Arrays of micro-electrospray emitters were fabricated on polycarbonate substrates using a laser etching technique. Stable multi-electrosprays were successfully generated in the liquid flow rate range relevant to mass spectrometric applications. Comparison of electrosprays generated from the micro-fabricated emitter array and conventional fused silica capillaries showed similar spray characteristics and reliability. Higher total electrospray ion currents were observed as the number of electrosprays increased at a given total liquid flow rate. Consistent with the theoretical prediction, the total spray current at a constant total liquid flow rate was shown experimentally to be approximately proportional to the square root of the number of electrosprays. It is further projected that when total flow rate is optimized the maximum achievable total current will be proportioned to the number of emitters. Evaluation of the multi-electrospray device using a triple quadrople mass spectrometer showed a factor of 2 to 3 sensitivity enhancement for the spray numbers ranging from two to nine compared to a conventional single electrospray ionization source under the same operating conditions.
Revised: July 11, 2001 |
Published: April 15, 2001
Citation
Tang K., Y. Lin, D.W. Matson, T. Kim, and R.D. Smith. 2001.Generation of Multiple Electrosprays Using Microfabricated Emitter Arrays for Improved Mass Spectrometric Sensitivity.Analytical Chemistry 73, no. 8:1658-1663.PNNL-SA-34087.