This document specifies a method for determining the total content (solvent extractable) of the following bisphenols in chemicals for the leather tanning industry: bisphenol A; bisphenol AF; bisphenol B; bisphenol F; bisphenol S. This method requires the use of liquid chromatography (LC) with either a single quadrupole mass spectrometer (MS), a triple quadrupole mass spectrometer (MS/MS), an ultraviolet (UV) detector, a diode array detector (DAD) or a fluorescence detector (FLD) to identify and quantify the bisphenols. NOTE This method can also be used for other bisphenols if they are validated by the laboratory.