CONFIRMATION OF THE ABSENCE OF BISPHENOL A IN COPOLYESTERS BY POLYMER HYDROLYSIS IN COMBINATION WITH LC-MS/MS AND LC-FLD

Abstract

A method was developed to validate that certain polyester and copolyester resins do not contain bisphenol A (BPA). This method satisfies the need for a timely screening method that can be utilized on a timescale that is appropriate for a laboratory in a manufacturing facility. This was accomplished by hydrolyzing the polymer and then analyzing the hydrolysate by either liquid chromatography-tandem mass spectrometry (LC-MS/MS) or liquid chromatography-fluorescence detection (LC-FLD). A hydrolysis procedure offers the unique advantage of a faster sample preparation step as compared to extraction procedures. The hydrolysis was complete after 20 min and the procedure was fully automated with the use of an autosampler. By hydrolyzing the polymer, total BPA is measured rather than only extractable monomeric BPA. Copolyester samples were purposely spiked with polycarbonate to validate the method. The detection limit for the LC-MS/MS method was 0.8 mg kg⁻¹ in the polymer, while the detection limit for the LC-FLD method was 2.6 mg kg⁻¹ in the polymer.

Keywords:

• bisphenol A
• copolyesters
• free BPA
• hydrolysis
• LC-FLD
• LC-MS/MS
• total BPA

Notes

^a Sample concentration of monomeric BPA calculated based on polycarbonate spike.

^b Statistically below Limit of Quantitation.

^a Sample concentration of monomeric BPA calculated based on polycarbonate spike.

^b Statistically below Limit of Quantitation.