1.1 ,This method applies to the determination of isotopic composition in hydrolyzed nuclear grade uranium hexafluoride. It covers isotopic abundance of  ,²³⁵U between 0.1 and 5.0 ,% mass fraction, abundance of  ,²³⁴U between 0.0055 and 0.05 ,% mass fraction, and abundance of  , ²³⁶U between 0.0003 and 0.5 ,% mass fraction. This test method may be applicable to other isotopic abundance providing that corresponding standards are available.