Comparison of solid-phase extraction and dialysis on pretreatment efficiency of blood urea analysis

Although the analysis of urea in blood using high-performance liquid chromatography has been reported, its automated solid-phase extraction (SPE) has not been reported. In addition to these two methods, dialysis may also be used to pretreat blood samples. The separation efficiency of automated SPE is discussed and compared with automated dialysis using a condensing column. The results indicate that automated SPE and dialysis have an almost identical separation efficiency for urea analysis. However, the dialysis technique is not as efficient for the removal of admixtures eluted after urea.