电位法测定茶水中氟含量的实验改进探索

doi:10.3866/PKU.DXHX201912020

University Chemistry ›› 2021, Vol. 36 ›› Issue (2): 1912020.doi: 10.3866/PKU.DXHX201912020

• Chemistry Laboratory • Previous Articles Next Articles

Improving the Potentiometric Determination of Fluoride Content in Tea Solution

Weimin Fang¹^,*(), Yuxiu Wei¹, Jiqing Cai¹, Haijuan Zhu¹, Yeer Yu², Tong Chen²

¹ Department of Chemistry, Zhejiang University, Hangzhou 310058, China
² Department of Tea Science, Zhejiang University, Hangzhou 310058, China

Received:2019-12-02 Accepted:2019-12-04 Published:2019-12-10
Contact: Weimin Fang E-mail:fangwm@zju.edu.cn

Abstract

Abstract:

The original experimental scheme was further optimized and improved by quantitatively measuring the effects of total ionic strength adjusting buffer, different tea leaves and tea-making water temperature and time. The objective is to enable students to understand the importance of controlling the experimental conditions for determination, so as to further stimulate students' interest in the science and pleasure of chemistry experiments.

Key words: Ion selective electrode, Fluoride content, Experimental improvement

Weimin Fang, Yuxiu Wei, Jiqing Cai, Haijuan Zhu, Yeer Yu, Tong Chen. Improving the Potentiometric Determination of Fluoride Content in Tea Solution[J].University Chemistry, 2021, 36(2): 1912020.

编号	c_F^-/mo1·L^-1	E_已加/mV	E_未加/mV
1	10^-6	379	378
2	10^-5	326	364
3	10^-4	265	314
4	10^-3	206	255
5	10^-2	147	198

4.0 g茶样	煮沸时长/min	E/mV	10⁵c_F^-/(mo1·L^-1)	茶中氟含量/(mg·kg^-1)
炒青绿茶	30	277	6.13	116.5
	60	271	7.77	147.6
	90	272	7.47	141.9
祁门红茶	30	299	2.58	49
	60	297	2.79	53
	90	297	2.79	53

4.0g茶样	煮沸时长/min	ΔE/mV	10⁵c_F^-/(mo1·L^-1)	茶中氟含量/(mg·kg^-1)
炒青绿茶	30	79	4.83	91.8
	60	74	5.93	112.7
	90	74	5.93	112.7
祁门红茶	30	102	1.92	36.5
	60	101	1.99	37.8
	90	101	1.99	37.8

1	GB/T 5009.18-2003.食品中氟的测定.
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3	刘超; 吴方正; 傅柳松; 陈雪松. 农业环境保护, 1998, 17 (3), l32.
4	谢忠雷; 邱立民; 董德明; 包国章; 王俊英. 吉林大学自然科学学报, 2001, 2 (4), 81.
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6	蔡荟梅; 侯如燕; 郜红建; 宛晓春. 茶叶科学, 2009, 29 (3), 225.

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Improving the Potentiometric Determination of Fluoride Content in Tea Solution

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