Simultaneous determination of three herbicide residues in wheat flour based on the hollow fiber supported carbon dots.

A solid-phase micro extraction (SPME) coupled high performance liquid chromatography (HPLC) strategy was explored for trace concentrations of dicamba, 2,4-dichlorophenoxyacetic acid (2,4-D), and picloram residues simultaneous determination from complex matrix of food samples. The SPME system was established by immobilizing flavonoid moiety incorporated carbon dots (CDs) into the wall-pores of hollow fiber (HF) based on their electrostatic interactions, and as an effective extractant, functional groups incorporated CDs exhibited desirable sensitivity and selectivity to carboxyl contained aromatic herbicides. Associated SPME extraction parameters were investigated, and the proposed SPME-HPLC analytical method was proved to have satisfactory reproducibility with the RSD less than 6.9%, feasible linearity with the linear coefficients above 0.99, low limits of detection (LOD) that were 0.96,1.21, and 0.83 ng/g for dicamba, 2,4-D, and picloram, desirable accuracy with the recoveries in the range of 76.4-106.9%. The analytical method has promising potentials for carboxyl contained aromatic herbicides sensitive and selective determination...