Optimization of Teaching Experiment Conditions of “Inspection of Iron in Food”
PAN Kang-Ya1, YU Lin-Xi1, SU Lin2, FU Jin-Song1, ZHANG Yan-Hua1*, ZHAO Huai-Yong3
1. College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610068,China;
2. Sichuan Mianyang Puming High School, Mianyang 621000,China;
3. Guangyuan High School, Guangyuan 628000,China
Abstract The “inspection of iron in food” experiment has been added to the 2019 People's Education Edition senior high school chemistry textbook compulsory one, according to this experimental scheme, iron in spinach was detected, but experimental phenomena could not be observed obviously due to pigment interference. In view of this, the color transmittance of the extraction solution after color development was used as the index to evaluate the experimental effect, and the control variable method was used as the experimental method. The common iron-containing food, iron extraction method, extraction time, concentration of hydrochloric acid in the extraction agent and the amount of the extraction agent were optimized. The optimized experimental results showed that 2 g bean tendon and 20 mL hydrochloric acid with the concentration of 4 mol/L were stirred by the wall-breaking machine and extracted for 5 min, and the color value of the extract was 62%, showing a good blood red. It can effectively prove the existence of iron in food and has obvious experimental phenomenon. It can be well applied to teachers' demonstration experiments and students' group experiments.
PAN Kang-Ya, YU Lin-Xi, SU Lin, FU Jin-Song, ZHANG Yan-Hua, ZHAO Huai-Yong. Optimization of Teaching Experiment Conditions of “Inspection of Iron in Food”[J]. Chinese Journal of Chemical Education, 2022, 43(5): 91-95.
