Method for detecting 24 polycyclic aromatic hydrocarbons in edible oil based on molecularly imprinted polymer solid-phase extraction-gas chromatography/mass spectroscopy hyphenated technique

Abstract

The invention provides a method for detecting 24 polycyclic aromatic hydrocarbons in edible oil based on a molecularly imprinted polymer solid-phase extraction-gas chromatography / mass spectroscopy hyphenated technique. The method comprises the following steps: (1) preparing a 1.0mg / L standard using liquid, and fixing the volume of an isotope internal standard using liquid to 1.0mg / L; and (2) pre-treatment: accurately weighing 0.50g of edible oil in a 10mL test tube with a plug, firstly, adding 20[mu]l of a mixed internal using liquid, then adding 3mL of normal hexane, whirling and uniformly mixing the mixture for purification, separately activating a high molecularly imprinted polymer solid-phase extraction small column with 5mL of normal hexane and 5mL of dichloromethane, then adding a diluted oil into the small column, separately spraying the small column twice with 6mL of normal hexane and then abandoning the small column, eluting the mixture with a mixed liquid of 10mL of dichloromethane and ethyl acetate in a proportion of 1: 1, collecting the eluent, blowing nitrogen to be nearly dried, adding 0.3mL of normal hexane to dissolve for GC / MS analysis. The method provided by the invention has the beneficial effects of good precision and accuracy and meets the demand of limit valve.

Description

technical field [0001] The invention belongs to the technical field of detection of polycyclic aromatic hydrocarbons, and in particular relates to a method for detecting 24 kinds of polycyclic aromatic hydrocarbons in edible oil based on molecular imprinted solid phase extraction-gas / mass spectrometry technology. Background technique [0002] Polycyclic aromatic hydrocarbons (PAHs) refer to a class of compounds in which two or more benzene rings are connected in the form of fused rings. Those with 4 or less benzene rings are light polycyclic aromatic hydrocarbons, and those with more than 4 benzene rings are light polycyclic aromatic hydrocarbons. of heavy polycyclic aromatic hydrocarbons. As an important kind of persistent organic pollutants (POPs), it widely exists in nature. Such substances are generally lipophilic and easily soluble in organic solvents such as toluene, n-hexane, and ethyl acetate. PAHs are mainly a class of compounds produced by the pyrolysis and incom...

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Problems solved by technology

The content of polycyclic aromatic hydrocarbons in edible oil is low, the background is complicated, the traditional liquid-liquid extraction method is complicated to operate, the result is low recovery rate, and it will consume a large amount of organic solvents, which is harmful to the environment; SPE is a widely used micro sample pretreatment technology , but due to the lack of column packing that specifically adsorbs PAHs, the sensitivity and precision are low, and the purification effect is not good; the GPC solvent uses a large amount, and it has a good effect on removing impurities such as macromolecular oils, pigments, waxes, etc. The removal effect is poor, and the cost of automation equipment is high; the detection speed of DACC method is fast, but the online DACC method has high requirements for instruments, and the offline DACC method requires a lot of work to collect fractions manually, and DACC chromatography cannot detect small-ring polycyclic aromatic hydrocarbons

The magnetic dispersion solid phase extraction method requires the synthesis of corresponding magnetic polymer materials, which has high technical requirements and is difficult to guarantee the repeatability of the materials, and is not easy to commercialize

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