First, the current response was measured for each diluted sample. After that, a various volume of a BPR standard solution was added and increasing oxidation current was observed. The results for the determination of BPR in real samples are summarized in Table 3. The results of the recovery ranged from 95.9 to 100.5% for the determination of BPR in sample that was attained by standard addition method. The detected result revealed that this method can be used for the measurement of BPR in clinical routine test.