CN105445395A

CN105445395A - Solid-phase extraction column used cooperatively with GC-FID instrument and application thereof

Info

Publication number: CN105445395A
Application number: CN201510920818.XA
Authority: CN
Inventors: 武彦文; 李冰宁; 刘玲玲; 黄华; 欧阳杰; 汪雨; 王欣欣
Original assignee: Beijing Physichemistry Analysis & Measurment Centre
Current assignee: Beijing Physichemistry Analysis & Measurment Centre
Priority date: 2015-12-11
Filing date: 2015-12-11
Publication date: 2016-03-30

Abstract

The invention discloses a solid-phase extraction column used cooperatively with a GC-FID instrument and application thereof. The solid-phase extraction column used cooperatively with the GC-FID instrument is applied to pretreatment of a to-be-detected sample for mineral oil contaminant detection of food. The solid-phase extraction column comprises a hollow glass column and a plurality of glass fiber sieve plates which are arranged in the hollow glass column and isolate the interior of the hollow glass column into a silver nitrate impregnated silica gel filling space used for filling of silver nitrate impregnated silica gel, an anhydrous sodium sulfate filling space used for filling of anhydrous sodium sulfate and an alumina filling space used for filling of alumina, wherein the silver nitrate impregnated silica gel filling space, the anhydrous sodium sulfate filling space and the alumina filling space are successively arranged from top to bottom. Through pretreatment of the sample for analysis of mineral oil contamination of food by using the solid-phase extraction column, analysis pollution can be effectively reduced, and repeatability and accuracy of sample detection are improved; and the solid-phase extraction column is applicable to most food.

Description

With GC-FID instrument with the use of solid-phase extraction column and application

Technical field

The present invention relates to GC-FID instrument with the use of solid-phase extraction column and application, particularly, relate to GC-FID instrument with the use of solid-phase extraction column, pretreated method is carried out, for detecting the system of Mineral Oil in Food pollutant and detecting the method for Mineral Oil in Food pollutant to the testing sample that food pollutant mineral oil detects.

Background technology

In recent years, the pollution problem of Mineral Oil in Food received much concern, and main cause is the migration of residual ink in paper of being recycled and packaged.In addition, lubricant in plastics package (as polystyrene, polyolefin), the mineral oil related in bonding agent in paraffin paper, bast fibre packaging, food processing and white oil, the chip of engine oil, imperfect combustion gasoline, tire and pitch that raw-food material contacts in harvesting, airing and process and unholiness air etc., all can cause the mineral oil stain of food., in the numerous food products such as edible oil, infant food, flour, cereal, bread, biscuit, nut, all there is mineral oil stain in various degree in investigation display.

Mineral oil is that petroleum crude oil is formed in physical separation (distillation, extraction) and chemical conversion (as hydrogenation reaction, cracking, alkylation and isomerization) process, its composition comprises alkane and the alkyl naphthene mineral oil (MOSH of straight chain and side chain, and alkyl polycyclic aromatic compounds mineral oil (MOAH, mineraloilaromatichydrocarbons) mineraloilsaturatedhydrocarbons).The toxicity of mineral oil is low by the time medium, can cause lipogranuloma, autoantibody and systemic lupus erythematosus and arthritis.Meanwhile, mineral oil destroys digestion, makes people produce the symptoms such as Nausea and vomiting, causes sudden food poisoning; Damage nervous system, cause human body because of CNS dysfunctions death; Destroy respiratory system, reduce the red blood cell in blood, cause respiratory failure.In addition, mineral oil makes skin produce inflammation allergic phenomena etc. in addition.Given this, European Union has put into effect the standard method of MOSH in vegetable oil at the beginning of 2015.The United Nations grain farmer and the World Health Organization (WHO) (FAO/WHO) specify that the acceptable daily intake (ADI) of mineral oil can not more than 45mg/kg simultaneously.

Because mineral oil is a large amount of straight chain, side chain, the cyclic alkane of alkyl replacement and the complex mixture of aromatic hydrocarbon composition, its quantitative analysis method is comparatively special, usually adopts high performance liquid chromatography-gas chromatography combined usage (HPLC-GC-FID).But, due to HPLC-GC-FID expensive equipment, common laboratory cannot be popularized, and the instrumental analysis of coupling simultaneously will consider the multinomial conditional parameters such as the temperature programme of the mobile phase of HPLC, the interfacing of HPLC-GC and GC, needs sophisticated experiment operator.Therefore, effective artificial purification techniques just becomes the focus that people constantly explore.The purification method of Mineral Oil in Food analysis mainly comprises off-line HPLC, column chromatography and Solid-Phase Extraction column technology.Its principle be separated is all the matrix such as the animal and plant fat in food be detained on a column, wherein, because solid-phase extraction column is easy, quick, efficient, economical and become the first-selected sample pretreating method of Mineral Oil in Food analysis.

At present, market is not analyzed the Special sample pre-service SPE post of Mineral Oil in Food, the homemade SPE post in some laboratories is due to problems such as column jecket material, capacity and column packings, cause pollute and clean-up effect bad, part Experiment room due to the capacity of SPE too small, large volume sample injection equipment (LVI) must be adopted just to obtain good sensitivity and detection limit during follow-up GC-FID assaying oil.But the detection unit and the department that have LVI-GC-FID are at present considerably less, and the stability of LVI sampling system and repeatability are also undesirable.Thus the application of this solid-phase extraction column is restricted.

Thus, at present in the research field of quantitative test Mineral Oil in Food pollutant, the testing sample for detecting food pollutant mineral oil carries out pretreated solid-phase extraction column and still haves much room for improvement.

Summary of the invention

The present invention is intended at least to solve one of technical matters existed in prior art.For this reason, one object of the present invention be propose one can with GC-FID instrument effectively with the use of, carry out pretreated solid-phase extraction column for the testing sample detected food pollutant mineral oil.

According to an aspect of the present invention, the invention provides a kind of with GC-FID instrument with the use of solid-phase extraction column, it carries out pre-service for the testing sample detected food pollutant mineral oil.According to embodiments of the invention, should with GC-FID instrument with the use of solid-phase extraction column comprise: double glazing post; Multiple glass fibre sieve plate, it is inner that described multiple glass fibre sieve plate is arranged on described double glazing post, and described double glazing post internal insulation is become to be used for fill silver nitrate stain silica gel silver nitrate stain silicone filler space, be used for filling the anhydrous sodium sulfate packing space of anhydrous sodium sulfate and be used for filling the alumina filled space of aluminium oxide, wherein, described silver nitrate stain silicone filler space, described anhydrous sodium sulfate packing space and described alumina filled space are arranged in order from the top down.

Inventor is surprised to find, utilize of the present invention with GC-FID instrument with the use of solid-phase extraction column effectively can realize to the testing sample that food pollutant mineral oil detects pre-service, and then follow-up carry out GC-FID instrument pollutant mineral oil detect time, effectively can reduce to analyze and pollute, improve repeatability and the accuracy of sample detection.In addition, according to some embodiments of the present invention, of the present invention with GC-FID instrument with the use of solid-phase extraction column, solve clean-up effect and the off-capacity problem of conventional solid extraction column product, and be applicable to the sample pretreatment of most of Mineral Oil in Food contamination analysis, have good versatility, cost is low, easy to use, is easy to promote.

According to a further aspect in the invention, the invention provides a kind of testing sample to the detection of food pollutant mineral oil and carry out pretreated method.According to embodiments of the invention, the method comprises the following steps: obtain the fat in testing sample, and dissolving obtains pending test solution; Utilize foregoing with GC-FID instrument with the use of solid-phase extraction column described pending test solution is extracted, and collect eluent; And concentrated by described eluent, and redissolve constant volume, to obtain solution to be measured.According to embodiments of the invention, testing sample to the detection of food pollutant mineral oil of the present invention carries out pretreated method, adopt with GC-FID instrument with the use of solid-phase extraction column pre-service is carried out to the testing sample that food pollutant mineral oil detects, can carry out effectively reducing to analyze when GC-FID instrument detects polluting follow-up, improve repeatability and the accuracy of sample detection.In addition, the method is applicable to the sample pretreatment of most of Mineral Oil in Food contamination analysis, there is good versatility, and cost is low, easy and simple to handle, be easy to promote, and relative to adopting the preprocess method of conventional solid extraction column, clean-up effect significantly strengthens, and does not have the problem of off-capacity.

According to another aspect of the invention, the invention provides a kind of system for detecting Mineral Oil in Food pollutant.According to embodiments of the invention, this system comprises: foregoing with GC-FID instrument with the use of solid-phase extraction column; And GC-FID instrument.Utilizing the system for detecting Mineral Oil in Food pollutant of the present invention, effectively can detect the pollutant mineral oil in food, and relative to traditional detection system, analyze pollution low, repeatability and the accuracy of sample detection are high, and testing cost is low.In addition, according to some embodiments of the present invention, this system is applicable to the mineral oil stain analysis of most of food, has good versatility, and cost is low, easy to use, is easy to promote.

In accordance with a further aspect of the present invention, the invention provides a kind of method detecting Mineral Oil in Food pollutant.According to embodiments of the invention, the method comprises the following steps: carry out pretreated method according to the foregoing testing sample to Mineral Oil in Food pollutant monitoring, carry out pre-service to testing sample, to obtain solution to be measured; And utilize GC-FID instrument to carry out pollutant mineral oil detection to described solution to be measured, to determine the mineral oil stain situation in described testing sample.Inventor is surprised to find, the method of detection Mineral Oil in Food pollutant of the present invention, the aforesaid system for detecting Mineral Oil in Food pollutant of actual employing is carried out, effectively can detect the pollutant mineral oil in food, and relative to traditional detection method, analyze pollution low, repeatability and the accuracy of sample detection are high, and testing cost is low.In addition, according to some embodiments of the present invention, the method is applicable to the mineral oil stain analysis of most of food, has good versatility, and easy to operate, is easy to promote.

Additional aspect of the present invention and advantage will part provide in the following description, and part will become obvious from the following description, or be recognized by practice of the present invention.

Accompanying drawing explanation

Above-mentioned and/or additional aspect of the present invention and advantage will become obvious and easy understand from accompanying drawing below combining to the description of embodiment, wherein:

Fig. 1 is according to one embodiment of the invention, the quantivative approach schematic diagram of the GC spectrogram of Mineral Oil in Food;

Fig. 2 is according to one embodiment of the invention, the experimental result that solid-phase extraction column material is selected;

Fig. 3 is according to one embodiment of the invention, the experimental result that solid phase extraction column stuffing kind is selected;

Fig. 4 and Fig. 5 is according to one embodiment of the invention, the experimental result of the amount of filler of solid-phase extraction column and the optimization of applied sample amount;

Fig. 6 is according to one embodiment of the invention, edible oil after solid-phase extraction column process of the present invention obtains, the mineral oil analysis of spectra that conventional GC-FID analytical instrument obtains;

Fig. 7 is according to one embodiment of the invention, milk powder after solid-phase extraction column process of the present invention obtains, the mineral oil analysis of spectra that conventional GC-FID analytical instrument obtains;

Fig. 8 is according to one embodiment of the invention, biscuit after solid-phase extraction column process of the present invention obtains, the mineral oil analysis of spectra that conventional GC-FID analytical instrument obtains;

Fig. 9 is according to one embodiment of the invention, bread after solid-phase extraction column process of the present invention obtains, the mineral oil analysis of spectra that conventional GC-FID analytical instrument obtains;

Figure 10 is according to one embodiment of the invention, rice after solid-phase extraction column process of the present invention obtains, the mineral oil analysis of spectra that conventional GC-FID analytical instrument obtains;

Figure 11 is according to one embodiment of the invention, baby rice powder after solid-phase extraction column process of the present invention obtains, the mineral oil analysis of spectra that conventional GC-FID analytical instrument obtains;

Figure 12 is according to one embodiment of the invention, vermicelli after solid-phase extraction column process of the present invention obtains, the mineral oil analysis of spectra that conventional GC-FID analytical instrument obtains;

Figure 13 is according to one embodiment of the invention, instant noodles after solid-phase extraction column process of the present invention obtains, the mineral oil analysis of spectra that conventional GC-FID analytical instrument obtains;

Figure 14 is according to one embodiment of the invention, peanut after solid-phase extraction column process of the present invention obtains, the mineral oil analysis of spectra that conventional GC-FID analytical instrument obtains;

Figure 15 is according to one embodiment of the invention, potato chips after solid-phase extraction column process of the present invention obtains, the mineral oil analysis of spectra that conventional GC-FID analytical instrument obtains;

Figure 16 be according to an embodiment of the invention with GC-FID instrument with the use of the structural representation of solid-phase extraction column; And

Figure 17 is according to an embodiment of the invention for detecting the structural representation of the system of Mineral Oil in Food pollutant.

Embodiment

Be described below in detail embodiments of the invention, the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or has element that is identical or similar functions from start to finish.Being exemplary below by the embodiment be described with reference to the drawings, only for explaining the present invention, and can not limitation of the present invention being interpreted as.

According to an aspect of the present invention, the invention provides a kind of with GC-FID instrument with the use of solid-phase extraction column, it carries out pre-service for the testing sample detected food pollutant mineral oil.According to embodiments of the invention, with reference to Figure 16, should with GC-FID instrument with the use of solid-phase extraction column 1000 comprise: double glazing post 100 and multiple glass fibre sieve plate 101.

Particularly, according to embodiments of the invention, it is inner that described multiple glass fibre sieve plate 101 is arranged on described double glazing post 100, and described double glazing post 100 internal insulation is become to be used for fill silver nitrate stain silica gel silver nitrate stain silicone filler space A, be used for filling the anhydrous sodium sulfate packing space B of anhydrous sodium sulfate and be used for filling the alumina filled space C of aluminium oxide, wherein, described silver nitrate stain silicone filler space A, described anhydrous sodium sulfate packing space B and described alumina filled space C are arranged in order from the top down.

It should be noted that, carry out the testing sample of food pollutant mineral oil detection, its in leaching process because of the animal and plant fat in food can with mineral oil in the lump stripping, thus general all simultaneously containing mineral oil and animal and plant fat, its mineral oil in fluid is nonpolar fat-soluble potpourri, and the principal ingredient of animal and plant fat is triglyceride, there is faint polarity, can by silica gel adsorption, thus, utilize silica gel can animal and plant fat in Adsorption testing sample; Further, in triglyceride, the double bond of unsaturated fatty acid and silver ion have faint acting force, and thus silver nitrate stain silica gel is significantly greater than common silica gel to the absorption affinity of animal and plant fat.Thus, after the fat-extraction liquid of food passes through the solid-phase extraction column of filling silver nitrate stain silica gel, animal and plant fat is adsorbed, and mineral oil flows out, thus reaches the object of mineral oil purification.Aluminium oxide can adsorb long chain alkane, such as, in the vegetable fat n-alkane of distinctive odd carbon chain, thus can utilize the vegetable fat in the further Adsorption testing sample of aluminium oxide, thus improves the purity of mineral oil; But the clean-up effect of aluminium oxide is vulnerable to polar material interference, and aqueous polar is very large, therefore, the higher meeting of moisture has a strong impact on the adsorption effect of aluminium oxide, therefore needs on the upper strata of aluminium oxide to add one deck anhydrous sodium sulfate, for removing moisture residual in sample.To sum up, silver nitrate stain silicone filler space A, anhydrous sodium sulfate packing space B that inventor utilizes the multiple glass fibre sieve plates 101 being arranged on described double glazing post 100 inside to become to be arranged in order from the top down by described double glazing post 100 internal insulation and alumina filled space C, thus when carrying out extraction pre-service, non-mineral oil Impurity removal effect is good, animal and plant fat interference is few, it is high, reproducible that follow-up GC-FID detects the result precision analyzed.

In addition, current use for laboratory solid-phase extraction column mostly is plastic material, when extracting, and sample test solution and plastic contacts, sample vulnerable to pollution, thus the detection of interference mineral oil.And solid-phase extraction column 1000 of the present invention adopts glass material, thus effectively can get rid of the pollution in experimentation.

According to embodiments of the invention, the set-up mode of described multiple glass fibre sieve plate 101 is not particularly limited, as long as described double glazing post 100 inside effectively can be isolated the space of being convenient to load silver nitrate stain silica gel, anhydrous sodium sulfate and aluminium oxide respectively, and then testing sample solution can be made in use effectively by each packing space, effectively realize sorption extraction.According to concrete examples more of the present invention, described multiple glass fibre sieve plate be arranged in parallel.Thus, laboratory use time can easy, load solid-phase extraction column quickly, in Mineral Oil in Food analysis, there is stronger using value.

According to embodiments of the invention, the number of described multiple glass fibre sieve plate 101 is not particularly limited, as long as effectively described double glazing post 100 inside can effectively be isolated the space for loading silver nitrate stain silica gel, anhydrous sodium sulfate and aluminium oxide.According to concrete examples more of the present invention, described multiple glass fibre sieve plate is 4.Thus, just described double glazing post internal insulation can be gone out 3 packing spaces of relative closure, respectively as silver nitrate stain silicone filler space A, anhydrous sodium sulfate packing space B and alumina filled space C, thus progressively purification and the pre-service of testing sample can be effective to.

According to embodiments of the invention, the capacity of described double glazing post 100 is 50 ~ 100ml.Thus, effectively can meet the capacity requirement of Mineral Oil in Food contamination analysis sample pretreatment, and relatively increase sample test solution treatment capacity, and then efflux is through concentrated, be equivalent to add the concentration of mineral oil injecting GC-FID instrument, thus improve the sensitivity of whole analytical approach, ensure that the accuracy of method.

According to embodiments of the invention, the length-diameter ratio of described double glazing post 100 is 5 ~ 10:1, preferred 7:1.Thus, effect of extracting is good.

According to embodiments of the invention, the aperture of each of described multiple glass fibre sieve plate 101 is 10 μm ~ 50 μm, and thickness is 1 ~ 3mm.Thus, absorption, good filtration effect, effect of extracting is good.

According to embodiments of the invention, the particle diameter of described silver nitrate stain silica gel is 60 μm ~ 200 μm.Thus, effective to the Adsorption of animal and plant fat.

According to embodiments of the invention, in described silver nitrate stain silica gel, the ratio of silver nitrate is 0.1 quality % ~ 6 quality %.Thus, silver nitrate stain silica gel is given prominence to the absorption affinity of animal and plant fat, thus effect of extracting is good.

According to embodiments of the invention, the particle diameter of described aluminium oxide is 60 μm ~ 200 μm.Thus, effective to the Adsorption of animal and plant fat.

According to embodiments of the invention, described silver nitrate stain silica gel and described aluminium oxide activate through high temperature sintering all in advance.Thus, effect of extracting is good.

According to embodiments of the invention, described silver nitrate stain silica gel is 5 ~ 10g, and described anhydrous sodium sulfate is 2 ~ 4g, and described aluminium oxide is 1 ~ 10g.Thus, effect of extracting is good.

According to preferred embodiments more of the present invention, described silver nitrate stain silica gel is 10g, and described anhydrous sodium sulfate is 2 ~ 4g, and described aluminium oxide is 1g.Thus, effect of extracting is given prominence to, and animal and plant fat interference is few, and it is high, reproducible that follow-up GC-FID detects the result precision analyzed.

In addition, according to some embodiments of the present invention, can prepare in accordance with the following methods of the present invention with GC-FID instrument with the use of solid-phase extraction column 1000:

(1) glass chromatography column (i.e. double glazing post 100) of 50 ~ 100mL is prepared, extraction column outlet is provided with bottom column jecket, close to the bottom frit glass fibre sieve plate 101 of post, process the glass fibre upper sieve plate 101 (10 μm ~ 50 μm, aperture, thickness is 1 ~ 3mm) mated with glass column simultaneously.

(2) activated alumina: by particle diameter 60 μm ~ 200 μm aluminium oxide being, toasts 4 ~ 6h in 500 ~ 600 DEG C, is put in exsiccator for subsequent use in muffle furnace.

(3) activated silica gel: be that the silica gel of 60 μm ~ 200 μm toasts 4 ~ 6h in 500 ~ 600 DEG C in muffle furnace by particle diameter, take out after cooling, be put in exsiccator for subsequent use.

(4) prepare silver nitrate stain silica gel: accurately take analytically pure silver nitrate in volumetric flask, dissolve and constant volume with distilled water, be mixed with the aqueous solution of 0.50 ~ 1.00g/mL; Then with the liquor argenti nitratis ophthalmicus of this concentration, add in the silica gel after the activation that step (3) obtains according to predetermined ratio (in described silver nitrate stain silica gel, the ratio of silver nitrate is 0.1 quality % ~ 6 quality %).Limit interpolation limit mixing during operation, after having added, fully vibration mixes 0.5h again, uses after leaving standstill 12h.

(5) anhydrous sodium sulfate is prepared: adopt the pure anhydrous sodium sulfate of commercially available analysis, for removing the moisture in sample extracting solution.

(6) filling assembling: load activated alumina in the bottom of glass chromatography column (i.e. double glazing post) 100, press-in one deck isolation sieve plate (i.e. glass fibre sieve plate 101), reinstall anhydrous sodium sulfate, be pressed into one deck isolation sieve plate again, then silver nitrate stain activated silica gel is loaded, the last one deck that is pressed into again isolates sieve plate, obtains solid-phase extraction column 1000 of the present invention.

According to a further aspect in the invention, the invention provides a kind of testing sample to the detection of food pollutant mineral oil and carry out pretreated method.According to embodiments of the invention, the method comprises the following steps: obtain the fat in testing sample, and dissolving obtains pending test solution; Utilize foregoing with GC-FID instrument with the use of solid-phase extraction column 1000 described pending test solution is extracted, and collect eluent; And concentrated by described eluent, and redissolve constant volume, to obtain solution to be measured.According to embodiments of the invention, testing sample to the detection of food pollutant mineral oil of the present invention carries out pretreated method, adopt with GC-FID instrument with the use of solid-phase extraction column pre-service is carried out to the testing sample that food pollutant mineral oil detects, can carry out effectively reducing to analyze when GC-FID instrument detects polluting follow-up, improve repeatability and the accuracy of sample detection.In addition, the method is applicable to the sample pretreatment of most of Mineral Oil in Food contamination analysis, there is good versatility, and cost is low, easy and simple to handle, be easy to promote, and relative to adopting the preprocess method of conventional solid extraction column, clean-up effect significantly strengthens, and does not have the problem of off-capacity.

According to embodiments of the invention, n-hexane dissolution fat is utilized to obtain pending test solution.Thus, follow-up effect of extracting is good.

According to embodiments of the invention, described extraction comprises the following steps:

(1) the pre-drip washing solid-phase extraction column of 25ml normal hexane is utilized;

(2) carry out loading process to the solid-phase extraction column through pre-drip washing process, wherein said pending test solution applied sample amount is 1 ~ 3ml, preferred 2ml;

(3) utilize 10ml normal hexane to carry out the first wash-out to the solid-phase extraction column through loading process, discard eluent;

(4) utilize 40ml normal hexane to carry out the second wash-out to the solid-phase extraction column through the first wash-out, collect eluent.Thus, effect of extracting is good, and animal and plant fat interference is few, and it is high, reproducible that follow-up GC-FID detects the result precision analyzed.

According to embodiments of the invention, normal hexane is utilized to carry out described redissolution constant volume.Thus, be beneficial to follow-up GC-FID and detect analysis.

According to another aspect of the invention, the invention provides a kind of system for detecting Mineral Oil in Food pollutant.According to embodiments of the invention, with reference to Figure 17, this system 10000 comprises: with GC-FID instrument with the use of solid-phase extraction column 1000 and GC-FID instrument 2000.Inventor finds, utilizing the system for detecting Mineral Oil in Food pollutant of the present invention, effectively can detect the pollutant mineral oil in food, and relative to traditional detection system, analyze pollution low, repeatability and the accuracy of sample detection are high, and testing cost is low.In addition, according to some embodiments of the present invention, this system is applicable to the mineral oil stain analysis of most of food, has good versatility, and cost is low, easy to use, is easy to promote.

According to embodiments of the invention, GC-FID instrument is utilized to the condition that described solution to be measured carries out pollutant mineral oil detection to be: to adopt DB-5HT quartz capillary column as chromatographic column; Column temperature is 65 DEG C and keeps 10min, and rise to 370 DEG C with the speed of 50 DEG C/min, keep 10min, carrier gas is high pure nitrogen, and column flow rate is 1.35mL/min; Hydrogen flowing quantity is 30mL/min; Air mass flow is 400mL/min; Adopt Splitless injecting samples, sample size is 2 μ L; Injector temperature 350 DEG C; Fid detector temperature 380 DEG C.Thus, the result precision of GC-FID detection analysis is high, reproducible.

In addition, according to some embodiments of the present invention, the method of detection Mineral Oil in Food pollutant of the present invention can comprise: food samples is carried out successively fat-extraction, Solid phase extraction, concentrated rear injection GC-FID analysis, and the GC spectrogram obtained is analyzed based on GC-FID, it is quantitative to carry out mineral oil.Wherein, as shown in Figure 1, utilize GC-FID instrument to carry out pollutant mineral oil to described solution to be measured and detect in the GC spectrogram of the mineral oil obtained, there is a broad peak in similar " hump ", its quantivative approach, according to the area of this " hump ", utilizes internal standard method (as C ₁₈) or external standard method (as the mineral oil standard substance) total amount to mineral oil carry out quantitative measurement (specifically can be see: [1] MaurusBiedermann, KoniGrob, On-linecoupledhighperformanceliquidchromatography-gaschr omatographyfortheanalysisofcontaminationbymineraloil.Par t2:Migrationfrompaperboardintodryfoods:Interpretationofc hromatograms, J.Chromat.A, 2012,1255:76-99.; [2] ISO/DIS17780:2014 (E), Animalandvegetablefatsandoils-Determinationofaliphatichydrocarbonsinvegetableoils [S].; [3] Wu Yanwen, etc., the pollutant mineral oil [J] in quantitative test food, food security quality testing journal, 2015,6 (6): 2145-2150, be incorporated in full herein by referring to by it).This and traditional the utilize peak height of single chromatogram spike or peak area quantification are diverse methods.In addition, it is especially noted that the chromatographic peak of " hump " upper end is exactly natural intrinsic hydrocarbon compound, need deduction, thus obtain baseline with chromatogram peak-to-peak " hump " area for mineral oil quantitative.

Particularly, according to concrete examples more of the present invention, with reference to Fig. 1, the GC spectrogram based on mineral oil carries out the quantitative method of Mineral Oil in Food, can comprise the following steps:

A () draws baseline;

Spike above (b) deduction " hump ";

C () calculates baseline and chromatogram point peak-to-peak " hump " area.

According to the embodiment of the present invention with GC-FID instrument with the use of solid-phase extraction column and application have following advantages one of at least:

1, compared with prior art, solid-phase extraction column of the present invention is applicable to separation and the enrichment of the various leisure food mineral oil in fluid pollutants such as the bakery product such as edible oil, milk powder and goods thereof, bread, cake, biscuit, nut, rice, wheat flour and its products, various beverage, French fries, potato chips, effectively can get rid of the interference of animal and plant fat in sample.

2, solid-phase extraction column material of the present invention is glass, avoids the contact of sample test solution and plastics, effectively eliminates the pollution in experimentation.

3, Solid-Phase Extraction column capacity of the present invention is 50-100mL, increase sample test solution treatment capacity, efflux, through concentrated, effectively increases the concentration of mineral oil injecting GC-FID instrument, thus improve the sensitivity of whole analytical approach, ensure that the accuracy of method.

4, glass solid-phase extraction column of the present invention carries sieve plate, when laboratory is used can easy, load solid-phase extraction column quickly, in Mineral Oil in Food analysis, there is stronger using value.

5, utilize of the present invention with GC-FID instrument with the use of solid-phase extraction column effectively can realize to the testing sample that food pollutant mineral oil detects pre-service, and then follow-up carry out GC-FID instrument pollutant mineral oil detect time, effectively can reduce to analyze and pollute, improve repeatability and the accuracy of sample detection; Of the present invention with GC-FID instrument with the use of solid-phase extraction column, solve clean-up effect and the off-capacity problem of conventional solid extraction column product, and be applicable to the sample pretreatment of most of Mineral Oil in Food contamination analysis, there is good versatility, cost is low, easy to use, is easy to promote.

6, the method for detection Mineral Oil in Food pollutant of the present invention, the system for detecting Mineral Oil in Food pollutant of the present invention is adopted to carry out, effectively can detect the pollutant mineral oil in food, and relative to traditional detection method, analyze pollution low, repeatability and the accuracy of sample detection are high, and testing cost is low; The method is applicable to the mineral oil stain analysis of most of food, has good versatility, and easy to operate, is easy to promote.

Below in conjunction with embodiment, the solution of the present invention is made an explanation.It will be understood to those of skill in the art that the following examples only for illustration of the present invention, and should not be considered as limiting scope of the present invention.Unreceipted concrete technology or condition in embodiment, according to the technology described by the document in this area or condition or carry out according to product description.Agents useful for same or the unreceipted production firm person of instrument, being can by the conventional products of commercial acquisition.

Embodiment 1

According to following steps prepare of the present invention with GC-FID instrument with the use of solid-phase extraction column 1000 (as shown in figure 16):

(1) glass chromatography column (i.e. double glazing post 100) of 50mL is prepared, extraction column outlet is provided with bottom column jecket, close to the bottom frit glass fibre sieve plate 101 of post, process the glass fibre upper sieve plate 101 (10 μm, aperture, thickness is 1mm) mated with glass column simultaneously.

(2) activated alumina: by particle diameter 60 μm of aluminium oxide being, toast 4h in 500 DEG C in muffle furnace, be put in exsiccator for subsequent use.

(3) activated silica gel: be that the silica gel of 60 μm toasts 4h in 500 DEG C in muffle furnace by particle diameter, take out after cooling, be put in exsiccator for subsequent use.

(4) prepare silver nitrate stain silica gel: accurately take analytically pure silver nitrate in volumetric flask, dissolve and constant volume with distilled water, be mixed with the aqueous solution of 0.50g/mL; Then with the liquor argenti nitratis ophthalmicus of this concentration, add in the silica gel after the activation that step (3) obtains according to predetermined ratio (in described silver nitrate stain silica gel, the ratio of silver nitrate is 0.1 quality %).Limit interpolation limit mixing during operation, after having added, fully vibration mixes 0.5h again, uses after leaving standstill 12h.

(6) filling assembling: load activated alumina in the bottom of glass chromatography column (i.e. double glazing post) 100, press-in one deck isolation sieve plate (i.e. glass fibre sieve plate 101), reinstall anhydrous sodium sulfate, be pressed into one deck isolation sieve plate again, then silver nitrate stain activated silica gel is loaded, the last one deck that is pressed into again isolates sieve plate, obtain solid-phase extraction column 1000 of the present invention, wherein, loadings is respectively: described silver nitrate stain silica gel is 5g, described anhydrous sodium sulfate is 2g, and described aluminium oxide is 1g.

Embodiment 2

(1) glass chromatography column (i.e. double glazing post 100) of 100mL is prepared, extraction column outlet is provided with bottom column jecket, close to the bottom frit glass fibre sieve plate 101 of post, process the glass fibre upper sieve plate 101 (50 μm, aperture, thickness is 3mm) mated with glass column simultaneously.

(2) activated alumina: by particle diameter 200 μm of aluminium oxide being, toast 6h in 600 DEG C in muffle furnace, be put in exsiccator for subsequent use.

(3) activated silica gel: be that the silica gel of 200 μm toasts 6h in 600 DEG C in muffle furnace by particle diameter, take out after cooling, be put in exsiccator for subsequent use.

(4) prepare silver nitrate stain silica gel: accurately take analytically pure silver nitrate in volumetric flask, dissolve and constant volume with distilled water, be mixed with the aqueous solution of 1.00g/mL; Then with the liquor argenti nitratis ophthalmicus of this concentration, add in the silica gel after the activation that step (3) obtains according to predetermined ratio (in described silver nitrate stain silica gel, the ratio of silver nitrate is 6 quality %).Limit interpolation limit mixing during operation, after having added, fully vibration mixes 0.5h again, uses after leaving standstill 12h.

(6) filling assembling: load activated alumina in the bottom of glass chromatography column (i.e. double glazing post) 100, press-in one deck isolation sieve plate (i.e. glass fibre sieve plate 101), reinstall anhydrous sodium sulfate, be pressed into one deck isolation sieve plate again, then silver nitrate stain activated silica gel is loaded, the last one deck that is pressed into again isolates sieve plate, obtain solid-phase extraction column 1000 of the present invention, wherein, loadings is respectively: described silver nitrate stain silica gel is 10g, described anhydrous sodium sulfate is 4g, and described aluminium oxide is 1g.

Embodiment 3

(1) glass chromatography column (i.e. double glazing post 100) of 75mL is prepared, extraction column outlet is provided with bottom column jecket, close to the bottom frit glass fibre sieve plate 101 of post, process the glass fibre upper sieve plate 101 (30 μm, aperture, thickness is 2mm) mated with glass column simultaneously.

(2) activated alumina: by particle diameter 130 μm of aluminium oxide being, toast 5h in 550 DEG C in muffle furnace, be put in exsiccator for subsequent use.

(3) activated silica gel: be that the silica gel of 130 μm toasts 5h in 550 DEG C in muffle furnace by particle diameter, take out after cooling, be put in exsiccator for subsequent use.

(4) prepare silver nitrate stain silica gel: accurately take analytically pure silver nitrate in volumetric flask, dissolve and constant volume with distilled water, be mixed with the aqueous solution of 0.70g/mL; Then with the liquor argenti nitratis ophthalmicus of this concentration, add in the silica gel after the activation that step (3) obtains according to predetermined ratio (in described silver nitrate stain silica gel, the ratio of silver nitrate is 3 quality %).Limit interpolation limit mixing during operation, after having added, fully vibration mixes 0.5h again, uses after leaving standstill 12h.

(6) filling assembling: load activated alumina in the bottom of glass chromatography column (i.e. double glazing post) 100, press-in one deck isolation sieve plate (i.e. glass fibre sieve plate 101), reinstall anhydrous sodium sulfate, be pressed into one deck isolation sieve plate again, then silver nitrate stain activated silica gel is loaded, the last one deck that is pressed into again isolates sieve plate, obtain solid-phase extraction column 1000 of the present invention, wherein, loadings is respectively: described silver nitrate stain silica gel is 7.5g, described anhydrous sodium sulfate is 3g, and described aluminium oxide is 10g.

Comparative example 1:

Prepare solid-phase extraction column according to the method for embodiment 2, difference is only: double glazing post, bottom it and sieve plate adopt plastic material.

Comparative example 2:

Solid-phase extraction column is prepared according to following steps:

(2) activated silica gel: be that the silica gel of 200 μm toasts 6h in 600 DEG C in muffle furnace by particle diameter, take out after cooling, be put in exsiccator for subsequent use.

(3) prepare silver nitrate stain silica gel: accurately take analytically pure silver nitrate in volumetric flask, dissolve and constant volume with distilled water, be mixed with the aqueous solution of 1.00g/mL; Then with the liquor argenti nitratis ophthalmicus of this concentration, add in the silica gel after the activation that step (3) obtains according to predetermined ratio (in described silver nitrate stain silica gel, the ratio of silver nitrate is 6 quality %).Limit interpolation limit mixing during operation, after having added, fully vibration mixes 0.5h again, uses after leaving standstill 12h.

(4) filling assembling: load silver nitrate stain activation silicon in the bottom of glass chromatography column (i.e. double glazing post) 100, press-in one deck isolation sieve plate (i.e. glass fibre sieve plate 101), wherein, described silver nitrate stain silica gel loadings is 10g.

Comparative example 3

Prepare solid-phase extraction column according to the method for comparative example 2, difference is only, silver nitrate stain silica gel loadings is 8g.

Comparative example 4

Prepare solid-phase extraction column according to the method for comparative example 2, difference is only, silver nitrate stain silica gel loadings is 2g.

The selection of embodiment 4 solid-phase extraction column material

In accordance with the following methods, the effect of extracting of plastics solid-phase extraction column prepared by glass solid-phase extraction column and the comparative example 1 of embodiment 1 preparation is compared:

Sample ID: edible oil.

For two kinds of solid-phase extraction columns, all operate according to following steps:

1. take 6g edible oil sample in 10mL volumetric flask, add the C of 1mL40mg/L ₁₈inner mark solution, then be settled to 10mL with normal hexane, vibration mixing.

3., with the pre-drip washing solid-phase extraction column of 25mL normal hexane, efflux discards.When normal hexane liquid level adds 2mL said sample higher than during post bed 0.5cm, with 10mL hexane dead volume, discard.Add 40mL hexane again, collect eluent.

4. blown by wash-out liquid nitrogen concentrated near dry, be settled to 0.5mL with normal hexane, utilize conventional GC-FID to analyze, analysis condition is as follows: chromatographic column DB-5HT quartz capillary column (15m × 0.25mm × 0.1 μm); Column temperature is 65 DEG C and keeps 10min, and rise to 370 DEG C with the speed of 50 DEG C/min, keep 10min, carrier gas is high pure nitrogen, and column flow rate is 1.35mL/min; Hydrogen flowing quantity is 30mL/min; Air mass flow is 400mL/min; Adopt Splitless injecting samples, sample size is 2 μ L; Injector temperature 350 DEG C; Fid detector temperature 380 DEG C.

Comparative result is shown in Fig. 2.Wherein, Fig. 2 a is the GC spectrogram after the Solid-Phase Extraction column purification mineral oil of glass material prepared by embodiment 1, and Fig. 2 b is the GC spectrogram after the plastics solid-phase extraction column purification mineral oil of comparative example 1 preparation.Relatively find, the detection of solid-phase extraction column to object of plastic material pollutes.

The selection of embodiment 5 solid phase extraction column stuffing kind

In accordance with the following methods, filler embodiment 2 prepared is the solid-phase extraction column of silver nitrate stain silica gel, anhydrous sodium sulfate and aluminium oxide, and the filler prepared with comparative example 2 is that the effect of extracting of the solid-phase extraction column of silver nitrate stain silica gel compares:

Sample ID: edible oil.

Comparative result is shown in Fig. 3.Wherein, Fig. 3 a is filler prepared by comparative example 2 is GC spectrogram after the Solid-Phase Extraction column purification mineral oil of silver nitrate stain silica gel, Fig. 3 b GC spectrogram that to be filler prepared by embodiment 2 be after the Solid-Phase Extraction column purification mineral oil of silver nitrate stain silica gel, anhydrous sodium sulfate and aluminium oxide.From the above results, in order to remove the material such as intrinsic natural alkane and olefin polymerization in food comparatively thoroughly, need to adopt aluminium oxide purification; Wherein, due to the clean-up effect of aluminium oxide and moisture closely related, the higher meeting of moisture has a strong impact on the adsorption effect of aluminium oxide to alkene, therefore needs on the upper strata of aluminium oxide to add one deck anhydrous sodium sulfate, for removing moisture residual in test solution.

The amount of filler of embodiment 6 solid-phase extraction column and the optimization of applied sample amount

In accordance with the following methods, the silver nitrate stain silica gel loadings prepared for comparative example 4 is the solid-phase extraction column of 2g, silver nitrate stain silica gel loadings prepared by comparative example 3 is the solid-phase extraction column of 8g, and silver nitrate stain silica gel loadings prepared by comparative example 2 is the solid-phase extraction column of 10g, the effect of extracting carrying out different applied sample amount respectively compares, to optimize amount of filler and applied sample amount:

Sample ID: edible oil.

For each solid-phase extraction column, with reference to the method for embodiment 4, the effect of extracting constantly carrying out different applied sample amount compares.

The amount of filler of solid-phase extraction column correspond to its applied sample amount that can process.Filler is many, then the sample size of respective handling is large.Vice versa.The Large Copacity solid-phase extraction column that development meets the sensitivity requirement of GC-FID is related in the present invention.Because GC-FID sensitivity is lower, need abundant mineral oil content just can detect, the accuracy of ensuring method and sensitivity.Common experience is that the mineral oil quality entering GC-FID needs to be greater than 50ng.

As a result, inventor finds, amount of filler is the solid-phase extraction column solid-phase extraction column of 2g, only can meet the applied sample amount of 0.1-0.2g, and so few applied sample amount is not enough to the detection sensitivity reaching GC-FID, can not get analysis result (see Fig. 4 b) at all.Need the filler strengthening solid-phase extraction column, and when amount of filler is 10g, abundant specimen test can be processed, but the applied sample amount that need reach 1-2g just can reach the detection sensitivity of GC-FID (see Fig. 4 a).Thus, the present embodiment illustrates from two angles and must adopt jumbo solid-phase extraction column could with the use of the mineral oil traditional GC-FID instrumental analysis food.

Wherein, what Fig. 4 a adopted is solid-phase extraction column prepared by comparative example 2, and amount of filler is 10g, and applied sample amount is 1.2g; What Fig. 4 b adopted is solid-phase extraction column prepared by comparative example 4, and amount of filler is 2g, and applied sample amount is 0.12g.Conclusion: because the sensitivity of GC-FID is low, need abundant quantity of sample handling to inject GC, could meet the detection sensitivity requirement of GC-FID, thus the too small FID of applied sample amount cannot detect at all.

And, inventor also finds, filler is crossed that I haven't seen you for ages and is caused overload, the chaff interferences etc. such as the triglyceride in sample can not be adsorbed completely, but flow out altogether with mineral oil, cannot clean-up effect be reached, GC-FID more seriously can be caused to transship, make the separating power of chromatographic column decline (see Fig. 5).As shown in Figure 5, what Fig. 5 a adopted is solid-phase extraction column prepared by comparative example 2, and amount of filler is 10g, and applied sample amount is 1.2g; , what Fig. 5 b adopted is solid-phase extraction column prepared by comparative example 3, and amount of filler is 8g, and applied sample amount is 1.2g.

Embodiment 7:

Experiment purpose: the clean-up effect of solid-phase extraction column of the present invention

Sample ID: edible oil

Experimental procedure:

1. get a homemade glass column, long 14 centimetres, internal diameter 2.8 centimetres, filling 1g activated alumina, strikes reality gently, loads isolation sieve plate, then loads 2g anhydrous sodium sulfate, isolation sieve plate, 10g silver nitrate impregnating active silica gel successively, is finally pressed into import sieve plate.

2. take 6g edible oil sample in 10mL volumetric flask, add the C of 1mL40mg/L ₁₈inner mark solution, then be settled to 10mL with normal hexane, vibration mixing.

3., with the pre-drip washing of 25mL normal hexane SPE post of the present invention, efflux discards.When normal hexane liquid level adds 2mL said sample higher than during post bed 0.5cm, with 10mL hexane dead volume, discard.Add 40mL hexane again, collect eluent.

Analysis of spectra as shown in Figure 6.

Embodiment 8:

Experiment purpose: solid-phase extraction column clean-up effect of the present invention

Sample ID: milk powder

Experimental procedure:

1. get a homemade glass column, long 14 centimetres, internal diameter 2.8 centimetres, filling 1g aluminium oxide, strikes reality gently, loads isolation sieve plate, then loads 2g anhydrous sodium sulfate, isolation sieve plate, 10g silver nitrate impregnating active silica gel successively, is finally pressed into import sieve plate.

2. get milk powder 1g, dissolve with 10mL65 DEG C of warm water, add 10ml concentrated hydrochloric acid, 85 DEG C of hydrolysis 30min, frequently take out vibration, add 10mL normal hexane subsequently, relax but mix up hill and dale, leave standstill and wait for layering, take out upper strata settled solution in fat collecting bottle with Pasteur's glass dropper, in resting solution, add 10ml normal hexane, carry out second time to extract, after taking out extract, then add 5ml normal hexane in surplus solution, carry out third time and extract.Merge No. 3 extracts, decompression distillation, the solvent in removing fat collecting bottle.Obtain oil-like extracts in milk powder.

3. by concentrated for eluent near dry, be settled to 1mL with normal hexane, utilize conventional GC-FID to analyze, analysis condition is as follows: chromatographic column DB-5HT quartz capillary column (15m × 0.25mm × 0.1 μm); Column temperature is 60 DEG C and keeps 5min, and rise to 330 DEG C with the speed of 30 DEG C/min, keep 10min, carrier gas is high pure nitrogen, and column flow rate is 2.00mL/min; Hydrogen flowing quantity is 30mL/min; Air mass flow is 400mL/min; Adopt Splitless injecting samples, sample size is 1 μ L; Injector temperature 300 DEG C; Fid detector temperature 320 DEG C.

Analysis of spectra as shown in Figure 7.

Embodiment 9:

Sample ID: biscuit

Experimental procedure:

1. get a homemade glass column, long 14 centimetres, internal diameter 2.8 centimetres, filling 1g aluminium oxide, strikes reality gently, loads isolation sieve plate, then loads 2g anhydrous sodium sulfate, isolation sieve plate, 10g silver nitrate dipping silica gel successively, is finally pressed into import sieve plate.

2. take oven dry, grind uniform biscuit powder 12.0g, zeyssatite (500 DEG C activation 4h) 3.0g, anhydrous sodium sulfate 3.0g be in filtration paper cylinder (soaking with normal hexane in advance), filtration paper cylinder is put into the extracting barrel of apparatus,Soxhlet's, being connected with the dry flat bottom flask of known weight by extracting barrel is attempted by condenser, 200mL normal hexane is added by upper end of condenser, heat in 85 DEG C of water-baths, make the continuous refluxing extraction of normal hexane at least 7h.Take off flat bottom flask, rotate evaporate to dryness normal hexane, subsequently flat bottom flask is put into 60 DEG C of oven for drying to constant weight.(repeating this extraction step until obtain being no less than 3g oil sample).

3. taking the above-mentioned oil sample 1g by extracting in biscuit in 2mL volumetric flask, adding 200 μ L, the C of 40mg/L ₁₈inner mark solution, then add normal hexane constant volume, mixing of vibrating immediately.

4., with the pre-drip washing of 25mL normal hexane SPE post of the present invention, efflux discards.When normal hexane liquid level adds 2mL said sample higher than during post bed 0.5cm, with 10mL hexane dead volume, discard.Add 40mL hexane again, collect eluent.

5. blown by wash-out liquid nitrogen concentrated near dry, be settled to 0.5mL with normal hexane, utilize conventional GC-FID to analyze, analysis condition is as follows: chromatographic column DB-5HT quartz capillary column (15m × 0.25mm × 0.1 μm); Column temperature is 65 DEG C and keeps 10min, and rise to 370 DEG C with the speed of 50 DEG C/min, keep 10min, carrier gas is high pure nitrogen, and column flow rate is 1.35mL/min; Hydrogen flowing quantity is 30mL/min; Air mass flow is 400mL/min; Adopt Splitless injecting samples, sample size is 2 μ L; Injector temperature 350 DEG C; Fid detector temperature 380 DEG C.

Analysis of spectra as shown in Figure 8.

Embodiment 10:

Sample ID: bread

Experimental procedure:

2. take and be dried to constant weight and grind uniform bread powder 12.0g, zeyssatite (500 DEG C of activation 4h) 3.0g, anhydrous sodium sulfate 3.0g in filtration paper cylinder (soaking with normal hexane in advance), filtration paper cylinder is put into the extracting barrel of apparatus,Soxhlet's, being connected with the dry flat bottom flask of known weight by extracting barrel is attempted by condenser, 200mL normal hexane is added by upper end of condenser, heat in 85 DEG C of water-baths, make the continuous refluxing extraction of normal hexane at least 7h.Take off flat bottom flask, rotate evaporate to dryness normal hexane, subsequently flat bottom flask is put into 60 DEG C of oven for drying to constant weight.(repeating this extraction step until obtain being no less than 3g oil sample).

3. taking the above-mentioned oil sample 1g by extracting in bread in 2mL volumetric flask, adding 200 μ L, the C of 40mg/L ₁₈inner mark solution, then add normal hexane constant volume, mixing of vibrating immediately.

Analysis of spectra as shown in Figure 9.

Embodiment 11:

Sample ID: rice

Experimental procedure:

2. take the uniform rice powder 12.0g of grinding, zeyssatite (500 DEG C of activation 4h) 3.0g, anhydrous sodium sulfate 3.0g in filtration paper cylinder (soaking with normal hexane in advance), filtration paper cylinder is put into the extracting barrel of apparatus,Soxhlet's, being connected with the dry flat bottom flask of known weight by extracting barrel is attempted by condenser, 200mL normal hexane is added by upper end of condenser, heat in 85 DEG C of water-baths, make the continuous refluxing extraction of normal hexane at least 7h.Take off flat bottom flask, rotate evaporate to dryness normal hexane, subsequently flat bottom flask is put into 60 DEG C of oven for drying to constant weight.(repeating this extraction step until obtain being no less than 3g oil sample).

3. taking the above-mentioned oil sample 1g by extracting in rice in 2mL volumetric flask, adding 200 μ L, the C of 40mg/L ₁₈inner mark solution, then add normal hexane constant volume, mixing of vibrating immediately.

Analysis of spectra as shown in Figure 10.

Embodiment 12:

Sample ID: baby rice powder

Experimental procedure:

2. take baby rice powder 12.0g, zeyssatite (500 DEG C of activation 4h) 3.0g, anhydrous sodium sulfate 3.0g in filtration paper cylinder (soaking with normal hexane in advance), filtration paper cylinder is put into the extracting barrel of apparatus,Soxhlet's, being connected with the dry flat bottom flask of known weight by extracting barrel is attempted by condenser, 200mL normal hexane is added by upper end of condenser, heat in 85 DEG C of water-baths, make the continuous refluxing extraction of normal hexane at least 7h.Take off flat bottom flask, rotate evaporate to dryness normal hexane, subsequently flat bottom flask is put into 60 DEG C of oven for drying to constant weight.(repeating this extraction step until obtain being no less than 3g oil sample).

3. taking the above-mentioned oil sample 1g by extracting in baby rice powder in 2mL volumetric flask, adding 200 μ L, the C of 40mg/L ₁₈inner mark solution, then add normal hexane constant volume, mixing of vibrating immediately.

Analysis of spectra as shown in Figure 11.

Embodiment 13:

Sample ID: vermicelli

Experimental procedure:

2. take and pulverize even vermicelli 12.0g, zeyssatite (500 DEG C of activation 4h) 3.0g, anhydrous sodium sulfate 3.0g in filtration paper cylinder (soaking with normal hexane in advance), filtration paper cylinder is put into the extracting barrel of apparatus,Soxhlet's, being connected with the dry flat bottom flask of known weight by extracting barrel is attempted by condenser, 200mL normal hexane is added by upper end of condenser, heat in 85 DEG C of water-baths, make the continuous refluxing extraction of normal hexane at least 7h.Take off flat bottom flask, rotate evaporate to dryness normal hexane, subsequently flat bottom flask is put into 60 DEG C of oven for drying to constant weight.(repeating this extraction step until obtain being no less than 3g oil sample).

3. taking the above-mentioned oil sample 1g by extracting in vermicelli in 2mL volumetric flask, adding 200 μ L, the C of 40mg/L ₁₈inner mark solution, then add normal hexane constant volume, mixing of vibrating immediately.

Analysis of spectra as shown in Figure 12.

Embodiment 14:

Sample ID: instant noodles

Experimental procedure:

2. take and pulverize uniform instant noodles 12.0g, zeyssatite (500 DEG C of activation 4h) 3.0g, anhydrous sodium sulfate 3.0g in filtration paper cylinder (soaking with normal hexane in advance), filtration paper cylinder is put into the extracting barrel of apparatus,Soxhlet's, being connected with the dry flat bottom flask of known weight by extracting barrel is attempted by condenser, 200mL normal hexane is added by upper end of condenser, heat in 85 DEG C of water-baths, make the continuous refluxing extraction of normal hexane at least 7h.Take off flat bottom flask, rotate evaporate to dryness normal hexane, subsequently flat bottom flask is put into 60 DEG C of oven for drying to constant weight.(repeating this extraction step until obtain being no less than 3g oil sample).

3. taking the above-mentioned oil sample 1g by extracting in instant noodles in 2mL volumetric flask, adding 200 μ L, the C of 40mg/L ₁₈inner mark solution, then add normal hexane constant volume, mixing of vibrating immediately.

Analysis of spectra as shown in Figure 13.

Embodiment 15:

Sample ID: peanut

Experimental procedure:

2. take the uniform peanut 12.0g of grinding, zeyssatite (500 DEG C of activation 4h) 3.0g, anhydrous sodium sulfate 3.0g in filtration paper cylinder (soaking with normal hexane in advance), filtration paper cylinder is put into the extracting barrel of apparatus,Soxhlet's, being connected with the dry flat bottom flask of known weight by extracting barrel is attempted by condenser, 200mL normal hexane is added by upper end of condenser, heat in 85 DEG C of water-baths, make the continuous refluxing extraction of normal hexane at least 7h.Take off flat bottom flask, rotate evaporate to dryness normal hexane, subsequently flat bottom flask is put into 60 DEG C of oven for drying to constant weight.(repeating this extraction step until obtain being no less than 3g oil sample).

3. take the above-mentioned oil sample 1g by Extraction of Peanut in 2mL volumetric flask, add 200 μ L, the C of 40mg/L ₁₈inner mark solution, then add normal hexane constant volume, mixing of vibrating immediately.

Analysis of spectra as shown in Figure 14.

Embodiment 16:

Sample ID: potato chips

Experimental procedure:

2. take and pulverize uniform potato chips 12.0g, zeyssatite (500 DEG C of activation 4h) 3.0g, anhydrous sodium sulfate 3.0g in filtration paper cylinder (soaking with normal hexane in advance), filtration paper cylinder is put into the extracting barrel of apparatus,Soxhlet's, being connected with the dry flat bottom flask of known weight by extracting barrel is attempted by condenser, 200mL normal hexane is added by upper end of condenser, heat in 85 DEG C of water-baths, make the continuous refluxing extraction of normal hexane at least 7h.Take off flat bottom flask, rotate evaporate to dryness normal hexane, subsequently flat bottom flask is put into 60 DEG C of oven for drying to constant weight.(repeating this extraction step until obtain being no less than 3g oil sample).

3. taking the above-mentioned oil sample 1g by extracting in potato chips in 2mL volumetric flask, adding 200 μ L, the C of 40mg/L ₁₈inner mark solution, then add normal hexane constant volume, mixing of vibrating immediately.

Analysis of spectra as shown in Figure 15.

Embodiment 17:

Utilize solid-phase extraction column prepared by embodiment 1-3 respectively, carry out the detection of food pollutant mineral oil, specific as follows:

Sample ID: edible oil

For each solid-phase extraction column, all operate according to following steps:

Result, after Solid-Phase Extraction column purification mineral oil prepared by embodiment 1-3, all can obtain qualified GC spectrogram.

In the description of this instructions, specific features, structure, material or feature that the description of reference term " embodiment ", " some embodiments ", " example ", " concrete example " or " some examples " etc. means to describe in conjunction with this embodiment or example are contained at least one embodiment of the present invention or example.In this manual, identical embodiment or example are not necessarily referred to the schematic representation of above-mentioned term.And the specific features of description, structure, material or feature can combine in an appropriate manner in any one or more embodiment or example.

Although illustrate and describe embodiments of the invention, those having ordinary skill in the art will appreciate that: can carry out multiple change, amendment, replacement and modification to these embodiments when not departing from principle of the present invention and aim, scope of the present invention is by claim and equivalents thereof.

Claims

1. with GC-FID instrument with the use of a solid-phase extraction column, it carries out pre-service for the testing sample detected food pollutant mineral oil, it is characterized in that, comprising:

Double glazing post;

Multiple glass fibre sieve plate, it is inner that described multiple glass fibre sieve plate is arranged on described double glazing post, and described double glazing post internal insulation is become to be used for fill silver nitrate stain silica gel silver nitrate stain silicone filler space, be used for filling the anhydrous sodium sulfate packing space of anhydrous sodium sulfate and be used for filling the alumina filled space of aluminium oxide, wherein, described silver nitrate stain silicone filler space, described anhydrous sodium sulfate packing space and described alumina filled space are arranged in order from the top down.

2. according to claim 1 with GC-FID instrument with the use of solid-phase extraction column, it is characterized in that, described multiple glass fibre sieve plate be arranged in parallel,

Optionally, described multiple glass fibre sieve plate is 4.

3. according to claim 1 with GC-FID instrument with the use of solid-phase extraction column, it is characterized in that, the capacity of described double glazing post is 50 ~ 100ml.

4. according to claim 1 with GC-FID instrument with the use of solid-phase extraction column, it is characterized in that, the length-diameter ratio of described double glazing post is 5 ~ 10:1, preferred 7:1,

Optionally, the aperture of each of described multiple glass fibre sieve plate is 10 μm ~ 50 μm, and thickness is 1 ~ 3mm.

5. according to claim 1 with GC-FID instrument with the use of solid-phase extraction column, it is characterized in that, the particle diameter of described silver nitrate stain silica gel is 60 μm ~ 200 μm,

Optionally, in described silver nitrate stain silica gel, the ratio of silver nitrate is 0.1 quality % ~ 6 quality %,

Optionally, the particle diameter of described aluminium oxide is 60 μm ~ 200 μm.

6. according to claim 1 with GC-FID instrument with the use of solid-phase extraction column, it is characterized in that, described silver nitrate stain silica gel and described aluminium oxide activate through high temperature sintering all in advance.

7. according to claim 1 with GC-FID instrument with the use of solid-phase extraction column, it is characterized in that, described silver nitrate stain silica gel is 5 ~ 10g, and described anhydrous sodium sulfate is 2 ~ 4g, and described aluminium oxide is 1 ~ 10g,

Preferably, described silver nitrate stain silica gel is 10g, and described anhydrous sodium sulfate is 2 ~ 4g, and described aluminium oxide is 1g.

8. a pretreated method is carried out to the testing sample that food pollutant mineral oil detects, it is characterized in that, comprise the following steps:

Obtain the fat in testing sample, and dissolving obtains pending test solution;

Utilize described in any one of claim 1-7 with GC-FID instrument with the use of solid-phase extraction column described pending test solution is extracted, and collect eluent; And

Described eluent is concentrated, and redissolves constant volume, to obtain solution to be measured,

Optionally, n-hexane dissolution fat is utilized to obtain pending test solution,

Optionally, described extraction comprises the following steps:

(4) utilize 40ml normal hexane to carry out the second wash-out to the solid-phase extraction column through the first wash-out, collect eluent,

Optionally, normal hexane is utilized to carry out described redissolution constant volume.

9. for detecting a system for Mineral Oil in Food pollutant, it is characterized in that, comprising:

Described in any one of claim 1-7 with GC-FID instrument with the use of solid-phase extraction column; And

GC-FID instrument.

10. detect a method for Mineral Oil in Food pollutant, it is characterized in that, comprise the following steps:

Testing sample to Mineral Oil in Food pollutant monitoring according to claim 8 carries out pretreated method, carries out pre-service to testing sample, to obtain solution to be measured; And

GC-FID instrument is utilized to carry out pollutant mineral oil detection to described solution to be measured, to determine the mineral oil stain situation in described testing sample,

Optionally, GC-FID instrument is utilized to the condition that described solution to be measured carries out pollutant mineral oil detection to be:

Adopt DB-5HT quartz capillary column as chromatographic column; Column temperature is 65 DEG C and keeps 10min, and rise to 370 DEG C with the speed of 50 DEG C/min, keep 10min, carrier gas is high pure nitrogen, and column flow rate is 1.35mL/min; Hydrogen flowing quantity is 30mL/min; Air mass flow is 400mL/min; Adopt Splitless injecting samples, sample size is 2 μ L; Injector temperature 350 DEG C; Fid detector temperature 380 DEG C.