Residual status and risk assessment of forbidden and restricted pesticides of organophosphorus in Loincerae Japonicae Flos / 中国中药杂志

ABSTRACT

This paper reports the residual status of forbidden and restricted pesticides of organophosphorus in Loincerae Japonicae Flos to provide reference for the risk control and the formulation of maximum residue limits of the flower. A method for the determination of residues of 23 forbidden and restricted pesticides of organophosphorus was established, and 64 collected samples were tested. Then a risk assessment based on the maximum residue limit was carried out. Results showed that the detection rate of samples was 58%. 6 of 23 pesticides were detected and the ratio was chlorpyrifos 41%, omethoate 23%, triazophos 11%, isofenphos-methyl 6.3%, methamidophos 1.6%, isocarbophos 1.6%, respectively. And the median of pesticide residues in the positive samples was chlorpyrifos 0.037 mg·kg⁻¹, omethoate 0.043 mg·kg⁻¹, triazophos 0.030 mg·kg⁻¹, isofenphos-methyl 0.18 mg·kg⁻¹, methamidophos 0.041 mg·kg⁻¹, isocarbophos 0.041 mg·kg⁻¹, respectively. In the samples with pesticide residues, the residue amount of methamidophos and isocarbophos was lower than the theoretical maximum residue limit, and the residue amount of chlorpyrifos, isofenphos-methyl, triazophos were higher than it individually, while, all the residue amount of omethoate was higher than it. According to the assessment result of theoretical maximum residue limit, it is suggested that relevant departments should accelerate the formulation of the maximum residue limit standard, and strengthen the supervision of the use of forbidden and restricted pesticides of organophosphorus in Loincerae Japonicae Flos.