LIQUID-CHROMATOGRAPHY WITH ULTRAVIOLET ABSORBENCY DETECTION OF ETHYLENETHIOUREA IN BLOOD-SERUM AFTER MICROWAVE IRRADIATION AS AN AUXILIARY CLEANUP STEP

The report describes a method of deproteinizing serum that combines th e action of acids with microwave irradiation. The acid concentration i s ten times smaller than in the usual acid deproteinization method and the results are similar. The main advantages of the proposed method a re the maintenance of the pH of the supernatant at around 5, and the r eduction of the concentration of the deproteinizing agent, The procedu re was applied to the determination of ethylenethiourea in serum sampl es by HPLC with spectrophotometric detection. Using 0.5 mi of serum, 0 .04 mu g of ethylenethiourea were determined with recoveries between 8 9 and 109%.