Abstract
The effects of heating on the peroxodisulfate decomposition of phosphorus compounds for the determination of total phosphorus in water has been studied using adenosine-diphosphate (ADP), lecithin and tripolyphosphate as samples. Decomposition of ADP proceeded rapidly and completely at temperatures above 100°C in the absence of H2SO4, and at 100°C in the presence of H2SO4. In the presence of H2SO4, the complete decomposition of lecithin was difficult because lecithin was slowly decomposed while peroxodisulfate was rapidly consumed during thermal autolysis. Suitable amounts of acid was needed to hydrolyze tripolyphosphate, and the acid was supplied during the autolysis of peroxodisulfate. It was considered that the heating method which can elevate the temperature to above 100°C in a short time is suitable for the decomposition of the analytical samples.
