Possible matrix interferences were investigated using standard
additions, and the accuracy of the technique was determined using
the recovery of furosemide. Recovery tests were performed by spiking
synthetic and human urinewith known amounts of standard solutions,
followed by analyses using the proposed method.
The results obtained are presented in Table 2. The recoveries
ranged from 101.4% to 108.6%. These results show that there were
no significant matrix effects in the reflectometric measurements