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εtipTM ESI Tip     Analyze

Protea has pioneered improvement of the ESI process by engineering a revolutionary spray tip that directs ions to the Taylor cone surface, creating smaller droplets with more uniform charge distribution and less hydratioΕn. The enhanced ESI process leads to a reduction of background noise in your spectra, with an average improvement of 50%, compared to a pulled fused silica tip. This improved process is fully functional at both micro-ESI (0.4 to 5.0mL/min) and nano-ESI (50 to 400nL/min) flow rates. The etip construction is nearly unbreakable and has a longer lifetime than traditional pulled fused silica tips.


  • ESI Performance – Enhanced ionization improves signal-to-noise ratio
  • Spray Position – Adjustable tip holder allows variable angle spray
  • Durability – New space age composite makes tips resistant to breakage and clogging

Research Applications:

  • Direct infusion ESI-MS investigations
  • LC-MS/MS analyses of peptide and protein digest mixtures
  • Elecrospray ionization efficiency studies

Product Specifications:

Flow rate  

0.050 – 5 ml/min

Voltage range

1.5 – 6.0 kV

Working Distance

Range 2 – 8mm, optimum 5 mm   

Solvent compatibility   

No known incompatibilities


Positive and negative



             A- εtip
             B- Taylor cone
             C. Plume

Two standard proteins, cytochrome C and myoglobin, were analyzed by direct infusion ESI-MS in a Finnigan LTQ-MS using the Protea εtip and a New Objectives fused silica PicoTip (30um tip ID) at a concentration of 10-pmol/μL and a fl ow rate of 1.0-μL/min. The Total Ion Current (TIC) plots of these analyses show that the εtip demonstrates a more stable ESI performance (baseline RSD) and a general increase in sensitivity that are realized from the εtip’s more efficient electrospray ionization.