Noise electrospray ionization

Muddiman D.C., Rockwood A.L., Gao Q., Severs J.C., Udseth H.R., and Smith R.D. (1995), Application of sequential paired covariance to capillary electrophoresis electrospray ionization time-of-flightmass spectrometry unraveling the signal from the noise in the electropherogram, Anal. Chem. 67, 4371. 

Atmospheric pressure chemical ionization (APCI) is the ionization source that provides lower chemical noise and, subsequently, lower quantification limit than electrospray ionization (ESI) which is more robust. The use of mass spectrometric methods can be expected to increase, particularly as they become easier to use and the costs of instrumentation continue to fall. Despite the enormous progress in analytical technologies, methods based on HPLC with fluorescence detection are the most used today for aflatoxins instrumental analysis, because of the large diffusion of this configuration in routine laboratories. 

---