A semi-automatic solid phase extraction system based on MIL-101(Cr) foam-filled syringe for detection of triazines in...

In this study, several metal-organic framework-melamine foam columns were first developed and used as a laboratory-made semi-automatic solid phase extraction packed in syringe adsorber for the extraction of six triazine herbicides from vegetable oil samples coupled to high-performance liquid chromatography-tandem mass spectrometry. The metal-organic framework-foam columns were prepared using a simple approach by embedding the solid particles in melamine foam using polyvinylidene difluoride physical encapsulation. The method was applicable to a wide variety of metal-organic framework materials, and the incorporated materials retained their unique properties. Key factors that affect the extraction efficiency, including the MIL-101(Cr) amount, sample flow rate, type and volume of the eluting solvent, and flow rate of eluting solvent, were investigated. Under optimum conditions, the proposed method exhibited low limits of detection (0.017-0.096 ng/mL, S/N = 3) for six triazines. The relative standard deviations calculated for all herbicides ranged from 0.2 to 14.9%. This study demonstrated that the MIL-101(Cr)-foam column can be used as a high-quality adsorption material for the detection of triazines in vegetable oils.