There is a variety of liquid chromatography methods that you can use for BPA analysis. Have a look in the publication below where we described HPLC method for BPA, BPS, BPE, BPB, HPP and BPF.
Pivnenko, K.; Pedersen, G. A.; Eriksson, E.; Astrup, T. F. Bisphenol A and its structural analogues in household waste paper. Waste Manag. 2015, 44, 39–47.