The parabens, neutral esters derivatives of p-hydroxybenzoic acid, have been used in low concentrations as food and cosmetic preservatives, as it inhibits the growth of bacteria and fungi. Research conducted in vitro and in vivo have shown that parabens can minimize the action of the female hormone, estrogen, which can stimulate the growth of MCF7 cells, which are related to the development of breast cancer. In 2004, British researchers identified and quantified traces of parabens, in the form not hydrolyzed, collected from breast cancer tumor tissue samples. The parabens have also been found in other biological matrices, such as human milk. This biological matrix shows great variability in its composition, which is influenced by different factors, among which stand out not only the conditions of maternal nutrition, but also the environmental conditions to which wet-nurses are or have been exposed throughout life. For lactates, human milk may be the major excretory route of persistent lipophilic substances, which are stored in the human body, mainly in adipose tissue. Due to the complexity of milk samples, prior to chromatographic analysis have to perform the sample preparation stage, to remove most of the endogenous components of this matrix and concentrate the analytes, often present at trace levels. Modern analytical chemistry has been directed to simplification by the miniaturization of analytical systems. In this context, it is possible to highlight dispersive liquid-liquid microextraction (DLLME), fast analytical procedure based on the balance of partition, which uses only some µLs of organic solvent. In this project, the analytical techniques DLLME and liquid chromatography-tandem mass spectrometry will be employed in the determination of parabens in human milk samples to evaluate the exposure to these substances.
News published in Agência FAPESP Newsletter about the scholarship: