A miniature mass spectrometer for liquid chromatography applications.

A miniature mass spectrometer capable of detecting analytes eluting from a high-performance liquid chromatography (HPLC) system is described and demonstrated for the first time. The entire instrument, including all pumps and the computer, is contained within a single enclosure that may be conveniently accommodated at the base of the HPLC stack. The microspray ion source, vacuum interface, ion guide, and quadrupole ion filter are all microengineered.

Depth profiling of sterically-stabilised polystyrene nanoparticles using laser ablation/ionisation mass spectrometric methods.

An aerodynamic lens has been used to introduce polystyrene nanoparticles into an apparatus that combines laser vaporisation with mass spectrometric measurements of ion intensity. The particles have a mean diameter of 129 nm and are sterically-stabilised with poly(ethylene glycol) which coats the surface to a depth of approximately 5 nm. Measurements have been made at wavelengths of 266, 355, and 523 nm, and over a range of laser powers.