Analysis of Perfluorinated Compounds in Human Breast Milk

Thermo Fisher Scientific Inc has developed a new method for sensitive, accurate and reproducible quantitation of low levels of perfluorinated compounds (PFCs) in human breast milk. Using selected reaction monitoring (SRM) and highly selective reaction monitoring (H-SRM) on an integrated ultra high performance liquid chromatography mass spectrometry (UHPLC/MS) platform enables reliable and robust detection of PFCs at ppt concentrations in human breast milk.

Many PFCs are detectable in human serum and breast milk and have been found in the blood of newborns possibly through lactational transfer from mothers. By coupling the Thermo Scientific Accela UHPLC and the PAL autosampler to the Thermo Scientific TSQ Vantage triple-stage quadrupole MS the system was able to provide rapid, accurate and robust analysis and quantitation of six PFCs in human breast milk using SRM and H-SRM. Elimination of PFC contamination was achieved using a PFC-free Accela pump with a pre-cleaned PFC-free degasser, while also replacing Teflon tubing with PEEK tubing. The excellent sensitivity and selectivity afforded by SRM on the TSQ Vantage system obviated the need for any further modifications of the LC configuration, a distinct advantage over other commercial platforms that require the use of in-line contaminant traps or column-switching methods for PFC analysis.

Using the integrated UHPLC/MS platform, separation of the six PFC analytes in a spiked human breast milk matrix was achieved within nine minutes. As the majority of interferences from matrices elute early at void volume, elution of the first compound at 3.64 minutes ensured a robust quantitation method. Excellent linearity in detector response was observed while H-SRM eliminated matrix interferences without compromising sensitivity.

The Accela system, combined with 1.9 μm particle columns and the industry’s highest pressure quaternary pump, enables fast and efficient chromatographic separations over an expansive range of flow rates and pressures. Delivering up to a tenfold improvement in signal-to-noise ratio compared to existing triple-quadrupole MS systems, The TSQ Vantage facilitates highly sensitive quantitation in matrix-rich samples and enhances analytical precision. The instrument is capable of high resolution selection of precursor ions, enabling H-SRM for greater analytical selectivity and accuracy.