The rapid growth in the production and use of nanomaterials is observed in recent years. Nanoparticles of titanium dioxide (TiO2NPs) are one of the most frequently used nanomaterials. Sunscreens, food additives, food contact materials and textiles are the major fields of current application of TiO2NPs. Due to increasing use of nanomaterials in daily life and thus increasing exposure to them, concerns have been raised about their safety. Likely routes of human exposure to released TiO2NPs as well as their health and environmental effects are presented in this paper. At present, our knowledge about the risk of nanomaterials is incomplete. However, it is known that toxicity of nanoparticles depends on their size, shape, crystal structure, surface morphology, surface area, charge, concentration and solubility (the possibility of dissolution into ionic forms). Therefore, it is necessary to use several complementary analytical techniques to fully characterize the NPs. Common approaches used for the characterization of nanomaterials include microscopy based techniques e.g. transmission electron microscopy (TEM), X-ray techniques e.g. X-ray diffraction (XRD), methods based on optical properties e.g. dynamic light scattering (DLS). Separation of nanoparticulate and ionic forms of metal can be accomplished using chromatographic techniques (such as high performance liquid chromatography (HPLC), size exclusion chromatography (SEC), hydrodynamic chromatography (HDC)) or capillary electrophoresis (CE). Size-resolved NPs and dissolved (ionic) fractions can be further characterized by on-line detectors, such as ICP MS. Recently, single particle inductively coupled plasma mass spectrometry (sp ICP MS) has been gaining increasing attention as a technique for detection, characterization, and quantification of nanoparticles. This technique provides information on individual particles, including particle size, number size distribution, particle number concentration and mass concentration. In addition, sp ICP MS can distinguish dissolved and nanoparticulate forms of an element. The fundamentals, advantages and limitations of this technique, as well as its application for the characterization and quantification of TiO2NPs in different matrices (consumer products, food and environmental samples) are reviewed in this paper.