• Title/Summary/Keyword: 과도 전류

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Simultaneous determinations of anthracycline antibiotics by high performance liquid chromatography coupled with radial-flow electrochemical cell (고성능 액체 크로마토그래피/방사흐름 전기화학전지를 이용한 안트라사이클린계 항생제의 동시 정량)

  • Cho, Yonghee;Hahn, Younghee
    • Analytical Science and Technology
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    • v.20 no.4
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    • pp.308-314
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    • 2007
  • The analytical method of HPLC with the radial-flow electrochemical cell (RFEC) has been developed to determine doxorubicin, epirubicin, nogalamycin, daunorubicin and idarubicin simultaneously by employing a reversed-phase chromatography. Anthracyclines were detected at -0.74 V vs. a Ag/AgCl (0.01 M NaCl) reference electrode, a potential of diffusion current plateau in the mobile phase. At a $V_f$ of 1.0 mL/min doxorubicin, epirubicin, daunorubicin and idarubicin appeared at a retention time ($t_r$) of 6.4 min, 7.4 min, 12.7 min and 18.4 min, respectively, while at a $V_f$ of 0.6 mL/min, doxorubicin, epirubicin, nogalamycin, daunorubicin and idarubicin appeared at a $t_r$ of 9.9 min, 11.5 min, 13.5 min, 19.6 min and 28.7 min, respectively. The linearity between each anthracycline injected ($2.40{\times}10^{-7}M{\sim}1.42{\times}10^{-5}M$) and peak area (charge) was excellent with the square of the correlation coefficient ($R^2$) higher than 0.999. The detection limits were $1.0{\times}10^{-8}M{\sim}1.5{\times}10^{-7}M$ for the five anthracyclines. Within-day precision for the five anthracyclines were in reasonable relative standard deviations less than 3 % ($1.00{\times}10^{-6}M{\sim}1.42{\times}10^{-5}M$) except the lower concentrations less than $0.7{\mu}M$. Solid phase extractions of $1.00{\times}10^{-5}M$ epirubicin, $0.48{\times}10^{-5}M$ nogalamycin and $1.52{\times}10^{-5}M$ daunorubicin from human serum with a $C_{18}$ cartridge resulted in 97 %, 100 % and 90 % of recoveries, respectively.

Sodium and Potassium Content of School Meals for Elementary and Junior High School Students in Daegu, Masan, Gwangju, and Jeju (대구, 마산, 광주, 제주지역 학교급식의 나트륨 및 칼륨 함량 분석)

  • Lim, Hyeon-Sook;Ko, Yang Sook;Shin, Dongsoon;Heo, Young-Ran;Chung, Hae-Jung;Chae, In-Sook;Kim, Hwa Young;Kim, Mi-Hye;Leem, Dong-Gil;Lee, Yeon-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.8
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    • pp.1303-1317
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    • 2013
  • The purpose of this study was to determine the sodium (Na) and potassium (K) content of school meals served in elementary and junior high school in Korea. In this study, 872 kinds of school meal dishes were collected from twelve elementary and twelve junior high schools located in four different cities in Korea (Daegu, Masan, Gwangju, and Jeju). The dishes were classified into three main categories; staple dish, subsidiary dish, and dessert. Each main category was further sub-classified into 4 kinds of staple dishes, 15 kinds of subsidiary dishes, and 5 kinds of dessert dishes. The Na and K content of dishes were then analyzed by atomic absorption spectroscopy. The Na content of individual dishes showed considerable differences, ranging from 9 to 2,717 mg/100 g. Among the staple dishes, cooked rice contained relatively less Na, but other staple dishes such as a la carte, noodle, and rice-gruel contained considerably high amounts of Na. Regarding the subsidiary dishes, the Na content of salad was low, but those of Jangachi, stir-fried dishes, and kimchi were considerably high. Among the dessert dishes, beverages, fruit, and milk/dairy products contained relatively low amount of Na, while rice cakes and baked goods, and snacks contained noticeably high amounts of Na. Unlike the Na content, the K content between the dishes did not show much variability. Cooked rice and rice cakes contained relatively low amounts of K, similar to other dishes, and ranged from 104 to 220 mg/100 g. The Na/K ratio was especially high in rice cakes and Jangachi, while of the ratio in beverages, milk/dairy products, salad, and fruit were pretty low. The total content of Na and K and the Na/K ratio of elementary school meals were 974 mg, 378 mg and 2.7, respectively, and those in junior high school meals was 1,466 mg, 528 mg and 3.0. The results show that most school meals provide a significant amount of Na but significantly small amounts of K, as suggested by the Dietary Reference Intakes for Koreans.