Harnessing the resolution power of two-dimensional liquid chromatography (2D-LC) for the screening of bisphenol contaminants in canned food items

Overlapping peaks can be difficult to avoid in 1D-LC, which make the identification and quantification of compounds ambiguous, especially if the only available detector is a UV/DAD. To overcome this, a two-dimensional liquid chromatography (2D-LC) method to monitor Bisphenols (BPs), and particularly the chosen analogues BPA, BPB, BPF, BPS, BPZ, and BPAF, in a complex matrix (canned food) was developed and validated. BPs are endocrine disruptors present in the lining of the can, which may leach into the content of canned food. It is essential to continuously identify and monitor bisphenols that are unintentionally ingested using newly available and highly efficient methods such as 2D-LC. The coefficient of variation (CV) of peak areas and retention times for all analytes in both dimensions ranged from 0.050 to 2.960 %. The recovery of the whole procedure was determined to be 67.4 ± 0.1 % in the first dimension, and 64.3 ± 0.1 % in the second dimension. The limit of detection (LOD) determined in the second dimension for the analytes ranged from 0.075 to 0.301 ppm. Finally, four canned food samples were prepared by solid-liquid extraction, and surveyed for BPA, BPB, BPF, BPS, BPZ, and BPAF. BPF (0.093 ppm) and BPAF (2.656 ppm) were accurately detected in two separate samples. This report highlights the first successful application of 2D-LC to bisphenol compounds, an important class of emerging contaminants.