Background technology
Exposed problems gets more and more people's extensive concerning day by day in the food security.The food security malignant event successively takes place both at home and abroad, has not only brought tremendous loss to the people's lives and property, has also caused and abominable social influence simultaneously.Worldwide recur food security malignant events such as De bioxin, rabid ox disease, Escherichia coli no matter be.Or the food security incident that China takes place frequently for example adds melamine, with the carcinogen tonyred food is dyeed, sells the incidents of being polluted by aflatoxins such as rice in the milk powder; No matter be in developed country, still in developing country, food-safety problem has become global, as to have a great harm problem of environmental pollution.
The detection of objectionable impurities is one of important measures that ensure food safety, food safety detection has following characteristics: sample is contained meat, egg, milk, aquatic products etc., these materials all are the very complicated organism of composition and structure, comprising many to detecting noisy material; Poisonous and harmful substance kind and component are various; The detection material content concn often is μ g, ng level even pg level; Need do quick, easy qualitative and quantitative analysis.Usually relate to the detection of derivant and degradation product, need the valence state of difference with position isomer and element.
In view of food security to the significant impact that the mankind had, with many countries are the same in the world, China has also strengthened the attention of food security work.Yet China is also at the early-stage in the context of detection of food residue objectionable impurities, also there are a lot of problems at aspects such as analytical instrument, detection method, separation determination, data processing and quality controls, it is low to be faced with in the food residues of harmful substances amount, detect difficulty, existing Sensitivity of Analytical Method is not enough, sample substrate is measured objectionable impurities and is had difficulties such as interference, large-scale instrument cost an arm and a leg, are difficult to popularize.
How to take effective method that polluter residual in the food is detected and become the task of top priority.The a large amount of uses of antibiotics in clinical, aquaculture and agricultural, on the one hand can be by the residual human body of transferring in the animal body, the drug-fast bacteria of animal, bird generation also can be propagated to the mankind on the other hand, bring the serious danger side of body for human beings'health and existence, the research of aspects such as the analysis of residual antibiotic in the environment, migration, resistance has been become the focus that environmental chemistry man pays close attention to.
Therefore, it is most important for ensuring food safety to set up efficient, sensitive microbiotic detection method.Be subjected to the limitation that residual contaminants content is low, detect difficulty about the main at present analytical approach that adopts of the mensuration of residual antibiotic.To the analysis of the antibiotic medicine of trace/ultratrace in the environment, a restriction difficult problem is the The pretreatment technology.
The tradition volatile organic compounds is mainly used in the preprocessing process of analytic sample, exists bioaccumulation efficiency low, and poor selectivity is introduced the impurity of matrix easily, and sample is difficult to obtain problems such as purifying, and solvent itself can cause secondary pollution again simultaneously.Study novel, green replace solvents-ionic liquid, inquire into the antibiotic character of its extract and separate, mechanism and application, no matter be for ensuring food safety or reduce volatile organic matter and pollute, very important meaning all being arranged.
Summary of the invention
Low at the sensitivity that exists in the existing residual erythrocin detection method, range of choice is single, the shortcoming of poor accuracy, the objective of the invention is to, the method that provides a kind of hydrophobic ionic liquid to measure residual erythrocin in the environment, this method can improve the accuracy that residual erythrocin is measured, and can have easy and simple to handle simultaneously, do not use large-scale instrument, reduce the secondary pollution of using the organic volatile solvent to bring.
In order to realize above-mentioned task, the present invention takes following technical solution:
A kind of hydrophobic ionic liquid is measured the method for residual erythrocin in the environment, it is characterized in that, this method adopts the 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid that adds 2.5g in the erythromycin aqueous solution, under the temperature of 298.15K~323.15K, oscillation extraction at least once in constant temperature oscillator, the extraction time is 1.5h~3h, leave standstill after the extraction, after treating that phase-splitting is clear, measure the concentration of aqueous phase residue erythromycin, by the percentage extraction of the cubage erythromycin of aqueous phase erythromycin before and after the extraction.
Method of the present invention is 98.61% to the erythromycin percentage extraction, and it is wide to have the range of linearity, and detection limit is low, and relative standard deviation is less, the characteristics high to the mensuration recovery of sample.Can satisfy the detect requirement of country for residual erythrocin, operation simultaneously is comparatively simple, is applicable to the quantitative test of microscratch amount erythromycin residual in the food.
Embodiment
The present invention is on to existing erythromycin study on determination method basis, by a series of experiment, finally adopt with 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid as extraction solvent, residual erythrocin in the enrichment environment is a kind of quantitative analysis method of erythromycin.
Referring to Fig. 1~6, wherein:
Fig. 1 is the graph of a relation that influences of 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid consumption; Wherein, horizontal ordinate is represented 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid consumption, and ordinate is represented percentage extraction.1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid consumption is bigger to the consumption influence of erythromycin percentage extraction.1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid consumption hour, percentage extraction is also lower.But when 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid addition surpasses 1.5g, the percentage extraction of erythromycin increases slowly with 1-octyl group-ion liquid addition of 3-methyl imidazolium tetrafluoroborate, when 1-octyl group-when 3-methyl imidazolium tetrafluoroborate ionic liquid addition is 2.5g, the percentage extraction of erythromycin reaches maximum 88.89%, after this along with ion liquid adding, the percentage extraction of erythromycin slightly descends.
Fig. 2 is the Temperature Influence graph of a relation; Wherein, horizontal ordinate is represented temperature, and ordinate is represented percentage extraction, and along with the rising of temperature, 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid is the first trend that afterwards reduces that increases to the percentage extraction of erythromycin.Under the temperature of 323.15K, percentage extraction peaks, and therefore, (25 ℃~50 ℃) promptly also can reach better effects under the room temperature condition under 298.15K 323.15K temperature extremely.
Fig. 3 is that the extraction mode influences graph of a relation; Adopt vibration to help the extraction of erythromycin more than the mode that leaves standstill.
Fig. 4 is the graph of a relation that influences of extraction time; Horizontal ordinate express time wherein, ordinate is represented percentage extraction, and 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid reaches balance to the percentage extraction of erythromycin when the 1.5h, and this moment, percentage extraction was 93.3%
Fig. 5 is the graph of a relation that influences of extraction times; 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid is to the percentage extraction of erythromycin increasing and increase with extraction times.After extraction times surpassed 3 times, 1-octyl group-3-methylimidazole tetrafluoro boric acid ionic liquid all can reach more than 97% the percentage extraction of erythromycin.
Fig. 6 is the graph of a relation that influences of ionic liquid recycling number of times; Wherein horizontal ordinate represents to utilize number of times, ordinate is represented percentage extraction, along with the ion liquid recycling increased frequency of 1-octyl group-3-methylimidazole tetrafluoro boric acid, the percentage extraction of erythromycin slightly descends, when the recycling number of times surpasses 5 times, the percentage extraction of erythromycin will significantly diminish, even completely lose.This is because the ion liquid extraction function of 1-octyl group-3-methyl imidazolium tetrafluoroborate after repeatedly utilizing is tending towards saturated, the erythromycin in can not adsorbent solution.Therefore, in the extraction process of erythromycin, the ion liquid recycling number of times of 1-octyl group-3-methyl imidazolium tetrafluoroborate should be above 5 times.
It below is the specific embodiment that the inventor provides.
Embodiment 1:
Get 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid of 1.5g, place 60ml tool plug conical flask, add 3ml erythromycin standard solution and 25.0ml distilled water, fully mixing.In constant temperature oscillator, leave standstill behind the oscillation extraction 1.5h under 25 ℃, treat that phase-splitting is clear after, measure the concentration of aqueous phase residue erythromycin, by the percentage extraction of the cubage erythromycin of aqueous phase erythromycin before and after the extraction.
Embodiment 2:
Get 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid of 2.5g, place 60ml tool plug conical flask, add 3ml erythromycin standard solution and 25.0ml distilled water, fully mixing.In constant temperature oscillator, leave standstill behind the oscillation extraction 1.5h under 25 ℃, treat that phase-splitting is clear after, measure the concentration of aqueous phase residue erythromycin, by the percentage extraction of the cubage erythromycin of aqueous phase erythromycin before and after the extraction.
Embodiment 3:
Get 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid of 2.5g, place 60ml tool plug conical flask, add 3ml erythromycin standard solution and 25.0ml distilled water, fully mixing.In constant temperature oscillator, leave standstill behind the oscillation extraction 1.5h under 35 ℃, treat that phase-splitting is clear after.Measure the concentration of aqueous phase residue erythromycin, by the percentage extraction of the cubage erythromycin of aqueous phase erythromycin before and after the extraction.
Embodiment 4:
Get 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid of 2.5g, place 60ml tool plug conical flask, add 3ml erythromycin standard solution and 25.0ml distilled water, fully mixing.In constant temperature oscillator, leave standstill behind the oscillation extraction 2h under 25 ℃, treat that phase-splitting is clear after, measure the concentration of aqueous phase residue erythromycin, by the percentage extraction of the cubage erythromycin of aqueous phase erythromycin before and after the extraction.
Embodiment 5:
Get 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid of 2.5g, place 60ml tool plug conical flask, add 3ml erythromycin standard solution and 25.0ml distilled water, fully mixing.In constant temperature oscillator, leave standstill behind the oscillation extraction 3h under 25 ℃, treat that phase-splitting is clear after, measure the concentration of aqueous phase residue erythromycin, by the percentage extraction of the cubage erythromycin of aqueous phase erythromycin before and after the extraction.
Embodiment 6:
Get 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid of 2.5g, place 60ml tool plug conical flask, add 3ml erythromycin standard solution and 25.0ml distilled water, fully mixing.In constant temperature oscillator, leave standstill behind the oscillation extraction 1.5h under 25 ℃, with ionic liquid and water separately after, add 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid of 2.5g, re-extract 1 time again at aqueous phase.Leave standstill behind the extraction 1.5h, measure the concentration of aqueous phase residue erythromycin, by the percentage extraction of the cubage erythromycin of aqueous phase erythromycin before and after the extraction.
Embodiment 7:
Get 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid of 2.5g, place 60ml tool plug conical flask, add 3ml erythromycin standard solution and 25.0ml distilled water, fully mixing.In constant temperature oscillator, leave standstill behind the oscillation extraction 1.5h under 25 ℃, with ionic liquid and water separately after.Add 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid of 2.5g again at aqueous phase, so re-extract is 2 times.Measure the concentration of aqueous phase residue erythromycin, by the percentage extraction of the cubage erythromycin of aqueous phase erythromycin before and after the extraction.
Embodiment 8:
Get 1-octyl group-3-methyl imidazolium tetrafluoroborate ionic liquid of 2.5g, place 60ml tool plug conical flask, add 3ml erythromycin standard solution and 25.0ml distilled water, fully mixing.In constant temperature oscillator, leave standstill behind the oscillation extraction 1.5h under 25 ℃, treat that phase-splitting is clear after, measure the concentration of aqueous phase residue erythromycin, by the percentage extraction of the cubage erythromycin of aqueous phase erythromycin before and after the extraction.