Related Experiment Video
Updated: Feb 14, 2026
Using a Cyclic Ion Mobility Spectrometer for Tandem Ion Mobility Experiments
Published on: January 20, 2022
Key role of nitrogen-containing organic species in haze formation and health implications: an ion mobility-analysis
Mi Tian1, Xinquan Zhao1, Wei Zhang2
1Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China.
Abstract:
Despite the ubiquitous impacts on ecosystem and human health, the formation mechanisms of nitrogen-containing organic compounds (NOCs) remain poorly understood in the atmosphere. In this study, wintertime PM2.5 samples were collected in Chongqing with molecular-level composition characterized by an ion mobility spectrometry (IMS) - time of flight mass spectrometry to elucidate key formation/evolution factors and health implications of NOCs in ambient particles. Generally, nitrogen-containing organic species (CHNOs) were found to be critical PM2.5 components for haze formation and health impacts during polluted episodes. Evidence from IMS-derived collision cross sections calculation further illustrated organic nitrates/nitrites (ONs) as the main contributors to CHNOs observed in this study. Secondary transformation process was identified as the major formation pathway for CHNOs. Significant levels of NH4+ and NO2 accompanied by high relative humidity (RH) resulted in enhanced production of particulate CHNOs during wintertime haze episodes, which was also remediated by aerosol liquid water content and aerosol acidity. In addition, CHNOs (e.g., C8H13NO8-9, C9H13NO8, and C9H15NO8-9) were found to be associated with acellular and cellular oxidative potential metrics (OPAA, OPGSH, and in vitro ROS). Further in vitro results from human bronchial epithelial (BEAS-2B) cells confirmed that both authentic PM2.5 sampels and atmospherically relevant nitrogen containing species, including organonitrate/nitrite, nitrosamine, nitrophenol, amide, and amines, can significantly induce intracellular ROS and the expression of proinflammatory biomarkers (e.g., IL-8, NQO1, and Nrf2). By illustrating this very initial evidence between molecular-level CHNOs and oxidative stress effects characterized for wintertime PM2.5, our study sheds light on future regional air quality mitigation strategies based on source, composition, and health implications under complex pollution conditions.
Related Concept Videos
01:31Formation of Species
03:45Formation of Complex Ions
02:54Ions as Acids and Bases
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
01:49The Nitrogen Cycle
01:25Role of Vitamins in Maintaining Bone Health
Vitamin A
Vitamin A is involved in the process of bone remodeling. Retinoic acid, the active metabolite of Vitamin A, has nuclear receptors in osteoblasts and osteoclasts, which are involved in bone remodeling.
Vitamin B12
Vitamin B12 acts as a cofactor during the formation of osteoblast-related proteins, such as osteocalcin. Vitamin B12 plays a role...
01:19The Role of Ion Channels in Neuronal Computation
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential....