Applications of Hadamard transform to gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry

Cheng Huang Lin, Takashi Kaneta, Hung Ming Chen, Wen Xiong Chen, Hung Wei Chang, Ju Tsung Liu

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Successful application of the Hadamard transform (HT) technique to gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) is described. Novel sample injection devices were developed to achieve multiple sample injections in both GC and LC instruments. Air pressure was controlled by an electromagnetic valve in GC, while a syringe pump and Tee connector were employed for the injection device in LC. Two well-known, abused drugs, 3,4-methylene-dioxy-N-methylamphetamine (MDMA) and N,N-dimethyltryptamine (DMT), were employed as model samples. Both of the injection devices permitted precise successive injections, resulting in clearly modulated chromatograms encoded by Hadamard matrices. After inverse Hadamard transformation of the encoded chromatogram, the signal-to-noise (S/N) ratios of the signals were substantially improved compared with those expected from theoretical values. The S/N ratios were enhanced ∼10-fold in HT-GC/MS and 6.8 in HT-LC/MS, using the matrices of 1023 and 511, respectively. The HT-GC/MS was successfully applied to the determination of MDMA in the urine sample of a suspect.

Original languageEnglish
Pages (from-to)5755-5759
Number of pages5
JournalAnalytical Chemistry
Issue number15
Publication statusPublished - 2008 Aug 1


ASJC Scopus subject areas

  • Analytical Chemistry

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