1994 Volume 43 Issue 1 Pages 85-88
Organic and inorganic arsenic compounds in thermally cracked gasoline are known as catalyst poisons in the aromatization process. It is, therefore, important to determine trace arsenic in cracked gasoline. An oxy-combustion method was investigated to decompose the gasoline. During the decomposition, organic arsenic compounds were converted completely to inorganic arsenic species. After absorbing the inorganic arsenic in hydrochloric acid-iodate-iodide solution, arsenic was reduced to arsine with sodium tetrahydrogenborate and then the arsine was introduced into a quartz cell heated by an airacetylene flame. The peak height of the arsenic atomic absorption signal was measured. Several conditions; acidity in the reduction process, amount of sodium tetrahydroborate, and reaction time for arsine generation were optimized. The detection limit of the proposed method was 5 ng g-1. This method was applied to the determination of arsenic content in individual fractions from a fractionater in the aromatic hydrocarbon process.
