The Science Island team has made new progress in detecting atmospheric formaldehyde

Recently, Zhang Weijun, a research team of the Anguang Institute of the Chinese Academy of Sciences, Hefei Academy of Materials, made new progress in atmospheric formaldehyde detection, and the related achievements were published on the international TOP journal Sensors and Actors: B. Chemical under the title of "Portable highly sensitive laser absorption spectrum formaldehyde sensor based on compact spherical mirror optical multi-path cell".

Formaldehyde is an important atmospheric pollutant, mainly originating from industrial processes, chemical products, and motor vehicle emissions. In atmospheric chemistry, formaldehyde is a key intermediate product in the oxidative degradation process of volatile organic compounds (VOCs) emitted by humans and nature; In indoor environments, excessive formaldehyde levels are an important cause of cancer, especially leukemia. Therefore, real-time monitoring of atmospheric formaldehyde is of great significance for the study of atmospheric pollution chemistry and health effects.

In 2019, researcher Zhao Weixiong and assistant researcher Fang Bo from An Guang Institute team developed a TDLAS device for actual atmospheric formaldehyde measurement using a long path new spherical mirror cell combined with mid infrared tunable laser absorption spectroscopy (TDLAS) technology. They also participated in field observations in the Guangdong Hong Kong Macao Greater Bay Area and other areas.

Based on this research, a compact optical multi-pass cell with high optical path to volume ratio (optical path 50.6 m, volume~350 mL) was developed to meet the miniaturization, fast response, and high sensitivity development needs of TDLAS formaldehyde measurement devices. Its gas displacement response time is less than 1 second. Combined with fast background subtraction technology, this device can obtain 650 pptv in 1 second of integration time（ α Min~2.3 × Detection limit of 10-9 cm-1). This research work laid the foundation for the team to further develop portable handheld/vehicle formaldehyde detection equipment.

This work has been supported by the National Natural Science Foundation of China, the Youth Innovation Promotion Association of the Chinese Academy of Sciences, and the President's Fund of Hefei Research Institute.

Compact spherical mirror optical multi pass cell with high optical path volume ratio

Structure diagram of formaldehyde detection device

Fast background subtraction and detection limit

Source: Hefei Institute of Physical Sciences, Chinese Academy of Sciences