Choosing the Right Emitter

STEP 1: Determine if you need an online or offline emitter

Online/Dynamic Nanospray

Online nanospray analysis is when mobile phase is pumped, at low flow rates, through a small diameter emitter into a mass spectrometer. High voltage is applied to the mobile phase to generate an even spray into the mass spectrometer. The source of the mobile phase, most commonly a syringe pump or a liquid chromatograph (LC), delivers sample that has passed through chromatographic media.

Offline/Static Nanospray

Offline analysis is typically defined by a discrete sample being loaded by syringe or pipette into an emitter—usually borosilicate glass or quartz— that is then mounted into the mass spectrometer's source. To generate the sample flow, offline techniques rely on the electrostatic attraction of the liquid inside the emitter, which has been charged by application of high voltage, towards the counter-electrode.

MethodPumped Flow*Sample VolumeTip IDFlow Rate
OfflineNo0.1 to 5µL
(1 µL is typical)
1 - 4 µm10 to 80 nL/min
(25 µL/min typical)
OnlineYes*<0.1 to >10 µL
(1 - 5 µL is typical)
2 - 50 µm
(5 - 15 µm is typical)
100 nL to - 1 µL/min
(50 - 500 µL/min is typical)

I'm doing online analysis. Now what?

I'm doing offline analysis. What's next?