PMID- 18570388
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20080911
LR  - 20080801
IS  - 1520-6882 (Electronic)
IS  - 0003-2700 (Linking)
VI  - 80
IP  - 15
DP  - 2008 Aug 1
TI  - Applications of Hadamard transform to gas chromatography/mass spectrometry and 
      liquid chromatography/mass spectrometry.
PG  - 5755-9
LID - 10.1021/ac800201r [doi]
AB  - 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-methylenedioxy-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 approximately 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.
FAU - Lin, Cheng-Huang
AU  - Lin CH
AD  - Department of Chemistry, National Taiwan Normal University, 88 Section 4, 
      Tingchow Road, Taipei, Taiwan. chenglin@ntnu.edu.tw
FAU - Kaneta, Takashi
AU  - Kaneta T
FAU - Chen, Hung-Ming
AU  - Chen HM
FAU - Chen, Wen-Xiong
AU  - Chen WX
FAU - Chang, Hung-Wei
AU  - Chang HW
FAU - Liu, Ju-Tsung
AU  - Liu JT
LA  - eng
PT  - Journal Article
DEP - 20080621
PL  - United States
TA  - Anal Chem
JT  - Analytical chemistry
JID - 0370536
EDAT- 2008/06/24 09:00
MHDA- 2008/06/24 09:01
CRDT- 2008/06/24 09:00
PHST- 2008/06/24 09:00 [pubmed]
PHST- 2008/06/24 09:01 [medline]
PHST- 2008/06/24 09:00 [entrez]
AID - 10.1021/ac800201r [doi]
PST - ppublish
SO  - Anal Chem. 2008 Aug 1;80(15):5755-9. doi: 10.1021/ac800201r. Epub 2008 Jun 21.