Determination of Titanium Dioxide in Commercial Sunscreens by Inductively Coupled Plasma-Optical Emission Spectrometry

作者：Bunhu Tavengwa; Kindness Andrew; Martincigh Bice S^*

来源：South African Journal of Chemistry, 2011, 64: 139-143.

• Titanium dioxide
• sunscreens
• physical blocker
• inductively coupled plasma-optical emission spectrometry

A variety of sunscreen products have been developed to afford the consumer protection against some of the deleterious effects, for example erythema, caused by solar ultraviolet radiation. The requirement that suncare products offer broad-spectrum protection has resulted in the use of inorganic oxides, such as micronized titanium dioxide (TiO(2)), in their formulation. However, there are now concerns about the photocatalytic effects of the TiO(2) in these products and its potential phototoxicity to the skin through the generation of reactive oxygen species such as hydroxyl and superoxide anion radicals. It is important, therefore, that the amounts of TiO(2) in suncare products be closely monitored and maintained within stipulated ranges. A simple, fast and reliable analytical method for the determination of TiO(2) in commercial sunscreen products by inductively coupled plasma-optical emission spectrometry (ICP-OES) was developed and validated. The limits of detection and quantitation were found to be 0.018 and 0.062 mu g mL(-1), respectively. The average percentage recovery of TiO(2) was 102.32 +/- 2.87 % with a RSD of 2.81 %. The method was applied to determine the concentration of TiO(2) in 22 commercial suncare samples of which 14 contained TiO(2). The amounts of TiO(2) measured in these sunscreens ranged from 0.05 to 3.21 %. To our knowledge this is the first study that reports the amounts of TiO(2) in sunscreen products available on the South African market.

• 出版日期2011