A thermal desorption chemical ionization mass spectrometer has been developed for real time, quantitative chemical analysis of ultrafine particles. The technique combines recently developed nanoparticle separation and collection techniques with highly sensitive chemical analysis provided by selected ion chemical ionization mass spectrometry. Sensitivity tests using laboratorygenerated ammonium sulfate particles in the diameter range 10-16 nm show that sulfate and ammonium can be quantified with as little as 1 pg of collected aerosol mass. Such sensitivity makes this instrument suitable for real time measurements of the chemical composition of sub-10 nm particles reported recently from nucleation events.
Bibliographical noteFunding Information:
Received 5 July 2002; accepted 11 October 2002. We would like to thank DOE for their support of this project through grant No. DE-FG02-98R62556. Address correspondence to Didier Voisin, 3 Place Victor Hugo, Case 29, 13331 Marseille Cedex 3, France. E-mail: firstname.lastname@example.org