Development of a supercritical fluid extractor coupled with a time-of-flight mass spectrometer for online detection of extracts.
A combined apparatus of a supercritical CO2 extractor (SFE) and a time-of-flight mass spectrometer (TOF-MS) was developed aiming at the direct analysis of extracts. A fused-silica capillary acts as both a pressure restrictor and an effluent injection nozzle into the TOF-MS. The tip of the nozzle was narrowed by melting and abrasion so that a greater pressure drop occurred at the tip. In the TOF-MS chamber, differential pumping between the main and ionization chamber kept the pressure in the ionization chamber at around 10(-3) Pa when the SFE pressure was at 9.7 to 29.4 MPa. The TOF-MS performance, a mass resolution of 263 at m/z = 146, and a sensitivity of 1.6 ng (p-dichlorobenzene) were certified by direct injection of a standard organic solution. Online detection of SFE effluent containing naphthalene, p-dichlorobenzene, phenanthrene and pyrene were successfully performed by the TOF-MS only for 48000 ionization cycles corresponding to 7.5 s.
Sakamoto
Tetsuo
T
Environmental Science Center, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0013, Japan. sakamoto@esc.u-tokyo.ac.jp
Yamamoto
Azusa
A
Owari
Masanori
M
Nihei
Yoshimasa
Y