Practice question

Electrospray ionization creates a fine aerosol under high voltage, generating multiply protonated species [M+nH]n+ from a single protein or peptide chain. Multiple charging drastically reduces m/z values, bringing very large biomolecules of 50 to 100 kDa into quadrupole or Orbitrap detection range of 500 to 2000 m/z, allowing accurate mass determination with high resolution. It supports efficient coupling to liquid chromatography for proteomics workflows. Unlike methods limited to volatile gases, ESI preserves noncovalent complexes and yields characteristic charge-state envelopes useful for mathematical deconvolution and sensitive macromolecular analysis in biology.