Main Strategies of the Sample Preparation of Biological Samples Containing Nanoparticles for Their Subsequent Analysis by Single Particle Inductively Coupled Plasma Mass Spectrometry: A Mini-Review

The characterization of highly dispersed materials and nanoparticles (NPs), as well as the investigation of their transformations in biological systems, constitute a critical aspect of research aimed at assessing the potential for active NP applications in biomedicine and pharmacology. A promising method for characterizing nanoparticles involves single particle inductively coupled plasma mass spectrometry (SP ICP MS). This technique enables the determination of nanoparticle masses at the femtogram level and gives information on their distribution by the analyte form (soluble ionic or nanoscale), size, and quantity within the analyzed sample. Sample preparation for an SP ICP MS analysis is based on the quantitative extraction of nanoparticles from a biological sample while preserving their characteristics. Liquid samples for analysis are prepared by dilutions, involving filtration, centrifugation, sedimentation, and various fractionation and separation techniques. Enzymatic and alkaline hydrolysis have been applied to the decomposition of biological tissues. The discussion addresses the capabilities and limitations of primary sample preparation methods, using biomaterials containing gold and silver nanoparticles as examples. Particular attention is given to techniques that do not alter the analyte, such as dilution and filtration. A possibility of analyzing iron oxide-based materials, relevant to biomedical research, using SP ICP MS is noted, along with the challenges associated with such analyses. The combination of laser ablation (as a sampling method) with SP ICP MS is shown to be a promising approach to studying the spatial distribution of nanoparticles in biological systems.