MASS SPECTROMETER

摘要

A mass spectrometer is disclosed comprising an ion detector 4 positioned upstream of a quadrupole mass filter/analyser 2. Ions are passed through the quadrupole mass filter/analyser 2, are stored in an ion trap and are then passed back through the same mass filter/analyser 2 before being detected by the upstream ion detector 4. MS/MS experiments can be performed using apparatus having only a single mass filter/analyser 2.