Laser ablation low-flow ICP-MS for elemental bioimaging

Abstract

A laser ablation system (LA) was coupled to an in-house developed low-flow inductively coupled plasma ion source for mass spectrometry (ICP-MS). In this setup, the low-flow torch showed best analytical performance at a total argon gas flow rate of only 1.27 L min⁻¹ and a generator power of 900 W. The optimized system was applied to elemental bioimaging. Two different sections of one kidney sample were analyzed and images of the elements Al and Br from the staining agents hematoxylin and eosin, respectively, and I from a contrast agent iodixanol were recorded selectively and with high sensitivity. For detection of the elements, the mass traces ²⁷Al, ⁷⁹Br, ⁸¹Br, and ¹²⁷I were selected to demonstrate the system's analytical performance over a wide mass range. In total, the argon consumption could be reduced by >90% compared to conventional ICP-MS systems.