CN111380854A

CN111380854A - Surface enhanced Raman spectroscopy rapid detection method for ciprofloxacin in egg milk

Info

Publication number: CN111380854A
Application number: CN201811617929.3A
Authority: CN
Inventors: 常化仿; 倪天瑞; 马宁; 贾梦伟; 章祥; 尧伟峰
Original assignee: Polaris Scientific Instruments Suzhou Co ltd
Current assignee: Polaris Scientific Instruments Suzhou Co ltd
Priority date: 2018-12-28
Filing date: 2018-12-28
Publication date: 2020-07-07

Abstract

The invention discloses a rapid detection method of ciprofloxacin surface enhanced Raman spectroscopy in egg milk, which belongs to the technical field of food safety detection. The detection method provided by the invention is a new pretreatment method, the surface-enhanced Raman spectroscopy technology is used for detecting the ciprofloxacin in the eggs or the milk, the detection limit is 0.1ppm, the pretreatment of the sample is simple and convenient, the dosage of the sample and a reagent is small, the detection is rapid and simple, the precision is high, and the cost is low.

Description

Surface enhanced Raman spectroscopy rapid detection method for ciprofloxacin in egg milk

Technical Field

The invention belongs to the technical field of food safety detection, and particularly relates to a surface-enhanced Raman spectroscopy rapid detection method for ciprofloxacin in egg milk.

Background

Ciprofloxacin is a synthesized third-generation quinolone antibacterial drug, has broad-spectrum antibacterial activity and good bactericidal effect, almost has 2-4 times stronger antibacterial activity on all bacteria than norfloxacin and enoxacin, has antibacterial action on enterobacter, pseudomonas aeruginosa, haemophilus influenzae, gonococcus, streptococcus, legionella and staphylococcus aureus, and is one of the commonly used veterinary drugs in animal husbandry. The eggs and the milk are used as important protein food sources in the lives of residents in China, so that the safety problem is not small, and the phenomena of overproof use of antibiotics, non-strict execution of medicament compatibility contraindication and the like still exist widely in the aspect of the current domestic breeding conditions.

The ciprofloxacin detection method mentioned in the existing research and report is mainly high performance liquid chromatography, although the detection limit is low, the sensitivity and the accuracy are high, the pretreatment process is tedious, the period is long, the cost is high, the requirement on operators is high, and the practicability is greatly limited.

Therefore, a rapid and convenient method for detecting ciprofloxacin, which can solve the above problems, is required.

Disclosure of Invention

In order to overcome the defects of the existing detection method, the invention provides the rapid detection method of the surface enhanced Raman spectrum of the ciprofloxacin in the egg milk.

The technical scheme provided by the invention is as follows.

A surface enhanced Raman spectroscopy rapid detection method for ciprofloxacin in egg milk specifically comprises the following steps:

(1) taking 1mL of a sample to be detected, putting the sample into a 2 mL centrifuge tube, adding 300 mu L of milk reagent A, oscillating for 30s, and centrifuging for 120s for layering;

(2) putting all the supernatant into a 2 mL centrifuge tube, adding 500 mu L ethyl acetate, shaking and uniformly mixing, and centrifuging for 3 min to separate the supernatant into layers, wherein the supernatant is the solution to be detected;

(3) 500ul of the enhanced reagent A, 50ul of the solution to be detected and 100ul of the enhanced reagent B are sequentially and uniformly mixed in a detection bottle, and the mixture is placed in a detection cell of a Raman spectrometer to start detection.

Preferably, the sample to be detected in the step (1) is evenly stirred egg white or milk, and the milk reagent A is a 1% trichloroacetic acid solution and a 1% sodium chloride solution which are mixed according to a volume ratio of 1: 5.

Preferably, the centrifugation speed in the step (1) and the centrifugation speed in the step (2) are both 10000 r/min.

Preferably, in the step (3), the enhancing reagent A is self-made nanogold sol, and the enhancing reagent B is 0.2mol/L sodium chloride solution.

Preferably, in the step (3), the scanning parameters during detection by the Raman spectrometer are 200mW of laser power, 10s of scanning time, 2 scanning times and 4 smoothing parameters, and the ciprofloxacin positive spectrogram is 1267cm^-1There is a distinct raman peak at the shift.

Preferably, the ethyl acetate, water, etc. used in the detection are all HPLC grade.

The invention has the beneficial effects that: the detection method disclosed by the invention is a new pretreatment method, after proteins of an egg or milk sample to be detected are removed, ethyl acetate is used for extracting ciprofloxacin, the obtained upper layer clear liquid to be detected is uniformly mixed with a proper amount of nano enhancing reagent A and enhancing reagent B and then is detected by a Raman spectrometer, the detection limit is 0.1ppm, and compared with the existing detection method, the detection method has the obvious advantages of simple and convenient sample pretreatment, small sample and reagent dosage, quick and simple detection, high precision, low cost and the like.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

FIG. 1 is a surface enhanced Raman spectrum of ciprofloxacin in an example of the present invention.

Wherein the grey dotted line spectrogram is a ciprofloxacin negative sample, and the black solid line spectrogram is a ciprofloxacin positive sample with the concentration of 0.1 ppm.

Detailed Description

The present invention will be described in further detail with reference to examples, but the present invention is not limited to the following examples.

(1) preparing a ciprofloxacin negative milk sample, and preparing a ciprofloxacin positive milk sample with the concentration of 0.1 ppm;

(2) taking 1mL of a sample to be detected, putting the sample into a 2 mL centrifuge tube, adding 300 mu L of milk reagent A, oscillating for 30s, and centrifuging for 120s at 10000 r/min for layering;

(3) putting all the supernatant into a 2 mL centrifuge tube, adding 500 mu L ethyl acetate, shaking and uniformly mixing, centrifuging at 10000 r/min for 3 min to layer, wherein the supernatant is the solution to be detected;

(4) 500ul of the enhanced reagent A, 50ul of the solution to be detected and 100ul of the enhanced reagent B are sequentially and uniformly mixed in a detection bottle, the mixture is placed in a detection pool of a Raman spectrometer, and detection is started, wherein scanning parameters comprise 200mW of laser power, 10s of scanning time, 2 scanning times and 4 smoothing parameters.

The detection result is shown in FIG. 1, wherein the spectrum of the gray dotted line is ciprofloxacin negative sample, the spectrum of the black solid line is ciprofloxacin positive sample with concentration of 0.1ppm, and the spectrum of the ciprofloxacin positive sample is 1267cm^-1The displacement has obvious Raman peak, which is obviously distinguished from the negative sample spectrogram.

Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that various changes, modifications and substitutions can be made without departing from the spirit and scope of the invention as defined by the appended claims. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A surface-enhanced Raman spectroscopy rapid detection method for ciprofloxacin in egg milk is characterized by comprising the following steps:

2. The method for rapidly detecting ciprofloxacin in egg milk by using surface enhanced Raman spectroscopy according to claim 1, wherein the sample to be detected in step (1) is uniformly stirred egg white or milk, and the milk reagent A is a mixture of 1% trichloroacetic acid solution and 1% sodium chloride solution in a volume ratio of 1: 5.

3. The method for rapidly detecting ciprofloxacin in egg milk by using surface enhanced Raman spectroscopy as claimed in claim 1, wherein the centrifugation speed in step (1) and the centrifugation speed in step (2) are both 10000 r/min.

4. The surface-enhanced Raman spectroscopy rapid detection method of ciprofloxacin in egg milk according to claim 1, wherein the enhancing reagent A in the step (3) is self-made nano gold sol, and the enhancing reagent B is 0.2mol/L sodium chloride solution.

5. The method for rapidly detecting ciprofloxacin in egg milk by using surface enhanced Raman spectroscopy as claimed in claim 1, wherein in the step (3), the scanning parameters of the Raman spectrometer during detection are 200mW of laser power, 10s of scanning time, 2 times of scanning and 4 of smoothing parameters, and a ciprofloxacin positive spectrogram is 1267cm^-1There is a distinct raman peak at the shift.

6. The method for rapidly detecting ciprofloxacin in egg milk by using surface enhanced Raman spectroscopy according to claim 1, wherein ethyl acetate, water and the like used in the detection process are HPLC grades.