Research on Preparation Method of Static Head Space for Volatile Organic Compounds in Drinking Water

[Objective] This research aimed to study the pre-treatment conditions of head space so as to establish a HS-GC determination method, which is suitable for China's conditions, for trace volatile organic compounds in drinking water. [Method]The preparation method of head space was adopted for the volatile organic compounds in drinking water. [Result] The 20 kinds of volatile organic compounds in drinking water all could be detected simultaneously by using HS-GC-FID method,and they all could be separated well. The HS-GC-FID method could analyze the detected substances qualitatively and quantitatively. In addition, this detection method was characterized by larger linear range of concentration, higher precision, higher detection limit and higher recovery rate. [Conclusion] Under certain conditions, HSGC can reduce the loss of volatile organic compound in drinking water and improve the sensitivity of detection. Moreover, the detection results meet the requirements by quality control.

检测小麦不同发育阶段主要有机物的含量变化

《普通高中生物学课程标准(2017年版)》对于科学探究提出了更高的要求,要引导学生主动、深入、真实地进行研究性学习,需要教师提供容易上手、实验现象明显,且能引发深入思考的实验。带领学生开展研究性学习,通过检测小麦不同发育阶段主要有机物的含量变化,引导学生提出可被验证的问题,并尝试解释自己的问题(即提出假设),设计实验方案,进行实验操作,最后通过分析实验结果得出结论等一系列过程,引发学生深入思考,自主构建逻辑关系形成知识网络。实验中使用静态的研究手段(物质鉴定和显微观察)进行定量地、动态地研究发育问题,让学生体会实验设计分析实验结果和实验数据的重要性,经过思考和推理在应用层面上提高对概念的理解。