Characteristics of Molecular Secondary Ion Mass Spectrometry

Secondary ion mass spectrometry(SIMS) has been widely used for elementary analysis of solids. Since Benninghoven applied SIMS to analysis of amino acids in 1976[1], various large bio-organic compounds have been investigated using SIMS[2,3]. Introduction of the glycerol matrix by Barber et al. [4] prompted great progress in use of SIMS for such large bio-organic compounds[5,6]. They put a sample on a metal surface together with two or three μg of glycerol and hit it with a fast neutral argon beam. They called this technique fast atom bombardment(FAB). At first, it was thought that ion bombardment could not be used because of surface charging. However, it was found that an analogous spectrum could be obtained by SIMS using charged particle bombard-ment[7,8]. It is now widely admitted that the same physical phenomenon occurs with both ion and neutral fast atom bombardment.