A ship-lock-type reactor for ion-molecule reactions of mass-selected ions under high-pressure conditions.

A ship-lock-type reactor has been developed to study ion-molecule reactions of mass-selected ions under high-pressure conditions. Neutral gas molecules can be confined in the reactor by controlling two electromagnet valves to close both the inlet and the outlet of the reactor. Gas-phase ions can be trapped in an ion funnel trap installed in the reactor and interacted with a high-pressure (up to 1000 Pa) reactant gas for a period of time (up to 1 s). The reactions of mass-selected VO with CH and n-CH and mass-selected Au with n-CH were investigated to evaluate the performance of the reactor. The hydrogen atom abstraction product VOH was observed for the reaction of VO with CH, the rate constant was measured to be (1.9 ± 0.4) × 10 cm molecule s, and the kinetic isotope effect value was determined to be 5.4 ± 1.1. Furthermore, the detection limit of n-CH with 1-min measurements was determined to be (19 ± 2) pptv, which is significantly lower than those in previous studies. These results indicate that the current apparatus is a prospective for the study of slow ion-molecule reactions and the detection of trace amounts of gas species, such as volatile organic compounds.