Adsorption Of Paracetamol Research Articles

Imprinted silicas for paracetamol preconcentration prepared by the sol–gel process

Paracetamol-imprinted silicas were prepared by three sol–gel routes, including two basic-catalyzed gelification and precipitation routes, and an acid-catalyzed route. The resulting materials from basic gelification were subjected to Soxhlet, ultrasound and thermal extractions, and characterized by infrared spectroscopy, elemental analysis, nitrogen porosimetry, scanning electron microscopy, and atomic force microscopy. Ultrasound was shown to be the most efficient for template extraction. The resulting materials showed surface areas between 30 m2 g−1 (for the precipitation route) and 200 m2 g−1 (for the acid-catalyzed route). After paracetamol extraction, the resulting surface area was between 30 m2 g−1 and 290 m2 g−1. The presence of paracetamol was confirmed by the presence of an infrared absorption band at 1546 cm−1, which is assigned to ν (C=O). The adsorption of paracetamol from aqueous and urine matrixes on the imprinted materials produced by the acid-catalyzed route was ca. 60% of the nominal concentration present in such matrixes. In the silica without molecular imprints, the preconcentration was ca. 20%.

Adsorption of amoxicillin and paracetamol on modified activated carbons: Equilibrium and positional entropy studies

Two activated carbons were modified with iron benzoate and cobalt (MAC-1), and with iron oxalate and cobalt (MAC-2) to study the adsorption process of two pharmaceutical molecules named amoxicillin (AMX) and paracetamol (PCT). For this objective, a network of adsorption isotherms was well recorded at different temperatures ranged from 25 to 50°C. New explanations were deduced by application the double layer model with two adsorption energies on adsorption isotherms formulated by the statistical physics approach. By investigation the number of adsorbed molecules per site, a lateral interaction between the (AMX) and (PCT) pharmaceutical molecules and modified activated carbons was successfully described. In addition to this, an aggregation phenomenon of AMX and PCT was studied and interpreted. When the adsorption saturation is reached; an adsorbed quantity was calculated and interpreted of each pharmaceutical molecule on both adsorbents indicating that the MAC-2 adsorbent could present higher efficiency for wastewater treatment. Thermodynamically, the positional entropy was treated giving a good explanation of AMX and PCT pharmaceutical molecules arrangement on modified activated carbons during the adsorption period.

Pharmaceuticals removal by activated carbons: Role of morphology on cyclic thermal regeneration

This work aims to evaluate the performance of activated carbons as reusable adsorbents of pharmaceutical compounds. To achieve this objective, the behaviour of carbons with different morphologies (powdered, granular and cloth) in the adsorption of paracetamol and clofibric acid from aqueous solution was studied; as well as the thermal regeneration of paracetamol saturated activated carbons at 400 and 600°C. For that, the properties of the carbon materials were characterized by N2 and CO2 adsorption, pHPZC, XPS, TG, XRD and SEM. Kinetic results showed the importance of supermicropore volume for the diffusion of the probe molecules towards the adsorption active sites, and the negative effect of granular form which led to significantly lower adsorption rates. Paracetamol adsorption followed a Langmuir mechanism in almost all cases, whereas clofibric acid adsorption generally occurred through a more complex mechanism. This behaviour was explained considering the nature of the clofibric acid species present in solution. This compound was always the most adsorbed molecule, reaching a maximum adsorption capacity of ∼500mgdm−3 in the case of carbon cloth.Thermal regeneration proved to be an efficient methodology to recover the porosity of the granular and cloth paracetamol exhausted activated carbons. After the second regeneration treatment at 400°C both activated carbons retained around 57% of their initial paracetamol uptake.The conjugation of the adsorption and regeneration results pointed out the benefits of the carbon cloth (in felt form) morphology which, being an easy handling sample, gathered the performance of the best powdered sample assayed in adsorption experiments, with the behaviour of granular carbon upon regeneration.

Removal of pharmaceutical industry pollutants by coal-based activated carbons

Several studies have demonstrated the presence of pollutants from the pharmaceutical industry in surface and groundwater. The main inputs of pollutants come from households, hospitals and the industry and many of these compounds are not completely removed by WWTPs. The purpose of this research is to study the adsorption of paracetamol, phenol and salicylic acid using coal-based activated carbons. A lignite from Mequinenza (M) and an anthracite from Coto Minero Narcea (CN) from Spain were chemically activated with alkaline agents obtaining two activated carbons (MAC and CNAC). Two commercial activated carbons widely used in water treatment (F400 and NPK) were selected for comparison purposes. The activated carbons were characterized and the results showed a high surface BET (1839m2g−1) and total pore volume (0.83cm3g−1) on CNAC while MAC was characterized by high sulphur content (6%). Vapour isotherms indicated a chemical interaction between the surface functional groups of MAC and the water molecules. The highest uptake of the three pharmaceutical compounds was achieved by CNAC. MAC showed a high affinity for anion salicylates (at pH 4–8). The maximum adsorption capacity of the pollutants onto the activated carbons followed the order salicylic acid>phenol>paracetamol which can be explained by hydrophobicity.

Removal of paracetamol on biomass-derived activated carbon: Modeling the fixed bed breakthrough curves using batch adsorption experiments

The remediation of paracetamol (PA), an emerging contaminant frequently found in wastewater treatment plants, has been studied in the low concentration range (0.3–10mgL−1) using as adsorbent a biomass-derived activated carbon. PA uptake of up to 100mgg−1 over the activated carbon has been obtained, with the adsorption isotherms being fairly explained by the Langmuir model. The application of Reichemberg and the Vermeulen equations to the batch kinetics experiments allowed estimating homogeneous and heterogeneous diffusion coefficients, reflecting the dependence of diffusion with the surface coverage of PA. A series of rapid small-scale column tests were carried out to determine the breakthrough curves under different operational conditions (temperature, PA concentration, flow rate, bed length). The suitability of the proposed adsorbent for the remediation of PA in fixed-bed adsorption was proven by the high PA adsorption capacity along with the fast adsorption and the reduced height of the mass transfer zone of the columns. We have demonstrated that, thanks to the use of the heterogeneous diffusion coefficient, the proposed mathematical approach for the numerical solution to the mass balance of the column provides a reliable description of the breakthrough profiles and the design parameters, being much more accurate than models based in the classical linear driving force.

Interaction of paracetamol and 125I-paracetamol with surface groups of activated carbon: theoretical and experimental study

The selection of activated carbon (AC) filters for water decontamination is currently carried out empirically. The low concentrations of drugs in the environment make the radioisotope labeling a valuable tool for physical and chemical studies of the adsorption process. A theoretical study of paracetamol and 125I-paracetamol adsorption onto AC was performed to evaluate the interactions between pollutants and surface groups (SG) of AC. Paracetamol was labeled with 125I and adsorption isotherms were obtained using radioanalytical and spectrophotometric techniques. The radioanalytical method overestimates the paracetamol adsorption. The validity of the chosen approach for qualitative assessment of SG influence over the adsorption process was demonstrated.

Role of activated carbon properties in atrazine and paracetamol adsorption equilibrium and kinetics

Adsorption of two widespread emerging water contaminants (atrazine and paracetamol) onto three different activated carbons was investigated. The carbons were characterized and the influence of their physicochemical properties on the adsorption performance of atrazine and paracetamol was evaluated. The adsorption equilibrium data were fitted to different adsorption isotherm models (Langmuir, Freundlich, and Dubinin–Radushkevich) while the adsorption rates were described using three different kinetic models (pseudo second order, intraparticle diffusion and a new approach based on diffusion-reaction models). The results indicated that hydrophobic character of the compounds does not affect the sorption capacity of the tested carbons but does influence the uptake rate. The model proposed, based on mass balances, lead to interpret and compare the kinetic of different adsorbents in contrast to classical empirical models. The model is a simple and powerful tool able to satisfactorily estimate the sorption capacities and kinetics of the carbons under different operation conditions by means of only two parameters with physical meaning. All the carbons studied adsorbed paracetamol more effectively than atrazine, possibly due to the fact that sorption takes place by H-bonding interactions.

Preparation of Rice Hull Activated Carbon for the Removal of Selected Pharmaceutical Waste Compounds in Hospital Effluent

The adsorbent (activated carbon) was prepared from rice hull obtained from communal farmers in Mutoko North (Zimbabwe) by chemical activation using phosphoric acid and was used in the adsorption of aspirin, paracetamol and ibuprofen from hospital effluent. Characterization of the rice hull activated carbon was carried out using the following methods: SEM, XRD, FT- IR. Physical properties such as iodine number, porosity, ash content, moisture content and volatile matter content were also determined. Iodine number was found to be 815.0 ± 2.52 mg/g. FT-IR analysis showed the presence of various functional groups such as C=O, C=C, –OH, and C-H on the surface of the adsorbent whereas SEM micrograph showed that the external surface of the rice hull activated carbon is full of regular cavities. XRD pattern showed broad peaks indicating that rice hull activated carbon produced has amorphous structure. The effect of adsorbent dose, contact time, initial concentration and pH was studied. Adsorption of aspirin fits the Freundlich isotherm, whereas ibuprofen and paracetamol fit the Langmuir isotherm. Kinetic studies showed that adsorption of ibuprofen, aspirin and paracetamol obey pseudo-second order kinetics. Aspirin, paracetamol and ibuprofen were detected in two hospital wastewaters at the concentrations of 0.117 ± 0.0058 mg/L, 0.100 mg/L and 0.010 ± 0.0006 mg/L respectively. The studies showed that pharmaceutical compounds studied can be removed from wastewater using rice hull derived activated carbon.

Studying the Effect of Paracetamol Drug on the Conductivity of 0.5M Hydrochloric Acid Solution at Different Temperatures

In this study paracetamol drug is used to reduce the conductivity of 0.5M hydrochloric acid at different concentrations for each one of them at different temperatures ranged (30-60)°C. Generally , increasing of the concentration of  the inhibitor leads to reducing in conductivity of the acid at constant temperature. On the other hand, at constant concentration of inhibitor, the conductivity is reduced as temperature increased i.e., paracetamol can adsorbed chemically on the metal or alloy. Furthermore the kinetic study of the molar conductance process reveal that in presence of paracetamol the activation energy and enthalpy of activation are negative compared with their values in absence of paracetamol where they are negative because the reducing the conductivity in presence of paracetamol where the non spontaneous property for the conductance of acid is increased as the paracetamol concentration increased in addition to increasing the negative value of entropy in presence of paracetamol that indicate to restrict for the mobility of hydrogen and chloride ions which correspond to 90.47% as efficiency of reducing the conductance of acid by paracetamol. On the other hand thermodynamic study is achieved which explained the adsorption of paracetamol obey to Freundlisch model.Â

Adsorption of Diclofenac and Paracetamol by Activated Sludge

Adsorption of Diclofenac and Paracetamol by Activated Sludge

Enhanced adsorption of paracetamol on closed carbon nanotubes by formation of nanoaggregates: Carbon nanotubes as potential materials in hot-melt drug deposition-experiment and simulation

We present the new results of systematic studies of paracetamol adsorption on closed, commercially available, unmodified carbon nanotubes. The results of thermal analysis, static adsorption measurements and the comparison with phenol adsorption data lead to suggestion that the formation of paracetamol nanoaggregates in the interstitial spaces between nanotubes occurs. This effect is also confirmed by the results of (performed in two ways) independent dynamic measurements and by molecular dynamics simulation technique. Next, we show that the behavior of adsorbed paracetamol during heating leads to the creation of a new drug delivery system. The properties of this system depend on the type of applied nanotubes and the parameters of the process called hot-melt drug deposition. Thus, we conclude that confined nanoaggregate formation, as well as hot-melt deposition should be promising effects in the preparation of highly effective, new drug delivery systems.

Adsorption of paracetamol and chloroquine phosphate by some antacids.

The adsorption of paracetamol and chloroquine phosphate onto some antacids with adsorptive properties, has been studied. Dissolution of the drugs from commercial tablets was significantly retarded in the presence of the antacids. The adsorption and retardation of dissolution of both drugs by the adsorbent antacids studied followed the rank order magnesium trisilicate greater than magnesium oxide greater than aluminium hydroxide greater than edible clay. The concomitant administration of the drugs and antacid formulations containing any of these should be discouraged.

Combined paracetamol and amitriptyline adsorption to activated charcoal

Objectives. High-gram drug doses seen in multiple-drug poisonings might be close to the adsorption capacity of activated charcoal (AC). The aim was to determine the maximum adsorption capacities (Qm) of amitriptyline and paracetamol, separately and in combination, to AC. Methods. ACs (Carbomix® and Norit Ready-To-Use) were tested in vitro. At pH 1.2 and pH 7.2, 0.250 g AC and paracetamol and/or amitriptyline were mixed and incubated. The AC : drug ratios were 10 : 1, 5 : 1, 3 : 1, 2 : 1, and 1 : 1. The mixed-drug adsorption vials contained the same AC : paracetamol ratios, but amitriptyline was added as fixed dose (0.080 g) to all samples. Drug concentrations in the liquid phase were analyzed using high-performance liquid chromatography (HPLC)/UV-detection. Results. Qm, amitriptyline, were 0.49 g/g Carbomix® and 0.70 g/g Norit Ready-To-Use, and Qm, paracetamol, were 0.63 g/g Carbomix® and 0.72 g/g Norit Ready-To-Use. The tested pH differences had minor effect on the adsorption. The mixed-drug adsorption showed about 40% Qm reduction of each drug with increasing amounts of drug/g AC, but the total gram of drug adsorbed to AC was increased compared to one-drug conditions. Conclusion. The adsorption of the two compounds to AC seems to compete resulting in lower maximum adsorption capacity for both drugs when mixed. However, a great adsorptive capacity was noted and might be explained by adsorption of the drugs to different AC surface sites. Furthermore, the Norit Ready-To-Use preparation, with less volume and total weight for the same AC dose as Carbomix®, showed a higher Qm. This might be clinically significant in terms of preventing nausea, vomiting, and subsequent aspiration.

Adsorption of Paracetamol and Acetylsalicylic Acid onto Commercial Activated Carbons

The adsorption of paracetamol (PAR) and acetylsalicylic acid (ASA) onto high-surface-area, commercial activated carbons was investigated at 26°C via adsorption isotherms at different pH values, including pH 1.5 to simulate conditions existing in the stomach. A wide-ranging characterization of the carbons, including analysis of their morphology and surface chemistry, was undertaken, with the actual surface areas of the carbons available for PAR and ASA adsorption being estimated by taking the molecular sizes of the drugs into account. This provided an understanding of the differences in the drug adsorption behaviour of the carbons.

Comparison of the Adsorption Capacities of an Activated-Charcoal–Yogurt Mixture Versus Activated-Charcoal–Water Slurry In Vivo and In Vitro

Background. An activated charcoal–yogurt mixture was evaluated in vivo to determine the effect on the gastrointestinal absorption of paracetamol, as compared to activated-charcoal–water slurry. The potential advantage of the activated-charcoal–yogurt mixture is a better palatability and general acceptance by the patients without loss of efficacy. In addition, paracetamol adsorption studies were carried out in vitro to calculate the maximum adsorption capacity of paracetamol to activated-charcoal–yogurt mixture. Methods. In vivo: A randomized crossover study on 15 adult volunteers, using paracetamol 50 mg/kg as a simulated overdose. Each study day volunteers were given a standard meal 1 h before paracetamol, then 50 g activated charcoal 1 h later in either of two preparations: standard water slurry or mixed with 400 mL yogurt. Paracetamol serum concentrations were measured using HPLC. The areas under the concentration-time curve (AUC) of the two preparations were compared and used to estimate the efficacy of each preparation. The palatability of both preparations was evaluated using a visual-analogue scale where the volunteers were asked to evaluate the appearance, smell, flavor, texture, ability to swallow, and overall impression of the mixtures. The time spent to consume the activated charcoal was also registered. In vitro: Activated charcoal, simulated gastric (pH 1.2) or intestinal (pH 7.2) fluid, and paracetamol were mixed with yogurt followed by 1 h incubation. The maximum adsorption capacity of paracetamol to activated charcoal was calculated using Langmuir's adsorption isotherm. Paracetamol concentration was analyzed using HPLC. Results. In vivo there was no significant difference (p > 0.05) in the AUC of paracetamol between the two activated-charcoal preparations. Geometric mean values and 95% CI for the AUCs were (in mg/l · min): 6307 (4932–8065) for the activated charcoal–water slurry and 6525 (5111–8330) for the activated charcoal–yogurt mixture. The palatability study showed significant difference (p < 0.05) only in duration of administration, in favor of the activated charcoal-water slurry. In vitro the maximum adsorption capacity of activated charcoal with added yogurt was 544 mg paracetamol/g activated charcoal (pH 1.2), and 569 mg paracetamol/g activated charcoal (pH 7.2). Conclusion. The two activated-charcoal preparations showed equal (NS) absorption reduction of paracetamol in vivo. Mixing activated charcoal with yogurt rather than water prolonged the ingestion time, but did not improve the palatability in adults. The presence of yogurt reduced the adsorption capacity in vitro by 9–13% (p < 0.05) compared to control without yogurt (previous study with the same setup).

Molecular properties and intermolecular forces?factors balancing the effect of carbon surface chemistry in adsorption of organics from dilute aqueous solutions

Presented paper recapitulates the results of 6 years' study concerning the effect of carbon surface chemical composition on adsorption of paracetamol, phenol, acetanilide, and aniline from dilute aqueous solutions on carbons. Adsorption–desorption isotherms, enthalpy, and kinetics of adsorption data are shown for the measurements performed at three temperatures (300, 310, and 320 K) at two pH levels (1.5 and 7) on commercial activated carbons. The data were obtained for four carbons: the initial carbon D43/1 and forms modified by applying concentrated HNO 3 , fuming H 2 SO 4 , and gaseous NH 3 . The modification procedures do not change the porosity in a drastic way, but lead to drastic changes of the composition of carbon surface layer. By applying MOPAC (a general-purpose semiempirical molecular orbital package), the physicochemical constants characterizing the molecules of adsorbates are calculated, including the distribution of the Mulliken charges, the dipole moments and ionization potentials, and the energies of interaction with the unique positive and negative charges. They are correlated with the parameters characterizing the adsorption (and kinetics) process of studied molecules on the mentioned above carbons. The mechanisms proposed in the literature for the description of adsorption from dilute aqueous solutions are verified, and a general mechanism of adsorption is proposed.

Molecular properties and intermolecular forces—factors balancing the effect of carbon surface chemistry in adsorption of organics from dilute aqueous solutions

Presented paper recapitulates the results of 6 years' study concerning the effect of carbon surface chemical composition on adsorption of paracetamol, phenol, acetanilide, and aniline from dilute aqueous solutions on carbons. Adsorption–desorption isotherms, enthalpy, and kinetics of adsorption data are shown for the measurements performed at three temperatures (300, 310, and 320 K) at two pH levels (1.5 and 7) on commercial activated carbons. The data were obtained for four carbons: the initial carbon D43/1 and forms modified by applying concentrated HNO 3, fuming H 2SO 4, and gaseous NH 3. The modification procedures do not change the porosity in a drastic way, but lead to drastic changes of the composition of carbon surface layer. By applying MOPAC (a general-purpose semiempirical molecular orbital package), the physicochemical constants characterizing the molecules of adsorbates are calculated, including the distribution of the Mulliken charges, the dipole moments and ionization potentials, and the energies of interaction with the unique positive and negative charges. They are correlated with the parameters characterizing the adsorption (and kinetics) process of studied molecules on the mentioned above carbons. The mechanisms proposed in the literature for the description of adsorption from dilute aqueous solutions are verified, and a general mechanism of adsorption is proposed.

The effect of food and ice cream on the adsorption capacity of paracetamol to high surface activated charcoal: in vitro studies.

The effect of added food mixture (as if food was present in the stomach of an intoxicated patient) or 4 different types of ice cream (added as a flavouring and lubricating agent) on the adsorption of paracetamol (acetaminophen) to 2 formulations of activated charcoal was determined in vitro and compared with results from previous investigations showing a maximum adsorption capacity to the two activated charcoal-water slurries at about 0.62-0.72 g paracetamol/g activated charcoal. Activated charcoal (Carbomix or Norit Ready-To-Use), simulated gastric (pH 1.2) or intestinal (pH 7.2) fluid, and paracetamol were mixed with either food mixture or ice cream followed by one hr incubation. The maximum adsorption capacity of paracetamol to activated charcoal was calculated using Langmuirs adsorption isotherm. Paracetamol concentration was analyzed using high pressure liquid chromatography. In the presence of food, the paracetamol adsorption capacity of the 2 activated charcoals was reduced by max. 19% (P<0.05) for Carbomix(R) and by max. 11% (P<0.05) for Norit Ready-to-use compared to control without food (Hoegberg et al. 2002). Depending on which type of ice cream was mixed with the charcoal, the reductions compared to control (Hoegberg et al. 2002) varied between 11% and 26%. Even though a reduction in drug adsorption to activated charcoal was observed when food mixture or ice cream was added, the remaining adsorption capacity of both types of activated charcoal theoretically was still able to provide an effective gastrointestinal decontamination.

Adsorption of Biologically Active Compounds from Aqueous Solutions on to Commercial Unmodified Activated Carbons. Part IV. Do the Properties of Amphoteric Carbon Surface Layers Influence the Adsorption of Paracetamol at Acidic pH Levels?

Three previously characterised, unmodified commercial activated carbons (D43/1, WD and AHD), differing in porosity and surface layer composition, were further examined using some additional methods of surface chemical description (electrochemical studies, acid–base site distribution, pHPZC and resistance measurements). Paracetamol adsorption isotherms (as well as kinetic curves) were measured on these carbons at acidic pH (1.5) and three temperatures, i.e. 300, 310 and 320 K. Measurements of the enthalpies of immersion in HCl and paracetamol solutions were also performed at 310 K, and diffusion coefficients and energies calculated. The results of measurements at acidic pH were compared with those obtained under neutral pH conditions. Some new correlations between the properties of the carbon surface and the constants characterising the process of paracetamol adsorption suggested recently were extended from data measured initially for six carbons. The mechanism of adsorption at both pH values was elaborated with the importance of surface carbonyls and basic groups being emphasised. The adsorption of the polymerisation product of paracetamol at acidic pH was determined using FT-IR and UV–vis spectroscopic measurements.

New correlations between the composition of the surface layer of carbon and its physicochemical properties exposed while paracetamol is adsorbed at different temperatures and pH

The series of previously characterized commercial activated carbons D43/1 with almost the same porosity, however differing in the composition of the surface layer, was characterized using some additional methods of porosity and of surface chemistry description (DFT method, electrochemical studies, acid–base site distribution, pH PZC, and resistance measurements). On these carbons adsorption isotherms of paracetamol (as well as kinetic curves) were measured at acidic pH (1.50) and at three temperatures 300, 310, and 320 K. The measurements of the enthalpy of immersion in HCl and paracetamol solutions were also performed at 310 K. Diffusion coefficients and the energies of diffusion were calculated. The results of measurements at acidic pH are compared with those measured for adsorption at the neutral pH. Some new correlations between the constants describing the chemical properties of the surface layer are given. Moreover, the properties of the surface are correlated with the constants characterizing the process of paracetamol adsorption. The mechanism of adsorption at both pH values is elaborated, the importance of surface carbonyls and basic groups is emphasized, and the product of polymerization of paracetamol adsorbed at acidic pH is determined using FTIR and UV–vis measurements.