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Parabens and Sunscreens in the Environment: Determination by HPLC-ESI-MS/MS and GC-MS and Calculation of Phototoxicity
ROSAL, C. G. AND L. D. BETOWSKI. Parabens and Sunscreens in the Environment: Determination by HPLC-ESI-MS/MS and GC-MS and Calculation of Phototoxicity. Presented at 56th American Society of Mass Spectrometry, Denver, CO, June 01 - 05, 2008.
Ultraviolet (UV)-absorbing chemicals are widely used in cosmetics, sunscreens, and plastics to block UV radiation from the sun. Parabens are preservatives and are used extensively in cosmetics, pharmaceuticals, and foods to prevent microbial growth and preserve a product’s integrity over time. Studies show that some sunscreens and parabens demonstrate estrogenicity and multiple hormonal activities in vitro. Because of the high consumption volume and high lipophilicity of sunscreens, these compounds have the potential to enter and persist in the environment and bioaccumulate in tissues of living organisms. This research aims to monitor and evaluate potential sources of exposure of these compounds in different environmental compartments. This poster presents method development and preliminary data. Method: An HPLC-ESI-MS/MS and a complementary GC-MS method were developed to determine the presence of select parabens and sunscreens in environmental samples. Development of an extraction method of these compounds from sewage biosolids is underway. Additionally, excited-state calculations were performed on these compounds to determine possible phototoxicity to evaluate those compounds that may present health risks. Preliminary Data: The HPLC method developed was able to separate most of the target compounds. Analysis was performed in both positive and negative modes and using MS/MS experiments in a single run using gradient elution. The selected reaction monitoring (SRM) ion (most abundant fragment ion) for each compound was produced by reducing the precursor ion to about 15% abundance relative to the most abundant ion. The GC-MS method complements the LC-MS especially for lipophilic compounds. Excited state calculations were performed on 24 of these compounds. From previous work on polycyclic aromatic hydrocarbons, a correlation was made between excited-state energies and phototoxicity. Triplet excited-state energies between 2.0 and 2.5 eV showed phototoxicity based on experimental tests. None of the 24 compounds in this study was in this range. Only three of the compounds were under 3.0 eV. These three compounds, however, have demonstrated estrogenicity in vitro in some research, which indicates that the range from 2.5 to 3.0 eV should be watched for potential ill effects. Novel Aspect: Multifaceted approach for sunscreen products: theoretical methods to predict phototoxicity, LC-MS for polar compounds, and GC-MS for lipophilic compounds.