ASTM D5184 Standard Test Methods for Determination of Aluminum and Silicon in Fuel Oils by Ashing, Fusion, Inductively Coupled Plasma Atomic Emission Spectrometry, and Atomic Absorption Spectrometry
4. Summary of Test Methods
4.1 A weighed quantity of homogenized sample is heated in a clean platinum dish, the combustible material is removed by burning and the carbon finally removed by heating in a muffle furnace at a temperature of 550 +/- 25°C. The residue is fused with a lithium tetraborate/lithium fluoride flux. The fused mixture is digested in a solution of tartaric acid and hydrochloric acid and diluted to volume with water. The resulting solution is aspirated into an inductively-coupled plasma and the emission intensities of aluminum and silicon lines are measured. Standard calibration solutions are also aspirated and aluminum and silicon intensities are measured for comparison. Alternatively, the resulting solution is aspirated into the flame ofan atomic absorption spectrometer and the absorptions of the resonance radiation of aluminum and silicon are measured. Standard calibration solutions are also aspirated and aluminum and silicon absorption intensities are measured for comparison.
4.2 Information on proper protocols for conducting atomic absorption spectrometry can be found in Practice D7740.
4.3 Information on Proper protocols for conducting inductively coupled plasma-atomic absorption spectrometry can be found in Practice D7260.
5. Significance and Use
5.1 Catalyst fines in fuel oils can cause abnormal engine wear. These test methods provide a means of determining silicon and aluminum, the major constituents of the catalysts.
