of : vegetables > cereals > fruits. Bioconcentration factor was highest follwed by Sesame 37.88, Corn 21.51, Spinach 10.57, Tangerine 4.39, Chives 2.89 and Lettuce 1.90. The recoveries of perchlorate from spiked agricultural products and soils ranged from 87.72~111.26% and 102.09~111.23%. CONCLUSION(S): The health risk assessment results obtained in this study are lower than the RfD(Reference Dose, 0.0007 mg/kg/body weight/day) value as suggested by the Integrated Risk Information System(US IRIS). Our results indicate that, people currently exposed to perchlorate from agricultural products consumption are considered as safe.

• Membrane Journal
• /
• v.22 no.4
• /
• pp.235-242
• /
• 2012

Ammonium perchlorate (AP) is primarily derived from the process of liquid incineration treatment when dismantling a solid rocket propellant. A series of batch dead-end nanofiltration (NF) and reverse osmosis (RO) membrane experiments were conducted to explore the retention mechanisms of AP under various hydrodynamic and solution conditions. Low levels of silicate type of siloxane had been detected through the GC/MS and FTIR analysis of liquid solutions extracted from solid ammonium perchlorate composite propellant (APCP). It is indicated that NF/RO membranes fouling in the presence of APCP was mainly attributed to the AP interactions because the concentration of silicate type of siloxane was negligible compared to that of AP. The osmotic pressure of AP was presumably resulted in the flux declines ranging from 13 to 17% in the case of the application of low-pressure (551 and 896 kPa for NF and RO) compared to those in application of high-pressure. The retention of AP by NF/RO membranes significantly varied from approximately 10 to 70% for NF and 26 to 87% for RO, depending on the operating and solution water chemistry conditions. The results suggested that retention efficiency of AP was fairly increased by reducing concentration polarization (i.e. application of low-pressure and stirring speed of 600 rpm) and increasing the pH of a solution. The result of this study was also consistent with the previous modeling of 'solute mass transfer of NF/RO membranes' and demonstrated that hydrodynamic and solution water chemistry conditions are to be a key factor in the retention of AP by NF/RO membranes.

• Journal of the Korean Chemical Society
• /
• v.54 no.1
• /
• pp.13-22
• /
• 2010

The photophysical properties of 7-diethylaminocoumarin (DEAC) laser dye have been measured in different solvents. The emission spectrum of DEAC has also been measured in cationic (CTAC) and anionic (SDS) micelles. The laser parameters have been calculated in different solvents namely acetone, dioxane, ethanol and dimethylforamide(DMF). The photoreactivity of DEAC has been studied in $CCl_4$ solvent using 366 nm light. The values of photochemical yield (${\Phi}_c$) and rate constant (k) are determined. The interaction of organic acceptors such as picric acid (PA), tetracyanoethylene (TCNE) and 7,7,8,8-tetracynoquinonedimethane (TCNQ) with DEAC are also studied using fluorescence measurements in acetonitrile ($CH_3CN$). The electrochemical investigation of (DEAC) has been carried out using cyclic voltammetry and convolutive voltammetry combined with digital simulation technique at a platinum electrode in 0.1 mol $L^{-1}$ tetrabutyl ammonium perchlorate (TBAP) in $CH_3CN$ solvent. The electrochemical parameters of the investigated compound were determined using cyclic and convolutive voltammetry. The extracted electrochemical parameters were verified and confirmed via digital simulation method.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.19 no.4
• /
• pp.69-76
• /
• 2015

Recently, environmental sustainability of the transitional explosives and propellants is an issue of growing importance in energetic materials. For examples, ammonium perchlorate(AP) as an solid propellants oxidizer could create a poisonous gas and atmospheric pollutions, such as HCl. Among the several oxidizers, hydrazinium nitroformate(HNF) is an effective candidate substance for eco-friendly oxidizer, which has high density, pressure index, and less smog generating property during combustion for the Divert and Attitude Control System(DACS). This study was confirmed a synthesis through various conditions, was performed for the essential data of solubility the crystallization process. Also, crystallization process such as cooling, drowning-out and sonication were performed.

• Applied Chemistry for Engineering
• /
• v.18 no.6
• /
• pp.636-642
• /
• 2007

Software program to predict the packing density of multi-sized and multi-component particulate system was developed. For this purpose, the experiment to measure the packing density of AP (ammonium perchlorate) and Al (aluminum) particles with different sizes and their mixtures was carried out. The packing densities obtained from various experiments were compared with the predicted data from the developed software program. In the case of the packing density of the binary system, which is comprised of two different size particles and/or two different components, the relative errors were ranged 0.25~13.13%, and in the same venue the relative errors of the ternary system were 0.25~13.13%. Agreement between experimental data and the predicted results is reasonably accurate. In order to achieve the targeted packing density, the software program calculated the contour of the component particles and this will contribute the formulation of optimal packing systems.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.20 no.6
• /
• pp.76-82
• /
• 2016

Recently, environmental sustainability of the transitional explosives and propellants is an issue of growing importance in energetic materials. For examples, ammonium perchlorate(AP) as an solid propellants oxidizer could create a poisonous gas and atmospheric pollutions, such as HCl. Among the several oxidizers, hydrazinium nitroformate(HNF) is an effective candidate substance for eco-friendly oxidizer, which has high density, pressure index, and less smog generating property during combustion for the thrust control system. This study was controlled the size distribution and shapes through various conditions. Length and diameter ratio(L/D) of crystals has below 1 : 3, and the particle size was two types of $200{\mu}m$ and $50{\mu}m$.