Miniaturized solid phase extraction of multi-pesticide residues in food supplement using plant sorbent by microwave-induced activated carbons

Abstract A simple and green plant sorbent-based miniaturized solid phase extraction (mini-SPE) method was presented for the detection of multi-pesticide residues in Dendrobium officinale by ultra-high performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry. Activated carbons prepared from hawthorn leaves were used as a green sorbent in microwave (MW) assisted mini-SPE process. Various parameters such as the type and concentration of extraction solvent, MW time and MW temperature, were investigated in detail to obtain the optimum conditions in this procedure. Under the final optimized conditions, this method displayed a satisfactory linearity, with its correlation coefficients ranged from 0.9927-0.9991. The limits of detection ranged between 0.08 and 1.35 ng/mL for the seven pesticides. And the recoveries of the pesticides in Dendrobium officinale ranged from 81.17-106.12% at two spiked levels (0.05 and 5 ug/mL), indicating the accuracy of the proposed mini-SPE method was acceptable. Besides, the reproducibility of the method was satisfactory, with the RSDs lower than 0.37% for retention time, 3.72% for peak area, respectively. The proposed mini-SPE method was efficiently applied for the determination and extraction of the pesticides in Dendrobium officinale, thus demonstrating that this method was reliable.