Data acquisition and instrument control system for ion flight time measurements in mass spectrometry

Abstract

A microcomputer system is described that provides instrument control and data acquisition for ion flight time measurements in mass spectrometry. This system is designed specifically for time-resolved ion momentum spectrometry (TRIMS), a new mass spectrometry/mass spectrometry (MS/MS) technique that utilizes time-of-flight measurements in a magnetic sector instrument. The flexibility of the design, however, makes it applicable to many types of instruments that employ ion flight time measurements. The heart of the system is a digital boxcar integrator with 10-ns timing precision. The microcomputer has control of both the magnetic field and the sampled flight time. Software, written in forth, allows all standard MS/MS scans to be obtained, even those requiring complex linked scans of the magnetic field strength and the sampled flight time. Data that demonstrate the accuracy of these scans are shown for metastable decompositions of n decane.