Titanium dioxide (TiO2) is an insoluble and inactive material that is used as a coloring additive in many foods to make them look pretty and appealing to eat. It is used as a whitening and brightening agent in candies, chewing gum, white sauces and cake icing/frosting, and is used to provide texture to the foods.
Titanium Dioxide is generally recognized as safe (GRAS) by the U.S. Food and Drug Administration (FDA) and they allow food products to contain up to 1% food grade titanium dioxide without having to add it on the ingredient label.
So, you ask, “what is all the fuss about?” The answer is: Titanium dioxide as a nanoparticle.
The International Organization for Standardization (ISO) defines nanoparticles as particles that have at least one dimension (i.e. length, width or diameter) which is between 1 and 100 nanometers in size and come in a variety of shapes. Interest in nanoparticle analysis has increased steadily in the last few years as uses of engineered nanoparticles are proliferating and their behavior and potential negative effects on the environment and human health are not yet well understood. Regulatory bodies are also investigating the safety of some nanoparticles which are believed to be toxic for human health. Titanium dioxide in the form of a “nanoparticle” may pose a risk as it may pass into the lungs, liver or intestines. Researchers suggest that some powders can become more toxic in their nanoparticle forms and children are more exposed to titanium dioxide as they indulge in more candies, gums and sweet desserts.
France has taken the lead to move forward with placing a ban on titanium dioxide. As of 2019, no food product can contain titanium dioxide in France. Brunoe Poirson, a junior minister in environmental ministry said, “We want to suspend the use of this substance as a food additive by the end of the year.” Along with banning the substance, France has also asked the European Commission to take similar actions . Many French sweets manufacturers have already stopped using the food additive ahead of the upcoming ban. Dunkin’ Brands, a U.S. company, has also announced that they will be removing the alleged titanium dioxide nano particle from Dunkin’ Donuts’ powdered sugar donuts. As more companies follow suit in eliminating this nanoparticle, testing will become an integral part of monitoring for titanium dioxide around the world. Is your laboratory ready to monitor for titanium dioxide in foods?
To determine both the size and the composition of the nanoparticles techniques such as scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX), near infra-red (NIR) and single particle inductively coupled plasma mass spectrometry (spICP-MS) are suitable. If you are particularly interested in metal and metal oxide nanoparticles, such as Au, Ag and TiO2 particles, you can use NIR, SEM-EDX or spICP-MS, but to quantify the nanoparticles you need spICP-MS.
Single particle ICP-MS (spICP-MS) consists of diluting your samples by very large factors so that you can detect individual particles as they go through the plasma. All that’s required is a sensitive, fast scanning quadrupole ICP-MS with high signal to background and either some instrument software or a suitable spreadsheet to process the data to provide nanoparticle size, composition and concentration information. The single particle ICP-MS measurement technique allows analysts to determine the presence of nanoparticles in different food matrices with ease and confidence.
For more information on nanoparticles, please see the below resources:
Compendium: ICP-MS Nanoparticle Compendium