• The Korean Journal of Nuclear Medicine
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• v.28 no.3
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• pp.331-337
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• 1994

In order to develop a $^{18}F$-labelled myocardial perfusion agent(flow tracer) for PET, $^{18}F$-labelled organic ammonium cations were synthesized and evaluated in relation to their biodistribution. Five quaternary organic ammonium compounds were labelled with $^{18}F$ in a side chain with moderate to good yields by direct introduction of $^{18}F$-fluoride. Radiochemical yields have been achieved in 30-40min by the precursors (tosylates) in dimethylsulfoxide 15-60% (decay corrected). The reaction was found to be autocatalyzed. A remote controlled procedure was developed in these synthesis. $^{18}F$-Labelling and HPLC-purification of com-pounds needed about 60 min(Yield; 7-20%). Up to now the two compounds N-4-[$^{18}F$]fluorobutyl-pyridinium cation(1) and N, N dibenzyl-4(2-[$^{18}F$]fluoroethyl)piperidinium cation(2) were investigated in relation to their biodistribution in mice. Compound 1 showed at 1 min post injection the high uptake of 19.22% ID/g organ in the myocardium but a following fast decline to 1.12% ID/g organ after 40min. Uptake of compound 2 was after 1min in the heart 5.90% ID/g organ but after 40min at the relative high value of 4.33% ID/g organ. Heart:blood ratio for compound(1) at 1 min was 8.3, at 40 min 2.6 for compound II 2.0(1min) and 15.0(40 min). As data of compound 2 showed greater heart uptake, slower myocardial release, and higher heart: blood ratios, compound 2 is a good candidate for further evaluation.

• Textile Coloration and Finishing
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• v.15 no.5
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• pp.294-300
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• 2003

The anionic agent containing dichloro-s-triazinyl reactive group was synthesized and applied to the cotton fabrics to introduce covalent bonds. This attempt was expected to improve the affinities of cationic compounds, such as cationic dyes, chitosan, quaternary ammonium antimicrobial agents and metal ions, by the electrostatic attractive force. As expected, the anionic agent was reacted with cotton fabrics at room temperature. In order to examine the adsorptivity of the cationic compounds on to the anionized cotton fabrics, firstly a cationic dye(C. I. Basic Violet 7) was applied. The color strength of the dyeing of anioized cotton fabric was highly increased comparing to that of untreated fabric.

• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.135-141
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• 1999

In order to investigate the composition of extractive nitrogenous components in the diploid and the triploid oysters, Crassostrea gigas, cultured at the south coast of Korea, the whole edible part (whole body) was analyzed into extractive nitrogen, free amino acids, oligopeptides, ATP and its related compounds, quaternary ammonium bases, and guanidino compounds using specimens collected from April to May of 1992. The major free amino acids in the diploid and the triploid were taurine, proline, alanine, glycine, glutamic acid hypotaurine, glutamine, arginine, aspartic acid, and $\beta-alanine$. There was no conspicuous difference in the constituents of free amino acids between the diploid and the triploid. A lot of hypotaurine was detected in the diploid and the triploid of oyster and the contents of them were 107 mg and 123 mg/100g, respectively. The compounds, glycinebetaine, homarine and trigonelline were found in both the diploid and the triploid. Among them, glycinebetaine was the most prominent in all the samples. The amount of protein, glycogen, extractive nitrogen, oligopeptides, ATP and its related compounds, and free amino acids in the triploid was higher than that of the diploid (p<0.10)

• Journal of the Korean Applied Science and Technology
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• v.34 no.1
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• pp.142-151
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• 2017

Cationic surfactants have a bactericidal effect and the study for effective development of them became important parts in the industry. There have been increasing researches that focus on the development of products having not only outstanding features but also safety and biodegradability. In this work, novel ester-type cationic surfactants were obtained via Michael addition reaction. Intermediates were quantitatively prepared by the Michael addition reaction between alkyl acrylate and amine compounds under mild conditions without solvent and catalyst. The intermediates were quaternized with dimethyl sulfate. HQ21 with two hydrophobic groups and a hydrophilic group and HQ22 with two hydrophobic groups and two hydrophilic groups were obtained. The structures of the products were characterized by 1H-NMR, HR-MS and FT-IR and biodegradability of the products were tested.

• Journal of the Korean Magnetic Resonance Society
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• v.17 no.1
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• pp.40-46
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• 2013

For a case study of suspected paraquat intoxication, we developed a simple and rapid method of $^1H$ qNMR to determine the mili-molar amount of paraquat in postmortem blood samples. There were no interfering signals from endogenous compounds in the chemical shift of paraquat and diquat (internal standard). The amount of sample used ranged from 0.25 mM to 10.0 mM. Diquat, which has similar physicochemical properties with paraquat, was chosen as an internal standard. The NMR experimental conditions, relaxation delay time and CPMG spin-echo pulse sequence were optimized. The developed method was validated in terms of specificity, accuracy, precision, matrix effect, recovery, limit of detection (LOD), and low limit of quantification (LLOQ). The proposed qNMR method provided a simple and rapid assay for the identification and quantification of the quaternary ammonium herbicide, "paraquat" in postmortem blood samples. This method was tested by using the blood from the heart of a man who was intoxicated with paraquat. In this particular case, the level of paraquat was 1.07 mM in the blood. For the determination of quaternary ammonium herbicides, qNMR could also be used to provide a better understanding of the currently available techniques.

• Journal of the Korean Applied Science and Technology
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• v.3 no.1
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• pp.65-71
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• 1986

Four amphoteric surfactants, 1-(N-alkyl-N,N-dimethyl ammonio)-4-naphthalene sulfonates, were prepared by the alkylation of 1-(N,N-dimethylamino)-4,naphthalene sulfonic acid with chloroalkanes such as 1-decylchloride, 1-tetradecyl chloride and 1-hexadecyl chloride. These quaternary ammonium compounds such as 1-(N-decyl-N, N-dimethylammonio)-4-naphthalene sulfonate, 1-(N-dodecyl-N,N-dimethylammonio)-4-naphthalene sulfonate, 1-(N-tetradecyl-N,N-dimethylammonio)-4-naphthalene sulfonate and 1-(N-hexadecyl-N,N-dimethylammonio)-4-naphthalene sulfonate could be separated by means of thin layes chromatography and column chromatography. The surface chemical properties such as surface tension, foaming power, foam stability, wetting efficiency and solubilizing effect for these four compounds were measured. Also critical micelle concentration and hydrophilic-lipophilic balance(HLB) were evaluated. These compounds showed good surface as O/W type emulsifying agent and detergent.

• Journal of Microbiology and Biotechnology
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• v.6 no.2
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• pp.145-146
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• 1996

The 2.4-kb cryptic plasmid (pKH8) of multidrug-resistant Staphylococcus aureus SA2 was characterized by complete nucleotide sequencing and homology comparison. pKH8 was found to contain three open reading frames. Protein analysis of pKH8 showed that pKH8 was a multidrug resistance plasmid and mediated resistance to ethidium bromide and quaternary ammonium compounds.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1843-1847
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• 2010

An efficient method for the preparation of 1,4-disubstituted 1,2,3-triazole compounds is described using polymeric quaternary ammonium salts having azide or alkyne functionality to remove unreacted excess starting molecules (azide/alkyne). Copper metal could easily be removed by simple filtration with a short $Na_2SO_4$/silica cartridge, affording highly regioselective products in high yield and excellent purity without the need for work-up, extraction and chromatographic purification.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.4
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• pp.63-65
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• 2008

The increased interest in reducing the environmental effects caused by releasing organic compounds and aqueous waste has motivated the development of polymeric materials in supercritical fluids. Recently, supercritical fluids have been used in material synthesis and processing because of their special properties, such as high diffusivity, low viscosity, and low surface tension. Supercritical carbon dioxide is the most attractive because it is non-toxic, non-flammable, and has moderate critical temperature and critical pressure values. Supercritical carbon dioxide can also swell most polymers. In this study, we prepared polymer/clay nanocomposites using supercritical fluids. Cloisites 10A, 15A, 25A, and 30B used in this study are montmorillonites modified with a quaternary ammonium salt. The nanocomposites of polymer/clay were characterized by X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry.

• Journal of the Korean Applied Science and Technology
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• v.10 no.2
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• pp.29-33
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• 1993

n-Octyldimethylbenzylammonium chloride, dodecyldimethylbenzylammonium chloride, and octadecyldimethylbenzylammonium chloride were synthesized to be used as the accelerating weight loss agent. These synthesized compounds were used for the weight loss treatment of PET textile with sodium hydroxide. From the treatments, it was found that the lower carbon number of high alkyl group existed in quaternary ammonium salts, the better effect of weight loss was acquired. The proper concentration of accelerating weight loss agent was $8{\sim}10g/l$, the proper treatment time was $60{\sim}90$ minutes, the proper treating bath ratio was 1 : 50. It is proved that n-octyldimethylbenzylammonium chloride and dodecyldimethylbenzylammonium chloride are good accelerating weight loss agent.