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Application of Hadamard transform to gas chromatography/nonresonant multiphoton ionization/time‐of‐flight mass spectrometry
Author(s) -
Cheng ChaoChiang,
Chang HungWei,
Uchimura Tomohiro,
Imasaka Totaro,
Kaneta Takashi,
Lin ChengHuang
Publication year - 2010
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200900662
Subject(s) - hadamard transform , injector , chemistry , mass spectrometry , analytical chemistry (journal) , ionization , chromatography , nozzle , gas chromatography , ion , physics , organic chemistry , quantum mechanics , thermodynamics
The technique of Hadamard transform was successfully coupled with GC/nonresonant multiphoton ionization/TOFMS, for the first time. 1,4‐Dichlorobenzene and the fourth harmonic generation (266 nm) of a Nd:YAG laser were employed as a model sample and an ionization laser, respectively. A Hadamard‐injector coupled with a capillary‐based supersonic jet nozzle (capillary‐injector) was also developed in this study. The Hadamard‐injector was used to obtain the chromatogram, which was encoded by successive sample introduction based on Hadamard codes, and the capillary‐injector was used for injection of GC‐elutes into TOFMS. Compared with a conventional single injection method, the S / N ratios were substantially improved after inverse Hadamard transformation of the encoded chromatogram. Under optimized conditions, when Hadamard matrices of 103 and 255 were used, the S / N ratios of the signals for 1,4‐dichlorobenzene (concentration level, 4 μg/1 mL ACN) were substantially improved to 4.1‐ and 6.6‐fold, respectively, and those improvements are in good agreement with those obtained by theory (5.1‐ and 8.0‐fold).