Determination of Ti from TiO2 Nanoparticles in Biological Materials by Different ICP-MS Instruments: Method Validation and Applications

The accurate determination of nanoparticles (NPs) content in biological samples is of great interest for studying its potential impacts on health. This paper describes a method validation process for Ti determination from TiO2 NPs in biological matrixes using a closed-vessel microwave digestion with a mixture of 3 mL of HNO3 and 0.4 mL of HF and a detection by quadrupole inductively coupled plasma-mass spectrometry (Q-ICP-MS), in both standard and collision/ reaction cell (CCT) modes. As no suitable certified reference materials are available, several internal reference materials (IRMs) were prepared precisely and they were used for the optimisation and the analytical quality assurance of the method. Several criteria such as linearity, limits of quantification (LOQ), precision under repeatability conditions and intermediate precision reproducibility were evaluated. Furthermore, the method was compared on different Q-ICP-MS devices and on a high resolution (HR)-ICP-MS using the prepared IRMs and various samples of rat tissues exposed to two different sizes of TiO2 NPs. The results demonstrated that the Q-ICP-MS method evaluated permitted an accurate determination of Ti present as TiO2 NPs in both standard and CCT modes, with a greater accuracy in CCT mode at low concentration levels near the LOQ of 0.10 mg kg-1.