The product complies with DB35/T 1521-2015 Continuous Automatic Monitoring Method for Peroxyacetyl Nitrate (PAN) in Ambient Air Gaseous Pollutants; JJG 1055-2009 Verification Regulation for Online Gas Chromatograph.
Instrument Introduction
Peroxyacyl nitrates (PANs) are generated by reactions between some volatile organic compounds (VOCs) and nitrogen oxides (NOx) in the atmosphere, mainly including peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), and peroxy methacryloyl nitrate (MPAN). They are important indicators of photochemical smog pollution and can promote the formation of the photochemical oxidant ozone (O₃). They have important impacts on urban and regional air quality and can undergo long-range transport to the upper troposphere after diffusion.
PANs are not only the main irritating harmful substances causing eye irritation in photochemical smog but also plant toxins and potential mutagens causing skin cancer. They dissociate in rainwater into nitrate and organic matter, participating in the acidification of precipitation. PANs have no natural or anthropogenic direct emission sources and are all generated directly by photochemical reactions. Compared to ozone, they are better indicators of photochemical smog pollution.
The online atmospheric PANs monitoring system is based on advanced gas chromatography technology and ECD detection method for measuring peroxyacyl nitrates (PANs) in the atmosphere. The standard cabinet design and universal data format allow organic integration with ambient air automatic monitoring systems. The system can be widely used for online PANs measurement in environmental monitoring stations, meteorological bureaus, research institutes, and other ambient air quality monitoring sites.
Application Scope
The application scope of this product includes: online monitoring of trace PANs in the atmosphere, photochemical smog pollution warning systems, and research on compound atmospheric pollution.
Instrument Principle
After filtration, atmospheric samples enter the system and are stored in the quantitative loop via a six-way valve. Switching the six-way valve sends the sample from the quantitative loop to the low-temperature chromatographic column for separation. The separated components enter the ECD detector for detection to obtain PAN values. During calibration, NO and acetone flows are controlled separately by mass flow controllers, and PAN standard gas is generated under UV light irradiation, then diluted with zero gas to the required concentration.
Instrument Features
• Self-developed TEC refrigeration module with temperature as low as 5℃ to prevent thermal decomposition of PANs
• Low detection limit, with PAN minimum detection limit reaching 50 ppt
• Uses EPC technology for carrier gas pressure control, with precise and stable pressure control and programmable pressure control
• Short analysis cycle, completing one cycle within 5min
• Calibrator uses high-precision mass flow controllers with accuracy better than 1%FS, unaffected by ambient temperature and pressure changes
• Photochemical synthesis principle generates PAN standard gas in real time, with conversion efficiency >96%, stable yield, and simple operation
• Supports manual and automatic calibration modes to meet various customer needs
• Cabinet-style installation, compact structure, convenient maintenance
• Comprehensive after-sales service system with fast and timely response
