Dissipation rate of different commercial formulations of propamocarb-hydrochloride applied to potatoes using HPLC–DAD

Abstract Propamocarb-hydrochloride is a widely used fungicide around the world. Hence, only limited data are available on the fate of this fungicide. Residue levels and degradation rate of two different formulations propamocarb-hydrochloride (Previcur-N 72.2% SL and Proplant 72.2% SL) in potatoes was investigated by using high performance liquid chromatography with diode array detector (HPLC-DAD). The experimental data were used to determine the residual behavior and establish the preharvest intervals (PHI). Samples were prepared using QuEChERS methodology before quantification by high performance liquid chromatography with diode array detector (HPLC–DAD). Field trials showed a different degradation rate for two studied formulations. The initial deposit of 0.99 and 1.31 mg kg −1 for Previcur-N and Proplant, respectively after 10 days of application degraded to 0.02 mg kg −1 (97.98%) and 0.32 mg kg −1 (75.57%) and the half-lives ( t 1/2 ) were 2.26 and 6.29 days, respectively. We suggested that a waiting period of at least 3 and 10 days before harvesting the potatoes after application of two studied formulations that may be considered quite safe from point of health hazards due to the toxic effect of residues.