Extremely fast

Full FAIMS separation sweeps can be carried out in less than 1 second, allowing real-time LC-FAIMS-MS analysis

The extreme electric fields that can be attained within the microscale gaps of the ultra-FAIMS microchip enable much shorter separation times of ~20 to 50 µs, which is ~100 times faster than the fastest previous FAIMS devices. This high speed is crucial for adding FAIMS to online LC-MS, where typical peaks may only be 10-20s wide. Unlike macroscopic FAIMS devices, the ultra-FAIMS chip can scan the entire CF range multiple times as an LC peak elutes, enabling the full peak capacity of the FAIMS device to be used.

Dynamic range & sensitivity

FAIMS performance is sensitive to the shape of the gap between the electrodes. In the curved gaps of previous FAIMS-MS systems, an inhomogeneous field focuses ions, which improves the transmission of some ions but degrades others. In the planar gaps of the new chips, a homogeneous field provides much more uniform analyses. Planar gaps also provide a much better resolution/sensitivity balance for moderate ion currents. By using multiple separation channels, ultra-FAIMS microchips also avoid the ion current limitations that would be seen in a single narrow channel. This makes the device more suitable for quantitative measurements.

Operational flexibility

Previous FAIMS devices operated inherently near the electrical breakdown point, making them prone to failure and limiting the gases to more insulating ones rather than those optimum for routine use or the quality of analyses. In particular, helium/nitrogen mixtures can improve separations compared to nitrogen gas alone, and the benefit grows at higher helium fractions. However, the electrical breakdown occurs more easily in helium, which previously limited its content to <50%. The extremely high resistance to electrical breakdown in the microscopic gaps allows the use of up to 100% helium, which improves the achievable separation power and operational flexibility.

Very high separation fields

FAIMS separation fields more than twice as high as in other FAIMS-MS devices.

The extreme electric fields that can be attained within the microscale gaps of the ultra-FAIMS microchip enable much shorter separation times of ~20 to 50 µs, which is ~100 times faster than the fastest previous FAIMS devices. This high speed is crucial for adding FAIMS to online LC-MS, where typical peaks may only be 10-20s wide. Unlike macroscopic FAIMS devices, the ultra-FAIMS chip can scan the entire CF range multiple times as an LC peak elutes, enabling the full peak capacity of the FAIMS device to be used.

Small device size

A footprint smaller than an US quarter makes integration between the ESI source and MS inlet much more straightforward.

Other advantages

• Reduces chemical background noise
• Separates isobaric analytes (improving accurate mass measurement)
• Separates protein and peptide charge states
• Helps identification of low abundance analytes in a noisy background
• Separates conformers & isomers
• Filters complex samples