Choosing the Right Emitter

STEP 2: Select an offline PicoTip emitter for your analysis

Offline PicoTip Emitters

Borosilicate glass and quartz PicoTips® are an improved version of the traditional nanospray ionization emitters. Their special taper makes them virtually self-filling and their specified tip opening eliminates breaking open the tips prior to use.

The proper OD for the emitter is determined by the manufacturer of your nanospray source. The Micromass (Waters) ZSpray™ NanoFlow™ uses PicoTips with a 1.0 mm OD while the ABI/Applied Biosystems/Sciex, Bruker NanoSpray™, MSD Proteomics/Protana NanoES, and Thermo Scientific Nanospray Ion sources take PicoTips with a 1.2 mm OD.

Determine your target flow rate then locate the corresponding tip size on the table below. EconoTips™ have a 1 µm ID tip and are perfect for routine sampling with a standard single-layer conductive coating. GlassTips™ areavailable in 2 and 4 µm tip IDs, with or without a durable, inert, multilayer conductive coating (U.S. Patent 5,788,166) and undergo a rigorous inspection by video microscopy. Select QuartzTips™ for samples that are sodium sensitive or need an emitter with better resistance to high pH solvents.

Tip Size vs. Flow Rate
Tip Size, ID (µm)Flow Rate* (nL/min)
120-80
220-80
440-100

Approximate range of flow rates over which the tips will generate a stable electrospray plume without sheath gas assistance. Actual performance may differ considerably caused by variations in experimental parameters (mobile phase composition, applied voltage, source design etc.)

Once you've determined the physical dimensions of your emitter based upon your target flow rate, how will you apply voltage to your sample; to the outside or directly to the sample?

NEXT: Select a conductive coating style