Liquid chromatography with ultraviolet absorbance detection of ethylenethiourea in blood serum after microwave irradiation as an auxiliary cleanup step

The report describes a method of deproteinizing serum that combines the action of acids with microwave irradiation. The acid concentration is ten times smaller than in the usual acid deproteinization method and the results are similar. The main advantages of the proposed method are the maintenance of the pH of the supernatant at around 5, and the reduction of the concentration of the deproteinizing agent, The procedure was applied to the determination of ethylenethiourea in serum samples by HPLC with spectrophotometric detection. Using 0.5 mi of serum, 0.04 mu g of ethylenethiourea were determined with recoveries between 89 and 109%.