CN102928375B - Method for carrying out illegal cooking oil detection by using ultraviolet spectroscopic analysis method - Google Patents
Method for carrying out illegal cooking oil detection by using ultraviolet spectroscopic analysis method Download PDFInfo
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Abstract
The invention discloses a method for carrying out illegal cooking oil detection by using an ultraviolet spectroscopic analysis method. The method comprises the steps that: (1) an oil sample to be detected is subjected to pretreatment; (2) a standard curve is drawn by using a substrate standard addition method; a mixed oil product and a standard normal oil product are respectively pretreated by using the method provided by the step (1), and are scanned by using an ultraviolet spectrum colorimetric analysis method at wavelengths of 200-320nm; aqueous solution spectral absorption diagrams of the two samples are drawn and are adopted as standard curves of the two which are detection limits of illegal cooking oil detection; (3) a micro-emulsion liquid of oil in water molecules (W/O) is scanned by using an ultraviolet spectrum colorimetric analysis method at wavelengths of 200-320nm; an aqueous solution spectral absorption diagram of an oil sample to be detected is drawn; and whether the detected oil sample is illegal cooking oil is determined according to absorption value volume, spectral characteristics curve, and curve graphic similarity of the aqueous solution spectral absorption diagrams. Through many tests and validations, the success rate of the method can substantially reach 70-80%.
Description
Technical field
The invention belongs to food safety detection technical field, be specifically related to a kind of method that adopts ultraviolet spectral analysis method to carry out waste oil detection.
Background technology
Waste oil, all kinds of poor oils that general reference exists in life, as the edible oil, the frying oil of Reusability etc. that reclaim.Waste oil the largest source is the oil interceptor of large-scale restaurant, city sewer.Long-term edible may cause cancer, very harmful to human body.The at present domestic unified standard that not yet has detection waste oil.In existing state compulsory standard " edible vegetable oil hygienic standard " (2716-2005), detect about the physical and chemical index of edible oil comprise that acid value, peroxide value, leaching oil solvent are residual, free phenol (cottonseed oil), total arsenic, lead, aflatoxin, benzopyrene, residues of pesticides totally 9 indexs, respectively plant crude oil and vegetable edible oil are carried out to different standard detection.But plant crude oil, vegetable edible oil are not all waste oils.And these 9 basic edible oils detect index in standard, even waste oil is produced the oil coming, also all possibility is qualified, cannot go the property distinguished to detect for waste oil at all.
Carry out at present waste oil and often go analysis and research by four large spectral method means.They comprise nuclear magnetic resonance spectroscopy (NMR), mass spectrometry (MS), infra-red sepectrometry (IR), method of UV spectral analysis (UV).And first three methods needs operation/maintainer and the specific environment for use of expensive specialized equipment, specialty, and practical effect is not very good yet.And existing technological means testing result specificity is not strong, can not serve as " waste oil " decision means.The present invention therefore.
Summary of the invention
The object of the invention is to provide a kind of method that adopts ultraviolet spectral analysis method to carry out waste oil detection, has solved that in prior art, waste oil test result specificity is not high, detection method is expensive cannot carry out the problems such as practical application.
In order to solve these problems of the prior art, technical scheme provided by the invention is:
Adopt ultraviolet spectral analysis method to carry out a method for waste oil detection, it is characterized in that said method comprising the steps of:
(1) pre-service of oil sample to be measured: adopt alkanes solvent to dilute oil sample to be measured, then the oil sample to be measured after dilution is carried out to water extraction, described extract adopts the aqueous solution that adds surfactant, forms the microemulsion liquid of oil-in-water molecule (W/O);
(2) adopt matrix mark-on method drawing standard curve, described mixing oil product is that the normal oil product of standard and standard biological diesel oil are blent formation, and the normal oil product of described standard adopts one or more any mixing that is selected from normal soybean oil, rape oil, sunflower oil, peanut oil and corn oil; Respectively by mixing oil product, the normal oil product of standard carries out after pre-service according to the mode of step (1) oil sample to be measured, scan between 200nm ~ 320nm according to ultraviolet spectrum colorimetric analysis, the aqueous solution spectral absorption figure that draws two kinds of samples is as both typical curves the detectability that waste oil detects;
(3) the microemulsion liquid of oil-in-water molecule (W/O) is scanned between 200nm ~ 320nm according to ultraviolet spectrum colorimetric analysis, draw the aqueous solution spectral absorption figure of oil sample to be measured; Judge according to the light absorption value height of aqueous solution spectral absorption figure, spectral signature curve and curvilinear figure similarity whether oil sample to be measured is waste oil.
Preferably, described method step (1) alkanes solvent is selected from isooctane or normal hexane, and when described oil sample to be measured dilutes, the volume ratio of alkanes solvent and oil sample to be measured is 2:1.
Preferably, the hydrophilic lipophilic balance (HLB) of the middle surfactant of described method step (1) is between 0～20.
Preferably, in described method step (1), surfactant is selected from non-ionic surfactant and zwitterionic surfactant.
Preferably, in described method step (1), surfactant is selected from Tween20.Tween20, wherein/English name is respectively Polyoxyethylene sorbitan monolaurate, polyoxyethylene (20EO) sorbitan mono-laurate.
Preferably, the amount that in described method step (1), surfactant adds is 0.25% of aqueous solution gross mass.
Preferably, mixing oil product in described method step (2) is that special preparation detects reference standard as waste oil, for arm's length standard oil product and standard biological diesel oil are blent according to volume ratio 50:1 or 20:1 or 5:1.Mixing oil product is to get respectively normal soybean oil, rape oil, sunflower oil, peanut oil and corn oil, adds standard biological diesel oil to blend and forms.And the normal oil product of standard can be selected from one or more the combination in any in above-mentioned 5 kinds of normal oil products, preferably above-mentioned 5 kinds of higher one of normal oil product medium ultraviolet light absorption value.
The present invention, by the analysis of the contained organic compounds of grease is started with, dissects the molecular structure of its organic compound, finds out the main common feature that waste oil possesses, thereby realizes the discriminating of waste oil.Use method of UV spectral analysis (UV) to find out the main common feature that waste oil possesses, then carry out qualitative analysis exactly, complete the quick discriminating to waste oil, can reach the effect of getting twice the result with half the effort.The inventive method is simple, quick, economical, confirms the main common trait that waste oil possesses, and uses the means of qualitative analysis, realizes the quick discriminating of waste oil.
The cardinal principle of the inventive method adopts method of UV spectral analysis (UV) to carry out qualitative analysis to the contained organic compounds of oil product exactly.
The present invention adopts applicability and the feasibility of method of UV spectral analysis (UV)
(1) detect characteristic chemical constituent: polar compound (Polar Compound) is as the main detected content detecting
In order to embody quick, economic, easy, reliable principle, first must determine the specific features of waste oil and the normal edible vegetable oil of difference.Waste oil is after refining, although apparent upper identical with branded oil, it,, refining in processing procedure, is not easy thoroughly to dispose polar material (Polar Compound), polar material that still can more residual micro-concentrations in its component, and nonpolar aromatics.Therefore, the detection of oil product Semi-polarity component becomes the important symbol that waste oil is differentiated.Waste oil Semi-polarity component (organism) should comprise palycyclic aromatic, cholesterol (cholesterol), acrylamide, free gossypol and creosote, spices and essence etc., and these polar materials seldom can occur in general kind of high-quality edible plant oil (as soya-bean oil, rape oil, peanut wet goods).This also forms the obvious essential difference of good and bad grease, thereby becomes the key index that waste oil detects.
(2) absorption characteristic of polar compound (Polar Compound) to ultraviolet spectrum
Polar organic compounds often, at ultraviolet region (200-300nm), has light absorption feature.Polar molecule has absorbed luminous energy, can make outer-shell electron energy level generation transition, thereby occur different Absorption Characteristics.Therefore, adopt ultraviolet spectrophotometry, carry out the spectral absorption scanning analysis of different-waveband, can observe waste oil at the strong Absorption of ultraviolet band.In polar compound, 6 kinds of representational palycyclic aromatics (benzopyrene, firefly anthracene etc.) all have Absorption Characteristics in region, ultraviolet 230nm left and right.Also there are many benzene ring structures in animal fat cholesterol, has obvious absorption peak at 220nm.Free gossypol and creosote also have absorption more by force in 240 ~ 260nm region.Other polar compound is as aldehyde radical and carbonyl material, and the acrylamide in old oil etc. all has respective absorption characteristic at ultraviolet band.
The present invention also adopts some gordian technique means to solve the problem that method of UV spectral analysis (UV) runs into.
(1) oil sample is water insoluble
Although the objectionable impurities comprising in waste oil can have absorption characteristic to ultraviolet spectrum, the ultraviolet spectrum colorimetric operation of having no idea directly oil sample to be carried out, most colorimetric operations are all carried out in water.And oil sample can not directly carry out aqueous solution extraction.For this reason, we are by adding the water extraction solution of surfactant.The characteristic one side of the existing oleophylic of surfactant also has hydrophilic another side, and its oleophylic/water-wet behavior represents by HLB value.Its span is between 1 ~ 40.Its lipophilicity of the less expression of HLB value is better, fully adsorbed oil molecule; Its water wettability of the larger expression of HLB value is better, can be fully and water molecules.As long as choose suitable HLB value, the non-ionic surfactant TWEEN20 of for example HLB=16.7.The mass percent concentration of TWEEN20 aqueous solution is 0.25%, as oil sample water extraction solution main body, make oil sample and water fused to a certain extent, form the microemulsion liquid of oil-in-water molecule (W/O), can make polar compound effectively enter in extract on the one hand; Secondly, can strengthen to the absorption of ultraviolet light the feature that polar compound absorbs at ultraviolet light spectral coverage by these oil-in-water molecules (W/O).
Substantially approaching in order to ensure the microemulsified effect of oil sample in nonionic surfactant water-soluble liquid, must dilute pre-service to oil sample.Concrete grammar is oil sample to be diluted by the volume ratio of 2:1 with isooctane or normal hexane.
(2) the collection of illustrative plates qualitative analysis of method of UV spectral analysis (UV)
So-called qualitative analysis is exactly to analyze and then qualitative to oil sample kind to be measured by the ultraviolet spectrum curve map to oil sample to be measured.Curve map is analyzed respectively and started with from two aspects, the one, it is at ultraviolet section (200nm ~ 320nm) light absorption value height; The 2nd, analyze the feature pattern of its curve map at ultraviolet section (200nm ~ 320nm); The 3rd, oil sample to be measured is carried out to similarity contrast at feature pattern and the standard oil sample curvilinear figure of ultraviolet section (200nm ~ 320nm).Then, the conclusion of comprehensive three aspects:, makes final judgement.
With respect to scheme of the prior art, advantage of the present invention is:
Because the detection of waste oil is still to tackle key problems in science at present, await the problem solving.Existing various technological means has certain limitation, and the success ratio mostly detecting is not very high.At present, the present invention through in many ways testing and verifying, can reach 70% ~ 80% success ratio by ultraviolet spectrum waste oil detection method substantially.
Brief description of the drawings
Below in conjunction with drawings and Examples, the invention will be further described:
Fig. 1 is the embodiment of the present invention 1 Xinjiang finished product waste oil oil sample, the ultraviolet spectrum curve map that mixes oil product and arm's length standard oil product;
Fig. 2 is the normal corn oil oil sample of the embodiment of the present invention 2, the ultraviolet spectrum curve map that mixes oil product and arm's length standard oil product;
Fig. 3 is the embodiment of the present invention by arm's length standard oil product, mix oil product and palm oil carries out uv absorption according to the method for embodiment 1 and detects the ultraviolet spectrum curve map obtaining;
Fig. 4 is the ultraviolet spectrum curve map of thousand waste oil oil samples blending of the embodiment of the present invention 2 different proportions;
Fig. 5 is thousand waste oil oil samples blending of the embodiment of the present invention 2 different proportions, the ultraviolet spectrum curve map that mixes oil product and arm's length standard oil product;
Fig. 6 is the ultraviolet spectrum curve map of Guangzhou trench 2 oil samples blent of the embodiment of the present invention 3 different proportions;
Fig. 7 is the ultraviolet spectrum curve map of the embodiment of the present invention 4 variable concentrations biodiesel.
Fig. 8 is the embodiment of the present invention 5 detection method replica test results.
Embodiment
Below in conjunction with specific embodiment, such scheme is described further.Should be understood that these embodiment are not limited to limit the scope of the invention for the present invention is described.The implementation condition adopting in embodiment can be done further adjustment according to the condition of concrete producer, and not marked implementation condition is generally the condition in normal experiment.
The detection of embodiment 12-21# Xinjiang finished product waste oil 4 oil samples
1, the instrument adopting
The present embodiment adopts ultraviolet spectrum analyzer device---ultraviolet spectrum analyzer (miniature).Ultraviolet spectrum analyzer (miniature) can carry out data/diagram light absorption value analysis intuitively to the spectrum from 185nm to 800nm.Uv analyzer, for being effectively containing the alkene of conjugated structure and the analysis of phenyl ring type organic, can carry out the qualitative and quantitative analysis of science.Therefore, adopt miniature ultraviolet spectrometer (UVS), carry out the analysis of ultraviolet spectrometry absorbance, can be scientifically by the polar compound uv absorption status analysis in waste oil out.And for kind of high-quality edible plant oil, its polar compound is relatively less, uv absorption is also very weak.Both show obvious difference.Instrument computer diagram ultraviolet spectrum curve trend is different, can be intuitively, differentiate waste oil by eye diagram solution compactly.
2, concrete steps
(1) sample preparation
The present embodiment waste oil sample is the doubtful waste oil gathering from Xinjiang, is numbered 2-21# Xinjiang finished product waste oil 4.The normal oil product of standard adopts the peanut oil that can buy on the market.Mix oil product for respectively getting normal soybean oil, rape oil, sunflower oil, peanut oil and corn oil each 10 parts (volumes), add 1 part of standard biological diesel oil (volume) to blend and form.
1) dilution of oil sample
Because the viscosity of oil sample is generally all very large, even also have solid-state oil sample, if do not add dilution, cannot accomplish accurate sampling.Here be that alkanes solvent isooctane or the normal hexane that the volume ratio by adding alkanes solvent and oil sample to be measured is 2:1 diluted.
2) water extraction process of oil sample
By the testing sample dosage on request after dilution, add preprepared, fill in the glass test tube of water extraction solution, then adopt special blender to carry out timing agitation, to form the microemulsion liquid of oil-in-water molecule (W/O).Wait for 10 minutes, microemulsion body can be stablized fully.
(2) preparation of matrix mark-on standard working curve
In order to improve the reliability of discriminating, the present invention adopts relative pairing comparision.Can get rid of like this disturbing factor that instrument may exist.That is to say in some unknown oil product discrimination processes, add known standard oil and normal oil product, they together participate in an oil product discrimination process of taking turns.Then, after whole process finishes, by the spectrogram of unknown oil product respectively with the known normal oil product of standard with mixes oil product spectrogram and compare, thereby draw differentiation qualitatively.
The normal oil product of standard and mixing oil product role are the target thresholds that a visual judgement is provided for operator.Like this, the typical curve of the normal oil product of standard and mixing oil product has formed the upper and lower bound standard of judgement.
(3) measure
1) the microemulsion liquid of making oil sample
According to the method described in step (1), by oil product to be detected and the normal oil product of standard and mix oil product and be made into the microemulsion liquid of oil sample.
2) the ultraviolet colorimetric process of sample extraction aqueous solution
The microemulsion liquid of testing sample or standard oil and normal oil product is put into identifier, automatically added in cuvette by instrument.The extract adopting is the aqueous solution containing non-ionic surfactant TWEEN20, and the mass percent concentration of TWEEN20 is 0.25%.
3) draw sample aqueous solution spectral absorption figure and follow-up data processing procedure
According to added sample solution, carry out colorimetric operation.Then draw sample aqueous solution spectral absorption figure and follow-up data processing.
4) cuvette cleans
Completing after a sample test, automatically sample solution is extracted out from cuvette, then add respectively clean-out system and pure water to complete and clean and rinse cycle.
5) visual discriminating
All samples is completed after aforesaid operations step, adopt visual means, absorb figure curve according to the microemulsion liquid ultraviolet spectrum of drawing sample, respectively by oil sample curve to be identified with the normal oil product of standard and mix the contrast of oil product curve in light absorption value height, spectral signature curve and the curvilinear figure similarity of ultraviolet section (200nm ~ 320nm), intuitively differentiate oil types.Detect required time and also only have tens minutes.
(4) discussion of results
Result as shown in Figure 1.
1) light absorption value degree of contrast
By tested oil sample at ultraviolet section (200nm ~ 320nm) light absorption value height with the normal oil product of standard and mix oil product and contrast, can draw preliminary conclusion.Fig. 1 demonstration, its ultraviolet section (200nm ~ 320nm) light absorption value height is far above the normal oil product of standard and mix oil product, therefore can draw correct preliminary judgement.
In order more significantly to describe the problem, Fig. 2 is the present invention by arm's length standard oil product, mix oil product and corn oil carries out uv absorption according to the method for embodiment 1 and detects the ultraviolet spectrum curve map obtaining.The normal oil product of its Plays adopts the peanut oil that can buy on the market.Mix oil product for respectively getting normal soybean oil, rape oil, sunflower oil, peanut oil and corn oil each 4 parts (volumes), add 1 part of standard biological diesel oil (volume) to blend and form.Corn oil, as oil sample to be measured, is designated as 05# corn.Fig. 2 demonstration, ultraviolet section (200nm ~ 320nm) the light absorption value height of corn oil is far below the normal oil product of standard and mix oil product, therefore can draw correct preliminary judgement.
2) ultraviolet spectrum curvilinear characteristic pattern analysis
Complete the comparing at ultraviolet section (200nm ~ 320nm) light absorption value height and standard oil and normal oil product to tested oil sample, and draw after preliminary conclusion, feature pattern analysis may be there is to the ultraviolet spectrum curve map ultraviolet section (200nm ~ 320nm) of tested oil sample again, final judgement can be made.
Feature pattern refers in ultraviolet section (260nm ~ 300nm) whether have light absorption value rate of change flex point, thereby causes its figure whether to have corner feature.Can see at Fig. 2, there is such corner feature in the oil sample that mixes oil product.And arm's length standard oil product and other edible oil oil samples do not have such corner feature.
In order more significantly to describe the problem, Fig. 3 is the present invention by arm's length standard oil product, mix oil product and palm oil carries out uv absorption according to the method for embodiment 1 and detects the ultraviolet spectrum curve map obtaining.The normal oil product of its Plays adopts the peanut oil that can buy on the market.Mix oil product for respectively getting normal soybean oil, rape oil, sunflower oil, peanut oil and corn oil each 4 parts (volumes), add 1 part of standard biological diesel oil (volume) to blend and form.Palm oil, as oil sample to be measured, is designated as 03# palm.Fig. 3 demonstration, the absorbance of 03# palm will and mix oil product higher than the normal oil product of standard.But from Fig. 3, show, although it is not its absorbance will and mix oil product higher than the normal oil product of standard, fairly obvious.And there is no the corner feature possessing in most of waste oil figures, therefore comprehensively judge the non-waste oil of 03# palm.
The detection of 2,000 trench 3 oil samples of embodiment
(1) sample preparation
The present embodiment waste oil sample is the doubtful waste oil gathering from thousand, is numbered thousand trenches 3; Be divided into 3 kinds of oil samples to be measured, wherein thousand trench 3+ rapeseed oils of 30# 10% are that 3 and 9 portions of (volume) rapeseed oils of 1 part (volume) thousand waste oils mix; Thousand trench 3+ rapeseed oils of 15# 20% are that 3 and 4 portions of (volume) rapeseed oils of 1 part (volume) thousand waste oils mix; Thousand trench 3+ rapeseed oils of 02# 50% are that 3 and 1 portion of (volume) rapeseed oil of 1 part (volume) thousand waste oils mixes.The normal oil product of standard adopts the peanut oil that can buy on the market.Mix oil product for respectively getting normal soybean oil, rape oil, sunflower oil, peanut oil and corn oil each 4 parts (volumes), add 1 part of standard biological diesel oil (volume) to blend and form.
Add isooctane or normal hexane to dilute, the volume ratio of isooctane or normal hexane and oil sample to be measured is 2:1.By the testing sample dosage on request after dilution, add preprepared, fill in the glass test tube of water extraction solution, then adopt special blender to carry out timing agitation, to form the microemulsion liquid of oil-in-water molecule (W/O).Wait for 10 minutes.The extract adopting is the aqueous solution containing non-ionic surfactant TWEEN20, and the mass percent concentration of TWEEN20 is 0.25%.
(2) preparation of matrix mark-on standard working curve
The present invention adopts relative pairing comparision.After whole process finishes, by the spectrogram of unknown oil product respectively with the known normal oil product of standard with mixes oil product spectrogram and compare, thereby draw differentiation qualitatively.
(3) measure
The microemulsion liquid of testing sample or standard oil and normal oil product is put into identifier, automatically added in cuvette by instrument.According to added sample solution, carry out colorimetric operation.Then draw sample aqueous solution spectral absorption figure and follow-up data processing.Completing after a sample test, automatically sample solution is extracted out from cuvette, then add respectively clean-out system and pure water to complete and clean and rinse cycle.
All samples is completed after aforesaid operations step, adopt visual means, absorb figure curve according to the microemulsion liquid ultraviolet spectrum of drawing sample, respectively by oil sample curve to be identified with the normal oil product of standard and mix the contrast of oil product curve in light absorption value height, spectral signature curve and the curvilinear figure similarity of ultraviolet section (200nm ~ 320nm), intuitively differentiate oil types.
(4) discussion of results
Result as shown in Figure 4 and Figure 5.In Fig. 4,5, contain with a series of different waste oils, they are all to blend and form with thousand waste oil 3# and rapeseed oil, and just waste oil content is different.Wherein thousand trench 3+ rapeseed oils of 30# 10% are that 3 and 9 portions of (volume) rapeseed oils of 1 part (volume) thousand waste oils mix; Thousand trench 3+ rapeseed oils of 15# 20% are that 3 and 4 portions of (volume) rapeseed oils of 1 part (volume) thousand waste oils mix; Thousand trench 3+ rapeseed oils of 02# 50% are that 3 and 1 portion of (volume) rapeseed oil of 1 part (volume) thousand waste oils mixes.
In Fig. 4 and Fig. 5, can find out thousand waste oil 3#+ rapeseed oils 50% of 02# at the normal oil product of standard and mix between the absorbance height of oil product, and other waste oil oil product to be measured (thousand waste oil 3#+ rapeseed oils 20% of 15#; Thousand waste oil 3#+ rapeseed oils 10% of 30#) all lower than the absorbance height of the normal oil product of standard.But, as can be seen from Figure 4 and Figure 5, all possess corner feature with a series of 3 kinds of different waste oils.The height of its light absorption value has reflected the gradient situation of different content.
Embodiment 3 Guangzhou trenches 2 and the detection that mixes oil product miscella sample
(1) sample preparation
The present embodiment testing sample is the doubtful waste oil gathering from Guangzhou, is numbered Guangzhou trench 2; Be divided into 3 kinds of oil samples to be measured, wherein 02# Guangzhou trench 2+ contaminated product 10% is that the contaminated product of 1 part of (volume) Guangzhou trench 2 and 9 parts (volumes) is blent and formed; 01# Guangzhou trench 2+ contaminated product 20% is that the contaminated product of 1 part of (volume) Guangzhou trench 2 and 4 parts (volumes) is blent and formed; 07# Guangzhou trench 2+ contaminated product 50% is that the contaminated product of 1 part of (volume) Guangzhou trench 2 and 1 part (volume) is blent and formed.Contaminated product is blent and is formed for respectively getting blending stock, soybean oil, peanut oil each 1 part (volume).
Add isooctane or normal hexane to dilute, the volume ratio of isooctane or normal hexane and oil sample to be measured is 2:1.By the testing sample dosage on request after dilution, add preprepared, fill in the glass test tube of water extraction solution, then adopt special blender to carry out timing agitation, to form the microemulsion liquid of oil-in-water molecule (W/O).Wait for 10 minutes.The extract adopting is the aqueous solution containing non-ionic surfactant TWEEN20, and the mass percent concentration of TWEEN20 is 0.25%.
(3) measure
The microemulsion liquid of testing sample is put into identifier, automatically added in cuvette by instrument.According to added sample solution, carry out colorimetric operation.Then draw sample aqueous solution spectral absorption figure and follow-up data processing.Completing after a sample test, automatically sample solution is extracted out from cuvette, then add respectively clean-out system and pure water to complete and clean and rinse cycle.
All samples is completed after aforesaid operations step, adopt visual means, absorb figure curve according to the microemulsion liquid ultraviolet spectrum of drawing sample, respectively by oil sample curve to be identified with before obtain the normal oil product of standard and mix the contrast of oil product curve (other embodiment provide) in light absorption value height, spectral signature curve and the curvilinear figure similarity of ultraviolet section (200nm ~ 320nm), intuitively differentiate oil types.
(4) discussion of results
Result as shown in Figure 6.In Fig. 6,02# Guangzhou trench 2+ contaminated product 10% is that the contaminated product of 1 part of (volume) Guangzhou trench 2 and 9 parts (volumes) is blent and formed; 01# Guangzhou trench 2+ contaminated product 20% is that the contaminated product of 1 part of (volume) Guangzhou trench 2 and 4 parts (volumes) is blent and formed; 07# Guangzhou trench 2+ contaminated product 50% is that the contaminated product of 1 part of (volume) Guangzhou trench 2 and 1 part (volume) is blent and formed.Contaminated product is blent and is formed for respectively getting blending stock, soybean oil, peanut oil each 1 part (volume).
In Fig. 6, can find out that three kinds of oil samples to be measured all have corner feature, can directly be judged as waste oil.Can find out waste oil content difference, there is different light absorption value height.
The detection of embodiment 4 variable concentrations biodiesel
(1) sample preparation
The present embodiment testing sample is the mixing oil product of variable concentrations, wherein mixes 1.97% for respectively getting normal soybean oil, rape oil, sunflower oil, peanut oil and corn oil each 10 parts (volumes), adds 1 part of standard biological diesel oil (volume) to blend and forms; Mix 4.8% for respectively getting normal soybean oil, rape oil, sunflower oil, peanut oil and corn oil each 4 parts (volumes), add 1 part of standard biological diesel oil (volume) to blend and form; Mix 16.7% for respectively getting normal soybean oil, rape oil, sunflower oil, peanut oil and corn oil each 1 part (volume), add 1 part of standard biological diesel oil (volume) to blend and form.The normal oil product of standard (standard specimen 2) adopts the peanut oil that can buy on the market.
Add isooctane or normal hexane to dilute, the volume ratio of isooctane or normal hexane and oil sample to be measured is 2:1.By the testing sample dosage on request after dilution, add preprepared, fill in the glass test tube of water extraction solution, then adopt special blender to carry out timing agitation, to form the microemulsion liquid of oil-in-water molecule (W/O).Wait for 10 minutes.The extract adopting is the aqueous solution containing non-ionic surfactant TWEEN20, and the mass percent concentration of TWEEN20 is 0.25%.
(3) measure
The microemulsion liquid of testing sample and the normal oil product of standard is put into respectively to identifier, automatically added in cuvette by instrument.According to added sample solution, carry out colorimetric operation.Then draw sample aqueous solution spectral absorption figure and follow-up data processing.Completing after a sample test, automatically sample solution is extracted out from cuvette, then add respectively clean-out system and pure water to complete and clean and rinse cycle.
All samples is completed after aforesaid operations step, adopt visual means, absorb figure curve according to the microemulsion liquid ultraviolet spectrum of drawing sample, the contrast in light absorption value height, spectral signature curve and the curvilinear figure similarity of ultraviolet section (200nm ~ 320nm) by oil sample curve to be measured and the normal oil product of standard respectively.
(4) discussion of results
Result as shown in Figure 7.In Fig. 7, mix 1.97% for respectively getting normal soybean oil, rape oil, sunflower oil, peanut oil and corn oil each 10 parts (volumes), add 1 part of standard biological diesel oil (volume) to blend and form; Mix 4.8% for respectively getting normal soybean oil, rape oil, sunflower oil, peanut oil and corn oil each 4 parts (volumes), add 1 part of standard biological diesel oil (volume) to blend and form; Mix 16.7% for respectively getting normal soybean oil, rape oil, sunflower oil, peanut oil and corn oil each 1 part (volume), add 1 part of standard biological diesel oil (volume) to blend and form.
In Fig. 7, can find out that three kinds of oil samples to be measured all have corner feature, can be used as the reference of waste oil sample.Can find out the content difference of mixing oil product, there is different light absorption value height.
Embodiment 5 detection method replica tests.
In order to test repeatability and the reliability of described detection method, in the elite blind sample of second batch waste oil sample providing with Shanghai food security department 4 kinds, are respectively S2-1#, S2-2#, S2-4# and S2-6#.In the time that this batch of blind sample is provided, adopt duplicate sample design.Wherein, S2-1# and S2-6# are oil sample of the same race; And S2-2# and S2-4# are the another oil sample of planting.Result as shown in Figure 8, can be clear that clear and definite result on result ultraviolet spectrum absorption curve figure.S2-1# and S2-6# oil sample are all almost in full accord on light absorption value height or whole ultraviolet spectrum absorption curve figure; And the ultraviolet spectrum absorption curve figure of S2-2# and S2-4# has also illustrated same reason.
Above-mentioned example is only explanation technical conceive of the present invention and feature, and its object is to allow person skilled in the art can understand content of the present invention and implement according to this, can not limit the scope of the invention with this.All equivalent transformations that Spirit Essence does according to the present invention or modification, within all should being encompassed in protection scope of the present invention.
Claims (7)
1. adopt ultraviolet spectral analysis method to carry out a method for waste oil detection, it is characterized in that said method comprising the steps of:
(1) pre-service of oil sample to be measured: adopt alkanes solvent to dilute oil sample to be measured, then the oil sample to be measured after dilution is carried out to water extraction, described extract adopts the aqueous solution that adds surfactant, forms the microemulsion liquid of oil-in-water molecule (W/O);
(2) adopt matrix mark-on method drawing standard curve, respectively by mixing oil product, the normal oil product of standard carries out after pre-service according to the mode of step (1) oil sample to be measured, scan between 200nm～320nm according to ultraviolet spectrum colorimetric analysis, the aqueous solution spectral absorption figure that draws two kinds of samples is as both typical curves the detectability that waste oil detects; Described mixing oil product is that the normal oil product of standard and standard biological diesel oil are blent formation, and the normal oil product of described standard adopts one or more any mixing that is selected from normal soybean oil, rape oil, sunflower oil, peanut oil and corn oil;
(3) the microemulsion liquid of oil-in-water molecule (W/O) is scanned between 200nm～320nm according to ultraviolet spectrum colorimetric analysis, draw the aqueous solution spectral absorption figure of oil sample to be measured; Judge according to the light absorption value height of aqueous solution spectral absorption figure, spectral signature curve and curvilinear figure similarity whether oil sample to be measured is waste oil.
2. method according to claim 1, is characterized in that described method step (1) alkanes solvent is selected from isooctane or normal hexane, and when described oil sample to be measured dilutes, the volume ratio of alkanes solvent and oil sample to be measured is 2:1.
3. method according to claim 1, is characterized in that the hydrophilic lipophilic balance (HLB) of surfactant in described method step (1) is between 0～20.
4. method according to claim 1, is characterized in that in described method step (1), surfactant is selected from non-ionic surfactant.
5. method according to claim 1, is characterized in that in described method step (1), surfactant is selected from Tween20.
6. method according to claim 1, is characterized in that the amount that in described method step (1), surfactant adds is 0.25% of aqueous solution gross mass.
7. method according to claim 1, is characterized in that mixing in described method step (2) oil product and is arm's length standard oil product and standard biological diesel oil and blend according to volume ratio 50:1 or 20:1 or 5:1.
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| CN105092547B (en) * | 2014-08-15 | 2018-02-27 | 天津陆海石油设备系统工程有限责任公司 | Biased sample fluorescence analysis method based on collection of illustrative plates form |
| CN104483279A (en) * | 2014-12-13 | 2015-04-01 | 广西科技大学 | Method for qualitatively detecting hogwash oil |
| CN104535509A (en) * | 2014-12-13 | 2015-04-22 | 广西科技大学 | Method for qualitative detection of hogwash oil |
| CN104568803A (en) * | 2015-01-04 | 2015-04-29 | 河南师范大学 | Method for detecting quality of fried edible oil through ultraviolet spectrophotometer |
| CN106124440A (en) * | 2016-06-14 | 2016-11-16 | 云南中烟工业有限责任公司 | A kind of quality evaluating method of volume tobacco aromatics using |
| CN109738381A (en) * | 2018-08-01 | 2019-05-10 | 刘茂诚 | Minimal feeding device and its detection method |
| CN110726685A (en) * | 2019-10-28 | 2020-01-24 | 浙江华康药业股份有限公司 | Detection method of trace slipping agent |
| CN112051224B (en) * | 2020-08-12 | 2021-08-06 | 昆明理工大学 | Method for detecting blending ratio of biodiesel blending fuel based on ultraviolet-visible spectrophotometry |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4372567B2 (en) * | 2004-01-30 | 2009-11-25 | 倉敷紡績株式会社 | Method for measuring water and aqueous solution by ultraviolet light |
| CN102519953A (en) * | 2011-12-09 | 2012-06-27 | 黄耀江 | Method for rapidly identifying inferior edible oil |
| CN102539639A (en) * | 2011-12-27 | 2012-07-04 | 何联泉 | Method for marking and finding illegal cooking oil |
| CN102564996A (en) * | 2012-01-05 | 2012-07-11 | 上海理工大学 | Swill-cooked dirty oil detecting system and detecting method |
| CN102590405A (en) * | 2012-03-14 | 2012-07-18 | 李涛 | Identification method for illegal cooking oil |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009244283A (en) * | 2009-07-28 | 2009-10-22 | Kurabo Ind Ltd | Method of measuring water and aqueous solution with ultraviolet ray |
| CN102507656A (en) * | 2011-10-26 | 2012-06-20 | 桂林中辉科技发展有限公司 | Rapid detection method for determining whether edible oil contains waste oil |
-
2012
- 2012-07-25 CN CN201210258240.2A patent/CN102928375B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4372567B2 (en) * | 2004-01-30 | 2009-11-25 | 倉敷紡績株式会社 | Method for measuring water and aqueous solution by ultraviolet light |
| CN102519953A (en) * | 2011-12-09 | 2012-06-27 | 黄耀江 | Method for rapidly identifying inferior edible oil |
| CN102539639A (en) * | 2011-12-27 | 2012-07-04 | 何联泉 | Method for marking and finding illegal cooking oil |
| CN102564996A (en) * | 2012-01-05 | 2012-07-11 | 上海理工大学 | Swill-cooked dirty oil detecting system and detecting method |
| CN102590405A (en) * | 2012-03-14 | 2012-07-18 | 李涛 | Identification method for illegal cooking oil |
Non-Patent Citations (2)
| Title |
|---|
| JP特许4372567B2 2009.09.11 |
| JP特開2009-244283A 2009.10.22 |
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