This document specifies a method for determining the total content (solvent extractible) of the following bisphenols in leather: –     bisphenol A; –     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.