Electrospray ionization of selected low-molecular-weight natural biotoxins

Electrospray ionization (ESI) spectra were acquired for several low-molecular-weight marine and freshwater biotoxins. Spectra were dominated by ions that represented protonated molecules, contained few other ions, and corresponded well with spectra acquired by other soft ionization techniques. Each biotoxin was successfully analyzed using similar ESI conditions. Nozzle-skimmer differential voltage greatly influenced spectra of several compounds by enhancing collision-induced dissociation in the transport region of the ESI source.