Coupling on-chip solid-phase extraction to electrospray mass spectrometry through an integrated electrospray tip

Yanou Yang, Chen Li, Kelvin H. Lee, Harold G. Craighead

Research output: Contribution to journalArticlepeer-review

69 Scopus citations


We report the integration of solid-phase extraction (SPE) with mass spectrometry (MS) through an on-chip electrospray tip for sample precleaning and preconcentration. An in situ polymerized alkylacrylate-based monolithic column was used as the stationary phase for the on-chip SPE. Each microchip consists of two sets of microchannels and their respective integrated electrospray tips, with a common gold electrode. After the microchip was fabricated from cycloolefin polymer by hot embossing, thermal bonding, and annealing steps, a mixture of monomers and porogenic solvents was pumped into the microchannels and certain areas of the main microchannels were exposed to UV irradiation through a mask. The resulting porous monolithic beds that were polymerized from different compositions of the mixture were characterized by scanning electron microscopy. The microchip containing the monolithic column was then interfaced to an ion trap (IT) mass spectrometer by modifying a commercially available interfacing system. Makeup solution from the side channel was infused concurrently with the solution flowing into the main channel, and the mixture of these two solutions was sprayed into the MS orifice. Both the adsorption and elution of a pharmaceutical test compound, imipramine, to and from the on-chip SPE columns were monitored by MS. The potential application of this device for sample cleanup was demonstrated by pretreatment of urine samples spiked with imipramine.

Original languageEnglish (US)
Pages (from-to)3622-3630
Number of pages9
Issue number19
StatePublished - Oct 2005


  • Electrospray mass spectrometry
  • In situ polymerized monolith
  • Miniaturization
  • Polymer-based microfluidic device
  • Sample preconcentration
  • Solid-phase extraction

ASJC Scopus subject areas

  • Clinical Biochemistry


Dive into the research topics of 'Coupling on-chip solid-phase extraction to electrospray mass spectrometry through an integrated electrospray tip'. Together they form a unique fingerprint.

Cite this