CN103308612A - Method for rapidly detecting contents of lemon yellow and sunset yellow in food - Google Patents

Abstract

The invention discloses a method for rapidly detecting contents of lemon yellow and sunset yellow in a food. The method comprises the following steps of: preparing a standard solution of the lemon yellow and the sunset yellow; measuring the peak area of the standard solution of the pigments by using high performance liquid chromatography, and drawing a standard curve to obtain an equation of linear regression; filtering a liquid food sample or solid food sample solution, extracting by using an ionic liquid aqueous two-phase system composed of 1-butyl-3-methylimidzaole bromine salt and K2HPO4, and directly carrying out high performance liquid chromatography analysis on an ionic liquid after phase splitting; and respectively calculating the contents of the lemon yellow and the sunset yellow in the food according to the equation of linear regression. The method disclosed by the invention is simple in operation, free of a great deal of volatile solvents, short in separation time, good in ionic liquid phase mobility and capable of inter-dissolving with water or methanol and directly injecting for chromatography analysis. By using the method, the rapid, simple, convenient, environment-friendly, economic, qualitative and quantitative measurement can be provided for quality control departments and production enterprises.

Description

A method for rapid detection of tartrazine and sunset yellow content in food

technical field

The invention relates to a method for determining content by high-performance liquid chromatography, in particular to a method for quickly detecting the content of tartrazine and sunset yellow in food, and belongs to the technical field of food safety additive detection.

Background technique

Due to the wanton discharge of domestic wastewater rich in elements such as carbon, nitrogen, and phosphorus into natural water bodies, these elements can eventually lead to eutrophication of water bodies through enrichment effects. At present, there have been a lot of researches on the treatment of domestic and municipal wastewater. Among them, the research on the removal of phosphorus started relatively late, and it was not started until the 1980s and 1990s. Lemon yellow, a water-soluble synthetic pigment, bright bright yellow. Sunset yellow is also known as sunset yellow, sunset yellow, orange, and edible yellow No. 3. These two pigments can be safely used for coloring food, beverages, medicines, cosmetics, feed, tobacco, toys, food packaging materials, etc. Some researchers have found that this type of food coloring is unsafe or harmful to the human body. Although the hazards of synthetic food coloring are still inconclusive, they have no nutritional value and are of no help to human health. In recent years, in order to pursue profits, many unscrupulous traders have added excessive food coloring to food or used coloring to counterfeit yellow croaker and other illegal activities. In view of this situation, the health departments of various countries have regulated the use of food synthetic coloring in food production in the form of laws and regulations. Behavior. Since 1-butyl-3-methylimidazolium bromide is soluble in water and methanol, the ionic liquid extraction phase can be directly analyzed by chromatography;

At present, the main problem affecting the determination of pigment additives in food is the interference of various pigments and other related substances in the sample. At the same time, some food samples have a small amount of addition, and the sample needs to be enriched for determination. Therefore, pre-enrichment technology Commonly used in the separation and analysis of synthetic pigments.

In the pretreatment process of traditional analysis samples, volatile organic compounds are often used. At the same time, there are problems such as low enrichment efficiency, poor selectivity, easy introduction of matrix impurities, and difficult purification of samples. At the same time, the solvent itself will cause secondary pollution. Therefore, it is of great significance to study new and green alternative solvents - ionic liquids, and to explore the properties, mechanism and application of its extraction and separation of pigments, whether it is to ensure food safety or reduce volatile organic compound pollution.

Contents of the invention

The technical problem to be solved by the present invention is to provide a fast, accurate, intuitive qualitative and quantitative rapid detection method for the contents of tartrazine and sunset yellow in food for the deficiencies of the prior art.

The technical problem to be solved by the present invention is achieved through the following technical solutions. The present invention is a kind of method for quickly detecting the content of tartrazine and sunset yellow in food, and it is characterized in that: the steps of this method are as follows:

(1) Preparation of working curve: Prepare a series of tartrazine and sunset yellow standard solutions with a concentration of 0.05 μg/mL to 50.0 μg/mL by stepwise dilution method. Yellow standard solution; measure the peak area of each concentration standard solution above with high performance liquid chromatography, draw standard curve, obtain linear regression equation;

(2) Sample processing: Food samples are liquid samples or solid samples, and the following methods are used for processing:

Liquid sample: Take 2.0mL of suction-filtered sample into a 10mL centrifuge tube, add 0.3mL of 1-butyl-3-methylimidazolium bromide, dilute to 4mL, add 3.4gK ₂ HPO ₄ , shake until completely dissolved, 3000r Centrifuge for 2 to 3 minutes at 1/min to form a two-phase aqueous phase, take 20 μL of the ionic liquid phase, and directly carry out chromatographic analysis;

Solid sample: Weigh 2.0-5.0g of solid food, dissolve it in 10-20mL of distilled water, take 3.0mL of the solution into a 10mL centrifuge tube with stopper, add 0.3mL of 1-butyl-3-methylimidazolium bromide, and dilute to 4mL, add 3.4g K ₂ HPO ₄ , shake until completely dissolved, centrifuge at 3000r/min for 2-3min to form a two-water phase, take 20μL of the ionic liquid phase, and directly carry out chromatographic analysis;

(3) Perform high-performance liquid chromatography analysis on the liquid sample solution or solid sample solution in step (2);

High performance liquid chromatography conditions: chromatographic column: Zorbax ODS, inner diameter 4.6mm×column length 150mm×particle size 5μm; column temperature: 30 ℃; UV detection wavelength: lemon yellow detection wavelength is 410 nm, sunset yellow detection wavelength is 480 nm; flow rate : 1.0mL/min; mobile phase: add 2mL acetic acid solution to 0.02mol/L ammonium acetate solution to prepare acetic acid-ammonium acetate buffer A with pH=4.5; B is methanol; % uniformly changed to 40%, mobile phase B uniformly changed from 40% to 98% within 5 to 10 minutes, and mobile phase B uniformly changed from 98% to 15% within 10 to 15 minutes; the sampling volume of the sample solution was 20 μL;

(4) According to the linear regression equation in step (1), calculate the contents of tartrazine and sunset yellow in the food respectively.

Compared with the prior art, the advantages of the present invention are mainly reflected in:

1. The method of the present invention uses an ionic liquid/salt two-phase extraction system as a pretreatment method for sample enrichment. This method has the advantages of short phase separation time, low viscosity, difficult emulsification during the extraction process, and recyclable ionic liquid.

2. The method of the present invention uses ionic liquid two-phase extraction-high performance liquid chromatography to measure tartrazine and sunset yellow in food. It is simple to operate, does not need to use a large amount of volatile solvents, has short separation time, and has good fluidity of the ionic liquid phase. It is miscible in water or methanol, and can be directly injected for chromatographic analysis. It can provide fast, simple, environmentally friendly and economical qualitative and quantitative determination of tartrazine and sunset yellow for quality inspection departments and production enterprises.

Detailed ways

The present invention will be further described by examples below, but the protection scope of the present invention is not limited thereto.

Embodiment 1, a kind of method for quickly detecting tartrazine and sunset yellow content in food, the steps of this method are as follows:

(1) Preparation of working curve: Prepare a series of tartrazine and sunset yellow standard solutions with a concentration of 0.05 μg/mL to 50.0 μg/mL by stepwise dilution method. Yellow standard solution; use high performance liquid chromatography to measure the peak areas of the above various concentrations of standard solutions, draw a standard curve, and obtain a linear regression equation. The results of the measurement are shown in Table 1.

Table 1 Method parameters

Analyte Extraction rate linear regression equation Linear range (μg/mL) Detection limit (μg/mL) The relative standard deviation sunset yellow 98.91% Y=707.74x(μg/mL)+56.03(480nm) 0.05-50.0 0.011 0.80 lemon yellow 99.24% Y=264.46x(μg/mL)+21.24(410nm) 0.05-50.0 0.002 0.31

(2) Sample processing: Food samples are liquid samples or solid samples, and the following methods are used for processing:

Liquid sample: Take 2.0mL suction-filtered sample into a 10mL centrifuge tube, add 0.3mL 1-butyl-3-methylimidazolium bromide, dilute to 4mL, add 3.1-4.0g K ₂ HPO ₄ , shake until completely Dissolve, centrifuge at 2000-3000r/min for 2-3min to form a two-phase aqueous phase, take 20 μL of the ionic liquid phase, and directly carry out chromatographic analysis;

Solid sample: Weigh 2.0-5.0g of solid food, dissolve it in 10-20mL of distilled water, take 3.0mL of the solution into a 10mL centrifuge tube with stopper, add 0.3mL of 1-butyl-3-methylimidazolium bromide, and dilute to 4mL, add 3.1-4.0g K ₂ HPO ₄ , shake until completely dissolved, centrifuge at 2000-3000r/min for 2-3min to form a two-water phase, take 20μL of the ionic liquid phase, and directly carry out chromatographic analysis; (3) (2) The liquid sample solution or solid sample solution in (2) is analyzed by high performance liquid chromatography;

(3) HPLC conditions: Chromatographic column: Zorbax ODS, inner diameter 4.6mm x column length 150mm x particle size 5μm; column temperature: 30 ℃; UV detection wavelength: lemon yellow detection wavelength is 410 nm, sunset yellow detection wavelength is 480nm;; flow rate: 1.0mL/min; mobile phase: add 2mL acetic acid solution to 0.02mol/L ammonium acetate solution to prepare acetic acid-ammonium acetate buffer A with pH=4.5; B is methanol; gradient: flow within 0～5min The phase B is uniformly changed from 15% to 40%, the mobile phase B is uniformly changed from 40% to 98% within 5 to 10 minutes, and the mobile phase B is uniformly changed from 98% to 15% within 10 to 15 minutes; the sampling volume of the sample solution is 20 μL ;

(4) According to the linear regression equation in step (1), calculate the contents of tartrazine and sunset yellow in the food respectively.

Embodiment 2, a kind of method for fast detection tartrazine content in large yellow croaker, the steps of this method are as follows:

1. Making the working curve: the method is the same as the method in Step 1 of Example 1.

2. Sample processing:

Wash the large yellow croaker body dyed with lemon yellow, add distilled water for ultrasonic extraction once, the extraction time is 10-30 minutes, and the extraction temperature is 30°C; after the extraction is completed, it is filtered through a 0.45 μm microporous membrane and directly injected into the sampling bottle. Promptly get large yellow croaker for testing solution;

Take 3.00ml large yellow croaker test solution in a 10mL stoppered centrifuge tube, add 0.3mL 1-butyl-3-methylimidazolium bromide, dilute to 4mL with distilled water, add 3.5g K ₂ HPO ₄ , shake until complete Dissolve, centrifuge at 2000-3000r/min for 2-3min to form a two-water phase, take 20 μL of the ionic liquid phase, and directly carry out chromatographic analysis; according to the working curve obtained in Table 1, calculate the tartrazine content in the dyed large yellow croaker extract They are 1.42μg/mL respectively.

Embodiment 3, a kind of method for quickly detecting tartrazine and sunset yellow content in orange-flavored carbonated drinks, the steps of this method are as follows:

1. Making the working curve: the method is the same as the method in Step 1 of Example 1.

2. Sample processing

Take 3.00mL of a certain brand of orange-flavored beverage in a 10mL stoppered centrifuge tube, heat ultrasonically for 10min to remove CO ₂ , add 0.3mL, 1-butyl-3-methylimidazolium bromide, dilute to the 4mL mark with distilled water, add 3.5g K ₂ HPO ₄ , shake until completely dissolved, centrifuge at 2000-3000r/min for 2-3min to form a two-water phase, take 20μL of the ionic liquid phase, and directly perform chromatographic analysis. According to the working curve obtained in Table 1, a certain brand The contents of tartrazine and sunset yellow in orange-flavored drinks were 1.46 μg/g and 17.68 μg/g, respectively.

Embodiment 4, a kind of method for rapidly detecting tartrazine and sunset yellow content in orange mint candy, the steps of this method are as follows:

1. Making the working curve: the method is the same as the method in Step 1 of Example 1.

2. Sample processing

Take 5.000g of mints, dissolve them in 10mL of distilled water, pipette 3.0mL of the solution into a 10mL stoppered centrifuge tube, add 0.3mL of 1-butyl-3-methylimidazolium bromide, dilute to the mark with distilled water, add 3.5 g K ₂ HPO ₄ , shake until completely dissolved, centrifuge at 2000-3000r/min for 2-3min to form a two-water phase, take 20μL of the ionic liquid phase, and directly perform chromatographic analysis, and calculate according to the working curve obtained in step 1 The contents of sunset yellow in mints were ug/g0.059μg/g, and sunset yellow was not detected.

Claims (1)

1. the lemon yellow in the fast detecting food and the method for sunset yellow content, it is characterized in that: the step of the method is as follows:

(1) making of working curve: adopt the stepwise dilution method that lemon yellow and the sunset yellow standard solution that concentration is 500mg/mL is mixed with lemon yellow and the sunset yellow standard solution of a series of solution concentrations in 0.05 μ g/mL～50.0 μ g/mL scopes; With the peak area of each concentration standard solution more than the high-performance liquid chromatogram determination, the drawing standard curve obtains equation of linear regression;

(2) sample preparation: food samples is fluid sample or solid sample, adopts respectively following methods to process:

Fluid sample: get sample that the 2.0mL suction filtration crosses in the 10mL centrifuge tube, add 0.3mL1-butyl-3-methylimidazole bromine salt, be settled to 4mL, add 3.6g K ₂HPO ₄, vibration is to fully dissolving, and the centrifugal 2～3min of 3000r/min forms aqueous two-phase, gets mutually 20 μ L of ionic liquid, directly carries out stratographic analysis;

Solid sample: take by weighing the 2.0-5.0g solid food, use the 10-20mL dissolved in distilled water, get this solution of 3.0mL to 10mL tool plug centrifuge tube, add 0.3mL1-butyl-3-methylimidazole bromine salt, be diluted to 4mL, add 3.4g K ₂HPO ₄; Vibration is to fully dissolving, and the centrifugal 2～3min of 3000r/min forms aqueous two-phase, gets mutually 20 μ L of ionic liquid, directly advances look capable analysis of spectrum;

(3) the fluid sample solution in the step (2) or solid sample solution are carried out efficient liquid phase chromatographic analysis;

High-efficient liquid phase chromatogram condition: chromatographic column: Zorbax ODS, internal diameter 4.6mm * column length 150mm * particle diameter 5 μ m; Column temperature: 30 ℃; Ultraviolet detects wavelength: it is 410 nm that lemon yellow detects wavelength, and it is 480nm that sunset yellow detects wavelength; Flow velocity: 1.0mL/min; Mobile phase: add the 2mL acetic acid solutions in the 0.02mol/L ammonium acetate solution and become the acetic acid of pH=4.5-ammonium acetate buffer A; B is methyl alcohol; Mobile phase B is by 15% even variation to 40% in gradient: 0～5min, and Mobile phase B is by 40% even variation to 98% in 5～10min, and Mobile phase B is by 98% even variation to 15% in 10～15min; The sample solution sample volume is 20 μ L;

(4) according to the equation of linear regression of step (1), calculate respectively the content of lemon yellow and sunset yellow in the food.