Dissipation and acute dietary intake risk assessment of paclobutrazol in Solanum melongena

In order to study the effect of paclobutrazol on Solanum melongena, and investigate the residue behavior and the dietary intake risk of paclobutrazol in Solanum melongena, the residual trial of paclobutrazol in Solanum melongena was carried. A new method was developed to determine the residue of paclobutrazol in Solanum melongena and the influence of paclobutrazol on the yield and quality of Solanum melongena was detected. The acute risk assessment of paclobutrazol in Solanum melongena to different population was conducted. The samples were extracted with acetic acidacetonitrile and determined by UPLC-MS/MS. The calibration curve showed good linear relationship in the concentration of 0.02-5.0 mg/L. The limit of detection (LOD) and the limit of quantification (LOQ) were respectively 0.005 and 0.02 mg/kg. The recoveries ranged from 88% to 92%, and the relative standard deviation (RSD) was from 5.1% to 6.9%. The results indicated that the dissipation of paclobutrazol in Solanum melongena fitted to the first order kinetics with the half-live of 1.45 days and the highest residue of paclobutrazol in Solanum melongena was 0.02 mg/kg at the harvest period. The results also demonstrated that the application of paclobutrazol decreased the plant height, and increased the yield and content of vitamin C, soluble sugar and flavonoid. The recommended dosage of paclobutrazol applied to Solanum melongena was 12 a.i. g/hm2 and applied twice. The national estimated short-term intake (NESTI)of paclobutrazol residue in Solanum melongena for different population was 0.70-1.9 μg/kg bw, the percentage of ARfD was 0.07%-1.9%, and both results were within an acceptable limits, which indicated the low risk of paclobutrazol in Solanum melongena.