Validation of GCMS/MS Based Method for Residual Estimation of Fluopyram and Tebuconazole in Rose Applied as Combination Formulation

Dissipation patterns of fungicides were studied on rose following two applications of Luna Experience (Fluopyram 200 g/L + Tebuconazole 200 g/L SC) at 100 + 100 and 200 + 200 g a.i. ha −1 as single and double doses, respectively. Samples were collected at 0, 1, 3, 5, 7, 14, 21 and 28 days post‐treatment. A rapid and sensitive method for simultaneously quantifying fluopyram and tebuconazole in rose based on acetonitrile extraction combined with GCMS/MS spectrometry was validated. Limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.003 and 0.01 mg kg −1 , respectively. Half‐life of the applied pesticide at the different doses ranged from 1.48 to 1.86 days for fluopyram and 1.27 to 1.82 days for tebuconazole. Fluopyram residues dissipated below its LOQ of 0.01 mg kg −1 after 21 days post‐treatment at double dose, while residual dissipation of tebuconazole below LOQ was observed after 14 days in both doses.