Establishing the Effect of Solvent Polarity on Carotenoid Extraction: A Small-Scale Solid–Liquid Extraction and Alkene Identification Experiment for Senior High School Students

IF 2.9 3区教育学 Q2 CHEMISTRY, MULTIDISCIPLINARY

Journal of Chemical Education Pub Date : 2025-09-12 DOI:10.1021/acs.jchemed.5c00395

Cheng-Kun Lin*, , , Yu-Jin Huang, , , Yueh-Ling Huang, , , Xin-Shun Chiou, , and , Ci-Yi Zhou,

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引用次数: 0

Abstract

We present a small-scale, inquiry-based experiment for senior high school students that explores the effect of solvent polarity on the extraction of carotenoids and the identification of unsaturation through qualitative chemical tests. Using 3 g of diced carrot and three solvents─heptane, ethanol, or water─students conducted solid–liquid extractions, followed by bromine water and potassium permanganate testing. These visual tests detect the presence of unsaturated carotenoids based on color changes associated with electrophilic addition or oxidation reactions. Heptane, a nonpolar solvent, proved most effective in extracting carotenoids, while ethanol showed moderate effectiveness and water was ineffective due to its high polarity. This visually engaging and pedagogically robust experiment reinforces key organic chemistry concepts such as solubility, molecular polarity, and functional group reactivity within a 2 h lab session designed for classroom implementation.

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溶剂极性对类胡萝卜素提取的影响：高中生小型固液萃取及烯烃鉴定实验

本研究针对高中生进行了一项小规模的探究性实验，探讨了溶剂极性对类胡萝卜素提取的影响，并通过定性化学测试来鉴定不饱和。学生们使用3g胡萝卜丁和三种溶剂──庚烷、乙醇或水──进行固液萃取，然后进行溴水和高锰酸钾测试。这些目测检测基于与亲电加成或氧化反应相关的颜色变化的不饱和类胡萝卜素的存在。非极性溶剂庚烷对类胡萝卜素的提取效果最好，而乙醇对类胡萝卜素的提取效果一般，水对类胡萝卜素的提取效果较差。这个视觉上吸引人的、教学上强大的实验强化了关键的有机化学概念，如溶解度、分子极性和官能团反应性，在2小时的实验室课程中为课堂实施而设计。

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来源期刊

Journal of Chemical Education 化学-化学综合

CiteScore

5.60

自引率

50.00%

发文量

465

审稿时长

6.5 months

期刊介绍： The Journal of Chemical Education is the official journal of the Division of Chemical Education of the American Chemical Society, co-published with the American Chemical Society Publications Division. Launched in 1924, the Journal of Chemical Education is the world’s premier chemical education journal. The Journal publishes peer-reviewed articles and related information as a resource to those in the field of chemical education and to those institutions that serve them. JCE typically addresses chemical content, activities, laboratory experiments, instructional methods, and pedagogies. The Journal serves as a means of communication among people across the world who are interested in the teaching and learning of chemistry. This includes instructors of chemistry from middle school through graduate school, professional staff who support these teaching activities, as well as some scientists in commerce, industry, and government.