CN105628668A - Molecular imprinting-Raman combination detection method of sulfadimidine in milk - Google Patents

Abstract

The invention discloses a molecular imprinting-Raman combination detection method of sulfadimidine in milk. The method can realize rapid low-cost detection of excess sulfadimidine in milk. A hydrogel prepared through a molecular imprinting technology is used to complete adsorption and enrichment of sulfadimidine in a detected sample in 5min, and a portable Raman spectrometer is used to collect spectrum information, so the whole process is rapid and convenient; and the hydrogel can be repeatedly used, so the detection cost is reduced, environmental protection is realized, and onsite high-flux detection requirements are met.

Description

The molecular engram of sulfadimidine-Raman coupling detection method in a kind of milk

Technical field

The present invention relates to a kind of detection method, the molecular engram-Raman coupling detection method being specifically related in a kind of milk sulfadimidine.

Background technology

As a kind of conventional sulfonamides antibacterial, sulfadimidine is widely used in prevention and the bacterial infection disease for the treatment of milch cow. Because its action time in animal body and metabolism time are longer, easily remain in the tissue of animal, and then enter in animal secretions (such as milk). The milk product that long-term drink sulfa drug residue is too high, will cause serious consequence to the health of human body, particularly infant. At present, in milk, the detection method of sulfa drug residue has high performance liquid chromatography (HPLC), gas chromatography (GC), gas chromatographymass spectrum (GC/MS), liquid-mass chromatography method (LC/MS) etc. Though existing method has advantages such as highly sensitive, detection limit is low, but because of expensive equipment, length consuming time, testing cost is high and is difficult to meet the present situation that food-safety problem takes place frequently. Therefore, the new method develop a kind of low cost, meeting field quick detection is extremely necessary.

Summary of the invention

For solving the problems referred to above, the invention provides the molecular engram of sulfadimidine in a kind of milk-Raman coupling detection method, by molecular imprinting preparation, sulfamethazine is had the hydrogel of specific recognition effect, testing sample is after hydrogel adsorption and enrichment, Portable Raman spectrometer is utilized to carry out spectra collection, compared by the standard Raman spectroscopy with sulfamethazine, it is judged that whether sample contains this medicine.

For achieving the above object, the technical scheme that the present invention takes is:

In a kind of milk, the molecular engram of sulfadimidine-Raman coupling detection method, comprises the steps:

S1, prepare sulfadimidine molecule imprinting hydrogel: take 0.017g sulfadimidine (template molecule) respectively, 1.4ml acrylic acid (function monomer), 3.0g acrylamide (function monomer), 0.09gN ' N-methylene-bisacrylamide (cross-linking agent), 0.09g Ammonium persulfate. (initiator) and 4.0ml deionized water (solvent) are sufficiently mixed in beaker, after nitrogen deoxygenation, fill it in the clamping plate space formed by two panels microscope slide, it is placed in polyreaction 3h in the baking oven of 60 DEG C, obtain the sulfadimidine trace hydrogel of film like,

S2, removal template molecule: will be immersed in the acetum of 10% by the trace hydrogel of step S1 gained, and sonic oscillation 5min, to remove template molecule sulfadimidine therein;

S3, the sulfadimidine storing solution of variable concentrations is separately added into 10ml itself without, in the milk of sulfadimidine, making the concentration of sulfadimidine respectively 0mg/L, 0.01mg/L, 0.05mg/L, 0.1mg/L, 0.5mg/L, 1mg/L, 5mg/L, 10mg/L in gained solution;

In S4, the milk containing variable concentrations sulfadimidine being soaked in step S3 by the trace hydrogel of step S2 gained gained, after about 5min, (reach adsorption equilibrium), be drawn off and remove unnecessary cattle milk with deionized water drift;

S5, with Portable Raman spectrometer, the solution of step S4 gained is detected, the standard Raman spectroscopy of gained spectrum Yu sulfadimidine is compared, it is judged that whether sample contains sulfadimidine.

The method have the advantages that

The present invention can quickly, excessive sulfadimidine in low cost detection milk. By hydrogel prepared by molecular imprinting, can complete the adsorption and enrichment effect of sulfadimidine in sample within 5min, spectral information is gathered then through Portable Raman spectrometer, whole process rapid and convenient, and hydrogel can repeatedly circulate and reuse, while reducing testing cost, also there is eco-friendly advantage, and the demand of scene, high throughput testing can be met.

Detailed description of the invention

In order to make objects and advantages of the present invention clearly understand, below in conjunction with embodiment, the present invention is further elaborated. Should be appreciated that specific embodiment described herein is only in order to explain the present invention, is not intended to limit the present invention.

Embodiments provide the molecular engram of sulfadimidine in a kind of milk-Raman coupling detection method, comprise the steps:

S1, prepare sulfadimidine molecule imprinting hydrogel: take 0.017g sulfadimidine (template molecule) respectively, 1.4ml acrylic acid (function monomer), 3.0g acrylamide (function monomer), 0.09gN ' N-methylene-bisacrylamide (cross-linking agent), 0.09g Ammonium persulfate. (initiator) and 4.0ml deionized water (solvent) are sufficiently mixed in beaker, after nitrogen deoxygenation, fill it in the clamping plate space formed by two panels microscope slide, it is placed in polyreaction 3h in the baking oven of 60 DEG C, obtain the sulfadimidine trace hydrogel of film like,

S2, removal template molecule: will be immersed in the acetum of 10% by the trace hydrogel of step S1 gained, and sonic oscillation 5min, to remove template molecule sulfadimidine therein;

S3, the sulfadimidine storing solution of variable concentrations is separately added into 10ml itself without, in the milk of sulfadimidine, making the concentration of sulfadimidine respectively 0mg/L, 0.01mg/L, 0.05mg/L, 0.1mg/L, 0.5mg/L, 1mg/L, 5mg/L, 10mg/L in gained solution;

In S4, the milk containing variable concentrations sulfadimidine being soaked in step S3 by the trace hydrogel of step S2 gained gained, after about 5min, (reach adsorption equilibrium), be drawn off and remove unnecessary cattle milk with deionized water drift;

5, with Portable Raman spectrometer, the solution of step S4 gained is detected, the standard Raman spectroscopy of gained spectrum Yu sulfadimidine is compared, it is judged that whether sample contains sulfadimidine.

Principles of the invention is: molecular imprinting, first pass through and select suitable function monomer and template molecule pre-assembled formation specific recognition site in media as well, form polymer gel again through cross-linking polymerization and this specific recognition site is fixed up, then suitable solvent is utilized to be removed from gel by template molecule, so just in gel, leave the hole with " memory " function matched on three dimensions with template molecule, namely the specific recognition to template molecule is realized, such that it is able to template molecule is enriched with in certain substrate. in the present invention, template molecule is sulfadimidine, has multiple covalent bond in its molecular structure, and raman spectral signal intensity is big and spectral peak is sharp-pointed. after utilizing imprinted polymer gel it to be enriched with in sample, gather the Raman spectrum of polymer gel, compared by the standard Raman spectroscopy with sulfamethazine, it is judged that whether gel contains sulfadimidine, thus judging whether sample contains this composition.

Wherein, originally it is embodied in the concentration range of 0.05mg/L-10mg/L and all can detect that sulfadimidine.

In sum, the present invention can quickly, excessive sulfadimidine in low cost detection milk. By hydrogel prepared by molecular imprinting, can complete the adsorption and enrichment effect of sulfadimidine in sample within 5min, spectral information is gathered then through Portable Raman spectrometer, whole process rapid and convenient, and hydrogel can repeatedly circulate and reuse, while reducing testing cost, also there is eco-friendly advantage, and the demand of scene, high throughput testing can be met

The above is only the preferred embodiment of the present invention; it should be pointed out that, for those skilled in the art, under the premise without departing from the principles of the invention; can also making some improvements and modifications, these improvements and modifications also should be regarded as protection scope of the present invention.

Claims (1)

1. the molecular engram of sulfadimidine-Raman coupling detection method in a milk, it is characterised in that comprise the steps:

S1, take 0.017g sulfadimidine, 1.4ml acrylic acid, 3.0g acrylamide, 0.09gN ' N-methylene-bisacrylamide, 0.09g Ammonium persulfate. and 4.0ml deionized water respectively and be sufficiently mixed in beaker, after nitrogen deoxygenation, fill it in the clamping plate space formed by two panels microscope slide, it is placed in polyreaction 3h in the baking oven of 60 DEG C, obtains the sulfadimidine trace hydrogel of film like;

S2, will be immersed in the acetum of 10% by the trace hydrogel of step S1 gained, and sonic oscillation 5min, to remove template molecule sulfadimidine therein;

S3, the sulfadimidine storing solution of variable concentrations is separately added into 10ml itself without, in the milk of sulfadimidine, making the concentration of sulfadimidine respectively 0mg/L, 0.01mg/L, 0.05mg/L, 0.1mg/L, 0.5mg/L, 1mg/L, 5mg/L, 10mg/L in gained solution;

In S4, the milk containing variable concentrations sulfadimidine being soaked in step S3 by the trace hydrogel of step S2 gained gained, after about 5min, it is drawn off and removes unnecessary cattle milk with deionized water drift;

S5, with Portable Raman spectrometer, the solution of step S4 gained is detected, the standard Raman spectroscopy of gained spectrum Yu sulfadimidine is compared, it is judged that whether sample contains sulfadimidine.