| Abstract: | Abstract Solid polycyclic aromatic hydrocarbons with 4–7 rings on metal, glass, ceramic, and plastic substrates were desorbed and ionized in air with a quadrupled Nd-YAG laser. Gaseous product ions were analyzed at ambient conditions in air directly using ion mobility spectrometry. Ablation rates for perylene on borosilicate glass were estimated as 0.01 ng/mm2 per pulse and standard deviation for peak heights with roughly 1 ug/mm2 was 34 %. Substrate interference was avoided by using an unfocused laser beam at 0.5–1 mJ/pulse although gaseous ions also could be generated from substrates with a focused beam at 1 mJ/pulse. |
