Residue and dissipation dynamic of albendazole in tobacco

To investigate the residue and dissipation of albendazole in tobacco and provide reference for the setting of maximum residue limit (MRL), an analytical method and a good agricultural practices (GAP) experiment of albendazole residues in tobacco were established and had been tested for samples by using QuEChERS and high performance liquid chromatography-tandem triple quadrupole mass spectrometry (HPLC-MS/MS). Good linearity between the mass concentration of albendazole and the corresponding peak area was achieved from 0.001 to 1 mg/L, with a coefficient of determination higher than 0.998. At three addition levels of 0.02, 0.2 and 2 mg/kg, the recoveries of albendazole in fresh tobacco leaves ranged from 94% to 97%, with the relative standard deviation (RSD) was 1.2%-2.7%. At three addition levels of 0.01, 0.1 and 2 mg/kg, the recovery of albendazole in cured tobacco leaves were 85%-104%, with the RSD was 2.0%-8.1%. If the lowest spiked concentration was recognized as the limit of quantitation (LOQ), the LOQs of albendazole in cured tobacco leaves and fresh tobacco leaves were 0.01 and 0.02 mg/kg, respectively. The dissipation and terminal residue levels of albendazole in tobacco demonstrated that the half-life of albendazole in fresh tobacco leaves was 5.4 to 16.1 days. When sprayed at 90 and 135 g a.i./hm² for three times, the terminal residues of albendazole in cured tobacco leaves at the pre-harvest interval of 7, 14 and 21 days were 0.14-3.04 mg/kg, 0.33-2.20 mg/kg and 0.17-1.85 mg/kg, respectively. It is recommended that the MRLs should be 2 mg/kg. The pesticide should be used in accordance to the recommended dosage and application interval. 21 days after the last spray, the residue was less than 2 mg/kg, which demonstrated that the residual risk level was low.