Miniaturized high-resolution time-of-flight mass spectrometer MULTUM-S II with an infinite flight path.

A new miniature multiturn time-of-flight (TOF) analyzer "MULTUM-S II" has been designed and constructed. This instrument consists of an electron ionization source, the multiturn TOF ion optics, a detector, vacuum system, and electronic circuits. The multiturn TOF analyzer consists of four electrostatic toroidal sectors and two additional electric toroidal sectors for the purpose of ion injection/ejection. The size and weight of the system is less than 50 cm × 57 cm × 30 cm and 35 kg (including vacuum pumps and electronic circuits). The multiturn TOF analyzer is capable of high mass resolution because of its infinite flight path utilizing perfect space and time focused closed flight orbit. To evaluate the resolution in MULTUM-S II, separation of pyridine (¹²C₅H₅N) and the isotopic component of benzene (¹³C¹²C₅H₆) was performed at a mass resolution of about 20,000. Another performance characteristic of the MULTUM-S II was demonstrated by the separation of the greenhouse gas doublet CO₂ and N₂O (Δm = 0.0113 Da). While the mass difference is a mere 0.01 Da, the instrument could easily separate the two peaks at a calculated mass resolution of 31,600. The MULTUM-S II offers high mass resolution mass spectrometry in a miniaturized/portable enclosure.