Combining Laser Ablation/Liquid Phase Collection Surface Sampling and High-Performance Liquid Chromatography−Electrospray Ionization-Mass Spectrometry

摘要

This letter describes the coupling of ambientnpressure transmission geometry laser ablation with a liquidnphase sample collection method for surface sampling andnionization with subsequent mass spectral analysis. A commerciallynavailable autosampler was adapted to produce a liquidndroplet at the end of the syringe injection needle while in closenproximity to the surface to collect the sample plume producednby laser ablation. The sample collection was followed by eithernflow injection or a high-performance liquid chromatographyn(HPLC) separation of the extracted components and detectionnwith electrospray ionization mass spectrometry (ESI-MS). To illustrate the analytical utility of this coupling, thin films of ancommercial ink sample containing rhodamine 6G and of mixed isobaric rhodamine B and 6G dyes on glass microscope slides werenanalyzed. The flow injection and HPLC-ESI-MS analysis revealed successful laser ablation, capture, and with HPLC, the separationnof the two compounds. The ablated circular area was about 70 μmin diameter for these experiments. The spatial sampling resolutionnafforded by the laser ablation, as well as the ability to use sample processing methods like HPLC between the sample collection andnionization steps, makes this combined surface sampling/ionization technique a highly versatile analytical tool.