This study investigates the seasonal occurrence, sources and transformation mechanisms of piperazine and its nitrosated derivatives, mononitrosopiperazine and dinitrosopiperazine, alongside nitrate and nitrite in fine and coarse particulate matter in order to evaluate the influence of emissions and meteorological conditions. All target compounds exhibited significantly higher concentrations during the heating season, reflecting increased combustion activities as well as atmospheric conditions conducive to pollutant accumulation and secondary formation. The concentrations of fine and coarse particulates exhibited a highly significant correlation, suggesting the presence of shared sources, particularly residential and industrial heating, during the winter months. The secondary formation of mononitrosopiperazine and dinitrosopiperazine was a consequence of the atmospheric nitrosation of piperazine in the presence of nitrite. The formation of these compounds was found to be favoured by the following conditions: cold weather, stagnant conditions and low solar radiation. The dinitrosopiperazine exhibited a significant correlation with nitrite and nitrate, while demonstrating an inverse relationship with temperature and insolation, thereby supporting its secondary formation. However, a negative correlation was observed between relative humidity and mononitrosopiperazine, dinitrosopiperazine, nitrite, and nitrate, indicating enhanced scavenging or dilution processes. Principal component analysis (PCA) differentiated primary piperazine emissions from secondary nitrosamine formation, thereby reinforcing the role of NOx-related chemistry. ANOVA analysis was also performed to back up the findings from seasonal concentration trends, correlation analysis and PCA, and to provide a consistent understanding of their behavior, sources and atmospheric dynamics. The findings under consideration demonstrate the combined effects of precursor availability, emission strength, and meteorology on reactive nitrogen compounds and nitrosamines.