Laser ablation electrospray ionization

The mid-IR laser is used to generate gas phase particles which are then ionized through interactions with charged droplets from the ESI source.

Because molecules and aerosols are ionized by interacting with an electrospray plume, LAESI's ionization mechanism is similar to SESI and EESI techniques.

LAESI can be used to perform MS analysis of many different classes of compounds ranging from small molecules, such as pharmaceuticals, saccharides,[1][2][3][9][10] lipids,[5][7] and metabolites[1][2][3][4][5][6][7][8][9][10] to larger biomolecules like peptides[1] and proteins.

[1] LAESI has also been shown to have a quantitative dynamic range of 4 decades and a limit of detection (LOD) of 8 fmol with verapamil, a small pharmaceutical molecule.

[16] A small-scale explosion occurs in the target and a small portion of the sample is ablated into the gas phase by a short (5 ns), mid-IR (2,940 nm) laser pulse.

These analyses can also be performed on liquid samples, such as biofluids, containing peptides, proteins, metabolites, and other biomarkers for clinical, diagnostic, and discovery workflows.

[22] LAESI technology allows high throughput analysis of these sample types and the use of internal standards and calibration curves permit the absolute quantitation of targeted biomolecules.