“…Standards of BPA (≥99%), BPAF (≥99%), bisphenol B (BPB, ≥98%), BPF (≥98%), BPS (≥98%), bisphenol M (BPM, ≥99%), bisphenol P (BPP, ≥99%), benzophenone-1 (BzP-1, ≥99%), benzophenone-2 (BzP-2, ≥97%), benzophenone-8 (BzP-8, ≥98%) and 4hydroxybenzophenone (4-OH-BzP, ≥98%) were purchased from Sigma-Aldrich (Steinheim, Germany). Internal standards (ISs) were purchased from Cambridge Isotope Laboratories (Andover MA, USA): 13 C-isotope of BPA (BPA-13 C 12 ; ≥99%), BPAF (BPAF-13 C 12 ; ≥99%), BPB (BPB-13 C 12 ; ≥99%), BPF (BPF-13 C 12 ; ≥99%), and BPS (BPS-13 C 12 ; ≥98%).…”