presented by

Bryan Miller
Hewlett Packard

March 25, 1997
04:00:00 PM

The Scripps Research Institute, W.M. Keck Foundation Amphitheater

Bryan Miller is an LC/MS Product Manager with the California Analytical Division of the Hewlett-Packard Company, Palo Alto, California. Bryan earned B.S. and M.S. degrees in Chemistry from Stanford University, and was an Associate Staff Research Scientist with Raychem Corporation in Menlo Park, California prior to joining Hewlett Packard Company in 1984. Since then he has been involved with mass spectrometry at Hewlett-Packard in a variety of positions; most recently Bryan has been part of a team developing new LC/MS instrumentation and software.

A novel nebulization scheme for coupling liquid delivery systems to mass spectrometers for API-LC/MS will be described. In this scheme, a pneumatic nebulizer is oriented orthogonally with respect to the sampling axis of a fixed leak into the mass spectrometer. The orthogonal orientation results in a dramatic reduction in detector noise caused by liquid clusters, while providing highly efficient analyte ion production and capture. With this arrangement, signal to noise ratios can be enhanced by at least 10-fold compared to conventional on-axis or near-axis spraying orientations. The orthogonal geometry is applicable over a broad range of flow rates and mobile phase compositions. Applications examples from a new commercial instrument that employs the orthogonal spraying geometry will be shown.