Introducing Samples Directly into Electrospray Ionization Mass Spectrometers by Direct Infusion Using a Nanoelectrospray Interface

Terry D. Lee1, Roger E. Moore1, Denise Keen1

1 Beckman Research Institute of the City of Hope, Duarte, California
Publication Name:  Current Protocols in Protein Science
Unit Number:  Unit 16.8
DOI:  10.1002/0471140864.ps1608s74
Online Posting Date:  November, 2013
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Abstract

Procedures are described for constructing and using a microscale electrospray interface for direct infusion of samples into mass spectrometers. The sensitivity of the nanospray interface is a result of greatly reducing the flow of sample solution while preserving the analyte signal intensity. The described methodology provides a simple and robust way to analyze individual purified peptide and protein samples, i.e., samples that do not require liquid chromatography separation. Curr. Protoc. Protein Sci. 74:16.8.1‐16.8.7. © 2013 by John Wiley & Sons, Inc.

Keywords: mass spectrometry; nanoelectrospray; microscale electrospray interface

     
 
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Table of Contents

  • Basic Protocol 1: Analysis of Peptide and Protein Samples by Direct Infusion Nanoelectrospray
  • Commentary
  • Literature Cited
  • Figures
  • Tables
     
 
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Materials

Basic Protocol 1: Analysis of Peptide and Protein Samples by Direct Infusion Nanoelectrospray

  Materials
  • ∼10 pmol/µl suitably prepared peptide or protein sample (free from buffer salts and strong acids; see Commentary)
  • Sample solvent: 50% (v/v) aqueous acetonitrile/1% (v/v) formic acid
  • Nanoelectrospray mount (e.g., Universal Nanoflow Sprayer, cat. no. 70003890), Thermo or mount intended for LC/MS operation (e.g., Universal Nanoflow Sprayer, cat. no. 70003890, Waters)
  • 0.368‐mm diameter platinum wire (see Table 16.8.1 for suppliers)
  • 1‐mm o.d. × 0.75‐mm i.d. × 2‐cm length, tip i.d. 1 ± 0.5 µm, with filament pulled, borosilicate glass needles (see Table 16.8.1 for suppliers or Rae and Levis, , for fabrication)
  • 0.25‐mm o.d. gel‐loading pipet tips (e.g., Eppendorf, cat. no. 022351656; USA Scientific, cat. no. 1022‐8950) and pipettor
  • Electrospray mass spectrometer
Table 6.8.1   MaterialsCommercial Vendors of Nanoelectrospray Components

Company Location Phone Web site
Platinum wire
Alfa Aesar Ward Hill, Mass. 978‐521‐6300 http://www.alfa.com
ESPI Metals Ashland, Oreg. 800‐635‐2581 http://www.espimetals.com
Prepulled glass capillaries
Scientific Instrument Services Ringoes, N.J. 908‐788‐5550 http://www.sisweb.com
FIVEphoton Biochemicals San Diego, Calif. 800‐462‐4507 http://www.fivephoton.com
World Precision Instruments Sarasota, Fla. 866‐606‐1974 http://www.wpinc.com
Tritech Research Los Angeles, Calif. 800‐733‐3874 http://www.tritechresearch.com
Glass capillary pullers
Harvard Apparatus Holliston, Mass. 800‐323‐2380 http://www.harvardapparatus.com
Sutter Instrument Company Novato, Calif. 888‐883‐0128 http://www.sutter.com
World Precision Instruments Sarasota, Fla. 866‐606‐1974 http://www.wpiinc.com
MicroData Instrument S. Plainfield, N.J. 908‐222‐1717 http://www.microdatamdi.com
Vestavia Scientific Birmingham, Ala. 205‐979‐9852 http://www.microperfusion.com
Tritech Research Los Angeles, Calif. 800‐733‐3874 http://www.tritechresearch.com
C18 pipet tips
Varian (Omix C18 tips) Walnut Creek, Calif. 866‐377‐0104 http://www.varianinc.com
Sigma‐Aldrich (Supel‐Tips C18) Bellefonte, Pa. 800‐247‐6628 http://www.sigmaaldrich.com
EMD Milliopore (ZipTip C18) Billerica, Mass. 800‐645‐5476 http://www.millipore.com
Thermo Scientific (Pierce C18 Tips) Rockford, Ill. 800‐874‐3723 http://www.piercenet.com

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Figures

Videos

Literature Cited

Literature Cited
  Geromanos, S., Freckleton, G., and Tempst, P. 2000. Tuning of an electrospray ionization source for maximum peptide‐ion transmission into a mass spectrometer. Anal. Chem. 72:777‐790.
  Gibson, G.T., Mugo, S.M., and Oleschuk, R.D. 2009. Nanoelectrospray emitters: Trends and perspective. Mass Spectrom. Rev. 28:918‐936.
  Mao, P., Wang, H.T., Yang, P., and Wang, D. 2011. Multinozzle emitter arrays for nanoelectrospray mass spectrometry. Anal. Chem. 83:6082‐6089.
  Rae, K.L. and Levis, R.A. 2004. Fabrication of patch pipets. Curr. Protoc. Neurosci. 26:6.3.1‐6.3.32.
  Rob, T. and Wilson, D.J. 2009. A versatile microfluidic chip for millisecond time‐scale kinetic studies by electrospray mass spectrometry. J. Am. Soc. Mass Spectrom. 20:124‐130.
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  Van Pelt, C.K., Zhang, S., Fung, E., Chu, I., Liu, T., Li, C., Korfmacher, W.A., and Henion, J. 2003. A fully automated nanoelectrospray tandem mass spectrometric method for analysis of Caco‐2 samples. Rapid Commun. Mass Spectrom. 17:1573‐1578.
  Whitehouse, C.M., Dreyer, R.N., Yamashita, M., and Fenn, J.B. 1985. Electrospray interface for liquid chromatographs and mass spectrometers. Anal. Chem. 57:675‐679.
  Wilm, M.S. and Mann, M. 1994. Electrospray and Taylor‐Cone theory, Dole's beam of macromolecules at last? Int. J. Mass Spectrom. Ion Proc. 136:167‐180.
  Wilm, M. and Mann, M. 1996. Analytical properties of the nanoelectrospray ion source. Anal. Chem. 68:1‐8.
  Zhu, Y., Pan, J.Z., Su, Y., He, Q.H., and Fang, Q. 2010. Fabrication of low‐melting‐point alloy microelectrode and monolithic spray tip for integration of glass chip with electrospray ionization mass spectrometry. Talanta 81:1069‐1075.
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