Metal detection in hair

Abstract

Method for detecting the presence of at least one metal, particularly copper, in hair fibers, comprising contacting the hair fibers with a test composition comprising, in an aqueous medium at alkaline pH, at least one ammonium salt and hydrogen peroxide, so as to allow the formation of possible oxygen gas on the surface of the hair fibers, the presence of such gas revealing the presence of said metal in the hair fibers. Figure for the abstract: Fig. 1

Description

Title of the invention: Metal detection in hair technical field

[0001] The present invention relates to the field of hair treatments.

[0002] The invention relates in particular to compositions and methods for detecting the presence in hair of undesirable compounds that may affect a hair coloring, bleaching or styling treatment. Previous technique

[0003] Some swimming pool water disinfection systems use metals such as copper, and swimmers' hair can gradually become saturated with copper, which can react with compounds present in coloring or bleaching products or in permanent hair-shaping products, resulting in an undesired outcome. In particular, an excessive amount of copper in the hair can, in some situations, lead to a greenish tint when a bleaching product is applied to the hair.

[0004] Furthermore, the presence of metals such as copper in hair tends to weaken it, particularly when exposed to oxidizing agents, such as those commonly used in oxidative coloring, perming, or bleaching treatments. This weakening can lead to a loss of the surface cosmetic properties of the fibers, a loss of mechanical properties, or even premature breakage. Moreover, for certain oxidative colorings, the presence of metals, especially copper, can alter the proportions of dyes fixed in the hair, and the resulting color may not be the expected one.

[0005] It is therefore essential to be able to detect the presence of these metals in order to avoid such harmful effects.

[0006] It is therefore standard practice in hairdressing schools to perform a preliminary test on a strand of hair to check the result of the subsequent application of a hair treatment product. To do this, before applying the product to the entire head of hair, a small amount is applied only to an isolated strand to verify that the result obtained corresponds to what is expected.

[0007] This practice takes a considerable amount of time because it requires leaving the product to act on the wick used for the test, typically for about twenty minutes.

[0008] Moreover, the product applied to the strand for the test generally comes from the same packaging as that used to treat the whole head of hair, so that if the result does not correspond to the expected, the rest of the product contained in the opened packaging cannot be applied and will be lost, since it cannot be used quickly on another person.

[0009] Finally, this practice does not allow for easy identification of the cause of an undesirable result. Description of the invention

[0010] Thus, there is a need to facilitate the establishment of a diagnosis of the presence of undesirable compounds in hair fibers and to identify them.

[0011] There is also an interest in accelerating the highlighting of potential adverse effects, before the application of a coloring or bleaching product or a shape modification product.

[0012] The invention aims to meet all or part of these needs. Summary of the invention

[0013] According to a first aspect, the invention relates to a composition, a method and a set of devices for the detection of metals in hair fibers.

[0014] According to this first aspect, the invention relates to a method for detecting the presence of at least one metal, in particular copper, in hair fibers, the detection method comprising bringing the hair fibers into contact with a test composition so as to allow the formation of a possible release of dioxygen gas on the surface of the hair fibers, the presence of such a release of gas revealing the presence of said metal in the hair fibers, the test composition comprising in an aqueous medium at alkaline pH at least one ammonium salt, and hydrogen peroxide.

[0015] The presence of the ammonium salt allows for the release of dioxygen which is more or less significant depending on the metal content.

[0016] Preferably, the composition comprises at least one polyol. The presence of the polyol increases the range of variation of bubbling as a function of the metal content.

[0017] The preferred pH range of the composition may depend on the polyol content. The presence of polyol may allow operation at a lower pH.

[0018] The composition may have, particularly in the presence of polyol, a pH greater than or equal to 9.4, preferably greater than or equal to 9.6.

[0019] In an example allowing good results to be obtained, the composition includes a polyol and its pH is 9.8.

[0020] The composition may have a pH greater than or equal to 10, preferably strictly greater than 10, in particular greater than or equal to 10.2. A high pH tends to increase the amount of dioxygen produced for a given metal content in the hair.

[0021] Preferably, the test composition comprises, in an aqueous medium at alkaline pH, at least one ammonium salt, hydrogen peroxide, and at least one polyol.

[0022] The detection process may include a preliminary preparation step, in particular extemporaneous, of the test composition.

[0023] This method is particularly easy to use. It allows for the rapid identification of the presence of said metal in the tested fibers.

[0024] The detection method may include evaluating or quantifying the oxygen produced in order to deduce the amount of metal present in the hair fibers, the amount of oxygen released being related to the amount of metal present. In particular, the test composition advantageously allows for the rapid detection, typically in less than 7 minutes, of the presence of metals, especially copper, in hair, by simply observing the release of oxygen gas from the decomposition of hydrogen peroxide.

[0025] This makes it possible not only to detect the presence of a metal but also to quantify its content in said hair, by evaluating or measuring the amount of dioxygen released.

[0026] Optionally, the process includes a comparison of the quantity of dioxygen produced or the corresponding quantity of metal with a reference value or scale, in particular the comparison of the quantity of metal with a threshold value beyond which the quantity of metal present in the hair fibers is likely to significantly alter a subsequent treatment, in particular coloring, of said hair fibers, this threshold value preferably being chosen between 40 ppm and 200 ppm, in particular between 50 and 100 ppm.

[0027] Several threshold values ​​can be predetermined, each threshold value being indicative of the degree of alteration likely from a subsequent treatment of coloring, bleaching or modification of the shape of said hair fibers.

[0028] For example, a first threshold value of 50 ppm may indicate a medium probability of alteration, and a second higher threshold value, for example of 100 ppm, indicates a high probability of alteration of the result.

[0029] The detection method can be implemented on a sample of hair fibers with a relatively small quantity of fibers, in particular less than 100mg.

[0030] The process may include a preliminary step of collecting a sample of hair fibers, in particular by means of a hair fiber sampling wand, said sample then being brought into contact with the test composition.

[0031] The detection method according to the invention may comprise the following successive steps:

[0032] 1) taking a sample of hair fibers, in particular by means of a sampling rod;

[0033] 2) supplying a test composition according to the invention, or supplying compounds and / or solutions allowing such a test composition to be achieved by mixing;

[0034] 3) bringing the test composition into contact with the hair fibers to be tested, in particular at room temperature, for at least 2 minutes, and preferably a maximum of 7 minutes, preferably a maximum of 5 minutes, so as to put the said hair fibers in a condition to interact with the test composition, the presence of a metal within the hair fibers resulting in the formation of bubbles at the level of these and possibly by the rise of the bubbles to the surface of the composition.

[0035] Sampling hair fibers avoids having to perform the test directly on the client's hair. This improves client comfort and also prevents the test from being performed on a hair fiber sample containing more fibers than necessary.

[0036] In particular, the invention allows the hairdresser to quickly determine the condition of his client's hair, the implementation of the process generally not exceeding more than 10 minutes, or even 5 minutes.

[0037] The sample preferably comprises between 10 mg and 100 mg of hair fibers.

[0038] The provision of the test composition may include the implementation of the preparation step.

[0039] The preparation step, in particular extemporaneous, may include mixing a first solution comprising at least one ammonium salt, with a second aqueous solution of hydrogen peroxide, in which preferably at least one polyol has been incorporated.

[0040] In an alternative embodiment, the preparation step may include mixing a first solution comprising at least one ammonium salt and preferably at least one polyol, with a second solution being an aqueous solution of hydrogen peroxide.

[0041] Preferably, said at least one polyol, when present, is already mixed with the aqueous hydrogen peroxide solution in the second composition available to the end user.

[0042] Classically, an aqueous solution of hydrogen peroxide is called hydrogen peroxide water. Thus, the second solution can be hydrogen peroxide water, for example, 20Vol to 60Vol hydrogen peroxide water, to which preferably at least one polyol is added. In particular, the second solution can consist of 70-90% by volume of 33Vol hydrogen peroxide, and the remainder in polyol.

[0043] The preparation step may include mixing the first basic pH solution comprising water and at least one ammonium salt in a concentration of between 0.5g and 0.9g per 100 mL of solution with the second solution composed, for example, of more than 10%, for example about 20%, by volume of polyol and the complement to 100% of hydrogen peroxide, for example hydrogen peroxide with a strength between 30 and 40 Vol, the volume ratio of the first solution to the second solution in the test composition being between 0.4 and 1.

[0044] The preparation step may include adjusting the pH of the composition, in particular the first solution, by adding ammonia.

[0045] In step 3), the hair fibers can be brought into contact with an amount of test composition between 5 mL and 15 mL, such an amount being well suited to a mass of hair fibers between 10 mg and 100 mg.

[0046] In embodiments of the invention, the test composition is prepared in contact with the hair fibers.

[0047] In other words, the supply of the composition can be carried out in parallel with the contact with the hair fibers, steps 2) and 3) of the process then being carried out simultaneously.

[0048] In particular, the process may include contacting the hair fibers with a first alkaline solution and then adding a second hydrogen peroxide solution. The first solution may further include at least one ammonium salt. The second solution may further include at least one polyol.

[0049] In the event of a positive detection of the presence of a metal, a remediation composition can be applied to the hair fibers so as to eliminate and / or isolate the detected metal.

[0050] This remediation composition is, for example, a hair composition containing at least one remediation active ingredient, for example, a shampoo, a coloring, a bleaching, a product intended for performing perms or a hair treatment.

[0051] Optionally, after application of the remediation composition, a new test on the hair fibers treated with the remediation composition is carried out, allowing the action of the remediation composition on the metal content of the hair to be evaluated.

[0052] Furthermore, the detection method may include backlighting the test composition during any gas release.

[0053] Backlighting makes it easier to distinguish the bubbles forming on the surface of the capillary fibers and possibly their rise to the surface of the composition of test. Such backlighting improves the accuracy of the test result evaluation. It can be applied from the back of the bottle containing the test composition or, better yet, from the bottom of the bottle. To ensure good visibility of bubbles, the bottle can also be placed against a black background and illuminated from below. Test composition

[0054] An alkaline pH is a pH strictly greater than 7. The pH of the test composition is determined at room temperature (20°C) and atmospheric pressure. The pH of the test composition is preferably between 8 and 11, in particular between 9 and 10.5.

[0055] The ammonium salt can be selected from ammonium carbonate, ammonium carbamate, ammonium hydrogen carbonate, ammonium sulfates, ammonium glycerophosphates, ammonium chloride, ammonium nitrate, salts of carboxylic acids such as ammonium acetate, ammonium fumarate, as well as ammonium salts of hydroxy acids such as ammonium gluconate, citrate, tartrate, lactate, ammonium malate, or ammonium salts of amino acids such as ammonium aspartate, arginate or ammonium glycocholate, and mixtures thereof.

[0056] The test composition may include several ammonium salts, in particular chosen from the preceding list.

[0057] Preferably, said at least one ammonium salt comprises a primary ammonium salt, preferably a carboxylic acid salt such as ammonium acetate.

[0058] In one embodiment, the test composition contains a single ammonium salt, and preferably the single ammonium salt is a primary salt, and even more preferably the single ammonium salt is a carboxylic acid salt such as ammonium acetate. Such a salt provides good results.

[0059] The total content of ammonium salt(s) preferably ranges from 0.08 to 1% by weight, preferably from 0.15 to 0.4% by weight, relative to the total weight of the composition.

[0060] The polyol is preferably a diol.

[0061] The polyol may be in particular a vicinal diol or a glycol, preferably the polyol is a glycol.

[0062] In particular, the polyol may be a glycol comprising between 2 and 7 carbon atoms, inclusive, preferably with a linear chain. The glycol preferably comprises between 4 and 6 carbon atoms, preferably with a linear chain. Even more preferably, the glycol has 5 carbon atoms.

[0063] A glycol in the sense of the invention is a diol in which the two hydroxyl groups are borne by different carbon atoms.

[0064] The polyol may in particular be pentylene glycol.

[0065] The total polyol(s) content can range from 0% to 25% by weight, preferably 6% to 15% by weight, relative to the total weight of the composition.

[0066] The total mass content of polyol(s), when a polyol is present, is preferably greater than or equal to 10%.

[0067] Hydrogen peroxide is preferably present in a content ranging from 2% to 8% by weight, preferably 3% to 6% by weight, relative to the total weight of the composition.

[0068] The mass ratio of polyol(s) / hydrogen peroxide can be between 1 and 5, preferably 2 and 4.

[0069] According to a preferred embodiment of the invention, the test composition comprises between 0.15% and 0.4% by weight of ammonium salt relative to the total weight of the composition, between 3% and 6% by weight of hydrogen peroxide relative to the total weight of the composition, between 6% and 15% by weight of polyol relative to the total weight of the composition, and between 2% and 4% by weight of water relative to the total weight of the composition.

[0070] Test set for the detection of metastasis 1 in 1 in hair

[0071] The invention also relates to a test set, also called a kit, for the detection of at least one metal, particularly copper, in hair fibers, comprising at least:

[0072] - a test composition as defined above, already ready for use, or compounds and / or solutions that, by mixing, allow such a composition to be achieved; and

[0073] - a container intended to receive the test composition and the hair fibers.

[0074] The container is advantageously at least partially transparent or translucent, in order to allow visualization of bubbles forming on the surface of the hair and possible backlighting of the composition and the hair present in the container.

[0075] The compounds and / or solutions which, by mixing, make possible the test composition may be supplied in at least two separate containers, which contain, for example, respectively a first aqueous solution buffered at alkaline pH comprising at least one ammonium salt and a second aqueous solution comprising hydrogen peroxide and preferably at least one polyol.

[0076] Alternatively, the second container contains only a polyol. Before mixing with the first solution, hydrogen peroxide can be added to the second container.

[0077] The container intended to receive the test composition and the hair may advantageously include a visual marker indicating the quantity of test composition required to test a predefined quantity of fibers, for example in the form of a graduation.

[0078] In particular, the visual guide may take the form of at least two graduations indicating the respective quantities to be provided of a first aqueous solution buffered at alkaline pH comprising an ammonium salt and a second aqueous solution comprising hydrogen peroxide and preferably a polyol, to be added to the first to make the test composition with the desired concentrations of each of its constituents.

[0079] The kit may include a fiber sampling wand and / or a lighting or backlighting device, preferably in the form of a light base intended to serve as a support for the container.

[0080] Preferably, the kit includes packaging containing the container and the test composition (ready to use or in the form of ingredients to be mixed), optionally a sampling wand and / or a lighting or backlighting device.

[0081] The lighting or backlighting device preferably has the form of a luminous base intended to serve as a support for the container, the latter being at least partially transparent or translucent.

[0082] The lighting or backlighting device may have an electrical power of at least 1 watt, preferably at least 1.5 watts.

[0083] The hair fiber sampling rod may include a shaft extending along a longitudinal axis X and having in its distal part a slit extending substantially longitudinally so as to form at least a first branch and at least a second branch, the length of the first branch being less than the length of the second branch.

[0084] The first and second arms, separated by the slot, allow for the selection and retention of hair fibers for extraction. Specifically, the longer second arm is used to select the hair fibers to be extracted. Once the desired quantity of hair fibers has been selected, the operator can slide them into the slot to secure them between the first and second arms of the wand. The operator can then wrap the hair fibers around the first and second arms before finally cutting them.

[0085] The distal part of the stem may be beveled and / or truncated.

[0086] In addition, the rod may include a gauge extending transversely to the axis longitudinal X.

[0087] The gauge advantageously allows for a more precise estimation of the quantity of hair fibers to be extracted, thus enabling calibrated, rapid, and accurate fiber extraction. In particular, the extraction of hair fibers from a head of hair by a hairdresser is unpleasant for clients. This is why it is essential to extract only a limited and necessary number of hair fibers. The presence of a gauge is particularly advantageous because it allows for the efficient collection of the optimal quantity of hair fibers.

[0088] The wand may alternatively or additionally include a retaining element intended to hold hair fibers to be taken from the stem.

[0089] Such a retaining element advantageously allows the collected hair fibers to be transported to a container without loss, while avoiding, where appropriate, any direct contact between the operator and the collected hair fibers.

[0090] The gauge may be a hole, an annular groove, or a recess intended to receive capillary fibers. In particular, the gauge may form a V flush with the stem.

[0091] It may also be advantageous to be able to pack the hair fibers taken from a container and / or to be able to extract them from the container.

[0092] For this purpose, the sampling rod may include an enlarged proximal part, for example with a diameter greater than that of a median portion of the rod.

[0093] The enlarged part can be formed by molding, cutting or be an added end piece.

[0094] The rod may alternatively or additionally include a hook at the proximal end of the rod.

[0095] The rod may have a length greater than 10 cm, and / or less than 20 cm, and preferably the length of the rod is between 13 cm and 17 cm, in particular substantially equal to 15 cm.

[0096] The invention also relates to a hair treatment system, comprising:

[0097] - at least one detection kit according to the invention,

[0098] - at least one remediation composition enabling the treatment of the presence of a metal in the hair in case of positive detection and / or

[0099] - at least one hair coloring or styling composition hair.

[0100] The entire treatment unit is advantageously packaged in a container.

[0101] The treatment assembly may include several treatment compositions hair, which may or may not be applied depending on the presence or absence of a metal in the hair fibers, these hair treatment compositions being in particular hair coloring compositions.

[0102] The treatment set includes, for example, at least one coloring composition suitable for coloring hair in the event of a positive test for the presence of metals and at least one coloring composition suitable for coloring hair in the event of a negative test for the presence of metals. Hair coloring process

[0103] The term "coloration" here refers to coloring or bleaching. In other words, hair coloring means a change in the color or shade of the hair, even if partial.

[0104] The invention also relates, according to another of its aspects, to a hair coloring process comprising the implementation of a process for detecting at least one metal on at least a part of the hair fibers forming the hair, then in the event of positive metal detection, the application of a remediation composition preferably on the whole of the hair before applying any coloring to the hair, and / or the application of a coloring adapted to hair contaminated by a metal, and in the event of negative metal detection the application of any coloring to the hair.

[0105] In particular, a composition suitable for hair containing a metal may be a low-lightening composition, or a composition containing specific metal-chelating agents such as glycine or a relatively large proportion of sequestering agents such as polyacids (EDTA, GLDA, EDDS).

[0106] The coloring process includes an application of the coloring to the hair which advantageously depends on the results of the implementation of the process for detecting at least one metal.

[0107] In one embodiment, the test and / or oxidation compositions are gelled. In particular, the gelling of the test composition can be adapted to facilitate visualization of gas evolution. Brief description of the drawings

[0108] The invention will be better understood upon reading the detailed description that follows, the non-limiting examples of its implementation, and upon examination of the accompanying drawing, on which:

[0109] [Fig. 1] [Fig. 1] schematically represents an example of a test kit for the detection of at least one metal in hair fibers,

[0110] [Fig.2] [Fig.2] illustrates an example of a treatment assembly comprising, among other things, a test kit for the detection of at least one metal in hair fibers,

[0111] [Fig.3] [Fig.3] schematically illustrates the steps of a treatment process comprising the prior implementation of a process for detecting at least one metal in hair fibers, and

[0112] [Fig.4] [Fig.4] is a block diagram illustrating steps in a hair coloring process.

[0113] In the following description, identical elements or elements with analogous functions bear the same reference symbol. Their description is not repeated opposite each of the figures, only the main differences between the methods of implementation being mentioned. Detailed description

[0114] Figure 1 illustrates a test kit 1 for the detection of at least one metal in hair fibers. Figure 2 illustrates a treatment set 3 comprising a test kit 1, a remediation composition 20, and a coloring composition 90. Test kit

[0115] A test kit 1 comprises at least one ready-to-use test composition 10, as illustrated in [Fig.1], or in the form of compounds or solutions contained in containers 14 and 15, to be mixed extemporaneously, and a container 11, as illustrated in [Fig.2].

[0116] The test composition at the time of use is an aqueous solution at alkaline pH comprising at least one ammonium salt, hydrogen peroxide, and preferably at least one polyol, in particular a glycol, as detailed previously.

[0117] The container 11 may include, as seen in [Fig.2], graduations 12, 13 indicating the quantities of compounds or solutions from containers 14, 15 to be mixed to obtain the test composition 10.

[0118] For example, the first graduation 12 corresponds to filling with an aqueous solution at alkaline pH comprising at least one ammonium salt from container 14 and the second graduation 13 indicates the complement to be provided in the second solution contained in container 15.

[0119] The compounds to be mixed to obtain the test composition are not necessarily in liquid form and at least part of them may be in solid form, for example in the form of powder, granules, or capsules.

[0120] The entire test kit is advantageously packaged in a 50 package, for example a blister, a cardboard box, or a bag.

[0121] The test kit 1 may further include, as illustrated in [Fig.1], a capillary fiber sampling wand 30 and / or a lighting device 40 configured to allow backlighting of the composition at the time of the test.

[0122] The container 11 may be at least partially transparent or translucent.

[0123] The lighting device 40 preferably has the form of a luminous base allowing backlighting of the container 11, when the latter is positioned on it.

[0124] In a particular embodiment, the light base 40 is configured so as to also allow the agitation of the test composition 10. For example, the base 40 can emit ultrasound and / or operate with a magnetic bar (not shown) to form a magnetic stirrer.

[0125] The test kit 1 can also be included in a hair treatment set 3, with a remediation composition 20 and / or at least a coloring composition 90.

[0126] The treatment assembly 3 may include several coloring compositions, each coloring composition being, for example, adapted to be applied to hair in which a certain level of at least one metal has been detected, so as to adapt the choice of coloring to the result of the test previously carried out. Detection method

[0127] Different stages of a hair treatment process 110 comprising the implementation of a detection process 100 of the presence of at least one metal in hair fibers are schematically shown in [Fig.3].

[0128] The detection method includes at least one step 101 of providing a test composition, and a step 103 of interacting hair fibers with the test composition.

[0129] In step 101, the test composition can be prepared by mixing compounds and / or solutions in a container.

[0130] Alternatively, the test composition is supplied already mixed, preferably directly in the container intended to receive the hair fibers.

[0131] The container can be positioned relative to a lighting device 40 as above, so as to allow backlighting of the test composition.

[0132] The method for detecting 100 the presence of at least one metal in hair fibers preferably includes a step of sampling hair fibers 102, for example by means of a sampling rod 30 as mentioned above.

[0133] The hair fibers taken can then be introduced, during step 103 of interacting the fibers with a test composition, into the container containing the test composition so as to allow the formation of a possible release of dioxygen gas on the surface of the fibers, the presence of such a release of gas indicating the presence of at least one metal in the hair fibers.

[0134] During an optional step 104, the amount of dioxygen released during step 103 is measured, allowing the determination of a metal level present in the capillary fibers.

[0135] Depending on the result of the test, i.e. depending on the presence of gas release or beyond an estimated metal level in the hair fibers, a remediation composition 20 can be applied to the hair fibers, during a step 105.

[0136] In a particular embodiment of the treatment process 110, after step 105 of applying the remediation composition, the steps of the process of detecting at least one metal in the hair fibers are repeated. Hair coloring process

[0137] Figure 4 is a block diagram representing steps in a coloring process 300 of a head of hair according to the invention.

[0138] The application of a hair coloring product produces a result that depends on the initial condition of the hair. Many parameters such as the starting color, the fragility of the hair, the texture, frequent swimming, the use of special treatments, and previous coloring applications can influence the final result.

[0139] The coloring process preferably includes a preliminary step 301 of evaluating the condition of the hair, depending for example on one or more of the following parameters: starting color, hair fragility, texture, frequenting swimming pools, use of special care products, previous application of coloring, and the composition of the desired coloring.

[0140] The coloring process 300 includes the implementation of the detection process 100.

[0141] Depending on the results, the assessment of the condition of the hair can be refined in a step 302.

[0142] If the amount of metal, in particular copper, in the hair is low or zero, and no color residue has been detected, then the desired color can be applied in step 305.

[0143] If the amount of metals, especially copper, in the hair is significant or average, for example greater than or equal to 50 ppm, a remediation composition may be applied 303.

[0144] If the presence of colour residues likely to impact the desired colouring is demonstrated, an alternative colouring may be applied in step 304.

[0145] After the application of a remediation composition in step 303, an alternative color may be applied in step 304 or the desired color is applied in step 305.

[0146] Optionally, after the application of a remediation composition in step 303, the metal detection process 100 is implemented again to verify that the metal content has indeed decreased. Tests

[0147] Tests were carried out to observe the effectiveness of a test composition according to the invention for the detection of at least one metal, in particular copper, in hair fibers.

[0148] We consider 9 samples E; of 60mg of hair fibers, i ranging from 1 to 9, each sample having been divided into two equal parts E;,i ; Ei>2.

[0149] For each Eu sample, the fibers of the sample are ground by a ball mill, so as to obtain a pellet of 30mg of ground hair fibers, an X-ray fluorescence measurement of the pellet is then carried out so as to determine a copper level in each sample.

[0150] Alternatively, an inductively coupled plasma optical energy spectrometry (ICP-OES) method is implemented from each sample E^ after mineralization of the latter with nitric acid to determine a copper content in each sample.

[0151] Then, for each sample Ei>2, the bubbling intensity is observed when said sample Ei>2 interacts with a given composition.

[0152] Samples E1, 2, E2, 2, and E3 are interacted with a composition Ci of 10mL consisting of 4mL of a solution containing ammonium acetate at a concentration of 0.77g / 100g of solution and 6mL of 40 Vol hydrogen peroxide. Composition Ci has a pH of 9.8.

[0153] Samples E4>2, E5>2, E6>2 are interacted with a 10 mL composition C2 consisting of 4 mL of a solution containing ammonium acetate at a concentration of 0.77 g / 100 g of solution and 6 mL of 33 Vol. hydrogen peroxide containing 20% ​​by volume of pentylene glycol. Composition C2 has a pH of 9.6.

[0154] The samples, E7>2, E8>2 and E9>2 are made to interact with a composition C3 of 42mL consisting of 2mL of an aqueous solution containing 20% ​​ammonia and 40mL of 20 Vol hydrogen peroxide. Composition C3 has a pH of 10.

[0155] Composition C3 (without ammonium salt) corresponds to a composition described in the prior art.

[0156] The observed bubbling intensities were determined with respect to a bubbling intensity scale ranging from 0 to 8, with 0 indicating an absence of bubbles. The reference scale is presented in Table 2.

[0157] The test results are listed in Table 1 below:

[0158] [Tab 1] Samples Metal concentration in sample Ei (parts per million, ppm) Test composition pH Intensity of bubbling observed during interaction of the test composition with the sample Ei>2 E! 0 Composition Ci 9.8 3.25 e2 50 Composition Ci 9.8 3.5 e3 200 Composition Ci 9.8 4.5 e4 15 Composition with polyol C2 9.6 0 e5 50 Composition with polyol C2 9.6 5 e6 200 Composition with polyol C2 9.6 8 e7 12 Composition outside the invention C3 10 3 e8 50 Composition outside the invention C3 10 3 e9 218 Composition outside the invention C3 10 3

[0159] A metal content of 0 ppm corresponds to the absence of any metal or the presence of metal in a negligible quantity. Generally, a metal content strictly below 30 ppm is considered low or negligible, a metal content strictly above 150 ppm is considered high, and a metal content between 30 ppm and 150 ppm is considered medium.

[0160] Sample E[j2, when interacted with composition Ci, produces a reaction leading to bubble formation even when no metal is present (metal concentration equal to 0 ppm). Furthermore, a metal concentration of 50 ppm corresponds to an average amount of metal in the hair fibers, while a concentration of 200 ppm corresponds to a high amount of metal in the hair fibers. The bubbling intensity is, however, relatively similar whether the metal concentration is low or zero (0 ppm), average (50 ppm), or high (200 ppm).

[0161] Similarly, when samples E7>2, E8>2, E9>2 are put into interaction with composition C3, they produce a similar bubbling intensity, even though the metal levels of samples E7> b E8> b E9> is respectively low, medium and high.

[0162] Samples E4 >2, E5 >2 and E6 2 were interacted with a test composition C2 according to the invention. These examples show that observing the intensity of bubbling, i.e., the presence of a more or less significant release of dioxygen, makes it possible to discriminate between a low metal content in capillary fibers. (15 ppm), a medium metal concentration (50 ppm), and a high metal concentration (200 ppm). Indeed, for a low metal concentration in the hair fibers (sample E4), no bubbles are observed. The metal concentration in the hair fibers is negligible. For a medium metal concentration in the hair fibers (sample E5), a medium bubble intensity is observed. Finally, for a high metal concentration in the hair fibers (sample E6), a high bubble intensity is observed, 8 on a scale of 0 (no bubbles) to 8. This demonstrates the benefit of including polyol in the test composition.

[0163] [Tab 2] Samples Cu titration of samples (ppm) Composition with which the samples Ei0 to En s were interacted pH of the composition Boiling intensity Eio 152 Composition consisting of 4mL of a solution containing ammonium acetate at a concentration of 0.77g / 100g of solution and 6mL of 30 Vol. hydrogen peroxide 9 1 En 152 Composition consisting of 4mL of a solution containing ammonium acetate at a concentration of 0.77g / 100g of solution and 6mL of 30 Vol. hydrogen peroxide. 9.2 2 E12 152 Composition consisting of 4 mL of a solution containing ammonium acetate at a concentration of 0.77 g / 100 g of solution and 6 mL of 30 Vol. hydrogen peroxide. 9.6 3 e13 152 Composition consisting of 4 mL of a solution containing ammonium acetate. 10 4 ammonium acetate at a concentration of 0.77g / 100g of solution and 6mL of 30 Vol hydrogen peroxide. E]4 152 Composition consisting of 4mL of a solution comprising ammonium acetate at a concentration of 0.77g / 100g of solution and 6mL of 30 Vol hydrogen peroxide. 10.2 5 e15 517 Composition consisting of 4mL of a solution comprising ammonium acetate at a concentration of 0.77g / 100g of solution and 6mL of 30 Vol hydrogen peroxide. 9.3 6 E16 517 Composition consisting of 4 mL of a solution containing ammonium acetate at a concentration of 0.77 g / 100 g of solution and 6 mL of 30 Vol. hydrogen peroxide. 9.6 7 e17 517 Composition consisting of 4 mL of a solution containing ammonium acetate at a concentration of 0.77 g / 100 g of solution and 6 mL of 30 Vol. hydrogen peroxide. 10 8

[0164] The invention makes it possible to perform a rapid analysis of the condition of the hair before applying a hair treatment, in particular a coloring product. Thus, it is possible to determine which hair products can be applied without risk of obtaining an undesirable result.

[0165] The detection method according to the invention can be implemented regularly so as to establish temporal monitoring of the quantity of metal present in a person's hair, and thus indicate suitable products to prevent or limit the contamination of their hair.

Claims

Demands

1. A method for detecting the presence of at least one metal, in particular copper, in hair fibers, comprising bringing the hair fibers into contact with a test composition (10) comprising, in an aqueous medium at alkaline pH, at least one ammonium salt, and hydrogen peroxide, so as to allow the formation of possible gaseous release of dioxygen on the surface of the hair fibers, the presence of such gaseous release revealing the presence of said metal in the hair fibers.

2. Process according to the preceding claim, the composition having a pH greater than or equal to 9.4, preferably 9.

6.

3. A method according to any one of claims 1 and 2, comprising a preliminary preparation step, in particular extemporaneous preparation, of the test composition.

4. A process according to any one of the preceding claims, the composition comprising at least one polyol.

5. A process according to any one of the preceding claims wherein the ammonium salt is selected from ammonium carbonate, ammonium carbamate, ammonium hydrogen carbonate, ammonium sulfates, ammonium glycerophosphates, ammonium chloride, ammonium nitrate, salts of carboxylic acids, in particular ammonium acetate, ammonium fumarate, as well as ammonium salts of hydroxy acids such as ammonium gluconate, citrate, tartrate, lactate, ammonium malate, or ammonium salts of amino acids such as aspartate, arginate, ammonium glycocholate, and mixtures thereof.

6. A process according to any one of the preceding claims wherein the ammonium salt is a primary ammonium salt, preferably a carboxylic acid salt, preferably ammonium acetate.

7. A process according to any one of the preceding claims, the composition comprising a polyol, the polyol being a diol, preferably a vicinal diol or a glycol.

8. A process according to any one of the preceding claims, the composition comprising a polyol, the polyol being a glycol having between 2 and 7 carbon atoms, preferably with a linear chain, and preferably a glycol having 4 to 6 carbon atoms.

9. A method according to any one of claims 4 to 8, wherein the polyol / hydrogen peroxide mass ratio of the test composition is between 1 and 5, preferably 2 and 4.

10. A method according to any one of the preceding claims 4 to 8, wherein the test composition comprises between 0.15 and 0.4% by weight of ammonium salt relative to the total weight of the composition, between 3 and 6% by weight of hydrogen peroxide relative to the total weight of the composition, between 6 and 15% by weight of polyol relative to the total weight of the composition, and between 2 and 4% by weight of water relative to the total weight of the composition.

11. A method according to any one of the preceding claims comprising the quantification of the dioxygen produced.

12. A method according to the preceding claim, comprising a comparison of the quantity of dioxygen produced or the corresponding quantity of metal with a reference value, in particular the comparison of the quantity of metal with a threshold value beyond which the quantity of metal present in the hair fibers is likely to alter a subsequent coloring treatment of said hair fibers, this threshold value preferably being chosen between 40 ppm and 200 ppm, in particular between 50 and 100 ppm.

13. A method according to any one of the preceding claims, comprising the following successive steps: taking a sample of hair fibers, in particular by means of a sampling rod (30); providing a test composition or providing compounds and / or solutions enabling such a test composition to be prepared by mixing; bringing the test composition into contact with the hair fibers to be tested, for at least 2 minutes, and preferably a maximum of 7 minutes, preferably a maximum of 5 minutes, so as to put said hair fibers in a condition to interact with the test composition, the presence of a metal within the hair fibers resulting in the formation of bubbles at the level of the latter and possibly in the rising of the bubbles to the surface of the composition.

14. A method according to any one of the preceding claims, wherein the composition is prepared in contact with the hair fibers.

15. A method according to the preceding claim, comprising bringing the hair fibers into contact with a first alkaline solution and then adding a second hydrogen peroxide solution.

16. A method according to any one of the preceding claims, wherein, in the event of positive detection of the presence of a metal, a remediation composition is applied to the hair fibers so as to eliminate and / or isolate the detected metal.

17. A method according to any one of the preceding claims, comprising backlighting the test composition during any gas release.

18. Test kit (1) for the detection of at least one metal in hair fibers, comprising at least: - a test composition (10) comprising in an aqueous medium at alkaline pH at least one ammonium salt, and hydrogen peroxide, the composition preferably further comprising at least one polyol, the composition being ready for use, or the kit comprising compounds and / or solutions enabling such a composition to be produced by mixing; and - a container (11) intended to receive the test composition and the hair fibers.

19. Kit according to the preceding claim, wherein the compounds and / or solutions enabling the test composition to be prepared by mixing are supplied in at least two separate containers, which preferably respectively contain a first aqueous solution buffered at alkaline pH comprising at least one ammonium salt and a second aqueous solution comprising hydrogen peroxide and preferably at least one polyol.

20. Kit according to any one of claims 18 and 19, comprising a package (50) in which the container and the test composition or the compounds enabling it to be carried out, and optionally a sampling wand (30), and optionally a lighting device (40), are packaged.

21. A hair treatment system comprising: at least one detection kit according to any one of claims 18 to 20, at least one remediation composition to treat the presence of a metal in the hair in the event of a positive detection and / or at least one hair coloring or hair styling product.

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