A High Repetition Rate (1 kHz) Microcrystal Laser for High Throughput Atmospheric Pressure MALDI-Quadrupole-Time-of-Flight Mass Spectrometry

Abstract
Sample throughput has been increased in many areas of proteomics, but the last significant advance in lasers used for matrix-assisted laser desorption/ionization (MALDI) was the introduction of cartridge-type N2 lasers (337 nm, 4-ns pulse widths, 1−30-Hz repetition rates) more than a decade ago. This report describes the application of a 1-kHz repetition rate Nd:YAG laser (355 nm, <500-ps pulse widths) for atmospheric pressure MALDI-QqTOFMS, and data obtained are compared to a conventional nitrogen laser. For example, the signal intensity for angiotensin II using the 1-kHz laser was in some cases enhanced by a factor of 80 and high-quality data could be obtained in as little as 1 s.