Hadamard transform capillary electrophoresis combined with absorption spectrometry

Kazuki Hata, Takashi Kaneta, Totaro Imasaka

Research output: Contribution to journalArticlepeer-review

36 Citations (Scopus)


A novel injection device for applying absorption spectrometry to Hadamard transform (HT) capillary electrophoresis is described. A small hole, at the center part of the capillary, functions as an inlet port for the sample. The hole is immersed in a sample solution and the end of the capillary that is usually employed for sample introduction is immersed in a buffer solution. An ultraviolet absorption detector is placed between the sample injection port and the other end of the capillary filled with a buffer solution. A high potential is continuously applied between the injection port and the end of the capillary, which allows the sample solution to be introduced into the separation capillary. By application of a higher potential modulated according to a Hadamard code between both ends of the capillary, the buffer solution is injected into the separation capillary. In some preliminary experiments, this injection device was utilized to introduce a single sample segment into a capillary. As expected, a single peak was observed in the electropherogram for a sample containing a single component. This device was then employed for multiple sample injection in UT capillary electrophoresis. An 8-fold improvement in the S/N ratio was observed when the HT technique was used, in which a 255-order of a Hadamard matrix was used, as expected from theory. The present approach was also utilized for the sensitive detection of a sample comprised of multiple components.

Original languageEnglish
Pages (from-to)4421-4425
Number of pages5
JournalAnalytical Chemistry
Issue number15
Publication statusPublished - Aug 1 2004
Externally publishedYes

ASJC Scopus subject areas

  • Analytical Chemistry


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