Titanium dioxide (TiO2) is a versatile compound widely utilized in various industries, particularly in the production of paints, coatings, plastics, and paper. The accurate determination of titanium dioxide content is essential for quality control purposes in these manufacturing processes. Among the various methods available for quantifying TiO2, gravimetric analysis stands out due to its reliability and accuracy. This article explores the gravimetric determination of titanium dioxide, its significance in factory settings, and the technical processes involved.

Titanium dioxide (TiO2) is a chemically inert inorganic compound and an insoluble white solid that occurs naturally in several minerals, including rutile, anatase, and brookite. It is created synthetically from the mineral ilmenite. It is an insoluble white solid. Anatase, when compared to brookite and routine, has the most industrial applications, but it is the most toxic form of TiO2.

In the context of titanium dioxide determination, the process generally begins with the sample preparation, where a known mass of the sample containing TiO2 is dissolved or digested appropriately. The subsequent steps involve adding a precipitating agent, such as ammonium sulfate or sulfuric acid, to the prepared solution, which facilitates the formation of a titanium precipitate. This precipitate is often titanium hydroxide, which is not only insoluble but can be easily filtered out from the liquid phase.

As mentioned above, these oxide NPs are harmful in part because both anatase and rutile forms are semiconductors and produce ROS. Particularly, P25 kind has band-gap energies estimated of 3.2 and 3.0 eV, equivalent to radiation wavelengths of approximately 388 and 414 nm, respectively. Irradiation at these wavelengths or below produces a separation of charge, resulting in a hole in the valence band and a free electron in the conduction band, due to the electron movement from the valence to conduction bands. These hole–electron pairs generate ROS when they interact with H₂O or O₂ [43,44]. It was described that they can cause an increase in ROS levels after exposure to UV-visible light [45]. The NBT assay in the studied samples showed that bare P25TiO₂NPs produce a large amount of ROS, which is drastically reduced by functionalization with vitamin B2 (Fig. 5). This vitamin, also known as riboflavin, was discovered in 1872 as a yellow fluorescent pigment, [46] but its function as an essential vitamin for humans was established more than sixty years later, and its antioxidant capacity was not studied until the end of the XX century [47,48]. This antioxidant role in cells is partially explained because the glutathione reductase enzyme (GR) requires it for good functionality. This enzyme is the one in charge of the conversion of oxidized glutathione to its reduced form which acts as a powerful inner antioxidant and can quench the ROS [49,50]. The cost of this action is that the glutathione is converted to the oxidized form and needs to be recovered by the GR. Consequently, the cells need more vitamin B2. Another glutathione action is the protection against hydroperoxide. This activity is also mediated by riboflavin. Therefore, local delivery of this vitamin seems to significantly help the cells in their fight to keep the oxidative balance, once they are exposed to high levels of ROS.

By doing so, we achieve cost reduction, increased film strength and improved fungicidal and algaecidal properties. 

The risks associated with titanium dioxide exposure depend on a variety of factors, including the form of the mineral, the route of exposure (such as being inhaled or consumed), and the duration and intensity of exposure.

The whole scientific experimental design in some of these studies is‌ very flawed, Kaminski said.

Mexican researchers sought to evaluate the effects of E171 across a span of conditions in mice, including its influence on behavior, along with the effects on the colon and liver. The research, published in 2020 in the journal Food and Chemical Toxicology, showed that E171 promoted anxiety and induced adenomas, or noncancerous tumors, in the colon. They also found that E171 heightened goblet cells hypertrophy and hyperplasia, which is typically seen in asthma patients and triggered by smoking or external pollutants and toxins. They also noted mucins overexpression in the mice, which can be linked to cancer cell formation. 

EFSA's evaluation is related to the risks of TiO₂ used as a food additive, not to other uses.

But if thats not quite enough..............