CN112105920A

CN112105920A - Method for testing whether grease can permeate into hair and permeation capacity

Info

Publication number: CN112105920A
Application number: CN201980031766.7A
Authority: CN
Inventors: 梁新宇; 徐志远; 赵贵钧; 朱林林
Original assignee: Wacker Chemie AG
Current assignee: Wacker Chemie AG
Priority date: 2019-03-21
Filing date: 2019-03-21
Publication date: 2020-12-18
Also published as: WO2020186510A1

Abstract

The present disclosure relates to a test method comprising step S1, treating a blank hair bundle 1 with a grease a or b for no more than 10 min; s2, rubbing the hair strands with a surfactant solution, washing with water, and drying in the air; s3, taking the organic solvent soaked in the hair bundle 1 to be tested to perform a nuclear magnetic hydrogen spectrum test, and observing whether the hydrogen spectrum peaks at the comparison position; s4, if the hair bundle 1 to be measured does not peak at the comparison position, carrying out the step S5; if so, repeating the step S2 until the nuclear magnetic hydrogen spectrum in the step S3 does not generate a peak at the comparison position; s5, treating the blank hair bundle 2 with the grease a or b for at least 10min, and repeating the steps S2 and S3 by the same method; if the hair bundle 2 to be measured has a peak at the comparison position, it is judged that the grease a or b can penetrate into the hair, otherwise, it is judged that the grease a or b cannot penetrate into the hair. The method is simple and convenient to operate, low in cost and reliable and effective in test result.

Description

Method for testing whether grease can permeate into hair and permeation capacity

Technical Field

The disclosure relates to a testing method, in particular to a method for testing whether grease can permeate into hair and the permeation capacity.

Background

Fats and oils, particularly vegetable oils, have been widely used in hair care products because of their mildness and unique efficacy. According to research reports, the vegetable oil can be attached to the surface of hair and can permeate into the hair to play a role in double-effect care. Although there is no current debate as to the molecular weight and structure of vegetable oils that can penetrate into the interior of hair, vegetable oils such as coconut oil, which have C8-C18 fatty acid triglycerides as the main component, have been theoretically or practically confirmed to be able to penetrate into the interior of hair.

However, there are still major technical difficulties in characterizing the analysis of whether the vegetable oil has penetrated into the hair, since the vegetable oil adhering to the hair surface can cause a great interference to the analysis. The currently common effective characterization and analysis means is time of flight secondary ion mass spectrometry (TOF-SIMS), and the method adopts a gallium ion beam with positive charges to bombard the cross section of hair to obtain a secondary ion mass spectrogram. And identifying the characteristic peak of the vegetable oil in the spectrogram to judge whether the vegetable oil permeates into the hair. (J.Cosmet.Sci 52,169-184, 2001).

Considering the high cost and complicated operation of TOF-SIMS, it is still necessary to find a simple, cheap and effective method for testing whether vegetable oil can permeate into hair.

Disclosure of Invention

In order to overcome the defects in the prior art, the disclosure provides a new method for testing whether grease can penetrate into hair, which has the advantages of simple and convenient operation and low cost compared with TOF-SIMS, and compared with other methods tried by the inventor, such as a method for judging whether grease can penetrate into hair by testing the diameter change of hair through a microscope, the test result is more reliable and effective; furthermore, the new method can also show the capability of the grease to penetrate into the hair, and is used for screening the grease with strong penetrating capability and high speed.

In the present disclosure, the term "blank hair strands" refers to hair strands that have not been treated with oil, particularly vegetable oil, and may be any hair strands as long as they have not been treated with oil, for example, they may be hair strands of males or females taken from any age group, any country, any region, and may be healthy hair strands or damaged hair strands such as mechanically damaged hair strands, thermally damaged hair strands, chemically damaged hair strands, environmentally damaged hair strands, aged hair strands. The term "treating" includes, but is not limited to, coating, soaking, and the like. Tresses treated cumulatively with oil for no more than 10min, particularly no more than 5min, and then cleaned with a surfactant solution are also within the scope of the blank hair tresses of the present disclosure.

In the present disclosure, "capable of dissolving the fat" means that the solubility of the fat in the solvent at 20 ℃ is more than 1g, preferably more than 5g, and particularly more than 10 g. The term "solubility" refers to the mass of a substance dissolved at a certain temperature when the substance reaches a saturation state in 100g of a solvent.

The test method provided by the present disclosure includes the following steps:

s1, treating the blank hair bundle 1 with the grease a or b for no more than 10 min;

s2, rubbing the treated hair bundle with a surfactant solution, washing with water, drying in the air and testing;

s3, taking the organic solvent soaked in the hair bundle 1 to be tested to perform nuclear magnetic hydrogen spectrum test, and observing whether the obtained nuclear magnetic hydrogen spectrum has a peak at a comparison position, wherein the comparison position is located in a nuclear magnetic hydrogen spectrum non-peak area soaked in the test solvent of the blank hair bundle 1 and is located in a nuclear magnetic hydrogen spectrum peak area of the grease a or b; the organic solvent for soaking the hair bundle 1 to be tested and the testing solvent for nuclear magnetic hydrogen spectrum are solvents capable of dissolving grease;

s4, if the hair bundle 1 to be measured does not peak at the comparison position, carrying out the step S5; if so, repeating the step S2 until the nuclear magnetic hydrogen spectrum measured in the step S3 does not have a peak at the comparison position, and then performing the step S5;

s5, processing the blank hair bundle 2 with grease a or b for at least 10min, rubbing the hair bundle 2 by the same method in the step S2, wherein the repeated rubbing times are the same as the repeated times in the step S4, and then performing nuclear magnetic hydrogen spectrum test on the hair bundle 2 to be tested by the same method in the step S3; if the hair bundle 2 to be measured has a peak at the comparison position, the grease a or b is judged to be capable of penetrating into the hair, otherwise, the grease a or b is judged not to be capable of penetrating into the hair.

In the present disclosure, the oil and fat includes natural oil and synthetic oil, preferably natural oil. The natural oils include animal oils and vegetable oils, preferably vegetable oils. The term "vegetable oil" refers to oils and fats extracted from the roots, stems, leaves, flowers, fruits or seeds of plants, including, but not limited to, palm oil, palm kernel oil, coconut oil, olive oil, jojoba oil, argan oil, nigella oil, bearberry oil, crabapple oil, shea butter, almond oil, almond kernel oil, avocado oil, walnut oil, castor oil, corn oil, oat oil, cottonseed oil, rapeseed oil, linseed oil, grape seed oil, pomegranate seed oil, citrus seed oil, wheat germ oil, cashew nut oil, pine nut oil, macadamia nut oil, peanut oil, soybean oil, sesame oil, sunflower oil, safflower oil, tea tree oil.

In the present disclosure, the grease a and the grease b are different greases, wherein the letters a and b have no essential meaning, and are only used for convenience of reference.

In the present disclosure, the blank hair bundle 1 and the blank hair bundle 2 are blank hair bundles of the same origin, wherein the

numerals

1 and 2 have no substantial meaning, but are for convenience of reference. In order to eliminate the interference of the hair strand weight with the test results, the weight of the blank hair strand 1 and the blank hair strand 2 is preferably the same. The

blank hair strands

1 and 2 are preferably washed prior to use with a surfactant solution, primarily intended to clean the hair cuticle of dirt such as dust, dander, soot, grease, mineral oil, fatty acids, fatty alcohols, and the like, suitable surfactants being described below.

In the present disclosure, the hair bundle 1 to be tested and the hair bundle 2 to be tested are obtained by processing the hair bundles to be tested with grease for different time, and the operations of rubbing, washing, drying and the like of the hair bundles to be tested and the hair bundles to be tested are completely the same, wherein the

numbers

1 and 2 have no substantial meaning, and are only for the convenience of reference. The reference numerals of the hair bundle to be measured labels obtained by treating the hair bundle with different grease for the same time are the same, for example, the hair bundle to be measured 1 is marked, and it should be understood that the hair bundle to be measured at this time is different due to different types of the grease to be treated, and only the operations of the grease treatment time, the rubbing, the airing and the like are completely the same.

In this disclosure, penetrating into the hair generally refers to penetrating into the hair cuticle in the area adjacent to the cortex, the cortex and the medulla, especially the cortex and the medulla.

In the disclosure, the method can be used for testing whether grease can permeate into hair, and further judging the capability of the grease permeating into the hair, and the specific method is as follows: in step S5, if both of the oils a and b can penetrate into the hair, the peak signal intensities of the hair bundle 2 to be measured treated with the oil a and the hair bundle 2 to be measured treated with the oil b at the comparison positions are compared, if the peak signal intensity of the oil a is stronger than that of the oil b, it is determined that the ability of the oil a to penetrate into the hair is stronger than that of the oil b, otherwise, it is determined that the permeability of the oil b is stronger.

In step S1, the time for processing the blank hair bundle 1 is not more than 10min, such as not more than 9min, 8min, 7min, 6min, preferably not more than 5min, even not more than 3min, 1 min.

In step S2, the surfactant may be various surfactants conventionally used in daily chemical products, including anionic surfactants, nonionic surfactants, amphoteric surfactants, and cationic surfactants. The surfactant is preferably a surfactant having an HLB value of 9 or more, for example, 9 to 13, 14 to 18, 19 to 25, 26 to 40.

Non-limiting examples of suitable surfactants include fatty alcohol sulfates such as sodium lauryl sulfate, triethanolamine lauryl sulfate, fatty alcohol polyoxyethylene ether sulfates such as sodium laureth sulfate, triethanolamine fatty alcohol polyoxyethylene ether sulfate, sulfosuccinates such as disodium lauryl sulfosuccinate, disodium fatty alcohol polyoxyethylene ether sulfosuccinate, disodium coconut monoethanolamide sulfosuccinate, alkenyl sulfonates, N-acyl glutamates, alkyl phosphate esters, fatty alcohol polyoxyethylene phosphonate esters, alkylolamides, fatty alcohol polyoxyethylene ethers, alkylphenol ethoxylates, ethylene oxide sorbitan monolaurate, betaines such as dodecyl dimethyl betaine, cocamidopropyl betaine, hydroxyiodobetaine, ammonium oxides such as C12-18 alkyl dimethyl amine oxide, ammonium salts such as C12-18 alkyl dimethyl amine oxide, sodium lauryl sulfate, triethanolamine fatty alcohol polyoxyethylene ether sulfosuccinate, disodium coco monoethanolamide sulfosuccinate, alkenyl sulfonates, N-acyl glutamate, alkyl phosphate esters, fatty alcohol polyoxyethylene phosphonate esters, lauramidopropyl amine oxide, N-alkyl amino propionate.

The surfactant solution generally refers to an aqueous solution of a surfactant, and the concentration of the solution is not particularly limited.

In step S2, in order to better clean the oil on the surface of the hair bundle, the surface of the hair bundle is preferably wiped with an oil absorbing paper before the hair bundle is kneaded with the surfactant solution.

In step S2, the water used for rinsing is not particularly limited, and may be tap water, deionized water, purified water, or distilled water. The airing operation has no special requirements, and the airing operation can be carried out naturally.

In step S3, the time for soaking the hair bundle to be tested with the organic solvent is preferably at least 10min, for example, at least 15min, at least 30min, at least 45min, at least 1h, at least 1.5h, at least 2h, at least 2.5h, at least 3h, so as to dissolve the grease inside the hair into the organic solvent as much as possible.

Suitable organic solvents are organic solvents having a polarity parameter of less than 6, including but not limited to acetone, methyl isobutyl ketone, pyridine, n-propanol, isopropanol, n-butanol, isobutanol, ethyl acetate, butyl acetate, dichloromethane, chloroform, carbon tetrachloride, benzene, toluene, n-pentane, isopentane, n-hexane, cyclohexane, n-heptane, isooctane, trimethylpentane, petroleum ether, diethyl ether, propyl ether, tetrahydrofuran.

The amount of the organic solvent is not particularly limited as long as the hair strand to be measured can be completely immersed in the organic solvent. Nevertheless, in order to prevent the oil content dissolved out into the organic solvent from being too low and causing weak nuclear magnetic hydrogen spectrum signals of subsequent test samples, it is desirable to immerse as many hair strands to be tested into the organic solvent as possible.

In step S3, the test solvent for nuclear magnetic hydrogen spectroscopy is preferably selected to satisfy the following conditions: the oil can be dissolved, the oil does not react with the oil, and the resonance peak of the oil does not interfere with the signal of the oil. When the grease is vegetable oil, the test solvent preferably does not peak at the nuclear magnetic hydrogen peak position of at least one of the vegetable oil, such as A hydrogen and B hydrogen of carbon No. 1, hydrogen of carbon No. 2 and A hydrogen and B hydrogen of carbon No. 3, shown in formula (I), more preferably does not peak at the nuclear magnetic hydrogen peak position of the vegetable oil, such as B hydrogen of carbon No. 1 or B hydrogen of carbon No. 3, shown in formula (I):

wherein, the nuclear magnetic peak position is the same for a hydrogen atom A of carbon No. 1 and a hydrogen atom A of carbon No. 3 in many cases, the nuclear magnetic peak position is the same for a hydrogen atom B of carbon No. 1 and a hydrogen atom B of carbon No. 3 in many cases, and the nuclear magnetic peak position is different for a hydrogen atom B of carbon No. 2 from the above-mentioned hydrogen peak position.

In order to reduce interference of hydrogen in the test solvent on hydrogen in the grease during detection, the test solvent is preferably a deuterated organic solvent, suitably a deuterated organic solvent with a polarity parameter less than 6, preferably deuterated benzene, deuterated toluene, deuterated chloroform.

In step S3, the organic solvent used to soak the hair bundle to be tested may be the same as or different from the test solvent used for nuclear magnetic hydrogen spectroscopy. In one embodiment, the organic solvent is the same as the test solvent, and the sample of the organic solvent soaked with the hair bundle to be tested is directly subjected to the nuclear magnetic hydrogen spectrum test without treatment. In another embodiment, the organic solvent is different from the testing solvent, the organic solvent sample soaked with the hair bundle to be tested is dried to remove the organic solvent, and then the obtained substance is dissolved in the testing solvent to perform the nuclear magnetic hydrogen spectrum test.

In step S3, the nuclear magnetic hydrogen spectrum test conditions of the test solvent soaked in the blank hair bundle and the organic solvent soaked in the hair bundle to be tested, such as magnetic field strength, scanning times, sample soaking time of the test solvent, types of the test solvent, volume of the test sample, and the like, may be the same or different, preferably the same, so that when determining whether the grease can penetrate into the hair, especially into the hair cortex and/or the hair medulla, the interference of the signal of the blank hair bundle and other information is avoided.

In step S4, repeating step S2 until the nmr spectrum measured in step S3 does not show a peak at the comparison position, which may be repeated with steps S2 and S3 as a unit until the nmr spectrum does not show a peak at the comparison position; step S2 may be repeated for one unit, step S2 may be repeated for more than 3 times, and step S3 may be performed until the nmr spectrum does not show a peak at the comparison position.

In step S5, the blank hair bundle 2 is treated for a time of at least 10min, such as at least 20min, at least 30min, at least 1h, at least 2h, preferably at least 3h, such as at least 5h, at least 8h, at least 12 h.

In step S5, the same number of times of repeated rubbing of the hair bundle 2 as that in step S4 means that if step S2 is not repeated in step S4, the hair bundle 2 is rubbed 1 time in accordance with step S2, and if step S2 n times is repeated in step S4, the hair bundle 2 is rubbed n +1 times in accordance with step S2.

Drawings

Fig. 1a is a nuclear magnetic hydrogen spectrum diagram of a blank hair bundle in deuterated benzene, fig. 1b is a nuclear magnetic hydrogen spectrum diagram of coconut oil in deuterated benzene, fig. 1c is a nuclear magnetic hydrogen spectrum diagram of a hair bundle 1 to be tested in example 1 in deuterated benzene, and fig. 1d is a nuclear magnetic hydrogen spectrum diagram of a hair bundle 2 to be tested in example 1 in deuterated benzene.

Fig. 2a is a nuclear magnetic hydrogen spectrum of glycerol in deuterated benzene, fig. 2b is a nuclear magnetic hydrogen spectrum of the hair bundle 1 to be tested in example 2 in deuterated benzene, and fig. 2c is a nuclear magnetic hydrogen spectrum of the hair bundle 2 to be tested in example 2 in deuterated benzene.

Fig. 3 is a nuclear magnetic hydrogen spectrum diagram obtained by testing a hair bundle to be tested which is treated by coconut oil (upper) and glycerin (lower) in the same method under the same condition after being soaked in deuterated benzene for 3 hours.

Fig. 4a is a nuclear magnetic hydrogen spectrum diagram of the hair bundle 1 to be tested in deuterated benzene in the comparative example 1, and fig. 4b is a nuclear magnetic hydrogen spectrum diagram of the hair bundle 2 to be tested in deuterated benzene in the comparative example 1.

Fig. 5 is a schematic diameter view of the same position of hair after treatment with coconut oil at 0h (a), 1h (b), 2h (c), 16h (d) using a microscope.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.

Nuclear magnetic hydrogen spectrum test

This was done using a Bruker AscendTM 400 NMR spectrometer, BBO 400MHz S15 mm with Z-gradient SP probe.

Microscopic testing

This was done using an Axio Scope A1 polarizing microscope from Carl Zeiss.

The materials referred to in the following examples and comparative examples are commercially available.

Blank hair strands 1 and 2: both are hair tresses without vegetable oil treatment, and the sources of the two are the same.

Example 1

A method for testing whether coconut oil can permeate into hair by nuclear magnetic hydrogen spectrum comprises the following steps:

s1, taking 2g of blank hair bundle 1, uniformly coating 0.5mL of coconut oil on the blank hair bundle 1, and standing for 1 min;

s2, wiping coconut oil absorbed on the surface of the hair bundle with an oil absorption paper, then uniformly dripping 0.25mL of 16 wt% aqueous solution of sodium laureth sulfate (2-3EO, HLB being 30-40) into the hair bundle, kneading for 30S, and washing for 30S with water; repeating the rubbing step of the lauryl alcohol polyether sodium sulfate aqueous solution, and naturally drying the hair bundles;

s3, weighing 90mg of hair from the hair bundle 1 to be tested aired in the step S2, soaking the hair in a sample bottle filled with 3.6mL of deuterated benzene for 1min, 10min, 1h and 3h, and then respectively taking 0.6mL of sample from the sample bottle for nuclear magnetic hydrogen spectrum testing; in the step, the hair bundle to be measured is always completely immersed in the deuterated benzene;

weighing 90mg of blank hair bundle 1, immersing the blank hair bundle in a sample bottle filled with 3.6mL of deuterated benzene, taking 0.6mL of sample from the sample bottle after immersing for 3h for nuclear magnetic hydrogen spectrum test, wherein the blank hair bundle is completely immersed in the deuterated benzene all the time in the step;

adding 60mg of coconut oil into a sample bottle filled with 3.6mL of deuterated benzene, and taking 0.6mL of sample from the sample bottle after the coconut oil is completely dissolved for nuclear magnetic hydrogen spectrum test;

s4, observing that the nuclear magnetic hydrogen spectrum (figure 1a) of the blank hair bundle 1 does not peak near 4.2-4.3ppm, and the nuclear magnetic hydrogen spectrum (figure 1b) of the coconut oil peaks near 4.2-4.3ppm, therefore, the position near 4.2-4.3ppm is set as the comparison position;

observing that the nuclear magnetic hydrogen spectrum (figure 1c) of the hair bundle 1 to be measured does not generate a peak at the comparison position, and performing step S5;

s5, taking 2g of blank hair bundle 2, uniformly coating 0.5mL of coconut oil on the blank hair bundle 2, and standing for 12 h; wiping coconut oil absorbing the surfaces of the hair bundles with oil absorption paper, rubbing and washing the hair bundles 2 twice by the same method of the step S2, naturally drying, and then carrying out nuclear magnetic hydrogen spectrum test on the hair bundles 2 to be tested by the same method of the step S3;

when the nuclear magnetic hydrogen spectrum (fig. 1d) of the hair bundle 2 to be measured is observed to peak at the comparison position, the coconut oil is judged to be capable of penetrating into the hair.

In this embodiment, the

hair bundles

1 and 2 to be tested are both processed by the coconut oil, but the signal of the coconut oil is not detected by the hair bundle 1 to be tested, and the signal of the coconut oil is detected by the hair bundle 2 to be tested. This is because the coconut oil treatment time of the hair bundle 1 to be tested is short, the coconut oil is only attached to the surface of the hair and does not penetrate into the hair, and the coconut oil on the surface of the hair is cleaned by the sodium laureth sulfate in the step S2, so that the signal of the coconut oil is not detected subsequently. However, the coconut oil treatment time of the hair bundle 2 to be tested is long, the coconut oil is not only attached to the surface of the hair, but also permeates into the hair, although the coconut oil on the surface of the hair is cleaned by the sodium laureth sulfate in the step S5, the coconut oil inside the hair cannot be cleaned, and the coconut oil inside the hair is dissolved into the deuterated benzene, so that the signal of the coconut oil is detected.

Example 2

A method for testing whether the glycerin can penetrate into the hair by nuclear magnetic hydrogen spectrum.

The procedure of this example is the same as example 1 except that the coconut oil is replaced with argan.

The nuclear magnetic hydrogen spectrum of the argan (FIG. 2a) was observed to show a peak around 4.2 to 4.3ppm, while the nuclear magnetic hydrogen spectrum of the blank hair bundle 1 (FIG. 1a) did not show a peak around 4.2 to 4.3ppm, and therefore the position around 4.2 to 4.3ppm was defined as the comparative position; and (3) judging that the glycerin can permeate into the hair if the nuclear magnetic hydrogen spectrum (figure 2b) of the hair bundle 1 to be detected does not peak at the comparison position and the nuclear magnetic hydrogen spectrum (figure 2c) of the hair bundle 2 to be detected peaks at the comparison position.

Example 3

A method for measuring the penetration capacity of coconut oil and argan into hair by nuclear magnetic hydrogen spectrum.

In example 1, coconut oil and argan glycerin in example 2 were both measured to be able to penetrate into hair, and in the hair bundle 2 to be tested, coconut oil and argan glycerin were treated by the same method, and the nuclear magnetic hydrogen spectrum test conditions of the coconut oil and argan glycerin were the same, and the peak signal intensity at the comparative position (fig. 3) measured after soaking the hair bundle 2 to be tested in comparative example 1 and the hair bundle 2 to be tested in example 2 in deuterated benzene for 3 hours was found to be stronger in the capability of coconut oil to penetrate into hair than that of argan glycerin.

Comparative example 1

The same as in embodiment 1 except for the following operations in steps S2 and S5: wiping the coconut oil absorbed on the surfaces of the

hair bundles

1 and 2 by using an oil absorption paper, respectively immersing the

hair bundles

1 and 2 in 10mL of methylbenzene, soaking for 1min, absorbing the methylbenzene on the surfaces of the hair by using the oil absorption paper, then respectively placing the hair bundles in 10mL of methylbenzene, washing for 30s, taking out the hair bundles, and naturally drying in a fume hood.

It is observed that the nuclear magnetic hydrogen spectra of the hair bundle 1 to be tested (fig. 4a) and the hair bundle 2 to be tested (fig. 4b) measured in step S3 all peak at the comparison position, because the coconut oil on the hair surface is not cleaned by the toluene in step S2, the coconut oil on the hair surface of the subsequent hair bundle 1 to be tested and the coconut oil on the hair surface and inside of the hair bundle 2 to be tested are all dissolved into the deuterated benzene, and therefore, signals of the coconut oil are detected.

Comparative example 2

A method for microscopically testing the penetration of coconut oil into hair comprising the steps of:

s1, taking three blank hairs from the same source, respectively fixing the blank hairs on a glass slide, and measuring the initial diameters of the three blank hairs in a microscope transmission mode;

s2, soaking the three blank hairs in coconut oil for 1h, 2h and 16h respectively, and observing and measuring the diameters of the hairs at the same position in the same mode;

s3, comparing the hair diameter measured in the step S2 with the initial diameter of the step S1, if the hair diameter of the coconut oil treated in different time is observed to be larger than the initial diameter, judging that the coconut oil can permeate into the hair, otherwise, judging that the coconut oil can not permeate into the hair.

Specific test results as shown in fig. 5, no significant increase in hair diameter was observed after the coconut oil treatment at various times over the initial diameter. Theoretically, the coconut oil can be attached to the surface of the hair and can permeate into the hair, the hair treated by the coconut oil can be expanded in diameter due to swelling after different time, however, in practice, the judgment on whether the coconut oil can permeate into the hair by testing the diameter change of the hair with a microscope is not feasible.

Claims

1. A method of testing, comprising the steps of:

s3, taking the organic solvent soaked in the hair bundle 1 to be tested to perform nuclear magnetic hydrogen spectrum test, and observing whether the obtained nuclear magnetic hydrogen spectrum has a peak at a comparison position, wherein the comparison position is located in a nuclear magnetic hydrogen spectrum non-peak area soaked in the test solvent of the blank hair bundle 1 and is located in a nuclear magnetic hydrogen spectrum peak area of the grease a or b; the organic solvent for soaking the hair bundle 1 to be tested and the testing solvent for nuclear magnetic hydrogen spectrum are solvents capable of dissolving the grease a or b;

2. The method according to claim 1, wherein in step S5, if both of the oils a and b are able to penetrate into the hair, the peak signal intensities of the hair bundle 2 to be tested treated with the oil a and the hair bundle 2 to be tested treated with the oil b at the comparison positions are compared, and if the peak signal intensity of the oil a is stronger than that of the oil b, the ability of the oil a to penetrate into the hair is determined to be stronger than that of the oil b, and otherwise, the ability of the oil b to penetrate is determined to be stronger.

3. The method according to claim 1 or 2, wherein the penetratable into the hair is into the cortex and/or medulla of the hair.

4. A method according to any one of claims 1 to 3, wherein the fat is a vegetable oil.

5. The method according to any one of claims 1 to 4, wherein the time to treat the blank hair bundle 1 in step S1 does not exceed 5 min.

6. The method according to any one of claims 1 to 5, wherein the time for soaking the strand to be tested with the organic solvent in step S3 is at least 10 min.

7. The method according to any one of claims 1 to 6, wherein the blank hair bundle 2 is treated in step S5 for a period of at least 3 h.

8. The method of any one of claims 4-7, wherein the test solvent does not peak at a nuclear magnetic peak position of at least one of A and B hydrogens on carbon 1, carbon 2, and A and B hydrogens on carbon 3 of the vegetable oil as shown in formula (I):

9. the method of claim 8, wherein the test solvent does not peak at the nuclear magnetic peak position of the B hydrogen of carbon No. 1 or the B hydrogen of carbon No. 3 of the vegetable oil according to formula (I).

10. The method according to any one of claims 1 to 9, wherein the organic solvent is the same as the test solvent, and the sample of organic solvent soaked with the tress to be tested is directly subjected to the nmr spectroscopy test without treatment.

11. The method according to any one of claims 1 to 9, wherein the organic solvent is different from the test solvent, and the sample of the organic solvent soaked with the strand to be tested is subjected to a drying treatment to remove the organic solvent, and then the obtained substance is dissolved in the test solvent to perform the nuclear magnetic hydrogen spectroscopy test.

12. The method of any one of claims 1-11, wherein the test solvent is a deuterated organic solvent having a polarity parameter of less than 6.

13. The method of any one of claims 1-12, wherein the deuterated organic solvent is selected from the group consisting of deuterated benzene, deuterated toluene, and deuterated chloroform.

14. The method of any one of claims 1-13, wherein the surfactant has an HLB value of 9 or more.