| For the banana output, China was the second country in the world. However, the export of banana of China was less than the import these years. The most important reason was its residue of pesticide, cuased by the gap of good agricultural practice (GAP) and the maximum residue limit (MRL) between international organization and China. This study investigated the dissipation and residue of4triazole fungicides in banana under GAP in China. Meanwhile, the distribution of fungicides in banana peel and flesh was also studied. Further, dietary risk assessments of4fungicides in edible banana were calculated at the national and international level, respectively, and the recommended MRL was given to the Chinese government. Besides, the simultaneous analytical method of18fungicides and3metabolites in banana was established by LC-MS/MS. The main results were as follows:1. Residue dissipations of tebuconazole under different GAP conditions were investigated, and risk assessments were also evaluated. Results showed that half lives of tebuconazole in banana were10.8～14.1d, the terminal residue in whole banana and flesh was0.01～0.04mg/kg and0.10～0.69mg/kg, respectively, and the main residue was in peel of banana. When the mode with bagging was used, the terminal residue in banana and flesh was all below0.01mg/kg, which indicated that the mode with bagging could clearly reduce the residue of tebuconazole. The higher residue of tebuconazole was caused by the higher application dosage and the mode without bagging used in China. Based on the data of the mode with bagging, the risk assessment results showed that national estimated daily intake (NEDI) and national theoretical maximum daily intake (TMDI) of tebuconazole was0.46mg and0.50mg, respectively, which was24.2%and26.3%of acceptable daily intake (ADI), respectively. The recommended MRL of1.0mg/kg for tebuconazole had no public health concern at the national level.2. Residue dissipation of propiconazole under field condition was investigated, and risk assessments were also evaluated. Results showed that half lives of propiconazole in banana were9.4～3.8d, the terminal residue in whole banana and flesh was0.02～0.09mg/kg and0.05～0.16mg/kg, respectively, and the main residue was in peel of banana. The higher residue of propiconazole than other country was caused by the higher application dosage in China. The risk assessment results showed that NEDI and TMDI of propiconazole was0.26mg and0.30mg, respectively, which was5.9%and6.7%of ADI, respectively. The MRL of1.0mg/kg for propiconazole had no public health concern at the national level.3. Residue dissipation of epoxiconazole under field condition was investigated, and risk assessments were also evaluated. Results showed that half lives of epoxiconazole in banana were11.0～143d, the terminal residue in whole banana and flesh was<0.01～0.04mg/kg and0.15～0.48mg/kg, respectively, and the main residue was in peel of banana. The risk assessment results showed that NEDI and TMDI of epoxiconazole were0.14mg and0.26mg, which was10.9%and20.9%of ADI, respectively. For CAC did not set MRL for epoxiconazole in banana, the GAP and the related residue data from the field in China should be included in the establishment of MRL in CAC. 4. Residue dissipations of two formulation of difenoconazole under field condition were investigated, and risk assessments were also evaluated. Results showed that half lives of difenoconazole in banana were7.9～10.9d, the terminal residue in whole banana and in flesh was<0.01～0.03mg/kg and0.07～0.36mg/kg, respectively, and the main residue was in peel of banana. The risk assessment results showed that NEDI and TMDI of difenoconazole was0.50mg and0.54mg, which was78.7%and85.2%of ADI, respectively. As the GAP of China was almost same to other country including the application dosage and the mode with bagging, except less application times in China. However, the terminal residue of difenoconazole was higher than other country, it might be caused by the different speices of banana and the climate conditions.5. A multi-residue analytical method was established for determination of18fungicides and3metablites in banana by LC-MS/MS. The sample was extracted with acetonitrile and clean-up with PSA. Results showed that the method was effective, fast, and accurate, with a linear range of0.002～0.1mg/kg, LOQ (limit of quantification) of5.0～10μg/kg. And the recovery was70.2～115.7%and65.2～105.8%in whole banana and flesh with relative standard deviations of3.3～25.6%and2.1～19.7%, respectively.The results of this study showed that reason caused higher fungicides residue in banana was mainly because the different GAP, such as higher application dosage or the mode without bagging in China, besides influences from the speices of banana and the climate. It was suggested that the mode with bagging should be applied in controlling Sigatoka disease of banana in China. It could also give a reference for Chinese government to set harmonization MRL of these fungicides to the international organization, and also had positive effect on banana quality control and safety to consumers. |
PDF Full Text Request