Determination of four parabens and bisphenols A, F and S in human breast milk using QuEChERS and liquid chromatography coupled to mass spectrometry.

For the first time, a multiresidue, sensitive and high throughput method for determination of bisphenol A, F and S and 4 parabens (methyl paraben, ethyl paraben, propyl paraben and butyl paraben) in human breast milk was developed. The proposed method includes an extraction and clean-up procedure based on QuEChERS methodology followed by liquid chromatography coupled to triple quadrupole mass spectrometry determination. Negative atmospheric pressure chemical ionization in the selected reaction monitoring mode was used for mass detection. During the method validation the recoveries varied between 83 and 115% with a precision lower than 20% for all analytes using spiked levels from 0.1 to 50 ng mL-1. The LOQ was 0.10 ng mL-1 for most of the analytes. The proposed method was successfully applied for the determination of these compounds in 10 breast milk samples from volunteer lactating mothers from the Valencian region (Spain). Among parabens, methyl paraben presented the highest detection frequency (80%) with a concentration range of 0.11-7.00 ng mL-1, while bisphenol A was detected more frequently than BPF and BPS (80% of detection frequency) with concentrations ranging from 0.13 to 1.62 ng mL-1.