Sample No Detection (μmol/L) Addition (μmol/L) Found (μmol/L) Recovery (%)
1 1.0 1.0 1.93 96.5
2 2.0 1.5 3.38 96.6
3 1.5 1.5 2.89 96.3
4 5.0 4.5 9.84 103.6
5 1.7 2.0 3.82 103.2
6 9.0 5.0 13.87 99.1
Table 2: Analysis of catechol in waste water samples (n=6).