Application of metal-organic framework MIL-101(Cr) to microextraction in packed syringe for determination of triazine herbicides in corn samples by liquid chromatography-tandem mass spectrometry

In this work, a metal-organic framework material MIL-101(Cr) was prepared and used as the sorbent for a laboratory-made semi-automated microextraction in packed syringe (MEPS). Six triazine herbicides, including desmetryn, prometon, ametryn, prometryn, atraton, and dipropetryn, that are commonly found in corn samples, were extracted and determined by the MEPS method and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Key parameters affecting the extraction efficiencies, including type of extraction solvent, type and amount of sorbent, time of ultrasonic extraction and adsorption, and type, volume and flow rate of elution solvent, were investigated. The limits of detection (LODs, S/N = 3) and quantification (LOQs, S/N = 10) for all analytes obtained by the proposed method were in the ranges of 0.01–0.12 ng g⁻¹ and 0.04–0.35 ng g⁻¹, respectively, which were far lower than that of reported methods. The findings indicated that the proposed semi-automated MEPS method was easy and efficient for the extraction of triazine herbicides in corn samples.