Ultrasensitive detection of aromatic hydrocarbons by two-photon photoionization

Abstract
An optimized multiphoton photoionization detection system has been applied to monitor aromatic‐hydrocarbon vapor density as a function of temperature. The density curves established for naphthalene by this procedure permit estimation of a detection limit of 5×104 molecules/cm3 in a nitrogen buffer gas. With slight modification this method woud be capable of single‐molecule detection limits.