Analytical performance of a miniature cylindrical ion trap mass spectrometer.

The analytical performance of a fieldable cylindrical ion trap (CIT)-based miniature mass spectrometer is described. A detailed description of the instrument itself is to be found in the immediately preceding paper (Patterson, G. E.; Guymon, A. J.; Riter, L S.; Everly, M.; Griep-Raming, J.; Laughlin, B. C.; Ouyang, Z.; Cooks, R. G., Miniature Cylindrical Ion Trap Mass Spectrometer, Anal. Chem. 2002, 24, 6145-6153). Applications employing the MS/MS and MSn capabilities of the miniature instrument and analytical performance criteria are given here. The limit of detection for methyl salicylate, introduced as the pure vapor, is estimated as 1 pg. The resolution, R = m/delta m, where delta m, measured as full width at half-maximum, is estimated as 100. Monitoring of organic compounds in air is performed using a permeation membrane introduction device coupled to the mass spectrometer. Water monitoring is performed using an external membrane introduction mass spectrometry (MIMS) system, with acetophenone and toluene serving as model compounds. Data are given for chemical warfare agent simulants, methyl salicylate, and dimethyl methyl phosphonate (DMMP) in air. On-line detection of menthol vapor emitted from a cough drop is reported. Methyl salicylate in air gives a recognizable mass spectrum at 400 ppb in the ambient system, while use of a heated membrane brings the detection limit down to 10 ppb.