SinS - Abstract

Abstract Information :

A part of current diseases is related to the environmental contamination we are daily exposed to. The study of the exposure and consequent health issues is known as exposome. Among the available biological matrices for the research, breast milk is of special interest, since xenobiotics can accumulate there and eventually transfer to the neonate, affecting both mother and child. One of the main throwbacks this type of analyses own is the huge amount of pollutants (and potential metabolites) present in the matrices. Moreover, analytical procedures tend to target specific families (i.e. perfluoroalkyl compounds, antibiotics or pesticides); consequently, considering the broad spectrum of contaminants involved, non-targeted methods would fit better in the evaluation of the exposome. Based on the above mentioned, the objective the present project is to develop analytical procedures to study the exposome in breast milk, to later apply them in real samples and thus, study the exposure of nursing women in the Basque Country (Spain). The initial approach consisted on targeting 187 polar analytes (Log D between -3 and 6.7 at pH 2.5; Log D from -5.8 to 6.2 at pH 10.5), which were analysed through ultra-high performance liquid chromatography coupled to high-resolution tandem mass-spectrometry (UHPLC-HRMS/MS). Sample preparation was optimized and validated, testing polymeric filters and dispersive solid-phase extraction (dSPE) approaches as clean-up, and implementing a enzymatic digestion of samples to consider the total concentration of xenobiotics in milk, including free and conjugated species. The final multitarget method was extended to suspect screening of more than 14,000 suspects, including phase II metabolites, broadening the analyte scope as it was intended for the study of the exposome.