Efficiency of nano-electrospray ionization.
The efficiency of nano-electrospray ionization, defined as the flux of ions reaching the detector of a triple-quadrupole mass spectrometer divided by the flux of analyte ions leaving the needle, has been measured in a series of controlled experiments with dodecyltrimethyl ammonium (DDTMA) bromide, myoglobin, Glu- [1]-fibrinopeptide, and gramicidin S. By varying the flow rate from each needle, the optimum efficiency was determined. In general, the efficiency increased as the flow rate decreased. For DDTMA, efficiencies of up to 12% were measured, although efficiencies of approximately 1% were more common. Ion current measurements indicated efficient transfer of ions from the needle through to the detector. Significant needle-to-needle variations in efficiency were encountered and attributed to variations in ion-generation efficiency.
El-Faramawy
Ayman
A
Department of Chemistry and Center for Research in Mass Spectrometry, York University, Toronto, Ontario, Canada.
Siu
K W Michael
KW
Thomson
Bruce A
BA
D004867:Equipment Design; D019544:Equipment Failure Analysis; D017022:Flow Injection Analysis / Q000295:instrumentation* / Q000379:methods; D008832:Microchemistry / Q000295:instrumentation* / Q000379:methods; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013673:Technology Assessment, Biomedical