Typically the bioassay method for (210)Po in urine by alpha spectrometry (AS) involves wet decomposition of the sample, which may cause a loss of (210)Po if volatile species are present. To test this hypothesis, urine samples collected from two rats that were i.v. administered with polonium citrate were measured by both AS and liquid scintillation counting, where urine samples were mixed with a scintillation cocktail without any treatment. A split-plot design method was used to compare results from the two measurement methods, showing no evidence of a difference between the two methods. This suggests that the AS method is reliable for (210)Po urine bioassay.