Miniature time-of-flight mass spectrometer

The Johns Hopkins University Applied Physics Laboratory (JHU/APL) is designing, fabricating and testing a small, high resolution, time-of-flight mass spectrometer (TOFMS) suitable for biomedical applications requiring lightweight, low-powered and portable instrumentation. This instrument can be used to identify solids, liquids and gases of both chemical and biological origins to quantify the habitat environment and support biomedical research and medical care. The virtue of the JHU/APL TOFMS technology presented here, resides in the promise for a small (less than one cubic ft.), lightweight (less than 5 kg), low power (less than 50 watts), device that can be used continuously with advanced signal processing diagnostics. To date, JHU/APL has demonstrated mass capability beyond 10,000 Atomic Mass Units (AMU) in a very small, low power prototype for biological analysis. The JHU/APL approach, described in this paper, is to design the instrument for both wide mass range and fine mass resolution by the use of electronic control in a tandem mass spectrometer instrument. In this paper we will outline the principle behind the operation of the APL's miniaturized TOFMS system and present examples of the analysis of chemical and biological substances. In addition, we will also describe a novel method for the collection of airborne particles for TOFMS analysis suitable for automated collection and analysis applications.