Extraction method for benzo(a)pyrene in edible oil

Abstract

The invention relates to a pre-treatment technology for benzo(a)pyrene in edible oil and particularly discloses an extraction method for the benzo(a)pyrene in the edible oil. The extraction method comprises the following step: (1) carrying out liquid-liquid extraction on acetonitrile, which is saturated by n-hexane, by using the edible oil; (2) carrying out repeated extraction operation on the raffinate obtained by the step 1; (3) mixing acetonitrile layer extracted liquid obtained after each time of extraction to obtain general extracting liquid; (4) adding a solid adsorbent into the general extracting liquid; purifying and carrying out solid-liquid separation; and taking liquid supernatant; and (5) blowing the liquid supernatant to be dried under nitrogen gas; re-dissolving by using the acetonitrile; and filtering by a filtering membrane and then carrying out liquid chromatogram analysis. According to the extraction method, extraction operation steps for the benzo(a)pyrene are simple and are affordable; the recycling rate is guaranteed while the impurity interferences can be sufficiently eliminated; the detection sensitivity is improved, the maintenance to a detecting instrument is reduced and the service life is prolonged; the extraction method for the benzo(a)pyrene in the edible oil is applicable to actual production, is convenient for rapid and accurate detection and has a good popularization value and a good application prospect.

Description

technical field [0001] The invention relates to a pretreatment technology of benzo(a)pyrene, in particular to a method for extracting benzo(a)pyrene in edible oil, belonging to the field of food analysis. Background technique [0002] Benzo(a)pyrene is a polycyclic aromatic hydrocarbon (PAHs) compound composed of 5 benzene rings. produce. [0003] At present, the latest national standard determination method (GB / T22509-2008) for the detection of benzo(a)pyrene in vegetable oil in my country adopts alumina column packing and solid phase chromatography for pretreatment, which has the disadvantages of long operation time, large reagent consumption, Unstable recovery rate, high requirements for reagents and personnel, etc. make it impossible to use this method for rapid and effective detection of benzo(a)pyrene residues in vegetable oil. European document 208 / 2005 stipulates that the maximum limit of BaP in edible oil is 2μg / kg, the International Codex Alimentarius Commission (...

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Problems solved by technology

The detection limit of the fluorescence spectrophotometry method used in GB / T5009.27-2003 Determination Standard of Benzo(a)Pyrene in Food is not fixed, and the detection limit of 1ng / g cannot be reached when the sample volume is insufficient or the sample volume is insufficient ;Visual colorimetry can only be roughly quantified, and these two methods are susceptible to external interference

GB / T22509-2008 Determination of benzo(a)pyrene in animal and vegetable oils and fats In the reversed-phase high-performance liquid chromatography standard, a simple alumina purification column is used to purify the matrix. When the sampling volume of oil increases, it will flow out with the eluent , affecting the determination of

[0007] For several emerging detection methods, the hydrolysis and saponification method takes a long time, and incomplete saponification has a great influence on the results, resulting in a decrease in sensitivity and accuracy; in gel permeation chromatography, benzo(a)pyrene has a good affinity Lipidity, competitive combination in the elution process leads to unclear retention time, poor size exclusion separation effect, and a large amount of residual oil after treatment, which affects detection; solid phase extraction has strict requirements on column packing, and for edible oil with complex components, The composition of the filler is not easy to choose

At the same time, a large number of experiments show that a large amount of organic reagents will be consumed in the process of solid-phase extraction, and a large amount of waste liquid will be generated, which is not easy to popularize and apply, and there will be residual oil after elution with different solid-phase extraction columns. And (a) the accuracy of pyrene detection is affected; simple liquid-liquid extraction is likely to cause problems such as oil residue and insufficient recovery

The n-hexane saturated with acetonitrile mentioned in the existing literature is used for dissolving, and then in the benzo(a)pyrene extraction method that is extracted with acetonitrile saturated with n-hexane, at first adopts the n-hexane saturated with acetonitrile to dissolve the edible oil, and this step removes The grease effect is general, and after the two phases are mixed and separated in a certain proportion, the n-hexane layer in which the grease is dissolved is in the upper layer, which is not conducive to absorption and separation, thus affecting the subsequent liquid phase detection and polluting the instrument, resulting in low detection sensitivity and long service life of the instrument. short

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