(Equivalent Test Method: AFNOR M07-027)
EXPLANATION
Vanadium in fuels can form low melting compounds that are severely corrosive to metal parts. This test method covers the determination of 0 to 350 mg/kg of vanadium in heavy fuel oils, and is widely cited in commercial specifications and contracts for marine and power plants Number 6 oils. Other elements commonly found in fuel oils do not interfere.
TEST SUMMARY
The fuel oil is heated with concentrated sulfuric acid and reduced to acid-free coke and then dry ashed at 525° C. Mixed nitric and sulfuric acids are then added to the residue and evaporated to the white fumes of sulfuric acid. The residue is dissolved in water, phosphoric acid and sodium tungstate are added, and vanadium is determined by measuring the absorbance of its phosphotungstovanadic acid complex at 436 nm.
TEST PRECISION
