Chemicals and Reagents

All chemicals used were of analytical grade. BPA and creatinine standards were purchased from Sigma-Aldrich (St Louis, MO, USA). The isotope-labeled internal standards ¹³C₁₂-BPA (99%), creatinine-d3 and ¹³C₁₂-BPA β–D-glucuronide (¹³C₁₂-BPA-GLU) were obtained from Santa Cruz Biotechnology, Inc. (Santa Cruz, CA, USA). High-performance liquid chromatography (HPLC)-grade methanol and acetonitrile (KGaA, Darmstadt, Germany) were used. Ammonium acetate was obtained from J. T. Baker (Phillipsburg, NJ, USA). Stock solutions of the BPA (100 ng/mL) and BPA-GLU (1000 ng/mL) were prepared in methanol and were stored at -20 °C. Deionized water (18.2 MΩ) treated with the Millipore (Simplicity, 185) Milli-Q water purification system (Elga Labwater Veolia, Anthony, France) was used for all aqueous solutions.