Character of jet flows in mass-spectrometric interfaces at various pressures and chamber lengths

Samples-in particular, of bioorganic matter—are usually introduced into a mass spectrometer from atmosphere to high vacuum via a gasdynamic interface that represents a chamber with intermediate pressure or a system of chambers with gradually decreasing pressure. Transformation of the character of an expanding jet flow in a single-chamber interface has been studied as dependent on the chamber length and pressure. Knowledge of this character allows the system parameters to be most effectively used so as to ensure high ion transmission and decrease mass discrimination.