CN104697979A

CN104697979A - Method for detecting aspartame in food through raman enhancement spectrum

Info

Publication number: CN104697979A
Application number: CN201510146031.2A
Authority: CN
Inventors: 陈金凤; 杨黄浩; 张艳燕; 宋良; 田中群
Original assignee: Longyan Entry-Exit Inspection And Quarantine Bureau Of People's Republic Of China (prc)
Current assignee: Longyan Entry-Exit Inspection And Quarantine Bureau Of People's Republic Of China (prc)
Priority date: 2015-03-31
Filing date: 2015-03-31
Publication date: 2015-06-10

Abstract

The invention relates to a method for detecting aspartame in food through a raman enhancement spectrum, and belongs to the field of food safety detection. The method specifically comprises the steps that sodium citrate is adopted as a reducing agent to obtain nanogold sol with the particle size of about 50 nm in a synthesizing mode, the sol is adopted as a raman spectrum enhancement reagent, and the aspartame in the food is detected. In the detection process, the enhancement reagent and a sample to be detected are evenly mixed, the pH of a mixed solution is adjusted, laser focusing is carried out, and raman spectrum detection is achieved. The new fast detection method is provided for detecting the aspartame in the food, and the method is simple and fast in operation process, accurate in result and high in sensitivity.

Description

A kind of method utilizing Raman enhanced spectrum to detect Aspartame in food

Technical field

The present invention relates to field of detection of food safety, be specifically related to a kind of method utilizing Raman enhanced spectrum to detect Aspartame in food.

Background technology

Aspartame is a kind of artificial sweetener of non-carbohydrate class, and chemical name is L-asparagus fern ammonia phthalein-L-Phe methyl esters (APM), also known as sweetener, protein sugar, aspartame, radix asparagi sweet extract, sky benzene sugar etc.Within 1981, be used for going through to use in global more than 100 countries and regions after dehydrated food, nineteen eighty-three permission preparation soft drink through U.S. FDA approval, sugariness is 200 times of sucrose.China's regulation Aspartame can be used for cake, biscuit, bread, assembled alcoholic drinks, ice cream, ice lolly, beverage, candy, consumption by normal need of production.

At present, in the world very large dispute is existed to the security of Aspartame, studies have found that and can not get rid of the possibility that Aspartame can cause the serious consequences such as brain tumor, brain damage and lymph cancer.In July, 2005, a result of study that Italian scientist is announced claims, and zoopery proves, Aspartame can cause rat tumor; In October, 2014, Nature delivers the article that a section is entitled as " Artificial sweeteners induce glucose intolerance by altering the gut microbiota ".The author Eran Elinav of this article and colleague find, the consumption of three kinds of the most frequently used artificial sweeteners (asccharin, Sucralose and Aspartame) do not contained heat, and directly can bring out mouse and produce fat and glucose intolerance and be inclined to.

Due to Aspartame in vivo metabolism can produce phenylalanine, so the patient that this thing being not suitable for suffers from phenylketonuria uses, because it likely can cause phenylalanine cannot metabolism, and cause function not enough.Meanwhile, other two kinds of materials that Aspartame metabolism produces, aspartic acid and methyl alcohol also can cause certain harm to human body.Aspartame is as a kind of food additives, and be protection health, prevent it to the potential hazard of human body, its addition should be monitored, therefore necessary to the mensuration of Aspartame in various food.

In food, the assay method of Aspartame mainly contains titrimetry, chromatography etc.These method detection sensitivities are high, but existence needs complex precise instrument, requires high deficiency, can not meet the requirement of field quick detection to operative technique.Detection method pre-treatment of the present invention is simple, easy and simple to handle, and result is accurate, can provide effective method for the field quick detection of Aspartame.

Raman spectroscopy has without the need to sample preparation, is not subject to the interference of hydrone, can carries out the detection fast of nothing wound, the features such as checkout equipment is light.Surface enhanced raman spectroscopy technology makes its detectability improve 4 to 10 orders of magnitude, even can reach ten part per trillion (10 ^-12g/g), not only in material molecular structure analysis, and also more and more demonstrate huge potentiality in the quick context of detection of trace chemical.

Summary of the invention

The object of the invention is to provide a kind of method utilizing Raman enhanced spectrum to detect Aspartame in food.The present invention utilizes gold nano colloidal sol as Raman Contrast agent, directly mixes with testing sample, can detect the Aspartame in food fast.This law is highly sensitive, easy to operate, can be used for field quick detection.

Realize concrete grammar of the present invention:

Utilize Raman enhanced spectrum to detect a method for Aspartame in food, comprise the following steps:

1) synthesis of Raman Contrast agent: certain density gold chloride is heated to boil, adds sodium citrate in proportion, synthesis of nano aurosol;

2) sample pre-treatments: detect again after liquid sample is carried out pre-treatment;

3) in food, the Raman of Aspartame strengthens technology for detection: after liquid to be measured and the mixing of Raman Contrast agent, regulate pH value of solution, laser is assembled, and carries out Raman spectrum detection; Contrast according to the collection of illustrative plates with standard items, whether qualitative discrimination detects.

Concrete: described in step 1), the synthesis concrete operations of Raman Contrast agent are, get 0.5 ~ 1 mL 2% chlorauric acid solution, join in 50 ~ 100 mL ultrapure waters, rapid stirring, is heated to boil, and adds 0.5 ~ 1 mL 1% sodium citrate fast, add hot reflux 30 ~ 60 min, synthesis of nano aurosol.

Step 2) described in sample pre-treatments be: when liquid sample clarification without obvious solid matter time, after ultrasonic bubble removing, direct-detection; If any obvious solid matter, first cross the filter membrane of 0.22 μm, filtrate is to be measured;

Detection described in step 3), after liquid to be measured and Raman Contrast agent being mixed with the volume ratio of 1:1 ~ 1:5, regulate pH value of solution to 1 ~ 3, laser is assembled, and carries out Raman spectrum detection; Contrast according to the Raman collection of illustrative plates with Aspartame powder, whether qualitative discrimination detects.

Beneficial effect of the present invention is:

It is simple that detection method of the present invention has food samples pre-treatment, and operating process is easy, and result is accurate, sensitivity advantages of higher, meets the requirement of field quick detection.

Accompanying drawing explanation

Fig. 1 nm of gold strengthens the transmission electron microscope figure (TEM) of Raman particle;

Fig. 2 Aspartame standard model Raman spectrogram (10 μ g/mL-500 μ g/mL);

Fig. 3 Sprite actual sample strengthens Raman spectrogram (a is non-mark-on sample, and b is mark-on 50 μ g/mL Aspartame sample, and c is mark-on 100 μ g/mL Aspartame sample).

Embodiment

More being convenient to make content of the present invention understand, below in conjunction with embodiment, technical solutions according to the invention are described further, but the present invention being not limited only to this.

embodiment 1

1) synthesis of Raman Contrast agent

50 mL ultrapure waters and 0.75 mL 2wt% gold chloride (HAuCl is added in 100 mL round-bottomed flasks ₄) solution, under fast stirring, be heated to boiling, then add 1 mL 1wt% sodium citrate solution fast, continue to stir, heating reflux reaction 30 min, stop heating, naturally cool to room temperature, gained solution is Raman Contrast agent; Fig. 1 is the transmission electron microscope figure (TEM) that nm of gold strengthens Raman particle, and the scale in figure is 50 nm, and as can be seen from the figure, the size of particle is about 50 nm;

2) detection of Aspartame standard model

First prepare the Aspartame standard solution of 1 mg/mL, then this solution is diluted to 500 μ g/mL respectively, 100 μ g/mL, 50 μ g/mL and 10 μ g/mL; Using the nano Au particle of step 1) synthesis as Raman Contrast agent, the Contrast agent getting 300 μ L mixes with the testing sample of 150 μ L, then regulates pH to 2, gets 300 μ L in sample cell, and laser is assembled, and Raman spectrum detects; Figure 2 shows that 10 μ g/mL-500 μ g/mL Aspartame sample Raman enhanced spectrum figure, in figure, annotate portions is characteristic peak (821.4 cm of Aspartame ^-1, 997.8 cm ^-1, 1023.6 cm ^-1, 1203.1 cm ^-1); When testing sample and occurring the characteristic peak of Aspartame, think and have Aspartame to exist, detecting of sample is limited to 10 μ g/mL.

embodiment 2

1) synthesis of Raman Contrast agent

50 mL ultrapure waters and 0.5 mL 2wt% gold chloride (HAuCl is added in 100 mL round-bottomed flasks ₄) solution, under fast stirring, be heated to boiling, then add 0.7 mL 1wt% sodium citrate solution fast, continue to stir, heating reflux reaction 60 min, stop heating, naturally cool to room temperature, gained solution is Raman Contrast agent;

2) detection of Aspartame in Sprite

Sprite is as actual sample; Get the Sprite sample after ultrasonic degassing processing, respectively mark-on 100 μ g/mL and 50 μ g/mL Aspartames.Get 300 μ L Sprite mark-on samples and non-mark-on sample respectively to obtain with 150 μ L Ramans Contrast agent (by 1) respectively) mix, regulate pH to 2, get 300 μ L respectively in sample cell, laser is assembled, and Raman spectrum detects; Fig. 3 is the Raman spectrogram of Sprite mark-on sample and non-mark-on sample, and in figure, annotate portions is raman characteristic peak (997.8 cm of Aspartame ^-1, 1023.6 cm ^-1).With the standard model comparison of Aspartame, illustrate that mark-on sample has Aspartame to detect.The most low energy of Sprite sample detects 50 μ g/mL Aspartames.

The foregoing is only preferred embodiment of the present invention, all equalizations done according to the present patent application the scope of the claims change and modify, and all should belong to covering scope of the present invention.

Claims

1. utilize Raman enhanced spectrum to detect a method for Aspartame in food, it is characterized in that: comprise the following steps:

1) synthesis of Raman Contrast agent: gold chloride is heated to boil, adds sodium citrate in proportion, synthesis of nano aurosol;

2) sample pre-treatments; Liquid sample is carried out pre-treatment;

3) in food, the Raman of Aspartame strengthens technology for detection: after liquid to be measured and the mixing of Raman Contrast agent, regulate pH value of solution, laser is assembled, and carries out Raman spectrum detection; Contrast according to the collection of illustrative plates with Aspartame standard items, whether qualitative discrimination detects.

2. utilize Raman enhanced spectrum to detect the method for Aspartame in food as claimed in claim 1, it is characterized in that: step 1) the concrete synthesis step of described Raman Contrast agent is: get 0.5 ~ 1 mL 2wt% chlorauric acid solution, join in 50 ~ 100 mL ultrapure waters, rapid stirring, be heated to boil, add 0.5 ~ 1 mL 1wt% sodium citrate fast, add hot reflux 30 ~ 60 min, synthesis of nano aurosol.

3. utilize Raman enhanced spectrum to detect the method for Aspartame in food as claimed in claim 1, it is characterized in that: step 2) described in sample pre-treatments be: when liquid sample clarification without obvious solid matter time, after liquid sample ultrasonic bubble removing, direct-detection; When liquid sample has obvious solid matter, first cross the filter membrane of 0.22 μm, filtrate is to be measured.

4. utilize Raman enhanced spectrum to detect the method for Aspartame in food as claimed in claim 1, it is characterized in that: in step 3), the volume ratio of liquid to be measured and Raman Contrast agent is 1:1 ~ 1:5, regulate pH value of solution to 1 ~ 3.