"A solid-state infrared laser for two-step desorption–ionization processes in single-particle mass spectrometry"
A KrF excimer laser (248 nm, PhotonEx, Photonion GmbH, Germany) is used for ionization after laser desorption. The ion signals, from both cations and anions, were recorded by a 14-bit digitizer card with one channel per polarity (ADQ14, Teledyne SP Devices AB, Sweden) and were analyzed using custom MATLAB software, including preprocessing and peak area integration.