A Faraday cup detector for high‐mass ions in matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

A detector has been developed, which collects and amplifies the electric charge of an incoming bunch of ions, for use in matrix‐assisted laser desorption/ionization (MALDI) time‐of‐flight (TOF) mass spectrometry. The detector has a time‐of‐flight resolution of about 50 ns and a noise level of 750 electrons rms. It has been tested in a Finnigan LaserMAT spectrometer with a number of samples which Were expected to give reliable results in MALDI time‐of‐flight mass spectrometry. Clear mass peaks have been observed from samples with masses above 300 kDa.