This method is for determining total arsenic in petroleum naphthas by Hydride Generation-Atomic Absorption Spectroscopy (HG-AAS). The method is quantitative to one mass-ppb (ng/g) when a 100-g sample is used. This method yields results equivalent to, and can be used in place of, UOP Method 296. The method was validated by spiking with triphenylarsine, As(C6H5)3, for which 100% recovery was obtained at the 80 mass-ppb level.