Mercury determination in drug and cosmetic products

Mercury and its chemical compounds are considered very toxic for plants and human beings. Nevertheless, mercury compounds are used in cosmetic and drug products, and particularly in whitening creams in Eastern countries. Mercury is used as a preservative (antifungal and antiseptic) in pharmaceutical liquid or cremates products, even in eye, ear and nasal drops. Creams containing mercury have been manufactured and used despite their confirmed health risks. These products are widely available in pharmacies and beauty aid stores in Albania. They are primarily used by women for makeup and skin lightening effects and also for local pharmaceutical treatments in the human body. The aim of this work was to analyze the mercury content in some cosmetic and drug products by using the cold vapor atomic absorption technique (CVAAS). Preliminary studies were conducted in order to evaluate a proper digestion method able to destroy the matrix of the sample and to convert all forms of mercury to elemental mercury. The results showed that a mixture of H2SO4 and HNO3 digestion provided a higher signal of mercury by destroying first the matrix of the cream type samples. Microwave digestion of liquid pharmaceutical products in the presence of strong acids (HNO3) and strong oxidants (K2Cr2O7) was established as an effective method for a complete digestion of the liquid samples. A total of 19 samples from the local pharmacies and beauty shop market were investigated. No warning information was noted on the packaging of these products. The mercury content of six of them varied between 18.5-0.10 ppm (mg/L or mg/kg). The results are compared with the well known regulations regarding the limit of mercury content for each category of the samples. Even so, the products containing mercury are poorly controlled in Albania.