193 results about "Glyoxylic acid" patented technology

The invention relates to the technical field of polymer electrolyte, in particular to a self-repairing type gel polymer electrolyte membrane, a preparation method and application in an energy storage battery, the self-repairing type gel polymer electrolyte membrane is prepared by the following steps: dissolving amino-terminated polyethylene glycol in an organic solvent, adding trimesic acid under the protection of an inert atmosphere, heating, stirring and reacting to form a pre-polymerized solution, cooling, and then adding trimesic acid into the pre-polymerized solution to prepare a self-repairing type gel polymer electrolyte membrane; the preparation method comprises the following steps: adding glyoxylic acid and glacial acetic acid, carrying out a constant temperature reaction to obtain a solution A, adding LiTFSI into the solution A, carrying out ultrasonic dispersion to a homogeneous phase, pouring the obtained slurry onto a template, and carrying out a drying curing reaction to obtain the self-repairing gel polymer electrolyte membrane. A rigid aromatic cross-linking agent is used for inhibiting polymer crystallization and improving mechanical integrity, an imine bond-based dynamic covalent network is introduced to realize an autonomous interface repairing function at the working temperature of the battery, and meanwhile, a polyethylene glycol ether oxygen chain is used for constructing an efficient lithium ion transmission channel; therefore, the technical boundary that the conductivity, the mechanical strength and the interface stability of the traditional GPE are difficult to collaboratively optimize is broken through.

The invention discloses a liquid chromatography determination method for a mixed solution of glyoxylic acid, glycollic acid and oxalic acid and application. The method comprises the following steps: (1) preparing standard solutions with different concentrations; (2) detecting the standard solutions with different concentrations by using high performance liquid chromatography; (3) establishing a linear regression equation of each acid according to the relationship between the concentration of the standard solution and the corresponding peak area; (4) pre-treating a sample to be detected, detecting under the same condition as that in the step (2) by using high performance liquid chromatography, and recording the peak area of each acid in the sample to be detected; and (5) substituting the peak area of each acid in the to-be-detected sample into the corresponding linear regression equation, and calculating to obtain the concentrations of glyoxylic acid, glycollic acid and oxalic acid in the to-be-detected sample. The method is a liquid chromatographic determination method which is simple and convenient to operate, excellent in separation effect, mild in chromatographic condition and compatible with various detectors, can accurately quantify three strong-polarity mixed acids of glyoxylic acid, glycollic acid and oxalic acid, and has important practical application value.

The invention relates to the field of bioengineering, in particular to a construction method and application of recombinant yarrowia lipolytica with high succinic acid yield. The recombinant yarrowia lipolytica disclosed by the invention simultaneously expresses a reduced tricarboxylic acid pathway related gene, a glyoxylic acid circulation pathway related group, a heterologous dicarboxylic acid transport related gene and a mitochondrial transport related gene, and an endogenous dicarboxylic acid transport protein coding gene is also knocked out; and a natural promoter of an isocitrate dehydrogenase coding gene IDH1 is replaced. The recombinant yarrowia lipolytica constructed by the invention can produce 112.85 g / L of succinic acid after fed-batch fermentation under the condition of not controlling pH, and efficient synthesis of succinic acid in the yarrowia lipolytica is realized.

The invention discloses escherichia coli recombinant bacteria with high glycolic acid yield and a construction method of the escherichia coli recombinant bacteria, and belongs to the technical field of bioengineering. Lactate dehydrogenase ldhA, phosphate transacetylase pta, acetokinase ackA and pyruvate oxidase poxB are knocked out in escherichia coli, key enzymes isocitrate lyase aceA and glyoxylate reductase ghrA in a glycollic acid synthesis path are over-expressed in a genome level, conversion of carbon flow to glycollic acid is enhanced, and the glycolic acid is converted into glycolic acid. On the basis, malic acid synthase AaceB, malic acid synthase GglcB and glycollic acid oxidase glcDEF are knocked out, a branch metabolic pathway is blocked, an efficient strain which is free of plasmids and resistance genes and does not need to induce glycollic acid production is constructed, the accumulation amount of L-valine fermented in a 5L fermentation tank for 48 hours reaches 51.2 g / L, the yield is 0.6 g / g, and the production intensity is 1.06 g / L / h.

The invention discloses a core-shell structure adsorbent and a preparation method and a kit thereof, as well as a detection method for the concentration of styrene metabolites in plasma. The core-shell structure adsorbent includes ferroferric oxide magnetic microspheres, petal-shaped titanium dioxide coated on the surface of the ferroferric oxide magnetic microspheres, and a quaternary amine-carbon 18 bifunctionalized oligomeric polymer compound modified on a partial area of ​​the surface of the petal-shaped titanium dioxide. The core of the adsorbent of the present invention is ferroferric oxide magnetic microspheres, and the adsorbent as a whole is magnetic, which can achieve rapid solid-liquid phase magnetic separation, improve the sample purification efficiency, the titanium dioxide component in the material can effectively adsorb the phospholipid components in the plasma, and the quaternary amine-carbon 18 bifunctionalized oligomeric polymer component can effectively adsorb impurities such as fat and inorganic anions in the plasma, thereby effectively reducing the matrix interference effect in the sample detection process, so as to achieve the purpose of quickly and accurately detecting the concentration of trace phenylglyoxylic acid and mandelic acid in the plasma sample.

The invention belongs to the technical field of impurity separation, and particularly discloses a method for separating and purifying impurities in a process for preparing glyoxylic acid through oxalic acid electrolysis, a crystallization kettle is included, an isolation device is arranged in the crystallization kettle, and the isolation device comprises a conical top cover, a conveying pipe, an annular filter screen, a directional conveying assembly and a sealing assembly; the conical top cover is arranged at the axis of the crystallization kettle, an opening of the conical top cover faces downwards, and a plurality of fixing rods are fixedly connected between the top of the conical top cover and the inner wall of the side face of the crystallization kettle. According to the method, glyoxylic acid product solutions with different concentration specifications and the high-purity glyoxylic acid crystal can be obtained after the electrolyte is sequentially subjected to pre-evaporation, electrodialysis, secondary evaporation, cooling crystallization, solid-liquid separation, washing and drying and other procedures, so that the prepared high-purity glyoxylic acid crystal can be popularized and applied in the field of high-end medicine.

The invention discloses a preparation method of a biomass hard carbon negative electrode material, which is characterized by comprising the following steps: carrying out primary carbonization on a biomass material, sequentially introducing a phosphorus element, a boron element and a copper element, carrying out secondary carbonization on a modified hard carbon raw material, and introducing carbonyl to obtain the hard carbon negative electrode material. Preliminary carbonized powder, boric acid and phosphoric acid are added into a reaction kettle together for a low-temperature graphitization reaction, phosphorus and boron are introduced for a hard carbon raw material, the phosphorus can widen the spacing of a graphite layer, the boron can catalyze rearrangement of a graphitized carbon layer, then the hard carbon raw material and organic copper salt are mixed and ground in cooperation, secondary carbonization is conducted, and the hard carbon material is obtained. By introducing the copper element, graphitization of the product can be promoted, and meanwhile, copper atoms can also improve the conductivity; and glyoxylic acid is added to introduce carbonyl into the product, and the carbonyl can preferentially catalyze decomposition of the inorganic salt, so that decomposition of an organic solvent is inhibited, and then a uniformly distributed inorganic salt-rich SEI film is formed.

The invention discloses a device and a method for high-shear reinforced continuous synthesis of glyoxylic acid. The device comprises a first liquid storage bottle, a second liquid storage bottle, a continuous high-shear mixer and an intermittent high-shear mixer, the first liquid storage bottle and the second liquid storage bottle are connected with a feeding hole of the continuous high-shear mixer; the continuous high-shear mixer is connected with the intermittent high-shear mixer; the continuous high-shear mixer comprises a first feed port, a second feed port, a distributor, a rotor, a stator, a discharge port and a shell, the distributor, the rotor and the stator are arranged in the shell, the rotor is arranged outside the distributor, and the stator is arranged outside the rotor. According to the continuous high-shear mixer, high-speed shear force is generated through a rotor-stator structure to crush reactants into micron / nano-scale liquid drops, the liquid-liquid contact area is greatly increased, and efficient mass and heat transfer is achieved. Intermittent high shear further optimizes mixing, ensures efficient reaction, and improves the purity of the final product.

The application discloses a kind of corrosion and scale integrated fracturing fluid, and relates to fracturing fluid technical field.The fracturing fluid includes thickening agent, crosslinking agent, composite corrosion and scale inhibitor and water;The composite corrosion and scale inhibitor includes the first component and the second component with mass ratio of 3:0.5~1, wherein the first component is prepared by the reaction of polyethyleneimine, long-chain acrylate monomer, acrylic acid monomer and hydroxyethyl acrylate monomer, and the second component is prepared by imidazole compound containing a primary amine and glyoxylic acid.The corrosion and scale integrated fracturing fluid of the application has good compatibility between components, and at the same time, it has good corrosion and scale inhibition and anti-sloughing performance.

The invention belongs to the technical field of genetic engineering, and particularly relates to a genetically engineered bacterium for producing N-acetylneuraminic acid as well as construction and application of the genetically engineered bacterium. Accumulation of acetic acid is controlled by combining and applying different strategies: rational transformation is performed on an escherichia coli metabolic pathway, and acetic acid synthesis pathway related genes poxB, ackA and pta are knocked out to reduce acetic acid synthesis; the glyoxylic acid cycle is activated by knocking out the coding gene iclR of the glyoxylic acid cycle transcriptional regulation factor, and acetic acid overflow is reduced; the fermentation temperature is adjusted to control overall metabolism of cells to reduce acetic acid accumulation. Through comprehensive application of the strategy, the Neu5Ac production method capable of effectively controlling acetic acid accumulation is obtained, and the method has a good industrial application prospect.

The invention discloses a recombinant bacillus paralicheniformis and an application of the recombinant bacillus paralicheniformis in production of betaine. According to the invention, bacillus paralicheniformis Bp1 with heavy metal cadmium resistance is used as a chassis strain, and an de novo synthesis pathway which takes glucose as a substrate and synthesizes glycine betaine through glycolysis, glyoxylic acid pathway and glycine methylation pathway in sequence is established in the bacillus paralicheniformis, so that the survival rate of the glycine betaine in cadmium-polluted soil is increased; the effects of the microbial soil treating agent and the microbial fertilizer are improved, so that the growth of the plant-black nightshade with an enrichment effect on cadmium and the absorption of the black nightshade on the cadmium in the polluted soil are promoted.

A method of making paper and paperboard products, including absorbent structures, where the method includes mixing ultra-high molecular weight (“UHMW”) glyoxalated polyvinylamide (“GPVM”) adducts and high molecular weight (“HMW”) anionic polyacrylamide (“APAM”) with the furnish during stock preparation of a wet laid papermaking process.

A glyoxylate starch may be formed by dispersing a starch in a liquid to form a starch slurry. The starch may be one or more of a cationic starch, nonionic starch, and an anionic starch. 2-chloracetamide is added to the starch slurry mixture to form a first reaction mixture. The temperature of the first reaction mixture may then be raised, and then cooled to form a modified starch, and glyoxal may be added to the modified starch solution to form a second reaction mixture that may then be stirred to produce a glyoxylate starch.

The invention discloses a chemical plating method for plating copper on the surface of a silicon wafer, which belongs to the technical field of semiconductor coating, and comprises the following steps: modifying a semiconductor material BaTiO3 nanocrystal by a silane coupling agent to prepare quantum dot ink, spin-coating the quantum dot ink on the surface of a P-type silicon wafer cleaned by RCA to form a quantum dot array, and coating the quantum dot array on the surface of the P-type silicon wafer. The preparation method comprises the following steps: activating in a solution containing copper sulfate and trisodium citrate under the assistance of ultrasonic waves, carrying out chemical copper plating in a micro-fluidic reaction cavity by using an alkaline plating solution containing copper sulfate, disodium ethylene diamine tetraacetate and glyoxylic acid under the assistance of ultrasonic waves and lasers, and finally washing with deionized water and ethanol and drying with nitrogen to obtain a silicon wafer with a copper-plated surface. Through the BaTiO3 quantum dots, the micro-fluidic channel, the pulse liquid supply system and the auxiliary synergistic effect of the ultrasonic wave and the laser array, the copper film which is uniform in thickness, high in adhesive force, good in conductivity and excellent in corrosion resistance can be prepared, and the chemical copper plating efficiency and quality are improved.

The invention discloses a dual-mode optical fiber sensor and a glyphosate content determination and photo-thermal controlled release green conversion system and method. The integrated double-optical-fiber sensor capable of realizing specific detection and efficient degradation of glyphosate pollution comprises a first sensor for realizing glyphosate detection through local plasma resonance and a second sensor for realizing glyphosate degradation through a photothermal effect of a nano material layer. The glyphosate inhibits an enzymatic reaction of tyrosinase on the first sensor, causing an output spectral peak change. The detected solution releases glyphosate oxidoreductase through photo-thermal excitation of the second sensor, glyphosate is degraded into aminomethylphosphonic acid and glyoxylic acid, a degradation solution is generated and recycled for the first sensor, and multiple times of cyclic detection and degradation are achieved. The method has the advantages of simplicity and convenience in operation, small size, high detection sensitivity, low detection limit and the like, the glyphosate pollution detection and treatment efficiency is remarkably improved, and the method has good environmental protection property and economical efficiency.

The invention provides a copper-containing plating solution and a method for plating copper on the surface of graphene, and belongs to the technical field of chemical plating. The copper-containing plating solution provided by the invention comprises copper sulfate pentahydrate, hypophosphite, glyoxylic acid, ethylenediamine tetraacetic acid tetrasodium salt, sodium citrate and deionized water. The glyoxylic acid in the copper-containing plating solution can quickly provide electrons in the initial reaction stage, so that copper ions are quickly nucleated; hypophosphite can continuously reduce copper ions in the plating solution into copper atoms, and continuous growth of a copper layer is achieved; tetrasodium ethylene diamine tetraacetate and copper ions can form a complex with high stability, and the copper ions are slowly released; sodium citrate is used as an auxiliary complexing agent, so that the discharge potential can be adjusted, and the deposition process of copper ions is further optimized, so that compact coating of a to-be-plated copper matrix is realized, and the copper plating effect is effectively improved. Results of the embodiment show that the copper-containing plating solution provided by the invention can form a compactly coated copper layer on the surface of graphene.

The present invention relates to a process for the preparation of polyaminocarboxylic acids, in particular phenolic aryl- or alkyldiaminepolycarboxylic acids, preferably a compound of formula (I): wherein X is selected from the group consisting of: H, COOH, COO−Y+, OH, linear or branched C1-C5 alkyl, CH2OH, SO3H, SO3−Y+, wherein: —Y+ is independently selected from the group consisting of: Li+, Na+, K+, and NH4+; and wherein A is selected from: −A (CH2)n linear aliphatic system, wherein n=2, 3 or 4, preferably 2 or 3; and—an aromatic system of formula (II): wherein R1, R2 are independently selected from the group consisting of H, OH, and linear or branched C1-C5 alkyl; said process comprising the step of reacting, a phenol compound, glyoxylic acid and an aryl- or alkyldiamine in the presence of an iron source to obtain a reaction mixture comprising the compound of

This invention provides a method for synthesizing a sulfonylpyrazole intermediate, belonging to the field of herbicide intermediate preparation technology. The method includes a condensation reaction of glyoxylic acid and hydroxylamine to generate 2-(hydroxyimino)acetic acid, followed by a chlorobromination reaction of the 2-(hydroxyimino)acetic acid to generate a chlorobromination intermediate. The chlorobromination intermediate then reacts with isobutylene to generate a sulfonylpyrazole intermediate. The key feature is that the chlorobromination reaction is carried out in the presence of sodium bromide and chlorine. This invention can maintain a stable reaction environment while improving the yield and purity of the intermediate product.

The invention provides a method for high-selectivity preparation of synthesis gas and glyoxylic acid through photocatalysis of PET plastic. According to the method, the selectivity of a liquid product obtained by photocatalysis of the PET plastic is remarkably improved by controlling a single active oxygen species (specifically holes), and high-selectivity oxidation is realized. Furthermore, the proportion of carbon monoxide to hydrogen in the generated synthesis gas can be changed by regulating and controlling the mass ratio of cadmium sulfide to nickel aluminum hydrotalcite in the heterojunction composite material formed by compounding cadmium sulfide and nickel aluminum hydrotalcite. The method has the characteristics of low preparation cost, stable catalyst performance, simple preparation process, convenience in operation, environmental protection and the like, and has a very good application prospect.

This invention belongs to the field of conductor materials technology, and relates to a conductor paste for LED chip packaging and its preparation method. The invention provides a method for preparing a conductor paste, comprising: mixing copper powder and deionized water at a mass ratio of 1:5 to 1:7, dispersing evenly, adding triallyl citrate and sodium glyoxylate, and heating at 55-60°C for 1-2 hours; then adding γ-methacryloyloxypropyltrimethoxysilane and heating at 45-50°C for 1-2 hours; finally, vacuum drying to obtain antioxidant copper powder; and mixing the antioxidant copper powder, resin binder, solvent, and additives evenly to obtain the conductor paste. The conductor paste provided by this invention has excellent conductivity, good adhesion to LED chip substrates, and is not easily oxidized at high temperatures. This invention solves the technical problem of excessive sheet resistance in conductor pastes obtained by coating copper powder with γ-methacryloyloxypropyltrimethoxysilane to improve its antioxidant properties.

This invention proposes a method for synthesizing glyoxylic acid from methyl glycolate. Using methyl glycolate and oxygen / water as raw materials, glyoxylic acid is produced in a one-step process. This invention employs a novel catalyst based on ZSM-5 molecular sieve, modified with transition metals and organic bases, and finally extruded into strips. This catalyst can catalyze both oxidation and hydrolysis. This route is characterized by its simplicity, high reactivity, and high catalytic selectivity, making it a green route for glyoxylic acid synthesis.

This invention discloses a crystallization method for glyoxylic acid monohydrate, comprising the following steps: Step 1: Adding seed crystals to a drum granulator, the seed crystal mass being 9 times the mass of an 80% glyoxylic acid solution; Step 2: Adding the 80% glyoxylic acid solution to the drum granulator through spray guns located at the feed end of the drum granulator. The maximum flow rate of each spray gun is 2 t / h, and each spray gun is equipped with two solid conical atomizing nozzles with a solid cone angle of 55-60°. The number of spray guns is selected according to the production scale. This invention, by adding seed crystals at a mass of 9 times the mass of an 80% glyoxylic acid solution, allows the atomized 80% glyoxylic acid solution to mix with the seed crystals within the drum granulator, achieving rapid agglomeration and hardening of the mixture within a short time. After crystallization, the mixture is cooled. The product is graded according to particle size, with intermediate grades directly packaged. The implementation scheme is highly operable and economical to operate; it can be operated continuously and is suitable for large-scale industrial continuous production.

The invention belongs to the technical field of organic synthetic chemistry, and discloses a preparation method of an aromatic ketone compound, which comprises the following steps: by taking an unsaturated carbonyl compound obtained by condensing aryl acetaldehyde / acid and aldehyde / ketone molecules as a precursor, carrying out a reaction on the unsaturated carbonyl compound in the presence of a free radical precursor and molecular oxygen under the conditions of illumination and / or heating to obtain the aromatic ketone compound. And carrying out free radical mediated decarbonylation functionalization reaction in an organic solvent to obtain the aromatic ketone compound. The functional group contained in the free radical precursor is introduced to the alpha position of the ketone compound. By improving reaction participants and a reaction mechanism, the aromatic ketone compounds with various structures can be efficiently and highly selectively constructed in one step, the functionalization of the alpha position of the aromatic ketone compounds is synchronously realized, and the preparation method which is simple and convenient to operate, high in atom economy, green and environment-friendly is provided for the aromatic ketone compounds; the obtained compound is especially applicable to the fields of drug synthesis and synthesis of other materials.

The invention provides an aminomethylation reaction method based on a pyrazolo [1, 5-a] pyrimidine nitrogen-containing fused heterocycle substrate, a product and application, and belongs to the technical field of chemistry. Pyrazolo [1, 5-a] pyrimidine nitrogen-containing fused heterocycle, secondary amine and glyoxylic acid are used as raw materials, an aminomethylation reaction is achieved at the C3 site of pyrazolo [1, 5-a] pyrimidine through heating for the first time, a transition metal catalyst or a chemical oxidizing agent is not needed, the drug purification problem caused by metal residues and oxidation byproduct pollution are avoided, and the purity of the product is improved. The method is a novel efficient, simple, convenient and environment-friendly nitrogen-containing fused heterocyclic aromatic hydrocarbon functionalization strategy, the reaction can be directly carried out at the temperature of 100-120 DEG C, shielding gas does not need to be filled, and compared with some reactions needing high-temperature or high-pressure conditions, the mild reaction conditions are easier to control, side reactions are reduced, and the yield of the target product is increased. Meanwhile, the reaction conditions are also beneficial to reducing energy consumption, and conform to the concept of green chemistry.

The application discloses a method for industrial production of sulindac. The method comprises the following steps: condensation reaction of compound 1 (5-fluoro-2-1-(4-methylthio benzyl) indene) and glyoxylic acid under catalysis of an organic base (benzyl trimethyl ammonium hydroxide) to generate compound 2, isomerization reaction of the compound 2 under hydrobromic acid-acetic acid solution to generate compound 3, which greatly improves reaction conversion rate and yield, reduces three waste problems, and finally obtains compound 4 (sulindac crude product) through oxidation of the obtained compound 3 by hydrogen peroxide, and high-purity sulindac is obtained through recrystallization of the crude product by isopropyl alcohol. The raw materials and reagents used in the preparation process of the sulindac are relatively cheap and low in cost, the whole preparation process is mild in reaction condition, simple and safe in operation, and convenient for industrial production.

The utility model discloses a combined device for absorbing and treating glyoxylic acid synthesis reaction tail gas, and belongs to the technical field of chemical production devices and tail gas recycling. The device mainly comprises an absorption buffer tank, an A-stage absorption device, a B-stage absorption device, a C-stage absorption device, a D-stage absorption device, an induced draft fan, an activated carbon purification box, a harmless airflow outlet, a dilute nitric acid transfer tank and the like, the combined device for absorbing and treating glyoxylic acid synthesis reaction tail gas according to the technical scheme of the utility model effectively solves the problem of low absorption efficiency of a previous nitrogen oxide absorption device and the problem of low nitric acid content in absorption liquid, and is relatively beneficial to environmental protection and production cost control; the device also has the characteristics of safe process, convenience in operation and high production efficiency.

A construction composition comprises a) a cementitious binder comprising one or more calcium silicate mineral phases and one or more calcium aluminate mineral phases; b) optionally, an extraneous aluminate source; c) a sulfate source; d) an ettringite formation controller comprising (i) glyoxylic acid, a glyoxylic acid salt and / or a glyoxylic acid derivative; and (ii) at least one of a borate source and a carbonate source; and e) a polyol in an amount of 0.2 to 2.5 wt.-%, relative to the amount of cementitious binder a). The composition contains 0.05 to 0.2 mol of total available aluminate, calculated as Al(OH)4−, from the calcium aluminate mineral phases plus the optional extraneous aluminate source, per 100 g of cementitious binder a); and the molar ratio of total available aluminate to sulfate is 0.4 to 2.0. The construction composition exhibits high early strength and sufficient open time.

The invention relates to a method for producing a multilayer board in a cardboard machine. The multilayer board comprises at least two layers. A first fiber suspension comprising cellulosic fibers is obtained for the first layer and a second fiber suspension comprising cellulosic fibers is obtained for the second layer, the first and second fiber suspensions being different from each other and at least one of them comprising recycled cellulosic fibers. A multi-ply web is formed by combining a first ply and a second ply with each other, and then the web is wet-pressed at a press section. An acetaldehyde acidified polyacrylamide having a number average molecular weight of at least 15000 g / mol is added to the first fiber suspension and / or the second fiber suspension prior to forming the first layer and the second layer.

An object of the present invention is to provide a photosensitive composition capable of forming a pattern excellent in suppression of water stains after development and smoothness and having a small amount of change in line width.SOLUTION: Specifically disclosed is a photosensitive composition comprising a colorant (A), an alkali-soluble resin (B), a polymerizable compound (C) and a polymerization initiator (D), wherein the polymerization initiator (D) comprises a polymerization initiator (D1) represented by general formula (1) and a glyoxylate-based polymerization initiator (D2). (In General Formula (1), R1 and R2 each independently represent hydrogen atoms or alkyl groups having 1 to 8 carbon atoms. R3 represents hydrogen or a monovalent group. ) SELECTED DRAWING: Figure 1

COMPOSITIONS AND PROCESSES FOR REMOVING HAIR COLOR The disclosure relates to compositions and processes for removing color from keratinous fibers such as hair. The compositions include (a) at least one reducing agent selected from glutaric acid, glyoxylic acid, thiolactic acid, thioglycolic acid, glycolic acid, citric acid, or combinations of two or more of these, (b) at least one amino acid, (c) optionally, at least one amine compound, and (d) at least one solvent. Figure for abstract: none