Determination of five bisphenols in commercial milk samples by liquid chromatography coupled to fluorescence detection.

The presence of five bisphenols, i.e., bisphenol F, bisphenol A, bisphenol B, bisphenol F diglycidyl ether, and bisphenol A diglycidyl ether, was monitored in commercial milk packed in plastic bottles marketed in Italy. The new validated method includes a solid-phase extraction procedure followed by liquid chromatography with fluorescence detection. All positive results were confirmed by liquid chromatography-tandem mass spectrometry analysis. The limits of detection and quantification and the recovery percentages indicated that the method is suitable for detecting bisphenols in milk at concentrations far below the legal limits. Of 68 commercial milk samples analyzed, no bisphenol was found in 27 samples (39.7%), and 41 samples (60.3%) contained one or more bisphenols. The bisphenol most frequently found was bisphenol F (36 samples, 52.9%) followed by bisphenol A (20 samples, 29.4%) and bisphenol B (6 samples, 8.8%). Taking into consideration the limits of detection, no sample contained either bisphenol F diglycidyl ether or bisphenol A diglycidyl ether.