title: Data processing technique in gas chromatography/time-of-flight mass spectrometry.
abstract: A complete mass spectrum was measured at an acquisition rate of 1 kHz using a femtosecond-multiphoton-ionization time-of-flight mass spectrometer for analyte eluting from a gas chromatograph. A contour-map display, i.e. a two-dimensional plot, of the data was first constructed for a simultaneous overview of the mass spectra and the mass chromatograms. The noise component in the signal was then reduced by digital filtering and reduced further by smoothing the data. The detection limit (S/N = 3) was improved from 240 to 76 fg for 2,3,4,6,7-pentachlorodibenzofuran, with no appreciable loss of resolution in the chromatogram. The achieved value was lower than the value (<100 fg) required by Japanese Industrial Standards for dioxin analysis. A new parameter, referred to as a 'reliability factor', was defined in this study to calculate the similarity between the intensity distribution of the isotope peaks observed in the mass spectrum and that calculated from the natural abundance ratio of the isotopes. This parameter was useful for evaluation of the purity of the chromatographic peak.
authors.affiliation: Laboratory of Chemistry, Graduate School of Design, Kyushu University, 4-9-1 Shiobaru, Minami-ku, Fukuoka 815-8540, Japan. imasaka@design.kyushu-u.ac.jp
authors.forename: Tomoko
authors.initials: T
authors.lastname: Imasaka
authors.forename: Nami
authors.initials: N
authors.lastname: Nakamura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sakoda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Yuka
authors.initials: Y
authors.lastname: Watanabe-Ezoe
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Uchimura
authors.forename: Totaro
authors.initials: T
authors.lastname: Imasaka