새로운 HPLC용 형광유도체화제인 1-(N,N-dimethylamino)pyrene-6-sulfonyl chloride를 이용한 아민화합물의 분석

이윤중(Yoon Joong Lee),김용희(Yong Hee Kim),조정길(Jeung Kil Cho) 대한약학회 1991 약학회지 Vol.35 No.4

A new fluorescent derivatizing reagent was developed to be used in HPLC for the trace determination of primary and secondary amines. This new reagent, 1-(N,N-dimethylamino)pyrene-6-sulfonyl chloride, was synthesized by the chlorination of sodium 1-(N,N-dimethylamino)pyrene-6-sulfonate which was obtained from 1-(N,N-dimethylamino)pyrene after sulfonation. Ephedrine and norephedrine were derivatized quantitatively by this reagent. The optimum conditions for the derivatization such as pH, reagent concentration, reaction time and reaction temperature ware examined. The structures of derivatives were identified by IR, 1H-NMR and MS methods. The fluorescence properties and the stability of the derivatives were examined. The derivatives were separated on silica column with an isocratic elution using the mixture of n-hexane and ethylacetate and monitored by fluorescene detector. Linear calibration curves were obtained and detection limits in a 10 mcl injection volume were 5 picomole for ephedrine and norephedrine.

Native and Aluminum Chelate Fluorescence of 2-(Substituted anilino) nicotinic Acids

이강춘,이윤중,민신홍,Kang Choon Lee,Yoon Joong Lee,Shin Hong Min Korean Chemical Society 1982 대한화학회지 Vol.26 No.3

2-Anilinonicotinic acid를 기본 화합물로한 관련 유도체의 형광특성에 미치는 치환기의 영향을 검토하였다. 각 치환기의 Hammett substituent constant와 형광파장은 직선적인 정량적 관계를 나타내었으며 각 유도체의 알루미늄 착화합물에서도 동일한 경향성을 보였다. 측정용매의 영향은 유도체 및 알루미늄 착화합물에서 공히 용매의 polarity에 대해 정성적인 관련성을 나타내었다. Substituent effects on the fluorescence of 2-(substituted anilino) nicotinic acids and their aluminum chelate compounds were examined, and satisfactory linear relationships between Hammett substituent constant, ${\sigma}$, and the lowest excited singlet energy levels were obtained. Effects of solvent on the native and aluminum chelate compounds were also investigated.

(Ba_1-2xNa_2x)(Mg_0.5-xZr_xW_0.5)O₃ 세라믹스의 마이크로파 유전특성

윤상옥,홍창배,이윤중,김신,Yoon, Sang-Ok,Hong, Chang-Bae,Lee, Yun-Joong,Kim, Shin 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.6

We investigated the phase evolution, microstructure, and microwave dielectric properties of Na- and Zr-doped $Ba(Mg_{0.5}W_{0.5})O_3$ [i.e., ($Ba_{1-2x}Na_{2x})(Mg_{0.5-x}Zr_xW_{0.5})O_3$] ceramics. $BaWO_4$ as a secondary phase was observed in all compositions, and it increased as the dopant concentration increased. All specimens revealed a dense microstructure. For the composition of x=0.01, polyhedral grains were observed. As the dopant concentration increased, the densification and the grain growth were promoted by a liquid phase. The quality factor($Q{\times}f_0$) decreased remarkably, whereas the dielectric constant (${\varepsilon}_r$) tended to decrease as the dopant concentration increased. The dielectric constant, quality factor, and temperature coefficient of the resonant frequency of the composition of x=0.01 sintered at $1,700^{\circ}C$ for 1 h were 18.6, 216,275 GHz, and $-22.0ppm/^{\circ}C$, respectively.

왕겨로부터 제조한 활성탄의 입자표면특성과 흡착력

이동선(Dong Sun Lee),이명환(Myung Hwan Lee),이윤중(Yoon Joong Lee),안문규(Moon Gyu Ahn) 대한약학회 1988 약학회지 Vol.32 No.3

An activated carbon which showed big adsorption capacities of iodine, potassium permanganate and phenol was prepared from the Korean ricechaff. By scanning electron micrographs and IR spectra, it was observed that the organic components in the rice-chaff were decomposed to carbon dioxide and vapor by the pyrolysis and the activation, that activated carbon particles had carbon-carbon structures with a lot of microporosity. The adsorption capacities of iodine, potassium permanganate and phenol were determined. The adsorption isotherm of phenol was well fitted in Freundlich''s equation.

抗히스타민劑의 吸光度比法에 의한 定量

李允中,李康春,李東宣,李振九 成均館大學校 1980 論文集 Vol.28 No.-

The absorbance ratio method was applied to the quantitative determination of antihistamines, such as chlorpheniramine maleate(CPM), carbinoxamine maleate(CBM) and diphenhydramine hydrochloride. The influences of indicator and solvent concentration on the precision and accutacy of determination were investigated. And it was found that the effects of temperature and wavelength was negligible in case of averaging conditions. The standard deviations for three antihistamines tested were within 0.13%. As the results, the determination of antihistamines could be carried out easily, rapidly and accurately by the absorbance ratio method.

CTMAC에 依한 造血劑中의 微量鐵分의 吸光光度定量

李允中,李東宣 成均館大學校 1975 論文集 Vol.20 No.-

A method is described for the spectropohtometric determination of iron with cetyltrimethyl ammonium chloride(CTMAC) tha reacts with ferrithiocyanate chelate anion to form precipitate extractable in isoamylalcohol. As a result of experimentation, water insoluble red complex is produced by the reaction of the ferric ion with thiocyanate in the presence of cation surfactant just ad CTMAC. And the Fe(Ⅲ)-SCN-CTMAC associated complex is extracted from aqueous phase into organic phase(isoamylalcohol). The extracted species has an absorption maximum at about 495 nm, with a constant absorbance in the pH range from 1.0 to 2.0. It is found that the wave length of maximum absorption represents the bathochromic shift by the addition of CTMAC and that this method is more sensitive than the most widely used ferrithiocyanate procedure. Beer's law is obeyed up to 4 mcg/㎖ ferric ion in aqueous phase, for the absorbance of the associated complex under the optimum condition of pH, reagent concentrations and shaking time. This method can be used to the analysis of iron in commercial hematopoietics.

세파졸린의 산-염기의 거동

이동선,김수현,이윤중 서울여자대학교 자연과학연구소 1990 자연과학연구논문집 Vol.1 No.-

항생물질 cefazolin(CZH)의 산-염기 해리반응에 관해 실험하여 다음과 같은 결론을 얻었다. 1. 전위차법으로 25℃에서 측정한 CZH의 pKa 값은 3.78(±0.05) 이었다. 전도도법으로 측정한 경우 pKa=3.75였으며, [CZNa]/[CZH] = 1.00의 완충용액으로 측정하였을 때에는 pKa = 3.41이었다. 2. CZNa+CZH 혼합용액의 전기 전도도는 [CZNa] 농도가 증가될수록 공통이온외 영향으로 약간씩 감소되었다. 3. CZH의 용해도는 92.8mg/100mL이고, 해리도는 0.4650으로 산출되었다. 4. CZH의 pKa 값은 5~50℃ 범위에서 커다란 변화가 없었다. 5. CZH 산해리반응을 열역학적으로 고찰할 때, ΔG°=+19.995kJ/mol이었다. 따라서 CZH 외 난용성을 증명할 수 있었다. 6. 산-염기 분율조성을 고찰한 결과 pH<3.78의 수용액중에서는 산성형 CZH가 주된 화학종이고 pH>3.78인 용액중에서는 염기형인 CZ^(-)가 주된 화학종임을 알았다. 7. 5% 포도당 주사액중에서는 CZH가, Hartman용액중에서는 CZ^(-)가 주된 화학종이며, 생리식염 주사액중에서는 두 화학종이 비숫하게 분포하였다. 8. 생체액중에서의 CZH거동을 고찰한 결과 동맥혈, 정맥혈, 안방수, 누액, 십이지장, 회장, 소장 등에서는 99%이상 CZ^(-)형태로 분포하고, 위장에서는 약 99%가 CZH형태로 분포하리라 추정되었다. 9. UV 및 IR 흡광특성은 CZNa가 CZH에 비하여 장파장 이동을 나타내었다. The purpose of this study was to determine the acid dissociation constant of cefazolin antibiotics potentiometrically and conductometricaliy, and to identify the principal species in parenteral infusions and body fluids with different pH values. The pKa of cefazolin was 3.78(±0.05) at 25℃, and the pKa value of cefazolin was almost constant at temperature range of 5~50℃. As the concentration of basic form in the mixture of cefazolin(CZH) and cefazolin sodium(CZNa) increased the conductance decreased still further because of the common ion effect. The computed solubility of CZH was 92.8mg/100mL, the fractrion of dissociation a was found 0.4650. The low solubility was demonstrated thermodynamically. The Gibb's energy change for the dissociation was +19.995kJ/mol, reaction is disfavored. The acidic species(CZH) was the predominant form at pH<3.78, the basic species(CZ^(-)) was the principal form at pH>3.78. The results of pH measurement it was assumed that CZH was major in 5% dextrose inj., CZ^(-) in Hartman's solution, and CZH and CZ^(-) existed almost equally in saline solution. It was also assumed that the major form was basic in aqueous humor, blood venous, duodenum, ileum distal, lacrimal fluids, and intestine microsurface, while acidic in the stomch. UV and IR spectra of the basic form, CZ was showed bathochromic shift.

Chromatography에 의한 동물 담즙 中 담즙산류의 分析

李允中,辛昌鎬 成均館大學校 科學技術硏究所 1987 論文集 Vol.38 No.1

The separation and quantitation of bile acids in bile juices have been useful for the study of physiology and kinetics of gallbladder and enterohepatic circulation. Various analytical methods for separation of bile acids were reported by many authors. However, no other method was satisfactory for the separation of bile acids in bile juice. Two available chromatographic methods were used successfully. 1. GC analysis were developed for the rapid, simultaneous separation of free bile acids as their trifluoroacetyl, or trifluoroethyl ester to increase the sensitivity. The procedure involves derivatization of bile acid under vacuum at 30∼40℃ after rapid extraction using sep-pak C_18 cartridge and the derivative then is chromatographed on 1.5% silicone DC QF-1 on chromosorb W, (glass column: 4 mm i.d x 1.2 m) using N_2 as mobile phase. 2. HPLC analysis involves direct injection of bile acids after extraction using sep-pak C_18 cartrige. The sample is chromatographed on a Richrosorb RP-8 column(4 mm i.d. x 25 cm) using CH_3CN : 0.03 M(NH_4)_2CO_3(27 : 73), pH 7.5 for bear gall and MeOH : H_2O(70 : 30), PH 3.5 for other animal gall as mobile phase respectively. Also, conjugated bile acids were separated on a Richrosorb RP-8 column using CH_3CN : 0.03M (NH_4)_2CO_3(31 : 69), pH 3.5 as mobile phase for bear and chicken gall. The described methods are expected to be applied to quality assurance of pharmaceutical product containing bile acid, bear gall and other animal gall.

醫藥品製劑의 NBD 및 Dansyl 誘導體의 螢光分析學的 硏究 : p-Hydroxy ephedrine과 isoproterenol에 대하여 Studies on p-Hydroxy Ephedrine and Isoproterenol

李允中 成均館大學校 科學技術硏究所 1984 論文集 Vol.35 No.1

Fluorescent derivatives of p-hydroxy ephedrine and isoproterenol were synthesized by using 7-chloro-4-nitrobenzo-2-oxa-1, 3-diazole (NBD-C1) and 1-dimethylaminonaphthalene-5-sulfonyl chloride (Dansyl-Cl) as fluorescent agent. The optimum conditions such as pH, reaction time, temperature, solvent, concentration of fluorescent reagents were examined and a simple, rapid and sensitive fluorometric assay method was developed. The quantitative analytical ranges of NBD derivatives and Dansyl-isoproterenol are 0.8∼10㎍/ml, that of Dansyl-p-hydroxy-ephedrine is 0.6∼10㎍/ml. NBD and Dansyl derivatives were synthetized, the chemical structures were defined by Infrared spectroscopy and NMR spectroscopy. It was verified that NBD and Dansyl derivatives were formed by the reaction between the secondaryamine portions of p-hydroxy ephedrine and isoproterenol and 7-chloro-position of NBD-C1 and chloro position of Dansyl-Cl.

1-Bromoacetylpyrene 誘導體化劑를 利用한 Carboxyl基 含有成分의 分析에 관한 硏究(Ⅲ) : 生藥成分의 HPLC에 依한 定量 Determination of Carboxylic acids in Crude drugs by HPLC

李允中,曺正吉,丁海秀,嚴東玉 成均館大學校 科學技術硏究所 1988 論文集 Vol.39 No.2

A highly sensitive and selective fluoresence high-performance liquid chromatography using 1-bromoace-tylpyrene as a pre-labelling reagent was applied to the determination of cinnamic acid and glycyrrhetic acid at p mol level. The optimum conditions for the derivatization such as concentrations of KOH, 18-crown-6, and 1-bromoacetylpyrene, reaction temperature and reaction time were investigated. The derivatives were separated on a reversed phase column using the mixture of acetonitrile, methanol and water as the mobile phase. The effluent was menitored by fluorometer. Linearities of calibration curve were obtained between 0.5 p mol and 2.0 p mol. The detection limit of cinnamic acid and glycyrrhetic acid was 0.05 p mol in a 20 ㎕ of injection volume.