Demonstration of Ultraviolet Photodissociation Induced by Light-Emitting Diodes Externally Interfaced to a Linear Ion-Trap Mass Spectrometer

We report the first demonstration of ultraviolet photodissociation (UVPD) mass spectrometry achieved with light-emitting diodes (LEDs) externally interfaced to a linear ion-trap mass spectrometer. LEDs provide a low-cost, compact photon source that is technologically simpler to operate than the high-powered pulsed laser systems that are currently used in UVPD instruments. Mounting the LEDs external to the mass spectrometer provides improved flexibility for interchanging LEDs with different wavelengths. Here, we demonstrate 365 and 280 nm LED-UVPD on flavin mononucleotide, tryptophan, and the pentapeptide Leu-Enk. The UVPD fragments observed are in full agreement with fragments observed using pulsed lasers as the photon source.