Patent ID: 7525086

Claim:
An in-spray glow discharge ionization method comprising the steps of: (a) supplying a fluid containing a substance to be measured and a gas exhibiting Penning effect which is used for forming an a nebulized flow of the fluid; and (b) generating glow discharge in the nebulized flow of the gas exhibiting Penning effect and the fluid nebulized thereby by applying a voltage of several tens of volts to several tens of kilovolts to generate cations of the gas exhibiting Penning effect and excited atoms exhibiting Penning effect so as to ionize a chemical substance having low ionization probability with high sensitivity, directly or indirectly through an intermediately generated chemical species, wherein the chemical substance is an aromatic nitro compound, oxine copper, halogenated nitrobenzyl, or a polycyclic aromatic hydrocarbon.