The Observation of Urban Ambient 1,3‐Butadiene Based on Differential Optical Absorption Spectroscopy Technique and Its Potential Alteration on the Nighttime Chemistry

Abstract As a highly reactive dialkenes similar to isoprene, 1,3‐butadiene (BD) is rapidly oxidized and fully involved in atmospheric oxidation processes. We have established a method for the online measurement of ambient BD using Differential Optical Absorption Spectroscopy (DOAS) technique. Lab testing demonstrated that DOAS technique can accurately measure BD concentrations in high temporal resolution of minute‐level, with accuracy and precision within ±5% and 1%, respectively. Following field measurement, the detection limit for BD reached 90 pptv, the r between DOAS and the online VOCs system results reached 0.885, and the nighttime hourly averaged concentration peaked at 0.75 ppbv. At this BD level, if the NO 3 reaction pathway with BD was not considered, the maximum proportional variations in the NO 3 concentration simulated by the box model exceeded 10%. In conclusion, DOAS is suitable for long‐term BD measurements, and continuous attention should be given to the potential alteration on atmospheric chemistry caused by this type of easily neglected compounds.