Patent ID: 8399828

Claim:
A merged beam tandem time-of-flight mass spectrometer comprising: a) a first pulsed ion source producing a first pulsed beam of ions with ions having a first predetermined mass, first charge and first velocity; b) a second pulsed ion source producing a second pulsed beam of ions with ions having a second predetermined mass, second charge and second velocity, wherein the second charge is opposite in polarity to the first charge and the second velocity is substantially equal to the first velocity; c) an ion mirror that reflects the first pulsed beam of ions wherein the first and the second pulsed beams of ions are merged together in a field-free reaction region, wherein the first and second pulsed beams of ions arrive substantially simultaneously in both time and space, and with substantially the same velocity so that they react to form fragment ions; d) a time-of-flight mass analyzer that separates the fragment ions according to their mass-to-charge ratio; and e) an ion detector positioned in the flight path after the time-of-flight mass analyzer, the ion detector detecting the separated fragment ions.