IDENTIFICATION OF COMPLEX AROMATIC-MOLECULES IN INDIVIDUAL INTERPLANETARY DUST PARTICLES

Seventeen stratospherically collected particles-eight of which are cla ssified as interplanetary dust particles (IDPs), seven of which are cl assified as probable terrestrial contaminants, and two of which have u ncertain origins-were studied with a microprobe two-step laser mass sp ectrometer. Many polycyclic aromatic hydrocarbons (PAHs) and their alk ylated derivatives were identified in two of the eight IDPs. The PAHs observed include a high-mass envelope not found in meteorites or terre strial contaminants and prominent odd-mass peaks suggestive of nitroge n-containing functional groups attached to aromatic chromophores. In a ddition, the complexity of the IDP mass spectra has no precedence in p revious studies of meteorite samples or their acid residues. Extensive checks were performed to demonstrate that the PAH signals are not cau sed by terrestrial contaminants.