Estimated levels of xenoestrogens, bisphenol A and 4-nonylphenol, in human breastmilk in Beijing determined by high performance liquid chromatography-tandem mass spectrometry after derivatization

Abstract

To aid in the management of high-risk populations, bisphenol A (BPA) and 4-nonylphenol (4-NP) exposure from formula and human breastmilk was estimated in newborns and infants (aged 0–24 months) in Beijing. Derivatization with dansyl chloride coupled with high performance liquid chromatography-tandem mass spectrometry was performed to analyze traces of BPA and 4-NP in human breastmilk. Danyl-BPA and danyl-4-NP were easily obtained as a highly selective method, which was applied to 118 human breastmilk samples. The results indicate that newborns and infants (aged 0–24 months) are safe in terms of dietary exposure when fed by breastmilk, but are at higher exposure risk when fed by formula milk at 0–12 months of age. BPA and NP exposure from human breastmilk is under tolerable daily intake of 4 µg·kg⁻¹ bw.d⁻¹ and 5 µg·kg⁻¹ bw·d⁻¹, respectively. These results supplement the estimated exposure database for BPA and 4-NP in Beijing, especially for newborns and infants.