Development of a Specialized Mass Spectrometer for Measuring the Lithium Isotopic Ratio Using Electrospray Ionization with Controlled In-Source Fragmentation and Atomization (ERIAD).

We developed a specialized mass-spectrometer for measuring the lithium isotopic ratio using electrospray ionization with controlled in-source fragmentation and atomization (in-source atomization, ERIAD). We used a Mattauch–Herzog double-focusing mass analyzer suspended under accelerating voltage; this makes its coupling with the gas-dynamic interface much easier. The mass analyzer is optimized up to the second degree; it can operate with ion beams with a broad energy spread, typical for ERIAD. Both isotopes, 6Li and 7Li, are detected simultaneously by a two-channel microchannel plate detector. The gas-dynamic interface is of the Kontorovitz–Gray type; it is gas-dynamically "long": the nozzle-skimmer distance is four times longer than the Mach barrel at the operation pressure (200 Pa). The instrument is a desktop; it weighs approximately 20 kg. It is suitable for rapid analysis: one run takes 1000 s, and sample replacement takes only 100 s. The measurement precision in a series of 11 LiCl conventional measurements was 0.3%. [ABSTRACT FROM AUTHOR]