Phosphoric Acid Solution Research Articles

Development of HPLC method for isomeric impurities of key starting material of novel oral anticoagulant drug; Edoxaban Tosylate Monohydrate

Reverse-phase high-performance liquid chromatography method has been developed for the determination of EDO-S1 stereoisomeric impurities such as isomer 1, isomer 2, isomer 3, isomer 4, isomer 5, isomer 6 and isomer 7 with good resolution using the column, Bakerbond C18 (150 × 4.6 mm; 3 μm). The separation was achieved with mobile phase-A (10 mM dipotassium hydrogen phosphate pH-7.0 with 10% orthophosphoric acid solution in Milli-Q water) and mobile phase-B (n-Propanol: Acetonitrile ratio of 20:30 % V/V), which consisted of mobile phase mixture in the combination of moilephase-A: mobile phase-B (85:15). The total run time was 30 min at 0.8 mL/min flow rate, 20 µL injection volume and 30 ℃ column oven temperature. The column eluate was monitored at 210 nm to quantify the impurities The method showed adequate specificity, sensitivity, linearity, accuracy, precision, and robustness inline to ICH tripartite guidelines. The limit of detection and quantification limits were 0.1 and 0.3 μg mL−1, respectively, for all isomeric impurities and EDO-S1. The developed method was found to be linear over the concentration range of LOQ to 150% of specification range for isomeric impurities with a correlation coefficient >0.999. The method was precise (%RSD < 5.0), robust, and accurate (with 85%–115% recovery).

Unveiling polycrystalline silicon channel dissolution mechanism in wet etching process of 3D NAND fabrication

3D NAND is one of the most promising storage devices due to its high storage density and low energy consumption. Selective wet etching of Si3N4 by hot-concentrated phosphoric acid (PA) solution is a key process for 3D NAND fabrication. However, the channel material, polycrystalline silicon (poly-Si), is unexpectedly dissolved due to its inevitable exposure to the PA etching solution, which causes device failure and thus limits the stacking density of 3D NAND. Herein, to avoid the detrimental dissolution of poly-Si, we unveil the mechanism of poly-Si dissolution in PA solution from kinetic and thermodynamic perspectives. We find that the etch process shows a two-stage reaction, in which H2O plays a key role in lowering the activation barrier for poly-Si etching. Further thermodynamic analysis demonstrates that poly-Si prefers to be oxidized by H2O to suboxide rather than to SiO2. Combined with surface chemistry characterization, we propose the dissolution mechanism as a two-stage process involving the dissolution of suboxide interface and bulk poly-Si, where the nucleophilic substitution of Si–H with Si–OH on bulk poly-Si surface determines the overall etch rate. This study advances the 3D NAND development by establishing a theoretical foundation for identifying and implementing efficacious strategies to impede detrimental dissolution.

(Invited) Preparation of N-Type and P-Type Doped Single Crystal Diamonds with Laser-Induced Doping and Microwave Plasma Chemical Vapor Deposition

In this study, n-type doped single-crystal diamonds were successfully prepared under normal temperature and pressure conditions using laser-induced doping. 248nm pulsed laser beams with nanosecond duration were irradiated on the single crystal diamond substrate immersing in an 85% phosphoric acid solution and it introduced phosphorus doping to form an n-type doped thin layer. The resistivity of the doped region significantly decreased compared to that of the single-crystal diamond. After depositing a titanium electrode, the resistivity of the doped film obtained by Van der Pauw Technique was determined to be 1.5×10-4 Ω·cm. Furthermore, p-type doped single-crystal diamonds were successfully prepared by introducing boron during the growth process using Microwave Plasma Chemical Vapor Deposition（MPCVD）. It was demonstrated that the proposed technique can introduce impurities into single crystal diamonds to form doped conductive thin layers.

Leaching kinetics of waste pharmaceutical blister package aluminium in phosphoric acid media

This study investigated the process of treating secondary aluminium recovered from waste pharmaceutical blister packages (WPBs) using phosphoric acid solutions as a potential strategy for recycling this currently non-recycled waste material. The findings indicate that, when recycling via the hydrometallurgical process, the aluminium passivated during leaching can be effectively counteracted by employing moderately concentrated phosphoric acid solutions (1.0 M), elevated temperatures (60–80 °C) and specifically the addition of H2O2 (1.25–2.5 vol.%). Under these conditions, complete extraction of aluminium was achieved within four hours. The estimated activation energy (∼82 kJ/mol) indicates that the leaching reaction is primarily limited by the chemical reaction rate rather than film diffusion. An aluminium phosphate solution could be obtained by leaching WPBs in a way that is suitable for subsequent aluminium phosphate crystallisation. This approach could provide a promising pathway for valorising aluminium from the currently under-utilised waste fraction of pharmaceutical blister packages.

Use of a natural rock material as a precursor to inhibit corrosion of Ti alloy in an aggressive phosphoric acid medium

The mechanism of interaction between magnesite mineral and phosphoric acid (0.001–0.5 M) in addition to the determination of the protective properties for Ti alloy (working electrode) in phosphoric acid both with and without an inhibitor have been investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. Results of electrochemical tests show that the corrosion resistance of titanium alloy in phosphoric acid solution only increased and hydrogen production decreased by either decreasing acid concentration or increasing immersion time associated with the thickening of the oxide film formed on the alloy surface. On adding magnesite, the corrosion resistance of Ti alloy is enhanced by increasing the phosphoric acid concentration (0.001–0.5 M) due to the formation of sparingly soluble magnesium phosphate film on the alloy surface that inhibits the effect of increasing hydrogen evolution reaction due to the pH value decreases. The increasing adsorption behavior of the magnesite inhibitor and decreasing its diffusion were deduced from EIS measurements. Thus, the addition of 3% magnesite minimizes the corrosion by forming a new protective film (Mg3(PO4)2), which differs from the traditional passive film and prevents the effect of the increase of hydrogen evolution. The surface morphology and chemical composition of the tested alloy were determined using scanning electron microscopy (SEM), Fourier transform Infra-Red spectroscopy (FTIR), X-ray diffraction (XRD), X-ray Fluorescence (XRF) and In situ Raman spectroscopy.

Novel high temperature proton exchange membranes based on functionalized poly(arylene dimethylamino benzene) polymers

The electrolyte membrane is a critical component in high temperature proton exchange membrane fuel cells (HT-PEMFCs). We have developed a new triarylmethane-backboned polymer, poly(p-triphenyl dimethylamino benzene) (PTDB), by using p-triphenyl and 4-(dimethylamino)benzaldehyde as monomers through a one-step straightforward Friedel-Crafts reaction. The presence of tertiary amine groups in PTDB enables strong interaction with phosphoric acid (PA) molecules. To improve PA doping content and proton conductivity, both copolymers containing biphenyl repeat unite and side-chain quaternized polymers are synthesized. Results show that the 3-bromopropyl trimethylammonium bromide grafted membrane (PTDB-QA) outperforms the poly(triphenyl-biphenyl-dimethylamino benzaldehyde) (P(Tx%-By%-DB)) copolymer membranes. After being doped in an 85 wt% PA solution at 80 °C, the PTDB-QA membrane exhibits a PA uptake of 160%, resulting in an anhydrous proton conductivity of 0.054 S cm−1 at 180 °C and mechanical strength of 10.1 MPa at room temperature. Under the H2-air condition without any back pressure, the peak power density of a single cell based on PTDB-QA/160%PA reaches 230 mW cm−2 at 160 °C. This work presents a promising new membrane for HT-PEMFC applications.

Experimental study on the mechanism and thermodynamics of extraction of Fe3+ from phosphoric acid solution

The new extractant (P12) was used to remove Fe3+ from the simulated liquid of wet process phosphoric acid in this work. The solubility of P12 in white oil under the action of P204(Di-(2-ethylhexyl) phosphate) and n-octanol is discussed in detail. Then, the effects of reaction temperature, reaction time, the volume ratio of extraction phase and aqueous phase (O: A), pH of the phosphoric acid solution(simulated solution) and various anions on the extraction process were discussed. The extraction efficiency increases with the increase of extractant P12, the decrease of pH and the increase of O: A. Under the condition of pH=0.2, O: A= 1:1, the extraction efficiency of P12=5 %, 7 % and 9 % can be up to 70.86 %, 81.84 % and 90.93 % respectively. The extraction mechanism and extract composition were determined by slope method, FTIR and SEM. The ΔH< 0, ΔG< 0, ΔS < 0 in the extraction process proves that the extraction process was a spontaneous and exothermic process. The extraction mechanism proves that the extraction process involves both cation exchange and complexation of extractant. The composition of the extract may be [Fe(H2PO4)2.4A0.6(HA)0.84(H2O)](o), [Fe(H2PO4)2.2A0.8(HA)1.12(H2O)](o). And stripping efficiency of 5.5 M HCl can reach 100 % at A: O=4:1, ΔH=38.9357 kJ/mol in stripping process prove that it is endothermic.

Determination of antibiotics of the tetracycline group in water by high-performance liquid chromatography on a diode matrix detector with preliminary concentration by solid-phase extraction

Introduction. Antibiotic contamination of the environment is a serious environmental threat that poses a hazard to human health. To monitor the content of tetracycline antibiotics in environmental objects and control technological processes aimed at their disposal, accessible analytical methods are needed. &#x0D; Purpose of the study. Development of a method for determining antibiotics of the tetracycline group in water using a diode array detector with preliminary solid-phase concentration.&#x0D; Material and methods. The objects of the study were model solutions of minocycline, tetracycline, oxytetracycline, demeclocycline, metacycline, and doxycycline in deionized, tap, natural, and treated wastewater. For solid-phase extraction, Diapak P and Diapak PG cartridges were used. SPE was performed using a VacMaster-10 manifold (Biotage). Chromatographic separation was carried out on Diasphere C10CN and Kromasil Eternity 250 × 4.6 mm 5 µm columns on an Agilent 1100 liquid chromatograph (Agilent Technology).&#x0D; Results. Optimal conditions for the chromatographic separation of minocycline, tetracycline, oxytetracycline, demeclocycline, metacycline, and doxycycline were selected: isocratic mode, wavelength of 350 nm, mobile phase – acetonitrile: aqueous solution of phosphoric acid (pH = 3.0). The analysis time on Diasphere C10CN and Kromasil Eternity columns was 12 and 14 minutes, respectively. The reliability of the linear approximation in both cases was more than 0.99, however, the slopes on the Kromasil Eternity column were 1.35 –1.65 times higher than on Diasphere C10CN. The degree of extraction of tetracyclines from deionized water on Diapak P and Diapak PG cartridges was 90–95%, from tap water 61–89%, from purified waste water: 51–87%.&#x0D; Limitations. The method is not suitable for water bodies with tetracycline contents less than 2 µg/dm3.&#x0D; Conclusion. An HPLC method has been developed for the determination of minocycline, tetracycline, oxytetracycline, demeclocycline, metacycline, and doxycycline in water with preliminary SPE concentration on Diapak P and Diapak PG cartridges. The lower limit of determination for the sorption of target compounds from 0,1 dm3 of sample was 2 μg/dm3.

Inhibitory protection of low-carbon steel in solutions of hydrochloric, sulfuric, and phosphoric acids

Inhibitory protection of low-carbon steel in solutions of hydrochloric, sulfuric, and phosphoric acids

Quality Evaluation and Identification of Phyllanthi fructus (Yuganzi) Based on the Spectrum-Effect Relationship

To establish a quality evaluation and identification method for Phyllanthi fructus (Yuganzi), the spectrum-effect relationship was explored. A high-performance liquid chromatography (HPLC) fingerprint was established using ultraviolet spectrophotometry, and the in vitro antioxidant activity was determined using a total antioxidant capacity assay kit. Similarity analysis, hierarchical cluster analysis (HCA), and partial least squares regression (PLSR) were performed to establish the spectrum-effect relationships. Thirteen batches of Yuganzi were collected for testing. The results revealed that the optimal chromatographic conditions for the HPLC fingerprint were as follows: the mobile phase consisted of 0.1% phosphoric acid solution (A) and acetonitrile (B), the detection wavelength was 214 nm, the column temperature was 30 °C, and the flow rate was 0.8 mL/min. Among the batches of samples, the similarity values of 10 samples (S1–S10) from Yunnan were larger than 0.995; the similarity values of 3 samples (S11–S13) from India, Gaoligong Mountain, and Fujian were less than or equal to 0.986. Furthermore, nineteen characteristic peaks of Yuganzi were calibrated using fingerprint evaluation software. The study on the spectrum-effect relationship further revealed that compounds corresponding to peaks 5 and 8 were potentially key ingredients for the quality evaluation and identification of Yuganzi, closely related to the stable antioxidant activities of Yuganzi. The spectrum-effect relationship is an agile and efficient approach that can ensure the intra-assay stability of Yuganzi from same region and identify Yuganzi from different regions. Compounds with antioxidant activity can be identified as quality markers for Yuganzi.

Covalently crosslinked poly(biphenyl dimethylamino benzene) membranes for high temperature proton exchange membrane fuel cells

The electrolyte membrane plays a pivotal role in high temperature proton exchange membrane fuel cells (HT-PEMFCs). Herein, we develops a new triarylmethane-backboned polymer, poly (biphenyl dimethylamino benzene) (PBDAB), synthesized through a facile one-step Friedel-Crafts reaction using biphenyl and 4-(dimethylamino) benzaldehyde as monomers. The presence of tertiary amine groups in PBDAB facilitates strong interactions with phosphoric acid (PA) molecules. To enhance the membrane's dimensional and mechanical stabilities, covalent crosslinking is performed via the Menshutkin reaction between the tertiary amine groups in PBDAB and chloromethyl groups in various crosslinkers. In order to study the influence of crosslinker chemical structure on the properties of PBDAB-based membranes, five different crosslinkers are employed, including small-molecule types such as 1,2-bis(2-chloroethoxy) ethane (BCE) and 1,4-bis(chloromethyl) benzene (BCB), siloxane type 3-chloropropyl (trimethoxy) silane (CTS), polymer types such as poly (vinylbenzyl chloride) (PVBC) and polyepichlorohydrin (PECH). Results reveal that the flexible and ether containing polymer crosslinker of PECH crosslinked membrane, denoted as CL-y%PECH, exhibits superior overall performance. When doped in an 85 wt% PA solution, the CL-5%PECH membrane achieves a PA uptake of 201%, resulting in an anhydrous proton conductivity of 0.064 S cm−1 at 180 °C and a mechanical strength of 7.2 MPa at room temperature. Using H2 and O2 as fed gases without humidification and backpressure, a single cell with abovementioned membrane attains a peak power density of 302 mW cm−2 at 160 °C. This work offers a kind of promising PBDAB based membranes for HT-PEMFC applications.

Communication—Anodization of Aluminum in Phosphoric Acid Containing Glycerol at 30 °C

Aluminum was anodized in a phosphoric acid solution containing glycerol. Anodization in high concentration and high temperature electrolytes typically faces challenges due to the chemical dissolution of the anodic film. However, we found that the maximum attainable film thickness could be doubled by incorporating glycerol into the electrolyte. This enhancement was more effective under conditions of high concentration and temperature than in environments with lower concentrations and temperatures.

Soluble Troger’s base-based polybenzimidazoles containing naphthalene units with improved phosphoric acid tolerance for use as high-temperature proton exchange membranes

Most Troger's base (TB)-based polymers reported for high-temperature proton exchange membranes (HT-PEMs) exhibit low phosphoric acid (PA) tolerance due to excessive swelling in PA solution. In this work, a novel dicarboxylic acid monomer containing both naphthalene and TB units (TB-N-COOH) was successfully synthesized, and the corresponding TB-based PBI homopolymer (TB-N-HPBI) was prepared for HT-PEM fuel cells (HT-PEMFCs). In addition, naphthalene units were incorporated into TB-based PBI copolymers (TB-N-CoPBIs). The resulting TB-N-HPBI and TB-N-CoPBIs exhibited high molecular weight and excellent solubility in organic solvents (e.g., DMSO and NMP) because of the twisted TB units. The incorporated naphthalene units significantly improved the oxidative stability. More importantly, the existed naphthalene units in polymer backbones endowed the membranes with excellent PA tolerance capability because of the rigid structure and poor affinity to PA, which limited excessive swelling in 85 wt% PA solution and hence promoted acid uptake capability. Among of them, the TB-N-HPBI membranes showed ultrahigh PA uptake of 508.6%, and resulting in the proton conductivity of 201 mS cm−1 at 160 °C under non-humidity conditions, which are far superior to most reported TB-based polymer membranes. In addition, the maximum peak power density (H2/air) of 437.2 mW cm−2 was achieved. Our present work demonstrated that the incorporation of the naphthalene units into TB-based PBI significantly promoted the improvement of comprehensive performance for HT-PEMFCs.

Capillary zone electrophoresis method for quantification of therapeutic peptide glatiramer acetate

This study presents the development and validation of a novel capillary zone electrophoresis method for the precise determination of glatiramer acetate and its amino acid constituents. A 120 mmol dm−3 phosphoric acid solution adjusted to pH 1.9 with Tris, supplemented with 20 mmol dm−3 triethylamine to achieve a final of pH 2.1, resulted in a repeatable analysis of glatiramer acetate. The method demonstrated a limit of detection and quantification of 39.2 µg cm−3 and 130.7 µg cm−3, respectively. This method allows for the rapid control of glatiramer acetate-based pharmaceuticals and distinguishes glatiramer acetate from the amino acids used in its synthesis.Graphical abstract

Recovery of uranium from phosphate ore of Iran mine: Part II- solvent extraction of uranium from wet-process phosphoric acid

The current study in laboratory scale was aimed at developing an optimal two-stage extraction process for production of yellow cake from the phosphoric acid solution that was extracted from the Sheikh Habil phosphate rocks in central Iran. To attain an optimized extraction process, different mixtures of D2EHPA + TOPO + TBP were examined. A total extraction cycle including extraction, stripping and yellow cake precipitation was run to realistically evaluate the performances of the selected mixtures-conditions. As for optimization of the operational conditions, we exploited central composite design (CCD) method, that is a branch of the surface response methodology (RSM), and analyzed the results with standard statistical methods. The O/A (organic to aqueous ratio) = 2, 11 min extraction time, 5 wt% TOPO concentration, 10–15 wt% TBP concentration, 20 wt% D2EHPA concentration, 800 mv oxidation-reduction potential, and 25 °C temperature were obtained as optimum extraction parameters. The O/A = 15, 11 min stripping time, 50 wt% phosphoric acid concentration, 250 mv oxidation-reduction potential, and 40 °C temperature were obtained as optimum stripping parameters. Finally on the last uranium extraction from the H3PO4 strippant on the optimum conditions, the concentration of uranium was more than 4500 ppm with extraction efficiency near to 90 %. Scrubbing of organic phase was done by 2 wt% of sulfuric acid solution at 40 °C and precipitation of ammonium uranyl carbonate (AUC, (NH4)4UO2(CO3)3) was done with 2 M ammonium carbonate solution at an O/A ratio of 1/2 with efficiency more than 95 % in the uranium precipitation process.

Densification of hydroxyapatite through cold sintering process: Role of liquid phase chemistry and physical characteristic of HA powder

Hydroxyapatite is a well-known bioactive material widely employed in bone regeneration applications. Densifying hydroxyapatite at the nanoscale remains challenging with conventional sintering methods. This investigation focuses on the densification of commercially available nano-hydroxyapatite powders through the cold sintering process, utilizing water, acetic acid, and phosphoric acid solutions as transient liquids under 360 MPa pressure at 200 °C. The study systematically examines the influence of physical parameters of hydroxyapatite powder, liquid nature, and ionic concentrations of acid solutions on densification and microstructural characteristics. The relative density of consolidated samples varied with respect to the ionic concentration of the acid solution. Notably, a maximum relative density of 90% has been achieved for hydroxyapatite cold sintered using 2 M phosphoric acid solution without changing the original phase of hydroxyapatite. Overall, this study offers valuable insights into the impact of liquid chemistry on the densification of hydroxyapatite using the cold sintering technique.

Synthesis of Activated Carbon from Cassava Peeling and Its Applications for Removal of Methylene Blue

The present work aims to increase the value of cassava peelings by its transformation in activated carbon. The activated carbon was prepared by chemical activation using 40% of phosphoric acid solution as activation agent with an impregnation rate equal to 1.5 g of acid/g of precursor. The carbonization was carried out at 400°C for 90 minutes. Bohem titration and the Lopez-Ramon method were used to determine the chemical characteristics of the prepared activated carbon (ACCP), while surface area of the sample was estimated by methylene blue and iodine index methods. The best kinetic model that describes the adsorption reaction of MB on ACCP activated carbon is the pseudo-second-order model. Adsorption isotherm was also evaluated. Activated carbon (ACCP) has the following characteristics: pH&amp;lt;SUB&amp;gt;PZC&amp;lt;/SUB&amp;gt;= 3.9; Iodine index value equal to 914.4 mg/g and methylene blue index value equal to 643.72 mg/l. ACCP has more acid functions (5.95 meq/g) than basic function (1.3 meq/g). The “batch method” was used for pollutant removal and it reveals that the contact time value is equal to 40 minutes. The influence of activated carbon mass on its methylene blue adsorption capacity was studied. The experimental data are in agreement with the Langmuir and Freundlich isotherm models. The maximum adsorption capacity obtained using Langmuir isotherm model was 75.93 mg/g.

The method of determination for 2, 3-Butanedione in the air of workplace by high performance liquid chromatography with derivatization

Objective: To establish a method for the determination of 2, 3-Butanedione (BUT) in the air of workplace, which including the process of collection by absorption in phosphoric acid aqueous solution and the process of analysis and detection by high performance liquid chromatography with derivatization. Methods: In October 2022, a porous glass plate absorption tube containing 10 ml of 0.01% phosphoric acid solution was used to collect BUT in the air of the workplace at a flow rate of 0.2 L/min. The absorption solution was derived by 2, 4-dinitrophenylhydrazine for 75 min and separated on a SB-C18 column (250 mm×4.6 mm, 5 μm) . At the column temperature of 30 ℃, the mixture of acetonitrile-water (V∶V, 1∶1) was eluted at the flow rate of 1.0 ml/min. It was detected by UV detector (λ=365 nm) , qualitatived by retention time and quantitatived by external standard. Results: It showed that BUT in phosphoric acid aqueous solution could be stored for at least 7 d at 4 ℃. There was a linear relationship within the determination range of 0.05-6.00 μg/ml, the linear regression equation was y=89.610x+0.133, r=0.9999. The sampling absorption efficiencies were 98.33%-100.00%, the detection limit of the method was 0.005 μg/ml, the minimum detection concentration was 0.016 mg/m(3) (based on V(0)=3.0 L) . The recovery rates were 95.96%-102.44%, the intra batch precision were 4.36%-7.78%, and the inter batch precision were 4.96%-6.06%. Conclusion: The method has the advantages of simple operation, high sensitivity and good accuracy. It can prevent the loss and degradation of BUT. It can be used for the determination of BUT in the air of workplace.

Influence of Physical and Chemical Activation of Coconut Shell Applied to Reduce Free Fatty Acids of Used Cooking Oil in Biodiesel Plant

This research was conducted to compare the characteristics of activated carbon that synthesized via different methods, physical and chemical activation. It was applied to reduce Free Fatty Acids (FFA) in used cooking oil which will be used in the manufacture of biodiesel. Physical activation was carried out by heating dried coconut shell in a tube furnace at 900°C in N2 gas flowing, by varied the holding time; 2 hours, 3 hours, and 4 hours. Meanwhile, chemical activation was conducted using phosphoric acid solution with various concentrations: 9%, 10%, and 11%. The BET (Brunauer-Emmett-Teller) test was processed to determine the surface area of ​​the activated carbon. The FFA test was conducted to determine the FFA content in treated used cooking oil. The activated carbon with chemical activation has a surface area of ​​260.57 m2/gram, 323.55 m2/gram, and 162.21 m2/gram at concentrations of phosphoric acid 9%, 10%, and 11%, respectively. Meanwhile, for physical activation, the surface area were 278.58 m2/gram, 448.368 m2/gram, and 444.74 m2/gram with variations in heating holding time of 2 hours, 3 hours, and 4 hours, respectively. The lowest levels of FFA are found in cooking oil with a phosphoric acid concentration of 11%, which is 1.505%. The higher the concentration of chemical activator, the greater the adsorption power of an activated carbon. The lowest levels of fatty acids are found in cooking oil with a holding time of 4 hours, which is 1.805%. FFA (Free Faty Acid) test results show that the longer the heating holding time, the better the activated carbon will be.

Analysis of the adsorption mechanism of phosphoric acid-modified bamboo charcoal for chlorogenic acid based on density functional theory

BackgroundBamboo charcoal has garnered wide recognition as an adsorbent owing to its stability and availability. Phosphoric acid modification contributes to forming specific functional groups on the surface of bamboo charcoal, culminating in the augmentation of its adsorption capabilities.ResultsThe modification process in this study involved impregnating the bamboo charcoal in a 45% mass fraction of phosphoric acid solution with a 1:10 ratio (bamboo charcoal powder to phosphoric acid), followed by activation at a temperature of 500 °C for a duration of 1.5 h. The modification resulted in the formation of hydroxyl, carboxyl, and phosphate groups on the surface of the bamboo charcoal. Furthermore, the specific surface area of the modified bamboo charcoal surged from 4.91 m2/g to 115.18 m2/g, the average aperture decreased from 7.15 nm to 1.99 nm, and the pore volume escalated by 6.5 times. On this basis, a comparison in the adsorption capability for chlorogenic acid, a natural small-molecule active ingredient, was drawn before and after the modification of bamboo charcoal. The results indicate that the modified bamboo charcoal showcases an impressive 46.8-fold increase in its adsorption capacity when juxtaposed with the unmodified bamboo charcoal. Through the calculations based on density functional theory (DFT), the addition of functional groups on the surface of the modified bamboo charcoal module allows for the formation of hydrogen bonds with the chlorogenic acid module, with the highest binding energy reaching − 57.59 kJ/mol.ConclusionAs evidenced by the adsorption kinetic studies, the curve of modified bamboo charcoal for chlorogenic acid abides by a first-order kinetic equation. Additionally, adsorption thermodynamic studies reveal that the curve of modified bamboo charcoal for chlorogenic acid conforms to the Boltzmann equation. These results shed light on the mechanism of selectively adsorbing specific constituents using phosphoric acid-modified bamboo charcoal, thereby providing a solid theoretical foundation for the application of bamboo charcoal.Graphical