Abstract:

An ion chromatography method was developed for determination of contents of various phosphate forms in tripolyphosphate, in the present study. Phosphates were eluted with100 mmol/L NaOH solution in gradient at a flow rate of 1.0 ml/ min. The method presented good linearities between the peak areas and concentrations of orthophosphate, pyrophosphate, tripolyphosphate, and trimetaphosphate and their detection limit ranged from 0.010 to 0.063 mg/L. The relative standard deviations (RSD) of the retention time varied between 0.38% and 0.79% and the RSD of the peak area was between 2.21% and 6.96%. The recoveries of the above phosphates in spiked tripolyphosphate sample ranged from 97.45% to106.89%. This complete analysis procedure lasted 10 min. Our results indicated that this method is rapid and accurate with a wide linear range and less consumption of chemicals.

Key words: ion chromatography, tripolyphosphate, content determination