• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.581-587
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• 2005

In order to obtain a highly purified p-dioxanone (PDX) as monomer of biodegradable polymer, suitable solvent must be selected. The selection was based on the solubility of impurities, and partial layer melt crystallization were carried out under the presence of solvent. The solubility of PDX in various solvents such as ethyl acetate, tetrahydrofuran, acetone, alcohols (methanol, ethanol, 1-propanol, 1-butanol and 1-pentanol) were measured over the temperature range of $-10{\sim}15^{\circ}C$. As solubility parameters, the mixing and dissolution enthalpy between the PDX and the solvents was studied based on empirical equations and the regular solution theory. The solubility and the temperature dependency of the solubility with the solvents of acetone, ethylacetate, and tetrahydrofuran of PDX were shown to have relatively high values compared to the alcohol type solvents. Also, in same alcohols, the smaller molecules and higher polarity gave higher solvency. In partial layer melt crystallization, small amount of ethylacetate selectively dissolved impurities and gave highly purified p-dioxanone, over 99.9% purity.

• The Korean Journal of Nuclear Medicine
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• v.32 no.1
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• pp.81-88
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• 1998

The purpose of this study was to examine the radiolabeling and biodistribution of $^{188}Re(V)$-DMSA as a therapeutic cancer radiopharmaceutical. We made a DMSA kit($NaHCO_3$ 1.5 mg, meso-2,3-dimercaptosuccinic acid 1.0 mg, L(+)-ascorbic acid 0.7 mg, $SnCl_2{\cdot}2H_2O$ 0.34 mg, pH 2.9) for labeling with $^{188}Re$. In this kit, $^{188}ReO_4{^-}$ 5 mCi/2 ml added and boiled at $100^{\circ}C$ for 3 hr in water bath. The final pH adjusted to 7.5 with 7% $NaHCO_3$ solution. We checked the labelling efficacy with TLC-SG(n-butanol : acetic acid : $H_2O$ = 3 : 2 : 3) and examined the stability both in room temperature and in serum at $37^{\circ}C$. Biodistribution(1, 3, 13, 24, 48 hr) of $^{188}Re(V)$-DMSA compound was evaluated in Sarcoma 180 tumor-bearing mice. Each labeling efficiency and stability at room temperature for 48 hours was over 98% and 95%, respectively. The stability in serum were 82%(6 hr) and 85%(48 hr). Tumor uptake of $^{188}Re(V)$-DMSA in Sarcoma 180-bearing mice were $0.66{\pm}0.15%$(1 hr), $0.51{\pm}0.10%$(3 hr), $0.19{\pm}0.05%$(24 hr) and $0.13{\pm}0.02%$(48 hr). These result are consistent with those of $^{99m}Tc(V)$-DMSA which were reported previously. In conclusion, $^{188}Re(V)$-DMSA may be a useful therapeutic radiopharmaceutical for treating some cancers and metastatic bone lesion.

• Journal of Food Hygiene and Safety
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• v.20 no.4
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• pp.258-266
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• 2005

Licorice Extract and Erythritol, food additives used in korea, are widely used in foods as sweetener. Its application for use in food is regulated by the standard and specification for food additives but official analytical method far determination of these sweetener in food has not been established. Accordingly, we has been carried out to set up analytical method of the glycyrrhizic acid in several foods by the way of thin layer chromatography and high performance liquid chromatography glycyrrhizic acid is qualitative anaylsis technique consists of clean-up with a sep-pak $C_{18}$ cartridge, separation of the sweeteners by Silica gel 60 F254 TLC plate using 1-butanol:4Nammonia solution:ethanol (50:20:10) as mobile solvent. Also, the quantitative analysis for glycyrrhizic acid, was performed using Capcell prk $C_{18}$ column at wavelength 254nm and DW:Acetonitrile (62:38 (pH2.5)) as mobile phase. and we has been carried out to set up analytical method of the erythritol in several foods by the way of high performance liquid chromatography. erythritol is qualitative anaylsis technique consists of clean-up with a DW and hexane. The quantitative analysis for erythritol, was performed using Asahipak NH2P-50 column, Rl and DW:Acetonitrile (25:75) as mobile phase. The glycyrrhizic acid results determined as glycyrrhizic acid in 105 items were as follows; N.D$\∼$48.7ppm for 18 items in soy sauce, N.D$\∼$5.3ppm for 12 items in sauce, N.D$\∼$988.93ppm for 15 items in health food, N.D$\∼$180.7ppm for 26 items in beverages, N.D$\∼$2.6ppm for 8 items in alcoholic beverages repectively and ND for 63 items in the ethers. The erythritol results determined as erythritol in 52 items were as follows; N.D$\∼$155.6ppm for 13 items in gm, N.D$\∼$398.1ppm for 12 items in health foods repectively and ND for 45 items in the others.