We have been developing direct sampling analysis method and miniature mass spectrometry(MS)systems for point-of-care analysis of biological samples.Lipids are a class of biological compounds that are important to biological processes and can potentially serve as biomarkers for diseases.Direct sampling ionization lipids from biological samples such as tissues has also been done using various ambient ionization methods.With moderate extension of the m/z range,miniature ion trap mass spectrometers with ambient ionization interfaces [1] can also perform tandem MS analysis of the lipids,which is a critical step toward the point-of-car applications.In this presentation,a suite of technologies will be presented,which has been developed to enable the direct analysis and quantitation of the lipids in blood and tissue samples using miniature MS systems.The mass range of the miniature ion trap mass spectrometer has been extended to m/z 1000 with the combination of wider range of RF voltage scan and lower AC frequency for resonance ejection.Tandem MS scans are performed with the residue air molecules.Probes with polyporous organic polymer coatings have been developed to collect the lipids from blood and tissue samples,followed by an extraction ionization for analysis.Miniature MS system with an endoscopic sampling probe of 1.5 m length has also been developed for in-vivo sampling and analysis of tissue surfaces.In addition to the intensity profile that can be obtained through MS analysis,quantitation of the unsaturated lipid isomers has also been enabled by implementing an online photochemical((Paternò–Büchi)reaction [2].The C=C bonds were modified into an oxetane ring that can be easily fragmented during collisional induced dissociation.Quantitation of the unsaturated fatty acids in blood has also been developed using the combination of PB reaction and neutral loss scan.Comparative study involving normal and diseased samples have been successfully done and will be reported.