Validation of a liquid chromatography coupled with tandem mass spectrometry method for the determination of drugs in wastewater using a three-phase solvent system.

Pharmaceuticals constitute one of the most important emerging classes of environmental pollutants. A three-phase solvent system of water, water containing 0.1% of formic acid and acetonitrile was successfully used to separate, by liquid chromatography with mass spectrometry (LC-MS), polarity-matched pharmaceuticals, that is, carbamazepine, clarithromycin, and erythromycin, as well as amoxicillin and metformin. Despite of polarity similarities, these pharmaceuticals were completely resolved in the analytical run time of 15 min. The optimized three-phase solvent system based-method was validated for the simultaneous analysis of six matched-polarity pharmaceuticals in wastewater samples. Good linearity (coefficient of determination more than 0.993) and precision (relative standard deviation less than 15.66%) were achieved. Recovery of analytes from the wastewater was between 0.70 and 1.18. Limits of detections ranged from 0.0001 to 0.5114 µg/L. No significant matrix effect, evaluated by post extraction addition, was observed in the electrospray ionization (ESI) source. Then, this methodology has been successfully applied to environmental study of pharmaceutical residues occurring in influent and effluent wastewater samples, from the main wastewater treatment plant in Potenza (Basilicata, Southern Italy).

Implementation of continuously electro-generated Fe3O4 nanoparticles for activation of persulfate to decompose amoxicillin antibiotic in aquatic media: UV254 and ultrasound intensification.

In the present investigation, the treatment of amoxicillin (AMX)-polluted water by the activated persulfate (PS) was considered. As a novel research, continuously electro-generated magnetite (Fe3O4) nanoparticles (CEMNPs) were utilized as the activator of PS in an electrochemical medium. The PS/CEMNPs displayed a remarkable enhancement in the decomposition of AMX molecules up to 72.6% compared with lonely PS (24.8%) and CEMNPs (13.4%). On the basis of pseudo-first order reaction rate constants, the synergy percent of about 70% was achieved due to the combination of PS with CEMNPs. The adverse influence of free radical-scavenging compounds on the efficiency of the PS/CEMNPs process was in the following order: carbonate < chloride < tert-butyl alcohol < ethanol. Overall, these results proved the main role of free radical species in degrading AMX. The implementation of ultrasound (US) enhanced the performance of the PS/CEMNPs process. Nevertheless, the highest degradation efficiency of about 94% was achieved when UV254 lamp was joined the PS/CEMNPs system. Under UV254 and US irradiation, the results showed significant potential of the PS/CEMNPs process for degrading AMX antibiotic and generating low toxic effluent based on the activated sludge inhibition test. However, more time is needed to achieve the acceptable mineralization.

Characterization and Performance of Hollow Silica for Adsorption of Amoxicillin in Aqueous Solutions.

Two kinds of hollow silica materials, namely H-SiS1 and H-SiS2, were synthesized using the yeast template method and the Pickering emulsion polymerization method, respectively. The adsorbents were synthesized to adsorb amoxicillin (AMX) from an aqueous environment. Characterization results indicated that hollow silica adsorbents exhibited excellent thermal stability even at temperatures above 700 °C. Several batches of static adsorption experiments were prepared to analyze the adsorption performance on AMX. Isotherm data on different adsorbents fitted well with the Langmuir model (from 15 °C to 35 °C), indicating a monolayer molecular adsorption mechanism for AMX. The maximum adsorption capacities of H-SiS1 and H-SiS2 were 8.40 and 3.46 mg/g at 35 °C, respectively. The adsorption kinetics was described well by the pseudo-second-order model, which indicated that chemical interactions were primarily responsible for AMX adsorption and could be the rate-limiting step during adsorption. These results suggested that H-SiS1 could be significantly useful as adsorbents for removal of AMX residuals from aqueous solution.

Removal of a common antibiotic (Amoxicillin) from different aqueous systems using Octolig®.

Amoxicillin, used to manage bacterial infection, is among the top five popular pharmaceuticals in the United States, based on the number of prescriptions. Problems with environmentally available drugs can arise chiefly; biological resistance in excess amounts becomes available in wastewater samples. Previously, we observed that Amoxicillin could be removed quantitatively from deionized water by passage over Octolig®, a polythylenediimine covalently attached to high-surface-area silica gel. This study was concerned with testing the potential removal of Amoxicillin in different solutions (tap water, well water, river water, and the weakly saline water). These solutions were passed over chromatography columns at a rate of 10 mL per minute; 50-mL fractions were collected and analyzed for total dissolved solids and pH as well as concentration. As noted in our previous work, the percentage removal was related to the length of the column, and this aspect was evaluated again. Consistent results were obtained for DI water, tap water, well water, and river water, indicating quantitative removal, and but not artificial bay water, presumably because of ion competition.

Removal of amoxicillin and cefuroxime axetil by advanced membranes technology, activated carbon and micelle-clay complex.

Two antibacterials, amoxicillin trihydrate and cefuroxime axetil spiked into wastewater were completely removed by sequential wastewater treatment plant's membranes, which included activated sludge, ultrafiltration (hollow fibre and spiral wound membranes with 100 and 20 kDa cut-offs), activated carbon column and reverse osmosis. Adsorption isotherms in synthetic water which employed activated carbon and micelle-clay complex (octadecyltrimethylammonium-montmorillonite) as adsorbents fitted the Langmuir equation. Qmax of 100 and 90.9 mg g(-1), and K values of 0.158 and 0.229 L mg(-1) were obtained for amoxicillin trihydrate using activated carbon and micelle-clay complex, respectively. Filtration of antibacterials in the ppm range, which yielded variable degrees of removal depending on the volumes passed and flow rates, was simulated and capacities for the ppb range were estimated. Stability study in pure water and wastewater revealed that amoxicillin was totally stable for one month when kept at 37°C, whereas cefuroxime axetil underwent slow hydrolysis to cefuroxime.

Development of an orbital shaker-assisted fatty acid-based switchable solvent microextraction procedure for rapid and green extraction of amoxicillin from complex matrices: Central composite design.

In this study, a cheap, fast and simple orbital shaker-assisted fatty acid-based switchable solvent microextraction (OS-FASS-ME) procedure was developed for the extraction of amoxicillin (AMOX) in dairy products, pharmaceutical samples and wastewater prior to its spectrophotometric analysis. Fatty acid-based switchable solvents were investigated for extracting AMOX. The key factors of the OS-FASS-ME procedure were optimized using a central composite design. The linearity of OS-FASS-ME procedure was in the range 5-600 ng mL-1 with a correlation coefficient of 0.991. In five replicate experiments for 20 ng mL-1 of AMOX solution, the recovery and relative standard deviation were 95.8% and 2.2%, respectively. Limits of detection and quantification were found 1.5 ng mL-1 and 5 ng mL-1, respectively. The accuracy, precision, robustness and selectivity of the OS-FASS-ME procedure were investigated in detail under optimum conditions. The OS-FASS-ME procedure was applied to milk, cheese, wastewater, syrups and tablets. A comparison of the results obtained from the reference method and the OS-FASS-ME method showed that the OS-FASS-ME procedure can be successfully applied to complex matrices.

Ecotoxicology Evaluation of a Fenton-Type Process Catalyzed with Lamellar Structures Impregnated with Fe or Cu for the Removal of Amoxicillin and Glyphosate.

Antibiotics and pesticides, as well as various emerging contaminants that are present in surface waters, raise significant environmental concerns. Advanced oxidation processes, which are employed to eliminate these substances, have demonstrated remarkable effectiveness. However, during the degradation process, by-products that are not completely mineralized are generated, posing a substantial risk to aquatic ecosystem organisms; therefore, it is crucial to assess effluent ecotoxicity following treatment. This study aimed to assess the toxicity of effluents produced during the removal of amoxicillin and glyphosate with a Fenton-type process using a laminar structure catalyzed with iron (Fe) and copper (Cu). The evaluation included the use of Daphnia magna, Selenastrum capricornutum, and Lactuca sativa, and mutagenicity testing was performed using strains TA98 and TA100 of Salmonella typhimurium. Both treated and untreated effluents exhibited inhibitory effects on root growth in L. sativa, even at low concentrations ranging from 1% to 10% v/v. Similarly, negative impacts on the growth of algal cells of S. capricornutum were observed at concentrations as low as 0.025% v/v, particularly in cases involving amoxicillin-copper (Cu) and glyphosate with copper (Cu) and iron (Fe). Notably, in the case of D. magna, mortality was noticeable even at concentrations of 10% v/v. Additionally, the treatment of amoxicillin with double-layer hydroxides of Fe and Cu resulted in mutagenicity (IM ≥ 2.0), highlighting the necessity to treat the effluent further from the advanced oxidation process to reduce ecological risks.

Development of novel molecularly imprinted solid-phase microextraction fibers and their application for the determination of antibiotic drugs in biological samples by SPME-LC/MS(n).

Novel molecularly imprinted polymer (MIP)-coated fibers for solid-phase microextraction (SPME) fibers were prepared by using linezolid as the template molecule. The characteristics and application of these fibers were investigated. The polypyrrole, polythiophene, and poly(3-methylthiophene) coatings were prepared in the electrochemical polymerization way. The molecularly imprinted SPME coatings display a high selectivity toward linezolid. Molecularly imprinted coatings showed a stable and reproducible response without any influence of interferents commonly existing in biological samples. High-performance liquid chromatography with spectroscopic UV and mass spectrometry (MS) detectors were used for the determination of selected antibiotic drugs (linezolid, daptomycin, amoxicillin). The isolation and preconcentration of selected antibiotic drugs from new types of biological samples (acellular and protein-free simulated body fluid) and human plasma samples were performed. The SPME MIP-coated fibers are suitable for the selective extraction of antibiotic drugs in biological samples.

A novel approach to the rapid determination of amoxicillin in human plasma by solid phase microextraction and liquid chromatography.

A new approach to the rapid determination of amoxicillin (AMO) in human plasma followed by solid phase microextraction (SPME) fiber coatings based on conducting polymers (polypyrrole and polythiophene) and high performance liquid chromatography (HPLC) has been described. The porous structures of the electrochemically deposited polymer coatings have been characterized by scanning electron microscopy (SEM). The experimental parameters relating to the extraction efficiency of the SPME fibers such as pH, extraction time and desorption conditions (solvents, time) were studied and selected. The SPME/HPLC-UV method was linear over a working range of 1-50 µg ml(-1). The inter-day accuracy (expressed as coefficients of variations, CVs) was less than 15% and precision (expressed as the relative standard deviations, RSDs) with percentage values was less than 5.9%. Amoxicillin was found to be stable in the human plasma at room temperature (20 °C) within 8 hours. The developed method was successfully applied to the analysis of real human plasma samples. The limit of detection and limit of quantification for amoxicillin in plasma were 1.21 µg ml(-1) and 3.48 µg ml(-1), respectively.

Behavior of pharmaceuticals in waste water treatment plant in Japan.

The fate of pharmaceuticals in a wastewater treatment plant (WWTP) in Kumamoto, Japan with activated sludge treatment is reported. Selected pharmaceuticals were detected in influent. Results from the present study confirmed that Acetaminophen, Amoxicillin, Ampicillin and Famotidine were removed at a high rate (>90% efficiency). In contrast, removal efficiency of Ketoprofen, Losartan, Oseltamivir, Carbamazepine, and Diclofenac was relatively low (<50%). The selected pharmaceuticals were also detected in raw sludge. In digestive process, Indomethacin, Atenolol, Famotidine, Trimethoprim and Cyclofosamide were removed at a high (>70% efficiency). On the other hand, removal of Carbamazepine, Ketoprofen and Diclofenac was not efficient (<50%).

Rapid preparation of surface-enhanced Raman substrate in microfluidic channel for trace detection of amoxicillin.

A high sensitive surface-enhanced Raman scattering (SERS) substrate based on the Ag dendrite in a T-type microfluidic device was constructed by a simple and rapid strategy. According to the simulated results by COMSOL Multiphysics, the microfluidic-SERS sensor was fabricated by simultaneously introducing into 40 mmol·L-1 silver nitrate solution and 0.2 mol·L-1 sodium nitrate solution for about 15 min with the flow velocity at 20 µL·min-1 at room temperature, respectively. The analytical performance of this sensor was investigated with different concentrations of amoxicillin aqueous solution, and the detection limit was up to 1.0 ng·mL-1. And the semi-quantitation was obtained from the relationship between the Raman intensity and the logarithm of the amoxicillin concentration. This method can be employed to fabricate high sensitive microfluidic-SERS sensors as well as realize many lab-on-a-chip applications with the integration of other microfluidic networks.

Simple and reliable extraction and a validated high performance liquid chromatographic assay for quantification of amoxicillin from plasma.

This study presents the development of an efficient extraction protocol for amoxicillin from plasma with improved solubility and stability using pH control. Solubility and stability of amoxicillin in commonly used extraction solvents were determined using a newly developed stability-indicating high-performance liquid chromatography (HPLC) method. Following this, protein precipitation (PP) mediated sample purification protocol was developed and validated along with the HPLC method for the extracted amoxicillin from rabbit plasma. The protocol was applied in a pharmacokinetic study in rabbits. A five-fold increase in solubility and two-fold increase in stability of amoxicillin was found by addition of acetate buffer (0.1 M, pH 5.0) in acetonitrile. PP mediated extraction protocol containing acetate buffer-acetonitrile (1:18 v/v) resulted in an extraction recovery of >80% for all the samples. The HPLC assay following extraction was found linear (R2   >0.9999) over the range of 0.2-20 µg/mL with a lower limit of quantification of 0.2 µg/mL. The accuracy of the quality control samples was found between 97-115% and the relative standard deviation (RSD) was found to be below 6% for all samples. The samples were stable in the mobile phase (pH 5.0) for 72 h post-extraction. Amoxicillin-spiked plasma samples were found stable for up to three freeze-and-thaw cycles but, nearly 50% samples had degraded following storage for two months at -20 °C. Pharmacokinetic analysis indicated a half-life of amoxicillin of nearly 1 h following intravenous injection in rabbits, which is similar to that in humans. Thus, a simple and repeatable, extraction protocol was developed using pH control for quantification of amoxicillin from plasma based on its physicochemical properties.

Performance of activated carbon and bentonite for adsorption of amoxicillin from wastewater: mechanisms, isotherms and kinetics.

Amoxicillin's traces within pharmaceutical effluents have toxic impact toward the algae and other lower organisms within food web. Adsorption, as an efficient process to remove contaminants from water was chosen; in particular with bentonite and activated carbon as adsorbents. The study was carried out at several pH values. Langmuir and Freundlich models were then employed to correlate the equilibria data on which both models equally well-fit the data. For kinetic data, pseudo-first and second order models are selected. While chemisorption is the dominant adsorption mechanism on the bentonite case, both physisorption and chemisorption play important roles for adsorption onto activated carbon. Also, several possible mechanisms for these adsorption systems were elaborated further.

EDTA and electricity synergetic catalyzed Fe(3+)/H2O2 process for amoxicillin oxidation.

Three oxidation processes for amoxicillin wastewater pretreatment such as Electro-Fe(3+)(EDTA)/H2O2 (EDTA: ethylenediaminetetraacetic acid), Fe(3+)(EDTA)/H2O2 and Electro-Fe(3+)/H2O2 were simultaneously discussed at pH of 7.0 (+/-0.1). It was found that the above processes could achieve 78%, 64%, 33% chemical oxygen demand (COD(cr)) removal, and 86%, 70%, 47% amoxicillin degradation respectively. Moreover, the results of biodegradability (biological oxygen demand (BOD(5))/COD(cr) ratio) showed that the Electro-Fe(3+)(EDTA)/H2O2 process was a promising way to pretreat antibiotic wastewater due to the biodegradability of the effluent improved to 0.48 compared with the cases of Fe(3+)(EDTA)/H2O2 (0.40) and Electro-Fe(3+)/H2O2 process (0.12). Therefore, it was reasonable to note that EDTA and electricity showed synergetic effect on the oxidation process. Additionally, infrared spectra (IR) were applied to concisely propose a potential degradation way of amoxicillin. The characteristic changes of H2O2 and EDTA in the oxidation process were also investigated in detail.

Removal of amoxicillin from simulated hospital effluents by adsorption using activated carbons prepared from capsules of cashew of Para.

High-surface-area activated carbons were prepared from an agroindustrial residue, Bertholletia excelsa capsules known as capsules of Para cashew (CCP), that were utilized for removing amoxicillin from aqueous effluents. The activated carbons were prepared with the proportion of CCP:ZnCl2 1:1, and this mixture was pyrolyzed at 600 (CCP-600) and 700 °C (CCP700). The CCP.600 and CCP.700 were characterized by CHN/O elemental analysis, the hydrophobic/hydrophilic ratio, FTIR, TGA, Boehm titration, total pore volume, and surface area. These analyses show that the adsorbents have different polar groups, which confers a hydrophilic surface. The adsorbents presented surface area and total pore volume of 1457 m2 g-1 and 0.275 cm3 g-1 (CCP.600) and 1419 m2 g-1 and 0.285 cm3 g-1 (CCP.700). The chemical and physical properties of the adsorbents were very close, indicating that the pyrolysis temperature of 600 and 700 °C does not bring relevant differences in the physical and chemical properties of these adsorbents. The adsorption data of kinetics and equilibrium were successfully adjusted to Avrami fractional-order and Liu isotherm model. The use of the adsorbents for treatment of simulated hospital effluents, containing different organic and inorganic compounds, showed excellent removals (up to 98.04% for CCP.600 and 98.60% CCP.700). Graphical abstract.

Chitosan tailor-made membranes as biopolymeric support for electromembrane extraction.

A chitosan membrane composed by 60% (w/w) chitosan and 40% (w/w) Aliquat®336 has been proposed as a new biopolymeric support for electromembrane extraction. The new support has been characterized by Scanning Electron Microscopy, resulting a 30-35 µm thickness. Amoxicillin, nicotinic acid, hippuric acid, salicylic acid, anthranilic acid, ketoprofen, naproxen and ibuprofen have been successfully extracted using the proposed support. Better enrichment factors were obtained for the acidic polar analytes than for the non-steroidal anti-inflammatory compounds (ranging from 118 for hippuric acid and 20 for ibuprofen). Electromembrane extraction was developed applying a DC voltage of 100 V, 1-octanol as supported liquid membrane and 20 min of extraction. The target analytes have also been satisfactorily extracted from human urine samples, providing high extraction efficiencies. The chitosan membrane is presented as a promising alternative for supporting liquid membrane compared to commonly used materials for this purpose.

Medium-high frequency ultrasound and ozone based advanced oxidation for amoxicillin removal in water.

In this study, treatment of an antibiotic compound amoxicillin by medium-high frequency ultrasonic irradiation and/or ozonation has been studied. Ultrasonic irradiation process was carried out in a batch reactor for aqueous amoxicillin solutions at three different frequencies (575, 861 and 1141kHz). The applied ultrasonic power was 75W and the diffused power was calculated as 14.6W/L. The highest removal was achieved at 575kHz ultrasonic frequency (>99%) with the highest pseudo first order reaction rate constant 0.04min-1 at pH 10 but the mineralization achieved was around 10%. Presence of alkalinity and humic acid species had negative effect on the removal efficiency (50% decrease). To improve the poor outcomes, ozonation had been applied with or without ultrasound. Ozone removed the amoxicillin at a rate 50 times faster than ultrasound. Moreover, due to the synergistic effect, coupling of ozone and ultrasound gave rise to rate constant of 2.5min-1 (625 times higher than ultrasound). In the processes where ozone was used, humic acid did not show any significant effect because the rate constant was so high that ozone has easily overcome the scavenging effects of natural water constituents. Furthermore, the intermediate compounds, after the incomplete oxidation mechanisms, has been analyzed to reveal the possible degradation pathways of amoxicillin through ultrasonic irradiation and ozonation applications. The outcomes of the intermediate compounds experiments and the toxicity was investigated to give a clear explanation about the safety of the resulting solution. The relevance of all the results concluded that hybrid advanced oxidation system was the best option for amoxicillin removal.

Reverse micelle Extraction of Antibiotics using an Eco-friendly Sophorolipids Biosurfactant.

Reverse micelles extraction of erythromycin and amoxicillin were carried out using the novel Sophorolipids biosurfactant. By replacing commonly used chemical surfactants with biosurfactant, reverse micelle extraction can be further improved in terms of environmental friendliness and sustainability. A central composite experimental design was used to investigate the effects of solution pH, KCl concentration, and sophorolipids concentration on the reverse micelle extraction of antibiotics. The most significant factor identified during the reverse micelle extraction of both antibiotics is the pH of aqueous solutions. Best forward extraction performance for erythromycin was found at feed phase pH of approximately 8.0 with low KCl and sophorolipids concentrations. Optimum recovery of erythromycin was obtained at stripping phase pH around 10.0 and with low KCl concentration. On the other hand, best forward extraction performance for amoxicillin was found at feed phase pH around 3.5 with low KCl concentration and high sophorolipids concentration. Optimum recovery of erythromycin was obtained at stripping phase pH around 6.0 with low KCl concentration. Both erythromycin and amoxicillin were found to be very sensitive toaqueous phase pH and can be easily degraded outside of their stable pH ranges.

Use of Polymer Inclusion Membranes (PIMs) as support for electromembrane extraction of non-steroidal anti-inflammatory drugs and highly polar acidic drugs.

The use of polymer inclusion membranes (PIMs) as support of 1-octanol liquid membrane in electromembrane extraction (EME) procedure is proposed. Synthesis of PIMs were optimized to a composition of 29% (w/w) of cellulose triacetate as base polymer and 71% (w/w) of Aliquat®336 as cationic carrier. Flat PIMs of 25µm thickness and 6mm diameter were used. EME protocol was implemented for the simultaneous extraction of four non-steroidal anti-inflammatory drugs (NSAIDs) (salicylic acid, ketoprofen, naproxen and ibuprofen) and four highly polar acidic drugs (anthranilic acid, nicotinic acid, amoxicillin and hippuric acid). Posterior HPLC separation of the extracted analytes was developed with diode array detection. Recoveries in the 81-34% range were obtained. EME procedure was applied to human urine samples.

Efficient removal of amoxicillin and paracetamol from aqueous solutions using magnetic activated carbon.

Activated carbon (AC)/CoFe2O4 nanocomposites, MAC-1 and MAC-2, were prepared by a simple pyrolytic method using a mixture of iron(III)/cobalt(II) benzoates and iron(III)/cobalt(II) oxalates, respectively, and were used as efficient adsorbents for the removal of amoxicillin (AMX) and paracetamol (PCT) of aqueous effluents. The synthesized nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The sizes of cobalt ferrite nanoparticles formed from benzoates of iron(III)/cobalt(II) and oxalates of iron(III)/cobalt(II) precursors were in the ranges of 5-80 and 6-27 nm, respectively. The saturation magnetization (M s), remanence (M r) and coercivity (H c) of the MAC-2 nanocomposites were found to be 3.07 emu g-1, 1.36 emu g-1 and 762.49 Oe; for MAC-1, they were 0.2989 emu g-1, 0.0466 emu g-1 and 456.82 Oe. The adsorption kinetics and isotherm studies were investigated, and the results showed that the as-prepared nanocomposites MAC-1 and MAC-2 could be utilized as an efficient, magnetically separable adsorbent for environmental cleanup. The maximum sorption capacities obtained were 280.9 and 444.2 mg g-1 of AMX for MAC-1 and MAC-2, respectively, and 215.1 and 399.9 mg g-1 of PCT using MAC-1 and MAC-2, respectively. Both adsorbents were successfully used for simulated hospital effluents, removing at least 93.00 and 96.77% for MAC-1 and MAC-2, respectively, of a mixture of nine pharmaceuticals with high concentrations of sugars, organic components and saline concentrations.