Silicon membrane interface for the direct analysis of Kathon CG in aqueous solutions and cosmetic emulsions.

An easy determination of Kathon CG, an antimicrobial agent widely used in cosmetic and toiletry products, has been achieved by means of silicone membrane interfaced mass spectrometry. Low levels of the above preservative (up to p.p.b.) could be easily detected in both aqueous solutions and cosmetic emulsions. Valuable information has been obtained on the stabilization and decomposition processes to which the organic components of Kathon CG are subject. The role of magnesium ions, which are present as a stabilizing agent in Kathon CG formulation, in these processes has been investigated, leading to the identification of some degradation products.