LAUSR

This review intends to cover a range of brief description of the generation mechanisms, the determination of the concentration, and the identification of negative air ions (NAI). This is divided into two parts: (i) it pays attention to the generation of NAI, which contains natural and artificial methods. According to the variation of energy in the environment, different methods based on natural generation are introduced in detail. As for artificial generation of NAI, corona discharge is dominantly elaborated due to its preponderance in convenient to control of the concentration of ions. (ii) it tends to introduce the determination of NAI, containing quantitative and qualitative detection, by using ion counting device and mass spectrometer, respectively.