相关实验视频
Updated: Jun 30, 2025

08:29
Thermal Measurement Techniques in Analytical Microfluidic Devices
Published on: June 3, 2015
9.6K
使用水性二元混合物进行热光学分析 (TOA) 的评估
Courtney D Grimes1, Joseph M Conny2, Russell R Dickerson1,3
1Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742.
概括
本研究提出了一种新方法,用于描述热光学分析 (TOA),使用有机碳 (OC) 和元素碳 (EC) 的水性混合物. 该方法准确量化大气颗粒物中的碳成分.
科学领域:
- 环境科学 环境科学
- 分析化学 分析化学
- 大气化学 大气化学
背景情况:
- 热光学分析 (TOA) 是用于测量颗粒物中的有机碳 (OC) 和元素碳 (EC) 的标准技术.
- 准确地描述TOA方法对于可靠的大气碳测量至关重要.
- 现有的方法可能需要复杂的样品制备,或在区分碳分数方面缺乏精度.
研究的目的:
- 开发和验证一种用于描述热光学分析 (TOA) 传输技术的新方法.
- 评估TOA测量的准确性和可重复性,使用准备好的EC和OC水性混合物.
- 评估不同温度协议的有效性,以量化碳酸性气溶.
主要方法:
- 制备了一种含有已知数量的元素碳 (EC) 和有机碳 (OC) 的水性二元混合物.
- 混合物被沉积在石英纤维过器上,使用低体积沉积技术.
- 使用热光学分析 (TOA) 分析样品,并使用各种温度协议,包括NIST-EPA-C协议.
主要成果:
- 根据NIST-EPA-C的温度协议,EC,OC,总碳 (TC) 和EC/TC的基准值达成一致,超过2%.
- 所有测试的温度协议都显示总碳 (TC) 在参考值的5%以内.
- 所有协议都复制了EC/TC比率,不确定性低于10%.
结论:
- 开发的水性混合物方法提供了一种可靠和准确的方法来表征TOA仪器.
- 在大气样本中,NIST-EPA-C协议在量化EC和OC方面表现出很高的准确性.
- 这种方法提高了大气碳化合物气溶分析的精度和可靠性.
相关概念视频
Distillation: Vapor–Liquid Equilibria
2.8K
Distillation is a separation technique that takes advantage of the boiling point properties of disparate elements in a mixture. To perform distillation, we begin by heating a miscible mixture of two liquids with a significant difference in boiling points (at least 20°C). As the solution heats up and reaches the bubble point of the more volatile component, some molecules of the more volatile component transition into the gas phase and travel upward into the condenser, which is a glass tube...
2.8K
Temperature and Thermal Equilibrium
6.7K
Heat and temperature are essential concepts for everyone every day. The study of heat and temperature is part of an area of physics known as thermodynamics. It is not always easy to distinguish heat and temperature.
The concept of temperature has evolved from the common concepts of hot and cold. The scientific definition of temperature explains more than just our sense of hot and cold. Temperature is operationally defined as the quantity measured with a thermometer. Furthermore, temperature is...
The concept of temperature has evolved from the common concepts of hot and cold. The scientific definition of temperature explains more than just our sense of hot and cold. Temperature is operationally defined as the quantity measured with a thermometer. Furthermore, temperature is...
6.7K
Properties of Enantiomers and Optical Activity
17.0K
It is essential to understand the difference between chiral and achiral interactions and the implications thereof in optical activity and their applications. Just as our feet, which are chiral, interact uniquely with chiral objects, such as a pair of shoes, but identically with achiral socks, enantiomers of a molecule exhibit different properties only when they interact with other chiral media. An example of a significant implication from this facet is the phenomenon known as optical activity,...
17.0K

