Determination of Fe, Ba, Sn in sodium by inductively coupled plasma-atomic emission spectrometry

Sodium was used as a coolant in fast reactor. However, a negative influence on the heat trasmittability of sodium was exerted by metal impurities Fe, Ba and Sn. So the method for determination of trace elements Fe, Ba and Sn by inductively coupled plasma-atomic emission spectrometry (ICP-AES) was developed to monitor the quality of sodium. In this experiment, molten sodium was weighed in vacuum-glove box and dissolved by C₂H₅OH-H₂O; then Fe, Ba and Sn were separated from matrix element sodium by co-precipitation reagent-La³⁺ solution, being determinated by ICP-AES. The determination range for Fe, Ba and Sn was 2.0-30 ug/g Na. Standard addition and recovery experiments were carried out in pure sodium, the average percentage recoveries of Fe, Ba and Sn were 97.9%, 95.8% and 93.5%, and the relative standard deviations (RSD) were l.5%, 1.2% and l.8%. The method was used in analysis of impurities in depurative sodium and what's in the first circuit of China Experimental Fast Reactor, with satisfactory results. (authors)