Recently open graded mixes using epoxy modified bitumen have begun to be used in New Zealand for general road surfacing applications. To reduce cost and potential risk to plant and machinery, commercially available epoxy bitumen is commonly diluted with standard grade bitumen. To ensure that the specified concentration of epoxy resin is being used and detect possible quality control problems in plant operation, some means of measuring the resulting epoxy resin concentration is desirable. This work describes two test methods based on Fourier Transform Infrared Spectroscopy (FTIR) and elemental oxygen content measured by Fast Neutron Activation Analysis (FNAA), that have been developed for this purpose.