CN103234931A - Method for determination of green tea polyphenol stearate content - Google Patents

Abstract

Belonging to the field of chemical quantitative detection, the invention discloses a method for determination of a green tea polyphenol stearate content. The method comprises: preparing a reference substance and a test sample into a reference substance solution and a test sample solution respectively; drawing ultraviolet wavelength scan graphs of the reference substance solution and the test sample solution respectively to determine detection wavelength; drawing a standard curve of the reference substance solution and calculating a regression equation of the standard curve; determining absorbance of the test sample solution; and introducing the absorbance into the standard curve regression equation to calculate the green tea polyphenol stearate content in the test sample. By means of content determination on green tea polyphenol stearate and green tea polyphenol stearate-containing preparations, the method provided in the invention avoids indirect reflection of the green tea polyphenol stearate content by determining a phenolic hydroxyl group content, so that a color developing agent or an oxidant is unnecessary, the use of expensive standard substances and apparatuses can be avoided, and the cost is reduced. Also, the determination method is simple and accurate.

Description

A kind of method of measuring Tea Polyphenols stearate content

Technical field

The present invention relates to chemical quantitative detection field, particularly a kind of method of measuring Tea Polyphenols stearate content.

Background technology

Tea Polyphenols (Green Tea Polyphenols; GTP) be the very excellent natural antioxidant of a kind of performance; have no side effect; tool suppresses bacterium, performance such as anti-oxidant; be insoluble in fat but Tea Polyphenols is soluble in water; thereby the oxidation deterioration of directly using it for anti-grease and high-fat foods just is very limited; the Tea Polyphenols stearate is the stearic acid oxygen acylate of Tea Polyphenols; be a kind of of fat-soluble tea polyphenol; the same with Tea Polyphenols; the Tea Polyphenols stearate has pharmacological action widely such as anti-oxidant grade equally, and each component has stronger synergy.

A kind of method that detects micro-fat-soluble tea polyphenol in vegetable oil is arranged in the prior art, this method at first is standard items with the progallin A, adopt the ferrous tartrate colourimetry, be developer with the ferrous ion, can form the hyacinthine complex compound with ferrous ion by the Tea Polyphenols class, measure the content of fat-soluble tea polyphenol, then with the fat-soluble tea polyphenol of known content product in contrast, adopt forint phenol reagent oxidizing process, measure the content of micro-fat-soluble tea polyphenol in the vegetable oil.

In realizing process of the present invention, the inventor finds that there is following problem at least in prior art:

Physicochemical property with respect to Tea Polyphenols, fat-soluble tea polyphenol is being formed, structure, mean molecular weight, adjacent two phenolic hydroxyl groups or connect the quantity of three phenolic hydroxyl groups and with the intensity of ferrous ion colour developing etc. bigger variation has taken place all in the molecule, in this case, said method still adopt progallin A and Epigallo-catechin gallate (EGCG) under equal in quality with the ratio 1.5 of ferrous ion colour developing thing absorbance, and, said method is the content that reflects fat-soluble tea polyphenol by the content of measuring phenolic hydroxyl group indirectly, cause its measurement result on the low side, can not directly obtain the content of fat-soluble tea polyphenol, and this method is comparatively loaded down with trivial details, only is applicable to the detection of micro-fat-soluble tea polyphenol.

Summary of the invention

In order to solve the problem that can not accurately measure Tea Polyphenols stearate content in the prior art, the embodiment of the invention provides a kind of method of measuring Tea Polyphenols stearate content.Described technical scheme is as follows:

The invention provides a kind of method of measuring Tea Polyphenols stearate content, said method comprising the steps of:

Reference substance and test sample are prepared into reference substance solution and need testing solution respectively, and described reference substance is the Epigallo-catechin gallate (EGCG) stearate;

By drawing the ultraviolet wavelength scintigram of described reference substance solution and described need testing solution respectively, obtain the maximum absorption wavelength of described reference substance solution and described need testing solution, and determine to detect wavelength according to described maximum absorption wavelength;

Draw the typical curve of described reference substance solution and calculate the regression equation of described typical curve;

Adopt the absorbance of the described need testing solution of determined by ultraviolet spectrophotometry;

Described absorbance is brought into the content of Tea Polyphenols stearate in the described test sample of described typical curve regression equation calculation.

Particularly, described test sample is Tea Polyphenols stearate or the preparation that contains described Tea Polyphenols stearate, and the solvent of described need testing solution is organic solvent.

Particularly, the method of determining the maximum absorption wavelength of described need testing solution by the ultraviolet wavelength scintigram of described need testing solution is: when described test sample is described Tea Polyphenols stearate, described Tea Polyphenols stearate is mixed with every milliliter contains the described need testing solution that described Tea Polyphenols stearate is 0.04mg, be reference with described organic solvent, in the interscan of 200-400nm wavelength coverage, obtain the ultraviolet wavelength scintigram of described need testing solution, determine that by described ultraviolet wavelength scintigram the maximum absorption wavelength of described need testing solution is 275nm.

Particularly, the method of determining the maximum absorption wavelength of described need testing solution by the ultraviolet wavelength scintigram of described need testing solution is: when described test sample is the described preparation that contains the Tea Polyphenols stearate, it is an amount of to get described preparation, the accurate title, decide, place container, add an amount of described organic solvent, fully stir, in the centrifugal 30min of hydro-extractor 3600rpm, divide and get supernatant, and repeat to extract 3 times, merge described supernatant and filtration, filtrate is moved into volumetric flask, with described organic solvent constant volume, be mixed with every milliliter and contain the described need testing solution that described Tea Polyphenols stearate is 0.04mg, with the blank preparation extract of the quality such as method preparation that prepare described need testing solution as reference, in the interscan of 200-400nm wavelength coverage, obtain the ultraviolet wavelength scintigram of described need testing solution, determine that by described ultraviolet wavelength scintigram the maximum absorption wavelength of described need testing solution is 275nm.

Particularly, the solvent of described reference substance solution is described organic solvent.

Particularly, the method of determining the maximum absorption wavelength of described reference substance solution by the ultraviolet wavelength scintigram of described reference substance solution is: get described Epigallo-catechin gallate (EGCG) stearate, use described organic solvent dissolution, be mixed with every milliliter and contain the described reference substance solution that described Epigallo-catechin gallate (EGCG) stearate is 0.04mg, be reference with described organic solvent, in the interscan of 200-400nm wavelength coverage, obtain the ultraviolet wavelength scintigram of described reference substance solution, determine that by described ultraviolet wavelength scintigram the maximum absorption wavelength of described reference substance solution is 275nm.

Particularly, be 275nm according to the maximum absorption wavelength of described reference substance solution and described need testing solution, determine that described detection wavelength is ± 2nm for the 275nm error.

Particularly, the method of drawing the typical curve of described reference substance solution and calculating the regression equation of described typical curve is: get dry described Epigallo-catechin gallate (EGCG) stearate, use described organic solvent dissolution, being mixed with every milliliter contains described Epigallo-catechin gallate (EGCG) stearate and is respectively 0,20,40, the described reference substance solution of 60,80 and 100 μ g is reference with described organic solvent, measure absorbance in 275nm wavelength place, and draw the typical curve of described reference substance solution, by described typical curve as calculated described equation of linear regression is: Y=0.0091X, wherein, the range of linearity is 0-100 μ g/mL, determines coefficients R²Be that 0.9993, Y is the absorbance of described reference substance solution, X is the concentration of described reference substance solution.

Particularly, the method for measuring the absorbance of described need testing solution is: the concentration of described need testing solution when described test sample is described Tea Polyphenols stearate, is reference with described organic solvent in the range of linearity of equation of linear regression; When described test sample is the described preparation that contains the Tea Polyphenols stearate, be reference with described blank preparation extract, measure the absorbance of described need testing solution in 275nm wavelength place.

Particularly, the described preparation that contains the Tea Polyphenols stearate is at least a pharmaceutical preparation in the gel, creme, ointment, paint, plastics, film and the patch that are main ingredient with described Tea Polyphenols stearate.

Particularly, described organic solvent is at least a in absolute ethyl alcohol, normal butyl alcohol, ethyl acetate, chloroform, normal hexane, cyclohexane, sherwood oil and the dimethyl sulfoxide (DMSO).

Preferably, described organic solvent is absolute ethyl alcohol, ethyl acetate.

The beneficial effect that the technical scheme that the embodiment of the invention provides is brought is: the present invention is by carrying out assay to Tea Polyphenols stearate and the preparation that contains the Tea Polyphenols stearate, avoid reflecting Tea Polyphenols stearate content indirectly by the content of measuring phenolic hydroxyl group, so just need not to add developer, expensive standard items and expensive instrument and equipment condition have been avoided using, reduced cost, and assay method simple possible of the present invention, measurement result is accurate, be easy to apply, assay method of the present invention also is applicable to the assay of Tea Polyphenols stearate when having complicated coexistence composition to exist in the preparation that contains the Tea Polyphenols stearate, and its measurement result is accurate.

Description of drawings

In order to be illustrated more clearly in the technical scheme in the embodiment of the invention, the accompanying drawing of required use is done to introduce simply in will describing embodiment below, apparently, accompanying drawing in describing below only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.

Fig. 1 is the ultraviolet wavelength scintigram of Tea Polyphenols stearate provided by the invention;

Fig. 2 is the ultraviolet wavelength scintigram of Epigallo-catechin gallate (EGCG) stearate provided by the invention;

Fig. 3 is the ultraviolet wavelength scintigram that contains Tea Polyphenols stearate gel that the embodiment of the invention four provides;

Fig. 4 is the ultraviolet wavelength scintigram of the blank gel that provides of the embodiment of the invention four;

Fig. 5 is that Epigallo-catechin gallate (EGCG) stearate provided by the invention is at the canonical plotting at 275nm wavelength place.

Embodiment

For making the purpose, technical solutions and advantages of the present invention clearer, embodiment of the present invention is described further in detail below in conjunction with accompanying drawing.

Agents useful for same of the present invention is analyzes pure commercial reagent.

Method provided by the invention may further comprise the steps:

Reference substance and test sample are prepared into reference substance solution and need testing solution respectively.

By drawing the ultraviolet wavelength scintigram of reference substance solution and need testing solution respectively, obtain the maximum absorption wavelength of reference substance solution and need testing solution, and determine to detect wavelength according to maximum absorption wavelength.

Draw the typical curve of reference substance solution and calculate the regression equation of this typical curve.

Adopt the absorbance of determined by ultraviolet spectrophotometry need testing solution.

Absorbance is brought into the content of Tea Polyphenols stearate in the above-mentioned typical curve regression equation calculation test sample.Specific as follows:

Getting Tea Polyphenols stearate 4mg, with anhydrous alcohol solution and be settled to 100mL, is reference with the absolute ethyl alcohol, in the interscan of 200-400nm wavelength coverage, and determines that by the ultraviolet wavelength scintigram that obtains after the scanning there is maximum absorption band at 275nm wavelength place.

Test sample is Tea Polyphenols stearate or the preparation that contains the Tea Polyphenols stearate, and the solvent of need testing solution is organic solvent.

Particularly, organic solvent is at least a in absolute ethyl alcohol, normal butyl alcohol, ethyl acetate, chloroform, normal hexane, cyclohexane, sherwood oil and the dimethyl sulfoxide (DMSO).

When test sample provided by the invention is the Tea Polyphenols stearate, the Tea Polyphenols stearate is mixed with every milliliter contains the need testing solution that the Tea Polyphenols stearate is 0.04mg, particularly, get Tea Polyphenols stearate 4mg, with anhydrous alcohol solution and be settled to 100mL, be reference with the organic solvent absolute ethyl alcohol, in the interscan of 200-400nm wavelength coverage, obtain the ultraviolet wavelength scintigram of need testing solution, as shown in Figure 1, determine that by this ultraviolet wavelength scintigram need testing solution has maximum absorption band at 275nm wavelength place.

Test sample provided by the invention is when containing the preparation of Tea Polyphenols stearate, it is an amount of to get said preparation, the accurate title, decide, place container, add an amount of organic solvent absolute ethyl alcohol, fully stir, in the centrifugal 30min of hydro-extractor 3600rpm, divide and get supernatant, and repeat to extract 3 times, merge supernatant and filtration, filtrate is moved into volumetric flask, use the absolute ethyl alcohol constant volume, be mixed with every milliliter and contain the need testing solution that the Tea Polyphenols stearate is 0.04mg, prepare blank preparation extract as reference with the method for preparing this need testing solution, in the interscan of 200-400nm wavelength coverage, obtain the ultraviolet wavelength scintigram of need testing solution, determine that by this ultraviolet wavelength scintigram need testing solution has maximum absorption band at wavelength 275nm place.

Particularly, reference substance is the Epigallo-catechin gallate (EGCG) stearate, and the solvent of reference substance solution is organic solvent.

Particularly, the method of determining the maximum absorption wavelength of reference substance solution by the ultraviolet wavelength scintigram of reference substance solution is: get the Epigallo-catechin gallate (EGCG) stearate, use organic solvent dissolution, be mixed with every milliliter and contain the reference substance solution that the Epigallo-catechin gallate (EGCG) stearate is 0.04mg, be reference with the organic solvent, in the interscan of 200-400nm wavelength coverage, obtain the ultraviolet wavelength scintigram of reference substance solution, as shown in Figure 2, determine that by the ultraviolet wavelength scintigram maximum absorption wavelength of reference substance solution is 275nm.

Maximum absorption wavelength according to reference substance solution and need testing solution is 275nm, then determine to detect wavelength for the 275nm error be ± 2nm, namely in the 275nm error be ± the 2nm scope in detection effective.

Particularly, the preparation that contains the Tea Polyphenols stearate is for the Tea Polyphenols stearate being at least a pharmaceutical preparation in gel, creme, ointment, paint, plastics, film and the patch of main ingredient.

The method of drawing the typical curve of reference substance solution and calculating the regression equation of typical curve is: get dry Epigallo-catechin gallate (EGCG) stearate, use organic solvent dissolution, being mixed with every milliliter contains the Epigallo-catechin gallate (EGCG) stearate and is respectively 0,20,40, the reference substance solution of 60,80 and 100 μ g is reference with the organic solvent.Particularly, get dry Epigallo-catechin gallate (EGCG) stearate 50mg, with anhydrous alcohol solution and be settled to 100mL, get thissolution 0,2 respectively, 4,6,8 and 10mL in the 50mL volumetric flask, use the absolute ethyl alcohol constant volume, the solution that namely gets behind every milliliter of constant volume contains Epigallo-catechin gallate (EGCG)stearate 0,20,40,60, the reference substance solution of 80 and 100 μ g, be reference with the absolute ethyl alcohol, measure absorbance in 275nm wavelength place, and draw the typical curve of reference substance solution, as shown in Figure 5, getting equation of linear regression as calculated by this typical curve is: Y=0.0091X, and wherein, the range of linearity is 0-100 μ g/mL, the range of linearity is the span of X, R²=0.9993, R²For determining coefficient, this R²Value is more more reliable near 1 this equation of linear regression of expression, and Y is the absorbance of reference substance solution, and X is the concentration of reference substance solution.

The method of measuring the absorbance of need testing solution is: the concentration of need testing solution when test sample is the Tea Polyphenols stearate, is reference with the organic solvent in the range of linearity of equation of linear regression; When test sample is when containing the preparation of Tea Polyphenols stearate, be reference with blank preparation extract, measure the absorbance of need testing solution in 275nm wavelength place.

Reference examples

The assay of Tea Polyphenols stearate raw material

Tea Polyphenols stearate raw material is to be raw material with the Tea Polyphenols, when acylating agent is stearic acid carboxylic acid halides or stearic acid acid anhydrides, and the Tea Polyphenols stearate of preparation.

Get dry Tea Polyphenols stearate 200mg, accurate claim fixed, with anhydrous alcohol solution and be settled to 100mL, as need testing solution.The learnt from else's experience progallin A 100mg of 100 ℃ of dry lh accurately claims surely, and the water dissolving also is settled to 100mL, as standard solution; Draw the standard solution 2,4,6,8 of 100mg/100mL and 10mL respectively in the 10mL volumetric flask, water is settled to scale, is prepared into every 100mL and containsprogallin A 20,40,60,80 and the solution of 100mg.

Measure: each 1mL of standard solution that accurately draws need testing solution and various concentration respectively, in the 10mL color comparison tube, each adds triethanolamine aqueous solution 1mL, mixing, add tartrate ferrous solution 5mL, add water and be settled to 25mL, with blank reagent as reference, under the 540nm wavelength, colorimetric in the 1cm cuvette.

The result calculates: Tea Polyphenols stearate content (%)=sample is equivalent to standard items content * 1.5 * 100 ÷ sample qualities.Calculate by formula, Tea Polyphenols stearate content is 45.75%.

This method weak point is: with respect to Tea Polyphenols, composition at the Tea Polyphenols stearate, structure, mean molecular weight, the quantity of adjacent two phenolic hydroxyl groups or company's three phenolic hydroxyl groups in the molecule, all taken place under the situation of bigger variation with the physicochemical properties such as intensity of ferrous ion colour developing, this reference examples still adopt progallin A and Epigallo-catechin gallate (EGCG) under equal in quality with the experience ratio of ferrous ion colour developing thing absorbance namely 1.5, and be the content that reflects the Tea Polyphenols stearate by the content of measuring phenolic hydroxyl group indirectly, its measurement result is on the low side, can not directly measure the content of Tea Polyphenols stearate.

Embodiment one

The assay of Tea Polyphenols stearate raw material

Get Tea Polyphenols stearate 200mg, this sample is identical with the sample of reference examples, and accurate the title decides, place the 50mL volumetric flask, with anhydrous alcohol solution and constant volume, precision is measured this solution 1mL and is placed the 100mL volumetric flask, uses the absolute ethyl alcohol constant volume, be reference with the absolute ethyl alcohol, by ultraviolet spectrophotometry, in sample preparation 2 hours, measure absorbance in 275nm wavelength place, its absorbance is 0.3716, with the above-mentioned equation of linear regression of absorbance substitution and calculate content.

It is 102.09% that the result records Tea Polyphenols stearate content, and the actual content that the method that the embodiment of the invention provides records content value and Tea Polyphenols stearate approaches.

Embodiment two

The assay of Tea Polyphenols stearate raw material

Get Tea Polyphenols stearate 50mg, the accurate title, decide, place the 50mL volumetric flask, with normal butyl alcohol dissolving and constant volume, precision is measured this solution 1mL and is placed the 100mL volumetric flask, use the normal butyl alcohol constant volume, be reference with the normal butyl alcohol, by ultraviolet spectrophotometry, in sample preparation 2 hours, measure absorbance in 275nm wavelength place, its absorbance is 0.0909, with the above-mentioned equation of linear regression of absorbance substitution and calculate content, it is 99.87% that the result records Tea Polyphenols stearate content, and the actual content that the method that the embodiment of the invention provides records content value and Tea Polyphenols stearate approaches.

Embodiment three

The assay of Tea Polyphenols stearate raw material

Get Tea Polyphenols stearate 10mg, the accurate title, decide, and places the 100mL volumetric flask, with chloroform dissolving and constant volume, be reference with the chloroform, by ultraviolet spectrophotometry, in sample preparation 2 hours, measure absorbance in 275nm wavelength place, its absorbance is 0.9142, with the above-mentioned equation of linear regression of absorbance substitution and calculate content, it is 100.46% that the result records Tea Polyphenols stearate content, and the actual content that the method that the embodiment of the invention provides records content value and Tea Polyphenols stearate approaches.

Embodiment four

The assay of Tea Polyphenols stearate gel

Get labelled amount and be 0.5% Tea Polyphenols stearate gel 10g, accurately claim surely, place beaker, add an amount of normal hexane, fully stir, potpourri divides and gets supernatant in the centrifugal 30min of hydro-extractor 3600rpm, repeat to extract 3 times, merge supernatant, filter, filtrate moves in the 100mL volumetric flask, use the normal hexane constant volume, namely get need testing solution; The blank gel of quality such as get, and prepare blank gel extract according to the method for preparing need testing solution, and as reference; Get need testing solution, blank gel extract with preparation is made reference, by ultraviolet spectrophotometry, in gel extract preparation 2 hours, measure absorbance in 275nm wavelength place, its absorbance is 0.4616, wherein, contain the Tea Polyphenols stearate gel the ultraviolet wavelength scintigram as shown in Figure 3, the ultraviolet wavelength scintigram of the blank gel of handling as shown in Figure 4, with the above-mentioned equation of linear regression of absorbance substitution and calculate Tea Polyphenols stearate content, the content of Tea Polyphenols stearate is 0.5072% in this gel, and the actual content that the method that the embodiment of the invention provides records content value and Tea Polyphenols stearate gel approaches.

Embodiment five

The assay of Tea Polyphenols stearate ointment

Get labelled amount and be 2% Tea Polyphenols stearate ointment 10g, accurately claim surely, place beaker, add an amount of ethyl acetate, fully stir, potpourri is in the centrifugal 30min of hydro-extractor 3600rpm, divide and get supernatant, repeat to extract 3 times, merge supernatant, filter, filtrate moves in the 100mL volumetric flask, uses the ethyl acetate constant volume, and precision is measured this solution 1mL and placed the 50mL volumetric flask, use the ethyl acetate constant volume, namely get need testing solution; The blank ointment of quality such as get, and prepare blank ointment extract according to the method for preparing need testing solution, and as reference; Get need testing solution, blank ointment extract with preparation is made reference, by ultraviolet spectrophotometry, in need testing solution preparation 2 hours, measure absorbance in 275nm wavelength place, its absorbance is 0.3695, with the above-mentioned equation of linear regression of absorbance substitution and calculate Tea Polyphenols stearate content, the content of Tea Polyphenols stearate is 2.0301% in this gel, and the actual content that the method that the embodiment of the invention provides records content value and Tea Polyphenols stearate ointment approaches.

Need to prove, in embodiment provided by the invention, organic solvent adopts absolute ethyl alcohol, normal butyl alcohol, ethyl acetate, chloroform and normal hexane, but in other embodiments, also can adopt cyclohexane, sherwood oil or dimethyl sulfoxide (DMSO), by experiment as can be known, when organic solvent adopted absolute ethyl alcohol, normal butyl alcohol, chloroform, normal hexane, cyclohexane, sherwood oil or dimethyl sulfoxide (DMSO), experimental result data and the previous embodiment of acquisition were basic identical; Similarly, adopting the Tea Polyphenols palmitate in embodiment provided by the invention is gel and the ointment of main ingredient, but in other embodiments, adopt the Tea Polyphenols palmitate be creme, paint, plastics, film or the patch of main ingredient as test sample, experimental result data and the previous embodiment of acquisition are basic identical.

The above only is preferred embodiment of the present invention, and is in order to limit the present invention, within the spirit and principles in the present invention not all, any modification of doing, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (11)

1. a method of measuring Tea Polyphenols stearate content is characterized in that, said method comprising the steps of:

Reference substance and test sample are prepared into reference substance solution and need testing solution respectively, and described reference substance is the Epigallo-catechin gallate (EGCG) stearate;

By drawing the ultraviolet wavelength scintigram of described reference substance solution and described need testing solution respectively, obtain the maximum absorption wavelength of described reference substance solution and described need testing solution, and determine to detect wavelength according to described maximum absorption wavelength;

Draw the typical curve of described reference substance solution and calculate the regression equation of described typical curve;

Adopt the absorbance of the described need testing solution of determined by ultraviolet spectrophotometry;

Described absorbance is brought into the content of Tea Polyphenols stearate in the described test sample of described typical curve regression equation calculation.

2. method according to claim 1 is characterized in that, described test sample is Tea Polyphenols stearate or the preparation that contains described Tea Polyphenols stearate, and the solvent of described need testing solution is organic solvent.

3. method according to claim 2, it is characterized in that, the method of determining the maximum absorption wavelength of described need testing solution by the ultraviolet wavelength scintigram of described need testing solution is: when described test sample is described Tea Polyphenols stearate, described Tea Polyphenols stearate is mixed with every milliliter contains the described need testing solution that described Tea Polyphenols stearate is 0.04mg, be reference with described organic solvent, in the interscan of 200-400nm wavelength coverage, obtain the ultraviolet wavelength scintigram of described need testing solution, determine that by described ultraviolet wavelength scintigram the maximum absorption wavelength of described need testing solution is 275nm.

4. method according to claim 2, it is characterized in that, the method of determining the maximum absorption wavelength of described need testing solution by the ultraviolet wavelength scintigram of described need testing solution is: when described test sample is the described preparation that contains the Tea Polyphenols stearate, it is an amount of to get described preparation, the accurate title, decide, place container, add an amount of described organic solvent, fully stir, in the centrifugal 30min of hydro-extractor 3600rpm, divide and get supernatant, and repeat to extract 3 times, merge described supernatant and filtration, filtrate is moved into volumetric flask, with described organic solvent constant volume, be mixed with every milliliter and contain the described need testing solution that described Tea Polyphenols stearate is 0.04mg, with the blank preparation extract of the quality such as method preparation that prepare described need testing solution as reference, in the interscan of 200-400nm wavelength coverage, obtain the ultraviolet wavelength scintigram of described need testing solution, determine that by described ultraviolet wavelength scintigram the maximum absorption wavelength of described need testing solution is 275nm.

5. according to claim 3 or 4 described methods, it is characterized in that the solvent of described reference substance solution is described organic solvent.

6. method according to claim 5, it is characterized in that, the method of determining the maximum absorption wavelength of described reference substance solution by the ultraviolet wavelength scintigram of described reference substance solution is: get described Epigallo-catechin gallate (EGCG) stearate, use described organic solvent dissolution, be mixed with every milliliter and contain the described reference substance solution that described Epigallo-catechin gallate (EGCG) stearate is 0.04mg, be reference with described organic solvent, in the interscan of 200-400nm wavelength coverage, obtain the ultraviolet wavelength scintigram of described reference substance solution, determine that by described ultraviolet wavelength scintigram the maximum absorption wavelength of described reference substance solution is 275nm.

7. method according to claim 6 is characterized in that, is 275nm according to the maximum absorption wavelength of described reference substance solution and described need testing solution, determines that described detection wavelength is ± 2nm for the 275nm error.

8. method according to claim 7, it is characterized in that, the method of drawing the typical curve of described reference substance solution and calculating the regression equation of described typical curve is: get dry described Epigallo-catechin gallate (EGCG) stearate, use described organic solvent dissolution, being mixed with every milliliter contains described Epigallo-catechin gallate (EGCG) stearate and is respectively 0,20,40,60, the described reference substance solution of 80 and 100 μ g, be reference with described organic solvent, measure absorbance in 275nm wavelength place, and draw the typical curve of described reference substance solution, by described typical curve as calculated described equation of linear regression is: Y=0.0091X, wherein, the range of linearity is 0-100 μ g/mL, determines coefficients R²Be that 0.9993, Y is the absorbance of described reference substance solution, X is the concentration of described reference substance solution.

9. method according to claim 8, it is characterized in that, the method of measuring the absorbance of described need testing solution is: the concentration of described need testing solution when described test sample is described Tea Polyphenols stearate, is reference with described organic solvent in the range of linearity of equation of linear regression; When described test sample is the described preparation that contains the Tea Polyphenols stearate, be reference with described blank preparation extract, measure the absorbance of described need testing solution in 275nm wavelength place.

10. according to claim 2 or 4 described methods, it is characterized in that the described preparation that contains the Tea Polyphenols stearate is at least a pharmaceutical preparation in the gel, creme, ointment, paint, plastics, film and the patch that are main ingredient with described Tea Polyphenols stearate.

11., it is characterized in that described organic solvent is at least a in absolute ethyl alcohol, normal butyl alcohol, ethyl acetate, chloroform, normal hexane, cyclohexane, sherwood oil and the dimethyl sulfoxide (DMSO) according to claim 2,3 or 4 described methods.

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