Exploration of Matrix Effects in Laser Ablation Inductively Coupled Plasma Mass Spectrometry Imaging of Cisplatin-Treated Tumors
Calum J. Greenhalgh, Ellie Karekla, Gareth J. Miles, Ian Powley, Catia Costa, Janella de Jesus, Melanie J. Bailey, Catrin Pritchard, Marion MacFarlane, J. H. Pringle, Amy J. Managh
Abstract
The use of a low aerosol dispersion ablation chamber within a laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS) setup allows for high-resolution, high-speed imaging of the distribution of elements within a sample. Here we show how this enhanced capability creates new analytical problems and solutions. We report the distribution of platinum at the cellular level in non-small cell lung cancer (NSCLC) explant models after treatment with clinically relevant doses of cisplatin. This revealed for the first time a correlation between the platinum signal and the presence of carbon deposits within lung tissue. We show how complementary ion beam analysis techniques, particle-induced X-ray emission (PIXE) and elastic backscattering spectrometry (EBS), can be used to explore potential matrix effects in LA-ICP-MS data. For these samples, it was confirmed that the enhancement was unlikely to have resulted from a matrix effect alone. Thus, the presence of carbon deposits within tissue has potential implications for the effective distribution of the cisplatin drug.