One-step purification of solid phase micro-extraction based on MIL-101(Cr) for the determination of vanillin, methyl vanillin and ethyl vanillin in edible vegetable oil samples

A method for the determination of vanillin, methyl vanillin and ethyl vanillin in edible vegetable oil by one-step purification combined with high performance liquid chromatography tandem mass spectrometry was established. A solid-phase micro-extraction one-step purification and impurity removal device was constructed based on the needle filter filled with MIL-101(Cr) material, and the purification process was quickly completed in the filter head with the help of syringe driving force. Under the optimized conditions of several factors affecting the extraction efficiency, the linear range was 0–500 ng/mL and the correlation coefficient (r) was greater than 0.9994. Under the six spiked concentrations, the recovery of edible vegetable oil was between 88.6% and 98.5%, and the RSDs were between 2.41% and 5.78%. The recoveries of inter-day and intra-day tests were 90.9%–93.0% and 90.6%–100.5%, respectively. The precision of inter-day and intra-day analysis were 6.09%–7.05% and 2.75%–4.49%, respectively. This method was used to detect 100 batches of commercial vegetable oil, only vanillin was detected, the detection rate was 52.0%, and the detection concentration was 107–872 μg/kg. The positive samples were confirmed by HPLC-QTOF/MS. The results showed that this method had the advantages of simple operation and high detection throughput, and was suitable for rapid analysis of vanillin, methyl vanillin and ethyl vanillin in different types of edible vegetable oil samples. •MIL-101 (Cr) material was synthesized by hydrothermal reaction.•One-step purification of SPME based on MIL-101(Cr) was developed.•SPME procedure displayed highly efficient impurity removal capabilities.•One-step purification for vanillin compounds in oil samples was established.•The method delivered low LOQ, good recoveries and satisfactory precision.