阅读说明：本技术 一种检测尼泊金十二酯的方法 (Method for detecting dodecyl paraben ) 是由 杨立彬 沈承琪 刘伟国 于 2019-10-17 设计创作，主要内容包括：本发明公开了一种检测尼泊金十二酯的方法,采用高效液相色谱法检测尼泊金十二酯或含有尼泊金十二酯的物质的含量,包括依次进行的以下步骤：1)配制标准液；2)检测标准液；3)绘制标准曲线；4)测定样品含量。本发明采用高效液相色谱仪检测尼泊金十二酯,采用外标法定量分析,从而确定样品中尼泊金十二酯的含量,精密度高、准确度高、重复性好,能够实现对样品的直接检测,大大减少了分析时间,简单易行、方便可靠,减少了浓缩提取等不必要的复杂操作。同时,本发明采用的色谱条件对样品的分离度,峰形,对称度等方面的影响较小,尼泊金十二酯样品均能实现良好的分离。(The invention discloses a method for detecting dodecyl paraben, which adopts high performance liquid chromatography to detect the content of dodecyl paraben or substances containing the dodecyl paraben and comprises the following steps of: 1) preparing a standard solution; 2) detecting the standard solution; 3) drawing a standard curve; 4) and (5) measuring the content of the sample. The method adopts a high performance liquid chromatograph to detect the dodecyl paraben, adopts an external standard method to carry out quantitative analysis, thereby determining the content of the dodecyl paraben in the sample, has high precision, high accuracy and good repeatability, can realize direct detection of the sample, greatly reduces the analysis time, is simple, easy, convenient and reliable, and reduces unnecessary complex operations such as concentration and extraction. Meanwhile, the chromatographic conditions adopted by the method have small influence on the aspects of the separation degree, the peak shape, the symmetry degree and the like of the sample, and the dodecyl paraben can be well separated.)

1. A method for detecting dodecyl paraben is characterized by comprising the following steps: detecting the content of the decamethylene paraben or a substance containing the decamethylene paraben by adopting a high performance liquid chromatography, which comprises the following steps in sequence:

1) preparing a standard solution: preparing at least two parts of lauryl paraben standard solution according to different concentrations for later use by taking the lauryl paraben standard product;

2) detecting a standard solution: respectively injecting all the dodecyl paraben standard solutions prepared in the step 1) into a high performance liquid chromatograph for detection to obtain chromatograms corresponding to all the dodecyl paraben standard solutions;

3) drawing a standard curve: taking the concentration of each part of the dodecyl paraben standard solution as an abscissa, and taking the peak area of a dodecyl paraben chromatographic peak in a corresponding chromatogram as an ordinate to draw a standard curve to obtain a standard curve regression equation;

4) and (3) determining the content of the sample: preparing a sample solution by taking a sample containing the dodecyl paraben, injecting the sample solution into a high performance liquid chromatograph to detect the sample solution to obtain a sample chromatogram, substituting the peak area of the dodecyl paraben chromatographic peak in the sample chromatogram into the standard curve regression equation in the step 3), and obtaining the content of the dodecyl paraben in the sample according to an external standard method.

2. The method for detecting dodecyl paraben according to claim 1, wherein the method comprises the following steps: the high performance liquid chromatograph adopts a C18 reverse chromatographic column and takes 10-100% methanol water solution by volume percentage as a mobile phase.

3. The method for detecting dodecyl paraben according to claim 2, wherein the method comprises the following steps: the flow speed of the mobile phase is 0.6-1.0 mL/min.

4. The method for detecting dodecyl paraben according to claim 3, wherein the method comprises the following steps: the column temperature of the C18 reverse phase chromatographic column is 20-45 ℃.

5. The method for detecting dodecyl paraben according to claim 4, wherein the method comprises the following steps: detecting the dodecyl p-hydroxybenzoate standard solution injected into the high performance liquid chromatograph in the step 2) and the sample solution injected into the high performance liquid chromatograph in the step 4) by using a variable wavelength ultraviolet absorption detector.

6. The method for detecting dodecyl paraben according to claim 5, wherein the method comprises the following steps: the detection wavelength of the variable wavelength ultraviolet absorption detector is 245-265 nm.

7. The method for detecting dodecyl paraben according to claim 6, wherein the method comprises the following steps: the sample injection amount of the dodecyl paraben standard solution and the sample solution is 2-20 mu L.

8. The method for detecting dodecyl paraben according to any one of claims 1-7, wherein: the solvent used for preparing the lauryl paraben standard solution in the step 1) is methanol.

9. The method for detecting dodecyl paraben according to any one of claims 1-7, wherein: and 4) preparing the sample solution in the step 4), namely weighing the sample, putting the sample into a volumetric flask, adding methanol, ultrasonically treating to dissolve the dodecyl paraben in the sample, and diluting the methanol to a constant volume.

10. The method for detecting dodecyl paraben according to claim 9, wherein: and filtering the sample solution by using a filter membrane of 0.22 mu m, and then injecting the sample solution into a high performance liquid chromatograph.

Technical Field

The invention belongs to the technical field of analysis, and particularly relates to a method for detecting dodecyl paraben.

Background

The nipagin ester is an organic chemical mildew-proof preservative, is synthesized by a chemical method, and is a safe and efficient preservative adopted internationally. Nipagin ester (p-hydroxybenzoate ester, molecular formula p-HOC)₆H₄CO₂R) its antibacterial activity was reported as early as the 20 th early century; in 1923, parabens were suggested as preservatives for food and pharmaceutical products; in 1932, the use of paraben as preservatives has been approved for food products and has been known for over eighty years. In 1984, nipagin ester exists in 13200 formulations of various cosmetics, and is also applied to preservation of medicines and cosmetics. It is the earliest approved synthetic preservative.

The nipagin ester is a low-toxicity high-efficiency preservative which is widely used in many aspects of food, beverage, cosmetics, medicine, feed and the like, and the annual demand of the nipagin ester in the whole country of the cosmetics industry reaches more than 50 t.

At present, the products of the parabens produced and applied in China are low-carbon chain esters, such as methyl paraben, ethyl paraben, propyl paraben and butyl paraben, and the research on long-chain paraben is less, particularly the parabens with the number of carbon atoms on an R group more than 12. Some research groups begin the research work of long-chain parabens, and make certain progress, and the emphasis is on heptylparaben and octylparaben, but the industrialization of the long-chain parabens is not realized. The reported results show that the C11 and C12 alcohol esters in the nipagin ester have very good antibacterial activity, and have very good development prospects when being used as food preservatives and feed additives.

According to the literature reports, the detection method of the nipagin dodecanoate is mainly a chemical analysis method, a potentiometric titration method, a liquid chromatography tandem mass spectrometry method and the like. The chemical analysis method and the potentiometric titration method are simple, but have long time consumption and large human error, and the liquid phase tandem mass spectrometer has high price and is rarely equipped in a common laboratory. In addition, the literature reports that the detection method of the decamethylene paraben comprises the steps of concentrating, extracting a sample and then detecting by using a high performance liquid chromatograph, and the method is time-consuming and expensive.

Therefore, the research on a simple and easy-to-operate method for detecting the dodecyl paraben is a problem which needs to be solved urgently at present.

Disclosure of Invention

The invention aims to provide a method for detecting dodecyl paraben, which solves the problems of complex operation and high price of the dodecyl paraben detection method.

In order to achieve the purpose, the invention adopts the technical scheme that:

a method for detecting lauryl paraben adopts high performance liquid chromatography to detect the content of lauryl paraben or substances containing lauryl paraben, and comprises the following steps of:

1) preparing a standard solution: preparing a plurality of parts of dodecyl paraben standard solutions according to different concentrations for later use by taking the dodecyl paraben standard product;

2) detecting a standard solution: respectively injecting all the dodecyl paraben standard solutions prepared in the step 1) into a high performance liquid chromatograph for detection to obtain chromatograms corresponding to all the dodecyl paraben standard solutions;

3) drawing a standard curve: taking the concentration of each part of the dodecyl paraben standard solution as an abscissa, and taking the peak area of a dodecyl paraben chromatographic peak in a corresponding chromatogram as an ordinate to draw a standard curve to obtain a standard curve regression equation;

4) and (3) determining the content of the sample: preparing a sample solution from a sample containing dodecyl paraben, injecting the sample solution into a high performance liquid chromatograph to detect the sample solution to obtain a sample chromatogram, and substituting the peak area of the dodecyl paraben chromatographic peak in the sample chromatogram into the standard curve regression equation in the step 3) to obtain the content of dodecyl paraben in the sample.

The technical scheme of the invention is further improved as follows: the high performance liquid chromatograph adopts a C18 reverse chromatographic column and takes 10-100% methanol water solution by volume percentage as a mobile phase.

The technical scheme of the invention is further improved as follows: the flow speed of the mobile phase is 0.6-1.0 mL/min.

The technical scheme of the invention is further improved as follows: the column temperature of the C18 reverse phase chromatographic column is 20-45 ℃.

The technical scheme of the invention is further improved as follows: detecting the dodecyl p-hydroxybenzoate standard solution injected into the high performance liquid chromatograph in the step 2) and the sample solution injected into the high performance liquid chromatograph in the step 4) by using a variable wavelength ultraviolet absorption detector.

The technical scheme of the invention is further improved as follows: the detection wavelength of the variable wavelength ultraviolet absorption detector is 245-265 nm.

The technical scheme of the invention is further improved as follows: the sample injection amount of the dodecyl paraben standard solution and the sample solution is 2-20 mu L.

The technical scheme of the invention is further improved as follows: the solvent used for preparing the lauryl paraben standard solution in the step 1) is methanol.

The technical scheme of the invention is further improved as follows: and 4) preparing the sample solution in the step 4), namely weighing the sample, putting the sample into a volumetric flask, adding methanol, ultrasonically treating to dissolve the dodecyl paraben in the sample, and diluting the methanol to a constant volume.

The technical scheme of the invention is further improved as follows: and filtering the sample solution by using a filter membrane of 0.22 mu m, and then injecting the sample solution into a high performance liquid chromatograph.

Compared with the prior art, the invention has the following progress: the method adopts a high performance liquid chromatograph to detect the dodecyl paraben, adopts an external standard method to carry out quantitative analysis, thereby determining the content of the dodecyl paraben in the sample, has high precision, high accuracy and good repeatability, can realize direct detection of the sample, greatly reduces the analysis time, is simple, easy, convenient and reliable, and reduces unnecessary complex operations such as concentration and extraction.

Furthermore, the invention adopts a C18 reverse chromatographic column and a methanol aqueous solution flowing phase to separate better.

Furthermore, the flow velocity of the mobile phase is 0.6-1.0mL/min, and in such a flow velocity range, the sample injection is carried out under the completely same conditions, so that the influence on the aspects of the separation degree, the peak shape, the symmetry degree and the like of the sample is small, the separation time is short, and the excellent separation of the dodecyl paraben sample can be realized.

Furthermore, the temperature of the C18 reverse chromatographic column is 20-45 ℃, and in such a temperature range, the sample injection is carried out under the same conditions, so that the influence on the aspects of the separation degree, the peak shape, the symmetry degree and the like of the sample is small, and the excellent separation of the dodecyl paraben sample can be realized.

Meanwhile, the invention adopts a variable wavelength ultraviolet absorption detector to detect the sample solution of the dodecyl paraben standard solution, samples are injected under the completely same conditions at the detection wavelength of 245-.

Drawings

FIG. 1 is a chromatogram of a dodecyl paraben standard solution (1000 ppm);

FIG. 2 is a chromatogram of the sample solution in example 1;

FIG. 3 is a graph of a regression equation of a standard curve in example 1;

FIG. 4 is a chromatogram of the sample solution in example 2;

FIG. 5 is a graph of a regression equation of a standard curve in example 2;

FIG. 6 is a chromatogram of the sample solution in example 3;

FIG. 7 is a graph of a regression equation of a standard curve in example 3;

FIG. 8 is a chromatogram of a feed sample solution in example 4;

FIG. 9 is a graph of a standard curve regression equation in example 4;

FIG. 10 is a chromatogram of the sample solution in example 5;

FIG. 11 is a graph of a regression equation of a standard curve in example 5;

FIG. 12 is a chromatogram of a feed sample solution of example 6;

FIG. 13 is a graph of a regression equation of a standard curve in example 6;

FIG. 14 is a chromatogram of the sample solution of example 7;

FIG. 15 is a graph of a regression equation of a standard curve in example 7;

FIG. 16 is a chromatogram of a feed sample solution of example 8;

FIG. 17 is a graph of a standard curve regression equation in example 8.

Detailed Description

The present invention is further illustrated in detail by the following specific examples, which are to be construed as merely illustrative, and not limitative of the remainder of the disclosure.