GC–MS Quantitation and Identification of Bisphenol-A Isolated from Water

Isolation and identification of organic compounds is a necessary skill chemistry students must be able to do with proficiency. In this upper-level undergraduate laboratory, students isolate bisphenol-A (BPA; 4-4′-isopropylidenediphenol) from water using solid-phase extraction (SPE) followed by derivatization with analysis by GC–MS. The students learn the proper steps and techniques of SPE that include conditioning, equilibration, washing, and eluting. The students are then asked to identify the BPA peak from the GC–MS analysis of a mixture of standards based upon the molecular ion, keeping in mind the change in molecular weight upon derivatization. Interpretation of GC–MS data showed predictable fragmentation and highlights the formation of benzylic carbocations. Quantification was done by an external calibration curve and the sample was quantified and a percent recovery is calculated.