Easy dual-mode ambient mass spectrometry with Venturi self-pumping, canned air, disposable parts and voltage-free sonic-spray ionization.

An exceptionally easy to assemble source for ambient mass spectrometry is described. Based on Venturi easy ambient sonic-spray ionization (V-EASI), the source was further simplified by the use of a can of compressed air which simultaneously provides solution or solvent Venturi self-pumping and continuous, stable and abundant low-noise ion signal via voltage-free sonic-spraying. Further simplification was also attained by the use of inexpensive and readily commercially available parts: a surgical 2-way catheter, an aerosol can of compressed air, a 30 cm long fused-silica capillary and a hypodermic needle. This "Spartan" V-EASI source seems to offer one of the easiest and cheapest ways to make ions for ambient desorption/ionization mass spectrometry analysis of both liquid and solid samples.