한강하류의 환경학적 연구 - Ⅲ. 퇴적물 -

한영희,이진환,이순길 ( Younghee Hahn,Jin Hwan Lee,Soon Kil Yi ) 한국하천호수학회 1997 생태와 환경 Vol.30 No.4

In order to investigate the ignition loss, concentrations of organic carbon, organic nitrogen, cadmium, zinc and lead in the sediments of the lower part of the Han River, the present study was carried out seasonally at 7 stations during the period from June 1995 to June 1996. Ignition loss varied from the lowest value of 0.31% at Station 6 in October 1995 to the highest value of 37.03% at Station 3 in June 1996. Organic carbon varied from the lowest value of 0.10% at Station 7 in October 1995 to the highest value of 9.17% at Station 6 in May 1996. Organic nitrogen was hardly detected at any of the stations in May and June 1996, but in the other months, it varied in the concentration range of 0.01∼0.32%. Cadmium was not detected at any of the stations in June 1996 and at three stations in May 1996. However, cadmiun was detected particularly at high concentrations of 4.38㎍/g and 4.57㎍/g at Station 1 in May 1996 and at Station 3 in July 1995, respectively. Monthly average ooncentrations of zinc among 7 station varied considerably from the lowest value of 68.69㎍/g in October 1995 to the highest value of 244.77㎍/g in July 1995. Differences in average concentrations of zinc through a year were distinct among the stations with a tendency of a higher concentration at a lower station.The highest monthly average concentration of lead was 74.70㎍/g in July 1995 but it varied from 11.76㎍/g to 37.90㎍/g in the other months. Annual average concentrations of lead also showed a tendency of increasing at the lower part of the Han River. Annual average concentrations of organic nitrogen and carbon as well as zinc and lead appeared with the lowest value at station 1, with the highest value at Station 6 and with a relatively high value at Station 5. Temporal variation was greater than spatial variation in the concentrations of cadmium and lead in the sediments. Compared with a previous report in 1987, the concentrations of cadmium and lead at Station 1 in May and July were increased 3∼12 times in the present study. Continuous chemical studies are required to investigate characteristics of sediments at the lower part of the Han River.

$H_2O_2$-생성 산화효소계에 관한 분석 연구

한영희,조혜림,Younghee Hahn,Hae-Lim Cho 대한화학회 1993 대한화학회지 Vol.37 No.10

Spectrophotometric enzymatic analysis and amperometric enzymatic analysis for the determinations of glucose and ethanol were studied utilizing glucose oxidase (GO) and alcohol oxidase (AO), respectively, which commonly consume $O_2$ and produce $H_2O_2$. For the determination of glucose, $H_2O_2$ were coupled to $K_4Fe(CN)_6$ via peroxidase producing $K_3Fe(CN)_6$ whose absorbance was measured at 418 nm or whose diffusion current was measured on the glassy carbon electrode at an applied potential of -55 mV vs. Ag/AgCl (sat. KCl) reference electrode. Amperometric analysis was 1000 times more sensitive as well as 10 times better in the linear concentration range than spectrophotometric analysis. For the determination of ethanol, AO only was used for the enzymatic analysis, since $K_3Fe(CN)_6$ was completely disappeared as soon as AO was added. Either rate of $H_2O_2$ produced was amperometrically measured at +0.900 V or rate of $O_2$ consumed was measured at -0.500 V vs. Ag/AgCl(sat. KCl) reference electrode. 산소를 수용체로 하여 $H_2O_2$를 생성하는 산화효소인 glucose oxidase (GO) 와 alcohol oxidase (AO)를 이용하여 glucose와 ethanol에 대한 분광학적 효소분석법과 전기화학적 효소분석법을 연구하였다. Glucose에 대한 정량분석의 경우 GO 반응에서 생성된 $H_2O_2$를 peroxidase를 사용하여 $K_4Fe(CN)_6$에 반응시키고 그 결과 생성된 $K_3Fe(CN)_6$의 흡광도를 418 nm에서 측정하거나 Ag/AgCl (포화 KCl) 기준전극에 대하여 -55 mV를 부하시킨 유리질 탄소전극에서 $K_3Fe(CN)_6$의 확산전류를 측정하였다. 전류법 측정이 분광광도법 측정보다 1/1000 정도 더 낮은 농도까지 검출할 수 있었으며 직선성을 갖는 농도 범위도 10배 더 연장되었다. Ethanol에 대한 정량분석의 경우 $K_3Fe(CN)_6$가 AO에 의하여 순간적으로 소거되었으므로 AO 반응만을 이용하여 $H_2O_2$의 생성속도를 +0.900 V에서 측정하거나 용존 $O_2$의 감소속도를 -0.500 V에서 전류법으로 측정하였다.

미분 펄스 폴라로그래피에 의한 Chloramphenicol의 정량분석

한영희,전정선,Younghee Hahn,Jung-Sun Jeon 대한화학회 1992 대한화학회지 Vol.36 No.4

Chloramphenicol에 대한 미분 펄스 폴라로그래피 분석법을 연구하였다. Chloramphenicol은 Ag/AgCl(포화 KCl) 기준전극에 대하여 0.00∼-1.50 Volt 영역에서 pH 의존성을 갖는 하나의 환원 피이크를 나타내었다. 실온(20$^{\circ}C$)에서 측정한 피이크 전위(Ep)를 Chloramphenicol 용액의 pH에 대하여 조시하였을 때 직선적인 관계를 보여주었으며 pH 8.9에서 기울기(Ep/pH) 변화를 나타내었다. 기울기는 pH 2.7∼8.9 사이에서 -59.7mV/pH이었고 pH 8.9∼11.2 사이에서는 -24.3mV/pH이었다. pH 8.0 암모늄완충용액을 지지전해질로 사용하여 4.8 ${\times}$ 10$^{-7}$ M and 6.2 ${\times}$ 10$^{-5}$ M (0.16 ppm∼20 ppm), Chloramphenicol 용액의 피이크 전류(ip)를 농도에 대하여 도시하였을 때 직선성을 나타내었다. Chlormaphenicol에 대한 미분 펄스 폴라로그래피법과 공정서 방법인 278nm에서의 자외선 흡수분광분석법 사이에 상관계수는 0.996으로서 우수한 상관관계를 나타내었다. Chloramphenicol을 약알칼리성(pH 8.0) 용액에서 장기간 보관시 분해 생성물의 검출은 미분펄스 폴라로그래피법이 분광분석법보다 용이하였다. Chloramphenicol was studied by differential pulse polarography (DDP). A reduction peak which is dependent on pH of the solution appeared in the voltage range between zero and -1.50 volt vs. Ag/AgCl (sat. KCl) reference electrode. A plot of peak potentials (Ep) measured at room temperature (20$^{\circ}C$) vs. pH of the chloramphenicol solutions showed linear relationship changing slope (Ep/pH) at pH 8.9. The slope was -59.7 mV/pH in pH 2.7∼8.9 and -24.3 mV/pH in pH 8.9∼11.2, respectively. A log plot of peak currents (ip) vs. concentrations showed a linearity at the concentrations between 4.8 ${\times}$ 10$^{-7}$ M and 6.2 ${\times}$ 10$^{-5}$ M (0.16 ppm∼20 ppm) chloramphenicol in pH 8.0 ammonium buffer. Between the DPP method and the reference method measuring absorbance at 278 nm, the correlation coefficient was 0.996, which means an excellent linearity. The DPP method was able to detect degradation products of chloramphenicol in mild alkaline solution (pH = 8.0) more distinctly than the spectrophotometric method.

의약품 정제 중에 함유된 Ranitidine·HCl의 네모파 전압전류법 거동과 정량분석

신순호,한영희,Shin, Soon Ho,Hahn, Younghee 한국분석과학회 2009 분석과학 Vol.22 No.5

Ranitidine HCl을 함유하는 의약품 정제에 대한 네모파 전압전류법(SWV) 분석방법을 개발하고자 다양한 pH의 인산염 완충용액을 지지전해질로 하여 $5.00{\times}10^{-5}M$ ranitidine HCl용액의 SWV를 실행한 결과 ranitidine의 구조 내 $-NO_2$기의 전기화학적 환원에 기인한 주 봉우리는 Ep가 -70 mV/pH로 이동하여 수소가 관여함을 나타내었다. Ranitidine HCl용액 $1.00{\times}10^{-7}{\sim}1.00{\times}10^{-5}M$에 대하여 봉우리 전류(Ip)를 도시하여 검량곡선을 작성 시 좋은 직선성을 나타내었으며 기울기는 $232,530{\mu}A/M$ (pH 6.14), $289,015{\mu}A/M$ (pH 7.07)과 $232,843{\mu}A/M$ (pH 8.01)이었다. 의약품 정제 1정을 단순히 pH 6.14 인산염 완충용액에 용해시켜 표준물 첨가법에 의해 SWV로 정량분석 할 때 하루 중 정밀도 검사(n=4)는 큐란$^{(R)}$의 경우 1정 중 $171{\pm}2.1mg$(규정된 함량의 $102{\pm}1.3%$)의 ranitidine HCl이 함유되어 1.2% RSD를 보였으며, 5일에 걸쳐 날짜 간 정밀도 검사를 행하였을 때에도 1.1%의 RSD를 나타내었다. 잔탁$^{(R)}$ 역시 하루 중 정밀도 검사(n=4)를 하였을 때 1정 중 $167{\pm}0.8mg$(규정된 함량의 $99{\pm}0.5%$)의 ranitidine HCl이 함유되어 0.5%의 RSD를, 날짜 간 정밀도 검사도 0.3%의 RSD로 좋은 정밀도를 나타내었다.

네모파 전압전류법에 의한 Cimetidine 주사액의 정량분석

이수정(Soo Jung Lee),한영희(Younghee Hahn) 한국분석과학회 2010 분석과학 Vol.23 No.1

[화학] 수은피막 박막흐름전지를 이용한 Anthracycline계 항생제의 전류법 정량

김경은(Kyung Eun Kim),한영희(Younghee Hahn) 한국분석과학회 2004 분석과학 Vol.17 No.6

의약품 정제 중에 함유된 RanitidineㆍHCl의 네모파 전압전류법 거동과 정량분석

신순호(Soon Ho Shin),한영희(Younghee Hahn) 한국분석과학회 2009 분석과학 Vol.22 No.5

생체 시료 중 아세틸콜린 및 콜린에 대한 효소-분광학적 정량분석

남명화(Myung Hwa Nam),이성호(Sung-Ho Lee),김기택(Ketack Kim),한영희(Younghee Hahn) 대한약학회 2012 약학회지 Vol.56 No.4

In order to determine acetylcholine and choline in the biological samples, the specific enzymes of acetylcholinesterase (AChE) and choline oxidase (ChO), which utilize acetylcholine and choline as substrates, were employed to convert substrates to H2O2. The produced H2O2 was coupled to 4-aminoantipyrine/phenol with peroxidase (PO) yielding quinoneimine dye which was measured at 508 nm. In the present enzymatic spectrophotometric analysis the product at the equilibrium state was measured considering accuracy, precision, time and cost of the analysis. The developed analytical method yielded good linearity (calibration curve; A508=9534[acetylcholine]+0.009, correlation coefficient (R2); 0.999) with detection limit of 1.11×10-7 M, reasonable precision (relative standard deviation; 0.10~1.62% at 2.5×10-6 M~1.25×10-4 M) and accuracy (relative error; -0.24~0.97% at 4.13×10-6M~1.01×10-4 M) for acetylcholine chloride standard solution. The concentrations of acetylcholine and choline in human serum were found as 3.20×10-5 M and 1.14×10-4 M, respectively. The brain tissues of Sprague-Dawley strain rat contained 9.82 μg/g of acetylcholine and 6.53 μg/g of choline in the cerebrum, while 7.37 μg/g of acetylcholine and 5.34 μg/g of choline in the cerebellum.

콩 종류와 대두 가공식품에 함유된 isoflavone의 정량

김정숙(Chungsook Kim),이영선(Young-Sun Lee),김진숙(Jin-Sook Kim),한영희(Younghee Hahn) 한국식품과학회 2000 한국식품과학회지 Vol.32 No.1

효소 촉매반응을 이용한 총 콜레스테롤의 정량

韓英熙 상명대학교 기초과학연구소 1997 기초과학연구 Vol.10 No.-

혈청에 함유된 총 cholesterol(free cholesterol + cholesterol esters)의 정량에 관한 기존의 분석방법들을 재조사하고 탄소관전극을 사용하여 혈청중 총 cholesterol을 전류법 및 효소분석으로 정량하였다. 효소시약으로 사용된 cholesterol ester hydrolase 와 cholesterol oxidase 효소반응의 동력학적 거동을 연구하여 최적농도와 반응시간을 정하였으며 실제 사람의 혈청분석시에는 20 μL의 혈청시료를 2.02 mL의 시약혼합액(7.43mM sodium cholate, 0.37% Triton X-100, 1.49mM sodium azide, 149u/mL peroxidase, 0.0495u/mL cholesterol ester hydrolase, 0.0743u/mL cholesterol oxidase, 9.90mM K4Fe(CN)6을 함유하는 pH 7.0 인산염 완충용액)에 첨가하고 36.5℃에서 18분간 반응시켜서 생성된 K3Fe(CN)6를 포화 칼로멜 기준전극에 대하여 -75 mV를 부하시킨 탄소관 전극에서 전류법으로 측정하였다. 본연구에서 개발한 전류법 효소분석은 고감도이며, 선택적이고, 신뢰도가 높고, 요구되는 시료의 양이 적고, 물에 용해하기 쉽고 고순도의 K3Fe(CN)6로 검량할 수 있는 장점이 있다. 본연구의 전류법 효소분석으로 정량한 130명 환자의 혈청중 총 cholesterol 농도는 기존의 Leffler 방법으로 분석한 결과와 직선적인 상관관계가 있었다(상관관계 계수; 0.962). Conventional methods determining total cholesterol(free cholesterol + cholesterol esters) in serum have been reviewed. An amperometric enzymatic analytical procedure determining total cholesterol in human serum has been developed using a tubular carbon electrode(TCE). The kinetic behaviors of cholesterol ester hydrolase and cholesterol oxidase reactions have been studied to determine their optimum concentrations and optimum incubation times for the assay. Twenty μL of human serum sample was added to the 2.02 mL reagent mixture, pH 7.0 phosphate buffer consisting of 7.43 mM sodium cholate, 0.37% Triton X-100, 1.49 mM sodium azide, 149 μ/mL peroxidase, 0.0495 μ/mL cholesterol ester hydrolase, 0.0743 μ/mL cholesterol oxidase and 9.90 mM K₄Fe(CN)_{6} subsequently followed by incubation at 36.5% for 18 minutes. The incubated enzymatic reaction mixture was pumped through a TCE polarized at -75 mV vs. a saturated calomel reference electrode and the K₃Fe(CN)_{6} produced in the reaction mixture was measured by amperomtry. The advantages of the present ampemmetric enzymatic assay include high sensitivity, selectivity, reliability, small sample requirement and cabilibration with easily water-soluble, pure K₃Fe(CN)_{6}. The total cholesterol values of 130 patient sera determined by the present amperometric enzymatic assay were linely correlated with those determined by the conventional Leffler method(correlation coefficient; 0.962).