Monitoring techniques of airborne carbonyl compounds: Principles, performance and challenges

Airborne carbonyls are a significant class of indoor and outdoor air pollutants, and their accurate and timely measurement is critical for protecting human health. This article reviews the existing analytical techniques for monitoring atmospheric carbonyl compounds. We categorize the methods into real-time measurements and timeintegrated measurements and compare the commonly used methods, including proton transfer reaction-mass spectrometry (PTR-MS), liquid chromatography (LC) and gas chromatography (GC) coupled with different detectors and various derivatization methods. The operation theory, normal working conditions, and instrument performance in detecting carbonyls, are summarized and compared. The advantages and limitations of each technique are also discussed, along with the challenges and solutions for measurement bias. The review concludes with recommendations for selecting a suitable technique based on selectivity, sensitivity, time-resolution, and operability, as well as the need for improving accuracy and optimization to reduce influences.