TEP教学模式在分析化学教学中的应用--以“酸碱滴定分析法”教学为例

为了实现高等教育培养应用型和创新型人才目标,需要改变目前分析化学教学中“重知识和技能传授、轻能力培养和价值引领”的教学现状,提出“理论知识(Theory)–自主实验(Experiment)–实践应用(Practice)”融合教学模式(简称TEP)。TEP教学模式在实施过程中,通过“任务”这条主线将三个教学环节紧密相连,构建一个递进式教学体系。在理论教学中采用“任务和问题驱动式”教学,激起学生学习的主动性和积极性;在实验教学中要求学生自主完成相对简单的实验任务,培养学生自主学习和思考的能力;在实践应用环节,要求学生独立完成有意义有难度的任务,培养学生的应用能力和创新能力。在每个教学环节中巧妙地融入思政内容,实现“立德”与“树人”的有机统一。为了使TEP模式有效实施,还需做好课程的教学评价。

Determination of five endosulfan pesticides in the fish pond water by dispersive liquid–liquid microextraction combined with GC–MS

A simple and rapid dispersive liquid-liquid microextraction(DLLME)technique coupled with gas chromatography-ion trap mass spectrometry(GC-MS)was developed for the extraction and analysis of five endosulfan pesticides from the fish pond water.In this work,different parameters affecting the extraction process such as the type and volume of extraction solvent,type and volume of disperser solvent,and extraction time were studied and optimized.Under optimized conditions,the enrichment factor ranged from 189 to 269 and the relative recovery ranged from 88.5%to 94.9%.The linear range was 2.0-80.0 mg/L;the limits of detection and quantitation were in the range 0.04-1.06 mg/L and 0.12-3.53 mg/L,respectively.The relative standard deviations were in the range 0.94%-2.08%(n D 5).The obtained results show that DLLME combined with GC-MS is a fast and simple method for the determination of endosulfan pesticides in fish pond water.