Solvent-Assisted Extraction of Bisphenol A from Waste Printed Circuit Boards Using DMF and DMSO

Abstract

The nonmetal fraction (NMF) of waste printed circuit boards (WPCBs) is an underutilized electronic waste stream, containing extractable resin-associated organics. This study investigates solvent-assisted extraction of bisphenol A (BPA) from WPCB-derived NMF using N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), with ultraviolet (UV) pretreatment. Gas chromatography–mass spectrometry (GC–MS) showed that UV pretreatment markedly suppressed the photoinitiator 907 signal and simplified the extractable mixture, supporting qualitative improvement in extract composition toward BPA relative to this competing component. BPA identification was supported by an authentic standard and mass-spectral evidence, and selected ion monitoring (SIM) at m/z 213 was used for external calibration quantification. At 120 °C and 96 min, the reported extract concentrations were approximately 350 ppm in DMF and 153 ppm in DMSO. On a nominal extraction-volume basis, these correspond to apparent extraction yields of approximately 4.38 and 1.91 mg of BPA per gram of NMF, respectively. Approximately 95% of the solvent was recovered, and extraction performance was broadly retained over five cycles with fresh-solvent makeup. The contribution is the integration of extract profiling and compound-specific BPA determination to compare extraction and short-term solvent reuse in preisolated WPCB-derived NMF. The results establish laboratory-scale extraction potential; isolation of a usable BPA product and the overall environmental benefit remain to be assessed.