Simultaneous cyclic-injection spectrophotometric determination of aluminum and iron in petroleum products

A procedure is developed for the cyclic-injection spectrophotometric determination of iron and aluminum in petroleum products; it includes microwave sample mineralization followed by the determination of analytes as their complexes with Chrome Azurol S at pH 5. The classical least-squares technique is used for the simultaneous determination of iron and aluminum. The analytical range for elements covers from 10 to 100 mg/kg at a sample weight of 1 g. The limits of detection for both elements are 3 mg/kg. The developed procedure was used for the determination of iron and aluminum in the spent engine oil and marine fuel.