Selenium in shampoo!

Rapid and accurate analysis of Selenium in shampoo ensuring compliance with EU cosmetic products legislation

Thermo Fisher Scientific has published a new method guide for the analysis of selenium in shampoo. The method, which aligns with the European Union commission directive 97/73/EEC
stipulating the methods of analysis necessary for checking composition of cosmetic products, features the Thermo Scientific iCE 3000 Series atomic absorption spectrometers. These spectrometers include deuterium background correction as standard and offer a fast and accurate solution for the analysis of selenium in shampoo. The iCE 3000's wizard-driven SOLAAR software also provides simple spectrometer optimization and method development
tools. The method is detailed in an application note, entitled "The Determination of Selenium in Shampoo by Flame Atomic Absorption Spectrometry."


Pityriasis capitis, more commonly known as dandruff, and seborrheic dermatitis, an inflammatory disease of the skin, are treated with selenium disulphide, which is contained in lotions and shampoos. After rinsing, selenium disulphide residues may remain on the scalp and can enter the body through broken or damaged skin. Since the element is considered to be a potential carcinogen, limits have been set for its content in shampoos and lotions. Commission directive 93/73/EEC mandates flame atomic absorption spectrometry with deuterium background correction as the formal method to measure and regulate the concentration of selenium disulphide in shampoo.

The new application note demonstrates how the iCE 3000 Series can be used for the identification and determination of selenium disulphide in a range of medicinal shampoos. Identification is performed by observation of a reactionary color change, while flame atomic absorption spectrometry is used for the quantitative determination of selenium. The spectrometer can be optimized simply and quickly using the wizard-driven SOLAAR software.
Deuterium background correction is implemented to ensure regulatory compliance and spiked recoveries used to verify the accuracy of the method. Experimental results have demonstrated that flame atomic absorption spectrometry with deuterium background correction is the ideal technique for the dependable analysis of selenium disulphide in shampoo.

The iCE 3000 Series atomic absorption spectrometers are high-performance, flexible, easy-to-use and compact systems. The iCE 3300 is a fully PC-controlled flame atomic absorption spectrometer with full graphite furnace and vapour generation options. The iCE 3400 features a dedicated Zeeman furnace system, superior optics and flexible background correction options to maximize analytical performance and simplicity. The iCE 3500 is a dual flame/furnace atomiser allowing automatic, efficient and safe switching between flame and furnace analyses. Advanced optics and background correction accuracy ensure best analytical performance.