Laser Microprobe with Fourier Transform Ion Cyclotron Resonance Mass Spectrometer for Surface Analysis

Fourier transform ion cyclotron resonance laser microprobe mass spectrometry (FTICR LMMS) uses focused laser irradiation of solids with a spot of 5 μm and a FTICR mass analyzer for local analysis with high mass resolution. A new ion source design has been developed to improve the extraction and transfer of ions generated in an external laser microprobe source. Calculations predicted trapping of ions initially emitted with angles up to 40° and 60° from the surface and from a distance of 1 mm above the sample, respectively. The analytical performances of the method have been verified on two sets of test samples. First, detection of chemisorbed benzotriazole on copper, average of two monolayers, has been shown with less sample consumption than typically required in static secondary ion mass spectrometry with a time-of-flight analyzer. Second, experiments on a thermal plate for offset printing have shown the feasibility of analysis and quantification of dyes embedded in a polymer matrix.