Fractions % of TRR SPE fraction 1a - Non retained material 0.46 SPE fraction 2a - 1% acetic acid in water 0.54 SPE fraction 3a - 1% acetic acid in water:acetonitrile (95:5, v/v) 0.51 SPE fraction 4a - 1% acetic acid in water:acetonitrile (90:10, v/v) 1.37 SPE fraction 5a - 1% acetic acid in water:acetonitrile (75:25, v/v) 15.48 SPE fraction 6a - 1% acetic acid in water:acetonitrile (50:50, v/v) 57.68 SPE fraction 7a - 1% acetic acid in acetonitrile 14.36 Total recovery 90.36 TRR – Total radioactive residue

Table 1: The Extraction and Distribution of Radioactivity from Enzyme Hydrolysed Urine Using Solid Phase Extraction.