1.1 ,This test method covers the determination of total silicon by monochromatic, wavelength-dispersive X-ray fluorescence (MWDXRF) spectrometry in naphthas, gasoline, gasoline-ethanol blends, reformulated gasoline (RFG), ethanol and ethanol-fuel blends, and toluene at concentrations of 3 ,mg/kg to 100 ,mg/kg. The precision of this test method was determined by an interlaboratory study using representative samples of the liquids described in 1.1 and 1.2. The pooled limit of quantitation (PLOQ) was estimated to be 3 ,mg/kg.
Note 1: ,Volatile samples such as high-vapor-pressure gasolines or light hydrocarbons might not meet the stated precision because of the evaporation of light components during the analysis.