Polyethylene glycol grafted flower‐like cupric nano oxide for the hollow‐fiber solid‐phase microextraction of hexaconazole,penconazole, and diniconazole in vegetable samples

A simple, rapid, highly efficient, and reliable sample preparation method has been developed for the extraction and analysis of triazole pesticides from cucumber, lettuce, bell pepper, cabbage, and tomato samples. This new sorbent in the hollow‐fiber solid‐phase microextraction method is based on the synthesis of polyethylene glycol‐polyethylene glycol grafted flower‐like cupric oxide nanoparticles using sol–gel technology. Afterward, the analytes were analyzed by high‐performance liquid chromatography with ultraviolet detection. The main parameters that affect microextraction efficiency were evaluated and optimized. This method has afforded good linearity ranges (0.5–50 000 ng/mL for hexaconazol, 0.012–50 000 ng/mL for penconazol, and 0.02–50 000 ng/mL for diniconazol), adequate precision (2.9–6.17%, n = 3), batch‐to‐batch reproducibility (4.33–8.12%), and low instrumental LODs between 0.003 and 0.097 ng/mL (n = 8). Recoveries and enrichment factors were 85.46–97.47 and 751–1312%, respectively.