Direct Biological Sample Analyses by Laserspray Ionization Miniature Mass Spectrometry.

With improved performances, miniature mass spectrometers are becoming suitable for more practical applications. At the same time, the coupling of an approximate ionization source is essential in terms of minimizing sample preparation and broadening the range of samples that could be analyzed. In this study, an atmospheric pressure laserspray ionization (AP-LSI) source was coupled with our home developed miniature ion trap mass spectrometer. The whole system is compact in size, and biological samples could be directly analyzed with minimum sample preparation. Direct detections of peptides, proteins, drugs in whole blood, and urine could be achieved with high sensitivity. The analyses of tissue sections were demonstrated, and different regions in a tissue section could be differentiated based on their lipid profiles. Results suggest that the coupling of AP-LSI with miniature mass spectrometer is a powerful technique, which could potentially benefit target molecule analysis in biological and medical applications.