Enhanced detection of aromatic oxidation products using NO chemical ionization mass spectrometry with limited nitric acid.

Nitrate ion-based chemical ionization mass spectrometry (NO -CIMS) is widely used for detection of highly oxygenated organic molecules (HOMs). HOMs are known to participate in molecular clustering and new particle formation and growth, and hence understanding the formation pathways and amounts of these compounds in the atmosphere is essential. However, the absence of analytical standards prevents robust quantification of HOM concentrations.