Optimization of Bisphenol A Analysis in Breast Milk Using Liquid Chromatography and Mass Spectrometry

Studies suggest that exposure to Bisphenol A (BPA) may alter the immune profile of the breast, and this immune profile alteration may be associated with breast density. Breast density is a known risk factor for breast cancer, connecting BPA exposure with breast cancer risk. Controversies surrounding the relationship between BPA and breast cancer are due to inconsistent findings and weak study designs. In a newly designed study, we will analyze BPA and cytokine levels in breast milk collected from 16 primiparous women at 6 and 8 weeks postpartum. In order to accurately assess BPA levels, liquid chromatography and mass spectrometry parameters must be determined before the start of study sample analysis.

Our project aims to determine the optimal methods and LC/MS/MS instrumental parameters for extracting and analyzing study samples based on previously used procedures for BPA in similar matrices. During this process, practice samples spiked with known concentrations of BPA will be extracted and quantified in order to evaluate the efficiency of the four major steps involved in the process of BPA extraction and analysis: hexane partitioning, solid phase extraction, synthesis of pyridine sulfonyl derivative, and LC/MS/MS analysis. Although a significant amount of time was spent to optimize these procedures, our practice runs allowed us to diagnose and solve issues that may have interfered with study sample analysis. Thus, this project was important to the immediate analysis of BPA in the long term goal of determining the association between BPA and cytokine levels in breastmilk.