Analysis was conducted on a Supelco Spherisorb ODS-2 column (250 4.6 mm; Waters). The separation of chlorpyrifos and TCP was performed using an HPLC gradient system elution. The mobile phase was acidified water (1% glacial acetic acid), and the acetonitrile gradient flow rate was programmed to 1 mL/min. The gradient began at 50% acetonitrile and then increased to 90% acetonitrile at 3 min. Next, the system returned to 50% acetonitrile at 8.5 min and was held for 2 min for re-equilibration. The eluents were monitored by UV detection at a wavelength of 299 nm for chlorpyrifos and at 290 nm for TCP. The chromatographic analysis was performed at ambient temperature. Each sample replicate was injected three times to determine the average peak area. The percentage degradation of the compounds was calculated as the difference between the peak areas of the experimental and control samples, where the peak area of the control was used as the 100% point of reference.