A method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in various solvents

Abstract

The present application relates to the technical field of analytical chemistry, in particular to a method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in multiple solvents, comprising the following steps: S1. preparation of standard solution, S2. drawing of ultraviolet absorption spectrum, S3. selection of optimal wavelength, S4. drawing of standard curve, preparing standard solutions with different concentrations of two-component triazine ultraviolet absorbers, drawing a standard curve according to the first derivative value of the absorbance at the optimal wavelength selected above, S5. determination of sample content, taking a mixed triazine ultraviolet absorber sample for determination, and calculating the content according to the standard curve. The present application uses the first derivative spectrophotometry to simultaneously and rapidly determine the content of two-component triazine ultraviolet absorbers after mixing in multiple solvents, eliminates the interference of another component to be measured, has high accuracy, does not need complex pretreatment and separation process, is easy and fast to operate, and has low technical and equipment basic requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of analytical chemistry, in particular to a method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in multiple solvents. BACKGROUND

[0002] Organic ultraviolet absorbers are widely added to personal protective products to protect human skin from ultraviolet radiation. With the large-scale use of personal protective products, a large amount of organic ultraviolet absorbers are discharged into the environment. In recent years, triazine ultraviolet absorbers have been widely used due to their excellent characteristics such as broad-spectrum ultraviolet absorption capacity, inherent light stability, etc. However, due to their large octanol-water partition coefficient and large molecular weight, they can accumulate in the body. For example, as described in the literature Environ. Sci. Technol. Lett. 2022, 9, 844-850, the presence of triazine ultraviolet absorbers was detected in human breast milk. The currently reported detection methods of triazine ultraviolet absorbers mainly include HPLC, GC, ICPMS, etc.

[0003] In these methods, the sample needs to be filtered multiple times during the pretreatment process, and after filtration, a complex solid-phase extraction process is used, and finally the sample is introduced into HPLC, GC, etc. for quantitative analysis. A large amount of high-purity organic solvent is consumed in the process, and high-precision instruments are also difficult to carry, which cannot achieve real-time monitoring and analysis. For example, in the article Water Air Soil Pollut, 2019, 230:172, after the sample is filtered, it is acidified with high-purity formic acid, and then introduced into a solid-phase extraction column, extracted with methanol and dichloromethane, and detected by LC-MS / MS. The mobile phase is composed of water (A) and methanol (B), both of which are acidified with 0.1% formic acid and use gradient elution. The process is complicated, consumes a large amount of organic solvent, and requires high technical skills for the operator, which cannot achieve real-time detection.

[0004] Currently, there is no reported method for rapidly, conveniently and accurately detecting multi-component triazine ultraviolet absorbers. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application aims to provide a method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in multiple solvents. The method uses first-order derivative spectrophotometry to overcome the problem of overlapping and interference of the largest absorption peak in the traditional ultraviolet spectrophotometry due to the similar chemical properties of the two components to be measured. The method can simultaneously and quantitatively determine the content of two-component triazine ultraviolet absorbers in multiple solvents, and has the advantages of convenience, accuracy and high sensitivity.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] A method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in various solvents, comprising the following steps:

[0008] S1. Preparation of standard solutions: Prepare standard solutions containing a certain concentration of single-component bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone (ethylhexyl triazone) and diethylhexyl butamido triazone (diethylhexyl butamido triazone), and standard solutions containing two-component bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone mixture or bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone mixture, respectively.

[0009] S2. Drawing of ultraviolet absorption spectrum: Scan the standard solutions containing single-component bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone and diethylhexyl butamido triazone, and the standard solutions containing two-component bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone mixture, bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone mixture in the wavelength range of 200-400 nm with the blank solvent as the reference solution to obtain the ultraviolet absorption spectrum.

[0010] S3. Selection of optimal wavelength: After converting the ultraviolet absorption spectrum into the first derivative spectrum, analyze and determine the optimal absorption wavelength of each component triazine ultraviolet absorber, at which the first derivative value of absorbance is not interfered by other components.

[0011] S4. Drawing of standard curve: Prepare standard solutions containing two-component triazine ultraviolet absorbers with different concentrations, and draw the standard curve according to the first derivative value of absorbance at the optimal wavelength selected above.

[0012] S5. Determination of sample content: Determine the sample content of mixed triazine ultraviolet absorbers, and calculate the content according to the standard curve.

[0013] As a preferred technical solution, the triazine ultraviolet absorber is bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone and diethylhexyl butamido triazone, etc. triaryl-substituted triazine ultraviolet absorbers. (The chemical structure information of the three compounds is shown in Table 1).

[0014] As a preferred technical solution, the method "simultaneously determining the ultraviolet spectrum of triazine ultraviolet absorbers by spectrophotometry" specifically includes: adding triazine ultraviolet absorber standard to an organic solvent to prepare a standard stock solution, and then diluting the standard stock solution to prepare standard solutions with different concentrations.

[0015] As a preferred technical solution, the solvent for preparing the standard solution can be a medium or low polarity organic solvent, including but not limited to chloroform, dichloromethane, ethyl acetate, diethyl ether, etc., preferably chloroform and ethyl acetate, and further preferably ethyl acetate.

[0016] As a preferred technical solution, the solvent for preparing the standard solution can be a polar organic solvent, i.e. a solvent that can be miscible with water in any proportion, including but not limited to dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile, dioxane, n-propanol, isopropanol, tetrahydrofuran, etc., preferably dioxane and isopropanol, and further preferably isopropanol.

[0017] As a preferred technical solution, the solvent for preparing the standard solution can be a mixed solvent of an organic solvent and water, including but not limited to dimethyl sulfoxide / water, N,N-dimethylformamide / water, acetonitrile / water, dioxane / water, tetrahydrofuran / water, n-propanol / water, isopropanol / water, etc., preferably dioxane / water, isopropanol / water, n-propanol / water, dimethyl sulfoxide / water; and further preferably isopropanol / water.

[0018] As a preferred technical solution, the volume ratio of the mixed solution of the organic solvent and water is 1-99:99-1.

[0019] As a preferred technical solution, the method of "drawing of ultraviolet absorption spectrum and selection of optimal wavelength" comprises the following steps:

[0020] Using an organic solvent or a mixed blank solution of an organic solvent and water as a reference solution, different concentrations of standard solutions containing single-component and two-component mixtures of bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone and diethylhexyl butamido triazone;

[0021] The ultraviolet absorption spectrum in the wavelength range of 200-400 nm is determined, and then a first derivative spectrum is obtained by conversion.

[0022] As a preferred technical solution, the simultaneous determination of bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone comprises:

[0023] (i) In a medium or low polarity organic solvent, such as in chloroform and ethyl acetate, the first derivative absorption spectrum of the binary system of bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone is selected at about 319 nm to determine ethylhexyl triazone and at about 369 nm to determine bis-ethylhexyloxyphenol methoxyphenyl triazine, respectively;

[0024] (ii) in polar organic solvents, such as in isopropanol and dioxane, in the first derivative absorption spectrum of the binary system of bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone, ethylhexyl triazone is determined at about 323 nm, and bis-ethylhexyloxyphenol methoxyphenyl triazine is determined at about 370 nm;

[0025] (iii) in mixed solvents, such as organic solvent and water mixed solvents, in the first derivative absorption spectrum of the binary system of bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone in isopropanol / water solvent and dimethyl sulfoxide / water solvent, ethylhexyl triazone is determined at about 328 nm, and bis-ethylhexyloxyphenol methoxyphenyl triazine is determined at about 377 nm.

[0026] Simultaneous determination of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, comprising:

[0027] (i) in medium or low polarity organic solvents, such as in chloroform and ethyl acetate, in the first derivative absorption spectrum of the binary system of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, diethylhexyl butamido triazone is determined at about 318 nm, and bis-ethylhexyloxyphenol methoxyphenyl triazine is determined at 369 nm;

[0028] (ii) in polar organic solvents, such as in isopropanol and dioxane, in the first derivative absorption spectrum of the binary system of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, diethylhexyl butamido triazone is determined at about 322 nm, and bis-ethylhexyloxyphenol methoxyphenyl triazine is determined at about 370 nm;

[0029] (iii) in mixed solvents, such as organic solvent and water mixed solvents, in the first derivative absorption spectrum of the binary system of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone in isopropanol / water solvent and dimethyl sulfoxide / water solvent, diethylhexyl butamido triazone is determined at about 326 nm, and bis-ethylhexyloxyphenol methoxyphenyl triazine is determined at about 373 nm.

[0030] Compared with the prior art, the method has the advantages that:

[0031] The application discloses a method for directly determining the content of triazine ultraviolet absorbers, and the method comprises the following steps of preparing a standard solution, selecting an optimal wavelength in a first derivative ultraviolet spectrum, and establishing a standard curve.

[0032] The application utilizes the first derivative ultraviolet spectrophotometry to determine the method of the dual-component triazine ultraviolet absorber, selects the specific wavelength in different solvents for quantification, eliminates the interference of the coexisting components, improves the accuracy and sensitivity of the determination results, and the sample does not need special treatment, and the operation is simple and easy to implement.

[0033] The application adopts the ultraviolet derivative spectrophotometry to detect the triazine ultraviolet absorber, has high accuracy, can quickly determine the content of the mixed dual-component triazine ultraviolet absorber, does not need complex pretreatment and separation process, and is convenient, fast, and low in technical and equipment basic requirements. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0035] Figure 1 The names and chemical structure diagrams of the three triazine ultraviolet absorbers used in the application are shown in the following table:

[0036] Figure 2 The recovery experiment result diagram of the first derivative spectrophotometry for simultaneously determining the dual-ethylhexyloxyphenol methoxyphenyl triazine and the diethylhexyl butylamidyl triazone in the application is shown in the following table:

[0037] Figure 3 The recovery experiment result diagram of the first derivative spectrophotometry for simultaneously determining the dual-ethylhexyloxyphenol methoxyphenyl triazine and the ethylhexyl triazone in the application is shown in the following table:

[0038] Figure 4 The ultraviolet absorption spectrum diagrams of the single component and the mixed component of the dual-ethylhexyloxyphenol methoxyphenyl triazine and the diethylhexyl butylamidyl triazone in the ethyl acetate solvent in the embodiment 1 (a) of the application, the ultraviolet absorption spectrum diagrams of the single component and the mixed component of the dual-ethylhexyloxyphenol methoxyphenyl triazine and the ethylhexyl triazone in the ethyl acetate solvent in the embodiment 1 (b) of the application, the first derivative spectrum diagrams of the single component and the mixed component of the dual-ethylhexyloxyphenol methoxyphenyl triazine and the diethylhexyl butylamidyl triazone in the ethyl acetate solvent in the embodiment 1 (c) of the application, and the first derivative spectrum diagrams of the single component and the mixed component of the dual-ethylhexyloxyphenol methoxyphenyl triazine and the ethylhexyl triazone in the ethyl acetate solvent in the embodiment 1 (d) of the application are shown in the following table:

[0039] Figure 5(a) UV absorption spectra of the single component and mixed components of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butanamide triazone in isopropyl alcohol solvent, (b) UV absorption spectra of the single component and mixed components of bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone in isopropyl alcohol solvent, (c) first derivative spectra of the single component and mixed components of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butanamide triazone in isopropyl alcohol solvent, (d) first derivative spectra of the single component and mixed components of bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone in isopropyl alcohol solvent;

[0040] Figure 6 (a) UV absorption spectra of the single component and mixed components of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butanamide triazone in isopropyl alcohol / water mixed solvent, (b) UV absorption spectra of the single component and mixed components of bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone in isopropyl alcohol / water mixed solvent, (c) first derivative spectra of the single component and mixed components of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butanamide triazone in isopropyl alcohol / water mixed solvent, (d) first derivative spectra of the single component and mixed components of bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone in isopropyl alcohol / water mixed solvent;

[0041] Figure 7 (a) UV absorption spectra of the single component and mixed components of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butanamide triazone in isopropyl alcohol / water mixed solvent, (b) UV absorption spectra of the single component and mixed components of bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone in isopropyl alcohol / water mixed solvent, (c) first derivative spectra of the single component and mixed components of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butanamide triazone in isopropyl alcohol / water mixed solvent, (d) first derivative spectra of the single component and mixed components of bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone in isopropyl alcohol / water mixed solvent; DETAILED DESCRIPTION

[0042] The following disclosure provides many different embodiments or examples for implementing different applications of the present application. For simplicity of the present disclosure, the steps and settings of the particular examples are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application can repeatedly refer to reference numerals and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate a relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific solvents or materials, but those of ordinary skill in the art can realize the application of other solvents and / or the use of other materials.

[0043] The above method is applied in any one or more of the following practical cases:

[0044] (1) Quality control of triazine ultraviolet absorbers.

[0045] (2) Identification of triazine ultraviolet absorbers.

[0046] (3) Determination of the content of triazine ultraviolet absorbers in environmental matrices.

[0047] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with the drawings in the specification and specific embodiments.

[0048] According to the drawings Figures 1-7 The embodiment of the present application provides a method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in various solvents.

[0049] Example 1: Selection of determination solvent

[0050] Through the trial of different types of organic solvents, the most representative one in the medium polarity solvent is given in Example 1.

[0051] A first derivative spectrophotometric method for determining two-component triazine ultraviolet absorbers in ethyl acetate solvent includes the following steps:

[0052] (1): Using ethyl acetate as the solvent, prepare three standard stock solutions of bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone and diethylhexyl butanamide triazone with a concentration of 1 mg / mL, respectively.

[0053] (2): Dilute the 1 mg / mL standard stock solution, and obtain single-component standard solutions of bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone and diethylhexyl butanamide triazone with a concentration of 5 mg / L, respectively.

[0054] (3): Dilute the 1 mg / mL standard stock solution, and make up to volume, to obtain 5 mg / L of a mixture of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone.

[0055] (4): Measure the UV absorption spectra of the triazine monocomponents and two kinds of two-component mixture standard solutions containing bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, and bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone, respectively, at wavelengths of 200-400 nm, with ethyl acetate as the reference solution. (See Figures 2a, 2b, 2c and 2d) Figure 4 a and b).

[0056] (5): Convert the UV absorption spectra of the above standard solutions in the wavelength range of 200-400 nm to first derivative UV spectra (see Figures 3a, 3b, 3c and 3d) Figure 4 c and d).

[0057] (6): Take 318 nm and 319 nm as the quantitative wavelengths of diethylhexyl butamido triazone and ethylhexyl triazone, respectively, at which the first derivative value of bis-ethylhexyloxyphenol methoxyphenyl triazine is nearly zero, and the first derivative values of the mixture components bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, and bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone, respectively, coincide with the first derivative values of diethylhexyl butamido triazone and ethylhexyl triazone at these wavelengths; take 369 nm as the quantitative wavelength of bis-ethylhexyloxyphenol methoxyphenyl triazine, at which the first derivative values of diethylhexyl butamido triazone and ethylhexyl triazone are nearly zero, and the first derivative values of the mixture components bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, and bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone, respectively, coincide with the first derivative value of bis-ethylhexyloxyphenol methoxyphenyl triazine at this wavelength.

[0058] A first derivative spectrophotometric detection method for two-component triazine ultraviolet absorbers in isopropanol solvent, comprising the following steps:

[0059] (1): Prepare three standard stock solutions of bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone and diethylhexyl butamido triazone, respectively, with a concentration of 1 mg / mL, using isopropanol as the solvent.

[0060] (2): Dilute the 1 mg / mL standard stock solution, and make up to volume, to obtain 5 mg / L of a single-component standard solution of bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone, and diethylhexyl butamido triazone, respectively.

[0061] (3): Dilute the 1 mg / mL standard stock solution to obtain 5 mg / L of a mixture of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone standard solutions.

[0062] (4): Determine the UV absorption spectra of the triazine monomer and the two two-component mixtures of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, and bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone, respectively, in the wavelength range of 200-400 nm, using isopropanol as the reference solution. Figure 5 a and b).

[0063] (5): Convert the UV absorption spectra of the above standard solutions in the wavelength range of 200-400 nm to first derivative UV spectra. Figure 5 c and d).

[0064] (6): Take 322 nm and 323 nm as the quantitative wavelengths for diethylhexyl butamido triazone and ethylhexyl triazone, respectively, at which the first derivative value of bis-ethylhexyloxyphenol methoxyphenyl triazine is nearly zero, and the first derivative values of the mixtures of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, and bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone, respectively, coincide with the first derivative values of diethylhexyl butamido triazone and ethylhexyl triazone at these wavelengths; take 370 nm as the quantitative wavelength for bis-ethylhexyloxyphenol methoxyphenyl triazine, at which the first derivative values of diethylhexyl butamido triazone and ethylhexyl triazone are nearly zero, and the first derivative values of the mixtures of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, and bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone, respectively, coincide with the first derivative value of bis-ethylhexyloxyphenol methoxyphenyl triazine at this wavelength.

[0065] Example 2: Determination in a mixed water / polar organic solvent

[0066] This method can achieve good results in pure organic solvents, but in real environments, triazine UV absorbers mainly exist in water environments. Can this method be extended to real water environment detection? In view of this, we tried to mix a small amount of organic solvent with water.

[0067] A first derivative spectrophotometric method for determining two-component triazine UV absorbers in a mixed isopropanol / water (v:v, 8%) mixed solvent, comprising the following steps:

[0068] (1): Isopropyl alcohol as solvent, respectively, prepared with a concentration of 1 mg / mL of bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone and diethylhexyl butamido triazone three standard stock solution.

[0069] (2): 1 mg / mL of the standard stock solution dilution, isopropyl alcohol / water (v:v, 8%) mixed solvent constant volume, respectively, obtained 5 mg / L of bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone, and diethylhexyl butamido triazone single component standard solution.

[0070] (3): 1 mg / mL of the standard stock solution dilution, isopropyl alcohol / water (v:v, 8%) solvent constant volume, respectively, obtained 5 mg / L of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone mixture, bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone mixed standard solution.

[0071] (4): With solvent containing isopropyl alcohol 8% (volume ratio) of deionized water solution as reference solution, at 200-400 nm wavelength determination of triazine single component and two kinds of respectively containing bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone two component mixed standard solution of ultraviolet absorption spectrum. (See Figure 6 a and b).

[0072] (5): The above standard solution in the wavelength range of 200-400 nm ultraviolet absorption spectrum conversion to get the first derivative ultraviolet spectrum (See Figure 6 c and d).

[0073] (6): Respectively, take 326, 328 nm as diethylhexyl butamido triazone, ethylhexyl triazone quantitative wavelength, bis-ethylhexyloxyphenol methoxyphenyl triazine at this point the first derivative value is nearly zero, and mixed components bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone first derivative value respectively with diethylhexyl butamido triazone, ethylhexyl triazone at this point the first derivative value coincides; take 373, 377 nm as bis-ethylhexyloxyphenol methoxyphenyl triazine quantitative wavelength, diethylhexyl butamido triazone and ethylhexyl triazone at this point the first derivative value is nearly zero, and bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone, bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone first derivative value with bis-ethylhexyloxyphenol methoxyphenyl triazine at this point the first derivative value coincides.

[0074] Example 3 Method in the actual application instance: in the determination of diethylhexyl butamido triazone in the carbonic acid diethylhexyl ester sunscreen

[0075] The triazine UV absorbers have high lipid-water partition coefficient, in order to make them uniformly dispersed in sunscreen, often with the help of oil to solubilize them, dicaprylyl carbonate is a common solubilizer in sunscreen. To verify the practicability and accuracy of the method, dicaprylyl carbonate was used as a solvent to detect the method.

[0076] (1): dicaprylyl carbonate as solvent, respectively, preparation of concentration of 1 mg / mL of bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone and diethylhexyl butanamide triazone three kinds of standard stock solution.

[0077] (2): 1 mg / mL of standard stock solution dilution, dicaprylyl carbonate constant volume, respectively, to obtain 5 mg / L of bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone, and diethylhexyl butanamide triazone single component standard solution.

[0078] (3): 1 mg / mL of standard stock solution dilution, dicaprylyl carbonate constant volume, respectively, to obtain 5 mg / L of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butanamide triazone mixture, bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone mixed standard solution.

[0079] (4): with solvent dicaprylyl carbonate as reference solution, in 200-400 nm wavelength determination of triazine single component and two kinds of respectively containing bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butanamide triazone, bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone two component mixed standard solution of UV absorption spectrum.

[0080] (5): the above standard solution in 200-400 nm wavelength range of UV absorption spectrum conversion to get the first derivative UV spectrum (see Figure 7 a and c).

[0081] (6): Take 316, 318 nm as the quantitative wavelength of diethylhexyl butyrylaminotriazone, ethylhexyl triazone, respectively, the first derivative value of bis-ethylhexyloxyphenol methoxyphenyl triazine is nearly zero at this point, and the first derivative values of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butyrylaminotriazone, bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone are respectively coincided with the first derivative values of diethylhexyl butyrylaminotriazone and ethylhexyl triazone at this point; take 372 nm as the quantitative wavelength of bis-ethylhexyloxyphenol methoxyphenyl triazine, the first derivative values of diethylhexyl butyrylaminotriazone and ethylhexyl triazone are nearly zero at this point, and the first derivative values of bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butyrylaminotriazone, bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone are coincided with the first derivative value of bis-ethylhexyloxyphenol methoxyphenyl triazine at this point.

[0082] (7): First derivative spectrum of 1-9 mg / L binary mixture and standard curve drawing: take the first derivative values of absorbance at 316, 318 and 372 nm to draw two standard curves (see Figure 7 b and d).

[0083] (8): Spiked recovery experiment: take the concentration in the detection range of the standard curve, i.e. 2, 4, 6, 8 mg / L, as the spiked concentration, and perform the recovery rate experiment. Use formula 1 and formula 2 to calculate the recovery rate and relative error between the measured concentration and the spiked concentration, respectively, and the results are shown in Figure 2 and Figure 3 .

[0084] As shown in Figure 2 , using first derivative spectrophotometry to detect bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butyrylaminotriazone in the binary mixture, the recovery rate of bis-ethylhexyloxyphenol methoxyphenyl triazine is between 94.9% and 110.0%, with an average recovery rate of 101.8%, and the recovery rate of diethylhexyl butyrylaminotriazone is between 100.1% and 106.6%, with an average recovery rate of 103.8%.

[0085] As shown in Figure 3As shown, using the first derivative spectrophotometry to detect the binary mixture of bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone, the recovery rate of bis-ethylhexyloxyphenol methoxyphenyl triazine is between 97.4% and 110.4%, the average recovery rate is 103.4%, the recovery rate of ethylhexyl triazone is between 98.3% and 112.8%, and the average recovery rate is 103.5%. Based on the above recovery rate and relative error evaluation, the method has a higher recovery rate and a lower error, which proves the effectiveness of the method, and therefore the first derivative spectrophotometry used in the application can be used to accurately detect the content of two triazine ultraviolet absorbers in the binary mixture.

[0086] The method of the application can simultaneously and rapidly determine the content of two-component triazine ultraviolet absorbers in various solvents. In use, by measuring the first derivative value of one component having a zero value or a value close to zero at a wavelength, the first derivative value of the other component in the region is not affected by the concentration of other components, thereby overcoming the problem of overlapping absorption peaks in the initial absorption spectrum due to similar absorption bands of the two substances.

[0087] The basic principles, main features and advantages of the application are described above in combination with specific embodiments. It should be understood by those skilled in the art that the application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only preferred examples of the application and are not intended to limit the application. Without departing from the spirit and scope of the application, various changes and improvements can be made to the application, and these changes and improvements all fall within the scope of the claimed application. The scope of protection of the application is defined by the appended claims and their equivalents.

Claims

1. A method for simultaneously and rapidly determining the content of a two-component triazine-based ultraviolet absorber in a plurality of solvents, characterized by, The method comprises the following steps: S1. Preparation of standard solution: prepare standard solutions containing single-component bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone and diethylhexyl butamido triazone and double-component bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone mixture or bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone mixture respectively; S2. Drawing of ultraviolet absorption spectrum: scan the standard solutions containing single-component bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone and diethylhexyl butamido triazone and double-component bis-ethylhexyloxyphenol methoxyphenyl triazine and ethylhexyl triazone mixture or bis-ethylhexyloxyphenol methoxyphenyl triazine and diethylhexyl butamido triazone mixture in the wavelength range of 200-400 nm with the blank solvent as reference solution to obtain the ultraviolet absorption spectrum; S3. Selection of optimal wavelength: after converting the ultraviolet absorption spectrum into first derivative spectrum, analyze and determine the optimal absorption wavelength of each single-component triazine ultraviolet absorber, at which the first derivative value of absorbance is not interfered by other components; S4. Drawing of standard curve: prepare standard solutions containing double-component triazine ultraviolet absorber with different concentrations, and draw the standard curve according to the first derivative value of absorbance at the optimal wavelength selected above; S5. Determination of sample content: determine the mixed triazine ultraviolet absorber sample, and calculate the content according to the standard curve.

2. The method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in various solvents according to claim 1, characterized in that: The triazine ultraviolet absorber is bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone and diethylhexyl butamido triazone and triaryl-substituted triazine ultraviolet absorber.

3. The method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in various solvents according to claim 1, characterized in that: The specific method of "preparation of standard solution" comprises: preparing standard stock solutions containing single-component bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone and diethylhexyl butamido triazone with certain concentrations in different solvents respectively, and diluting the standard stock solutions to constant volume to obtain a series of standard solutions with different concentrations.

4. The method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in various solvents according to claim 3, characterized in that: The solvent used for preparing the standard solution can be a medium or low polarity organic solvent, specifically chloroform and ethyl acetate.

5. The method for simultaneously and rapidly determining the contents of two-component triazine ultraviolet absorbers in various solvents according to claim 3, characterized in that: The solvent used for preparing the standard solution can be a polar organic solvent, i.e. a solvent capable of being miscible with water in any proportion, specifically dioxane and isopropanol.

6. The method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in various solvents according to claim 3, characterized in that: The solvent used for preparing the standard solution can also be an organic solvent / water mixed solvent, specifically dioxane / water, isopropanol / water, n-propanol / water, dimethyl sulfoxide / water or isopropanol / water.

7. The method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in various solvents according to claim 6, characterized in that: The volume ratio of the organic solvent and water mixed solution is 1-99:99-1.

8. The method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in various solvents according to claim 1, characterized in that: The method "drawing of ultraviolet absorption spectrum" comprises the following steps: Determine the ultraviolet absorption spectrum of the standard solutions containing single-component bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazone and diethylhexyl butamido triazone and double-component mixture at 200-400 nm wavelength with the blank solvent of different standard solutions as reference solution, and then convert to obtain the first derivative spectrum.

9. The method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in various solvents according to claim 1, characterized in that: The simultaneous determination of the bis-ethylhexyloxyphenol methoxyphenyl triazine and the ethylhexyl triazone includes: (i) in a medium or low polarity organic solvent, such as in chloroform and ethyl acetate, in the binary system first derivative absorption spectrum of the bis-ethylhexyloxyphenol methoxyphenyl triazine and the ethylhexyl triazone, respectively select around 319 nm to determine the ethylhexyl triazone and around 369 nm to determine the bis-ethylhexyloxyphenol methoxyphenyl triazine; (ii) in a polar organic solvent, such as in isopropanol and dioxane, in the binary system first derivative absorption spectrum of the bis-ethylhexyloxyphenol methoxyphenyl triazine and the ethylhexyl triazone, respectively select around 323 nm to determine the ethylhexyl triazone and around 370 nm to determine the bis-ethylhexyloxyphenol methoxyphenyl triazine; (iii) in a mixed solvent, such as an organic solvent and water mixed solvent, in the binary system first derivative absorption spectrum of the bis-ethylhexyloxyphenol methoxyphenyl triazine and the ethylhexyl triazone in isopropanol / water solvent and dimethyl sulfoxide / water solvent, respectively select around 328 nm to determine the ethylhexyl triazone and around 377 nm to determine the bis-ethylhexyloxyphenol methoxyphenyl triazine.

10. The method for simultaneously and rapidly determining the content of two-component triazine ultraviolet absorbers in various solvents according to claim 1, characterized in that: The simultaneous determination of the bis-ethylhexyloxyphenol methoxyphenyl triazine and the diethylhexyl butamido triazone includes: (i) in a medium or low polarity organic solvent, such as in chloroform and ethyl acetate, in the binary system first derivative absorption spectrum of the bis-ethylhexyloxyphenol methoxyphenyl triazine and the diethylhexyl butamido triazone, respectively select around 318 nm to determine the diethylhexyl butamido triazone and around 369 nm to determine the bis-ethylhexyloxyphenol methoxyphenyl triazine; (ii) in a polar organic solvent, such as in isopropanol and dioxane, in the binary system first derivative absorption spectrum of the bis-ethylhexyloxyphenol methoxyphenyl triazine and the diethylhexyl butamido triazone, respectively select around 322 nm to determine the diethylhexyl butamido triazone and around 370 nm to determine the bis-ethylhexyloxyphenol methoxyphenyl triazine; (iii) in a mixed solvent, such as an organic solvent and water mixed solvent, in the binary system first derivative absorption spectrum of the bis-ethylhexyloxyphenol methoxyphenyl triazine and the diethylhexyl butamido triazone in isopropanol / water solvent and dimethyl sulfoxide / water solvent, respectively select around 326 nm to determine the diethylhexyl butamido triazone and around 373 nm to determine the bis-ethylhexyloxyphenol methoxyphenyl triazine.

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