Determination of Bisphenol A (BPA) in Plasma of Hemodialysis Patients Using Three Methods: LC/ECD, LC/MS, and ELISA

Bisphenol A (BPA) values were compared in plasma of hemodialysis patients and in recycling solvents using LC/MS, LC/electrochemical detector (ECD), and enzyme linked immunosorbent assay (ELISA). BPA values in the plasma and the solvent were 0-8.4 ng/ml and 0-0.8 ng/ml for LC/ECD, 0-4.9 ng/ml and 0-0.8 ng/ml for LC/MS, and 0-15.5 ng/ml and 0-3.1 ng/ml for ELISA, respectively. There was no significant difference among BPA values both in the plasma and the solvents using three methods. Single correlation coefficients between LC/ECD and LC/MS, LC/ECD and ELISA, and LC/MS and ELISA were, respectively, 0.373 (p < 0.002), 0.347 (p < 0.002), and 0.945 (p < 0.001) in the plasma (n = 68-109) and 0.916 (p < 0.001), 0.431 (p > 0.05), and 0.332 (p > 0.05) in the solvents (n = 19). An unknown substance present in the plasma of patients but not healthy volunteers influenced the LC/ECD values of plasma repeated freezing and thawing. The results indicate that LC/MS and ELISA are appropriate for BPA analysis in plasma and both LC/MS and LC/ECD in the recycling solvents and handling with plasma before analysis is important to the analysis of BPA in patients' plasma using LC/ECD.