Residue monitoring and dietary risk assessment of chlorantraniliprole and tolfenpyrad in Chinese kale under open‑field conditions

Chlorantraniliprole and tolfenpyrad has been used for the control of diamondback moth in kale around the world with a suspension concentrate formulation being prepared for marketing in China. In order to evaluate pesticide residues in kale and intake risks for different populations, a modified QuEChERS procedure of detecting chlorantraniliprole and tolfenpyrad were simultaneously established using liquid chromatography tandem mass spectrometry (LC-MS/MS). The average recoveries of chlorantraniliprole and tolfenpyrad were in the range of 83–98%, with the precision of intra-day (n = 5) and inter-day (n = 15) ranging from 1.7 to 6.7% and from 2.1 to 4.7%, respectively. The limits of quantification were all 0.01 mg kg−1 in kale. Supervised filed trials were conducted in 12 regions of China, and results showed that residues of chlorantraniliprole and tolfenpyrad in kale were 0.01 to 0.17 and 0.01 to 0.11 mg kg−1, respectively, within the recommended pre-harvest interval (10 days). Based on these data, dietary risk assessments were performed. The long-term intake risk quotient (RQc) values for chlorantraniliprole and tolfenpyrad were 0.33% and 28.09% respectively, while the short-term risk quotient (RQa) values of the more toxic tolfenpyrad were 21% (children, 1–6 years old) and 52% (the general population, >1 years old) respectively, which were all lower than 100%, highlighting the higher chronic risk for children compared with that of the general population. However, the less than 100% value revealed that not only the long-term but also short-term risks were acceptable when consuming kale under Good Agricultural Practice conditions. The paper will be helpful in rational use of chlorantraniliprole and tolfenpyrad on kale.