Aqueous Samples Research Articles

Direct determination of lithium in brine samples using handheld LIBS without sample treatment: sample introduction by venturi system.

Splashing is the main problem for the direct analysis of aqueous samples using LIBS since it generates serious precision and accuracy issues. This study demonstrates the direct determination of Li content in brines for the control of industrial mining processes using a portable LIBS device based on the direct laser impact on the sample, without any sample treatment, through the design of a sample injection system based on the Venturi effect. Our results demonstrated that the utilization of the 653.3 nm hydrogen line as an internal standard reduces the model calibration fitting error from 0.440 root mean square error in a standard calibration curve to 0.123 on the internal standard curve. Conversely, the development of a Venturi effect-based injection device using compressed air converts the brine into a fine mist which decrease splashing, resulting in an up to 10-fold error reduction, all without the necessity of employing an internal standard. Our results, evaluated by comparing them to the ASTM D3561-11 standard method using flame atomic absorption spectrometry, indicate that it is feasible to determine the lithium content in brine samples with an error of under 20% and a detection limit of 13 mg kg-1.

Quantification of tungsten in real samples spectrophotometrically using optical sensor

A new methodology was devised to detect tungsten in aqueous samples, employing a sensor membrane crafted by physically incorporating a tungsten-selective compound, 5-(2 -bromophenylazo)-6-hydroxypyrimidine-2,4-dione (BPAHPD), into a plasticized poly(vinyl chloride). The addition of Triton X-114 was observed to be advantageous in augmenting the absorption of HWO4− ions from the liquid phase into the membrane phase, thereby amplifying sensor absorption intensity. The method established a linear dynamic span of 15–350 ng mL−1 for W(VI), exhibiting a notable correlation coefficient of 0.9992. Quantification and detection limits were determined to be 14.85 and 4.45 ng mL−1, correspondingly, under optimized conditions. The Sandell responsiveness and molar absorptivity were calculated at 0.0455 ng cm−2 and 4.04 × 108 L/mol cm−1, respectively. The sensor demonstrated superb selectivity, as demonstrated by the negligible influence of potential interfering species. Statistical analyses, encompassing variance ratio F-tests and Student’s t-tests, indicated no substantial differences. The efficacy of the methodology was authenticated through the scrutiny of genuine samples, with statistical comparison to the ICP-AES method.

Phytochemical, spectroscopic analysis and antifungal activity on bell peppers of hydrothermal bioactive metabolites of Humulus lupulus L. extracts

This study aimed to evaluate the impact of temperature on the potential extraction of bioactive compounds from aqueous hop extract samples. The main bioactive components were characterised and analysed by LC-MS/MS, FT-IR, phenolic compounds and total flavonoids. Antifungal activity was evaluated in vitro and in vivo in bell peppers. LC-MS/MS analysis demonstrated increases and decreases of bioactive compounds in both extracts depending on the extraction temperature of 25 or 65 °C. The bioactive compounds showed significant changes in the bands between 2786 to 3600 cm−1 and 1022 to 1729 cm−1 in the FT-IR spectrum. The highest antifungal activity against the microorganisms was observed in the EkuanotMT extract at an extraction temperature of 65 °C. The in vivo test with bell peppers presented antifungal activity during five days of evaluation under normal environmental conditions without refrigeration, presenting ≤ 52% of the disease due to F. oxysporum and A. solani.

Prognostic factors associated with acute retinal necrosis treated non-surgically.

To analyse the prognostic factors for visual acuity in acute retinal necrosis (ARN) patients treated non-surgically. The clinical data of ARN patients who visited our hospital from January 2010 to January 2023 were retrospectively analysed. Twenty-four patients (29 eyes) were included. Aqueous humour samples were collected from 20 out of 29 eyes, and PCR confirmed that 85% (17/20) of the eyes had VZV infection, 10% (2/20) had CMV infection, and 5% (1/20) had HSV infection. All patients were treated with intravenous antiviral agents. Intravitreal ganciclovir and oral corticosteroids were given according to the patients' wishes. A comparison of visual acuity at the time of first identification of inactive ARN with that at the first visit revealed that 16 (55.2%) eyes improved and 13 (44.8%) did not improve. Logistic regression analysis revealed that risk factors for failure to improve vision after treatment included retinal detachment (odds ratio [OR],33.75; 95% CI, 3.245-351.067; P = 0.003), necrotising retinitis involving the posterior pole (odds ratio [OR],8.167; 95% CI, 1.297-51.403, P = 0.025), and arteritis involving the large retinal arteries (odds ratio [OR],9.167; 95% CI, 1.493-56.297; P = 0.017). The VZV viral load in the aqueous humour at initial presentation was significantly associated with visual prognosis (r = 0.688, P = 0.013), retinal detachment (τ = 0.597, P = 0.021) and the extent of retinal necrosis (τ = 0.57, P = 0.027). The neutrophil to lymphocyte ratio (NLR) of VZV-infected patients at first presentation was significantly correlated with the prognosis of visual acuity (r = 0.616, P = 0.033) and retinal detachment (τ = 0.728, P = 0.004). High NLR and viral DNA copy number in the aqueous humour at the initial presentation, as well as subsequent retinal detachment, necrotising retinitis involving the posterior pole, and arteritis involving the large retinal arteries were risk factors for poor visual prognosis in VZV-infected ARN patients.

Using a Stoichiometrically Imprinted Polymer to Directly Extract Penicillin G and Its Derivatives from Aqueous Samples

Using a Stoichiometrically Imprinted Polymer to Directly Extract Penicillin G and Its Derivatives from Aqueous Samples

Oxylipins in Aqueous Humor of Primary Open-Angle Glaucoma Patients.

Investigate the oxylipin profiles in the aqueous humor of primary open-angle glaucoma (POAG) patients. Aqueous humor samples were collected from 17 POAG patients and 15 cataract subjects and subjected to a liquid chromatography/mass spectrometry (LC-MS) analysis to detect the oxylipins. The prediction potential of the differential abundant oxylipins was assessed by the receiver operating characteristic (ROC) curves. Pathway and correlation analyses on the oxylipins and clinical and biochemical parameters were also conducted. The LC-MS analysis detected a total of 76 oxylipins, of which 29 oxylipins reached the detection limit. The multivariate analysis identified five differential abundant oxylipins, 15-keto-prostaglandin F2 alpha (15-kPGF2α), Leukotriene B4 (LTB4), 12,13-Epoxyoctadecenoic acid (12,13-Epome), 15-Hydroxyeicosatetraenoic acid (15-HETE) and 11-Hydroxyeicosatetraenoic acid (11-HETE). The five oxylipins are enriched in the arachidonic acid metabolism and linoleic acid metabolism pathways. Pearson correlation analysis showed that 11-HETE was positively correlated with intraocular pressure and central corneal thickness and negatively with cup/disk area ratio in the POAG patients. In addition, 15-kPGF2α was moderately and positively correlated with the mean deviation (MD) of visual field defect, and LTB4 was moderately and negatively correlated with macular thickness. This study revealed the oxylipin profile in the aqueous humor of POAG patients. Oxylipins involved in the arachidonic acid metabolism pathway could play a role in POAG, and anti-inflammatory therapies could be potential treatment strategies for POAG.

Formaldehyde quantification using gas chromatography–mass spectrometry reveals high background environmental formaldehyde levels

Formaldehyde (HCHO) is a human toxin that is both a pollutant and endogenous metabolite. HCHO concentrations in human biological samples are reported in the micromolar range; however, accurate quantification is compromised by a paucity of sensitive analysis methods. To address this issue, we previously reported a novel SPME–GC–MS-based HCHO detection method using cysteamine as an HCHO scavenger. This method showed cysteamine to be a more efficient scavenger than the widely used O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine, and enabled detection of aqueous HCHO in the nanomolar range and quantification in the micromolar range. However, quantification in this range required immersive extraction of the HCHO-derived thiazolidine, while a high background signal was also observed. Following on from these studies, we now report an optimised head-space extraction SPME–GC–MS method using cysteamine, which provides similarly sensitive HCHO quantification to the immersive method but avoids extensive wash steps and is therefore more amenable to screening applications. However, high background HCHO levels were still observed A Complementary GC–MS analyses using a 2-aza-Cope-based HCHO scavenger also revealed high background HCHO levels; therefore, the combined results suggest that HCHO exists in high (i.e. micromolar) concentration in aqueous samples that precludes accurate quantification below the micromolar range. This observation has important implications for ongoing HCHO quantification studies in water, including in biological samples.

The presence of nanoparticles in aqueous droplets containing plant-derived biopolymers plays a role in heterogeneous ice nucleation.

Organic matter can initiate heterogeneous ice nucleation in supercooled water droplets, thereby influencing atmospheric cloud glaciation. Predicting the ice nucleation ability of organic matter-containing cloud droplets is challenging due to the unknown mechanism for templating ice. Here, we observed the presence of nanoparticles in aqueous samples of known ice-nucleating biopolymers cellulose and lignin, as well as in newly identified ice-nucleating biopolymers xylan and laminarin. Using our drop Freezing Ice Nuclei Counter (FINC), we measured the median ice nucleation temperature (T50) of xylan and of laminarin droplets of 2 μl to be -14.2 and -20.0 °C, respectively. Next, we characterized these samples using nanoparticle tracking analysis, and we detected and quantified nanoparticles with mean diameters between 132 and 267nm. Xylan contained the largest nanoparticles and froze at higher temperatures. Xylan also dictated the freezing in a 1:1:1:1 mixture with cellulose, lignin, laminarin, and xylan. Filtration experiments down to 300 kDa with the xylan sample indicated that the presence of nanoparticles triggered freezing. Overall, only samples with mean diameters above 150nm froze above -20 °C. Furthermore, we determined the ice-active site densities normalized to particle concentrations, surface area, and mass of the nanoparticles to show that the samples' nucleation site densities are similar to sea spray aerosols and nanometer-sized dust. The identification and characterization of xylan and laminarin as nanometer-sized ice-nucleating substances expands the growing list of organic matter capable of impacting cloud formation and thus climate.

Identifying Quinones in Complex Aqueous Environmental Media (Biochar Extracts) through Tagging with Cysteine and Cysteine-Contained Peptides and High Resolution Mass Spectrometry Analysis.

Quinones are among the most important components in natural organic matter (NOM) for redox reactions; however, no quinones in complex environmental media have been identified. To aid the identification of quinone-containing molecules in ultracomplex environmental samples, we developed a chemical tagging method that makes use of a Michael addition reaction between quinones and thiols (-SH) in cysteine (Cys) and cysteine-contained peptides (CCP). After the tagging, candidates of quinones in representative aqueous environmental samples (water extractions of biochar) were identified through high-resolution mass spectrometry (HRMS) analysis. The MS and UV spectra analysis showed rapid reactions between Cys/CCP and model quinones with β-carbon from the same benzene ring available for Michael addition. The tagging efficiency was not influenced by other co-occurring nonquinone representative compounds, including caffeic acid, cinnamic acid, and coumaric acid. Cys and CCP were used to tag quinones in water extractions of biochars, and possible candidates of quinones (20 and 53 based on tagging with Cys and CCP, respectively) were identified based on the HRMS features for products of reactions with Cys/CCP. This study has successfully demonstrated that such a Michael addition reaction can be used to tag quinones in complex environmental media and potentially determine their identities. The method will enable an in-depth understanding of the redox chemistry of NOM and its critical chemical compositions and structures.

Colorimetric detection of platinum (IV) ions based on triangular silver nanoprism particles in aqueous environmental sample

Colorimetric detection of platinum (IV) ions based on triangular silver nanoprism particles in aqueous environmental sample

Clinical, serological and therapeutic profile of ocular toxoplasmosis diagnosed at Batna University Hospital, Algeria

Objectives. Toxoplasmosis is a widespread parasitic infection worldwide, caused by an obligate intracellular protozoan called Toxoplasma gondii. Ocular toxoplasmosis is a common condition, being the main cause of infection affecting the posterior part of the eye. In Algeria, the actual prevalence of this infection remains poorly documented. It is in this context, we undertook this study with the aim of evaluating the seroprevalence of ocular toxoplasmosis diagnosed at Batna University Hospital and identifying the clinical and therapeutic characteristics. Materials and Methods. This prospective, descriptive, crosssectional study is conducted in the parasitology laboratory of Batna University Hospital, over a period of 27 months, from April 2020 to June 2023, sera of patients suspected of ocular toxoplasmosis as well as their retinal angiographies were received and analyzed. Diagnosis was established by measuring IgG and IgM by ELISA in the blood, compared with radiological, clinical and therapeutic data. Results. Among the 37 patients suspected of toxoplasmic chorioretinitis, 21 were serologically positive and no aqueous humor sample could be taken. The seroprevalence of probable ocular toxoplasmosis in our sample is thus 56.75%, there was a diversity of ages, ranging from 10 days to 65 years, the distribution by age shows that the two age groups that predominate in this study are those from 30 to 40 years, the levels of antitoxoplasmic IgG vary from 25 IU to 715 IU, in our series, the main reason for consultation was a decrease in visual acuity and the involvement was unilateral in the majority of cases, we collected isolated fresh foci 3 times, while the others presented a combination of fresh and scar foci, all patients in our sample followed an identical treatment regimen, combining two antibiotics (Sulfamethoxazole / Trimethoprim) and a bolus of corticosteroids. Conclusion: Ocular toxoplasmosis, whether acquired or congenital, remains one of the most significant clinical manifestations during infection with the T. gondii parasite

Rapid and simultaneous determination of ultrashort-, short- and long- chain perfluoroalkyl substances by a novel liquid chromatography mass spectrometry method

Per- and Polyfluoroalkyl Substances (PFAS) are a group of persistent organic pollutants that have received considerable attention from public and regulatory groups. Due to regulations of long-chain PFAS, the use of short-chain and ultrashort-chain PFAS is rapidly growing. Thus, there is an urgent need to develop quantitative methods for determining PFAS with different chain lengths in various environmental matrices. This study introduces an innovative liquid chromatography-mass spectrometry (LC-MS) system combining large volume injection (LVI) and online solid phase extraction (SPE). This system incorporates three columns: a reverse-phase (RP) column, a weak anion exchange (WAX) trap column, and a hybrid HILIC/ion-exchange (HILIC/IE) column, controlled by two valves. With valve switching, ultrashort-chain PFAS that are not retained by the RP column are enriched by the trap column, while other PFAS are separated by the RP column. The trapped ultrashort PFAS are then transferred to the HILIC/IE column for further separation. The LVI significantly enhances the method's sensitivity, allowing for rapid and simultaneous determination of ultrashort-, short- and long- chain PFAS in aqueous samples. The matrix effects from various environmental samples were evaluated, and the results indicate that this unique LC-MS method is suitable for analyzing all chain-length PFAS in various matrices, including surface water, sewage effluent, and seawater. Finally, this novel LC-MS method was applied to quantify PFAS in various water samples.

Simultaneous quantification of alkanolamines and their dehydrogenation products in aqueous samples using high-performance liquid chromatography with pre-column derivatization with 2,4-dinitrofluorobenzene

BackgroundDiethanolamine, monoethanolamine, iminodiacetic acid, and glycine are important fine chemical intermediates, often requiring simultaneous quantitative analysis in various applications. This presents the challenge of accurately quantifying multiple substances within a single sample. The catalytic dehydrogenation of diethanolamine and monoethanolamine has garnered significant research interest, yet no analytical method has been reported for the simultaneous quantification of reactants and products in the dehydrogenation reaction mixtures of different alkanolamines. ResultsA high-performance liquid chromatography (HPLC) method has been developed for the simultaneous quantification of diethanolamine (DEA), iminodiacetic acid (IDA), glycine (Gly), and monoethanolamine (MEA) in aqueous solutions using 2,4-dinitrofluorobenzene (DNFB) for pre-column derivatization. The method demonstrated excellent linearity, with correlation coefficients (R2) of 0.9999, 0.9997, and 0.9998 for IDA, DEA, and Gly, respectively. The detection limits (LODs) were 0.02, 0.08, and 0.01 mg L−1, respectively. The quantification limits (LOQs) were 0.06, 0.24, and 0.03 mg L−1, respectively. Spiked recovery rates ranged from 96.99 % to 104.32 %, with relative standard deviations (RSDs) between 0.70 % and 3.03 %. For MEA and Gly, the R2 values were 0.9970 and 0.9990, the LODs were 0.12 and 0.01 mg L−1, the LOQs were 0.36 and 0.03 mg L−1, and spiked recoveries ranged from 96.24 % to 104.82 %, with RSDs between 1.22 % and 3.68 %. Compared to other methods, this HPLC approach offers superior sensitivity, accuracy, and precision. SignificanceThis method provides a robust reference for the individual or simultaneous quantification of alkanolamines, glycine, and iminodiacetic acid in aqueous matrices. It offers new insights into the simultaneous analysis of alkanolamines with multiple organic acids in complex matrices. Additionally, the method can guide the optimization of catalytic dehydrogenation processes for alkanolamines, potentially extending the advantages of dehydrogenation catalysts to other reactions.

Neurodegenerative biomarkers in different chambers of the eye relative to plasma: an agreement validation study

BackgroundProtein biomarkers have been broadly investigated in cerebrospinal fluid and blood for the detection of neurodegenerative diseases, yet a clinically useful diagnostic test to detect early, pre-symptomatic Alzheimer’s disease (AD) remains elusive. We conducted this study to quantify Aβ40, Aβ42, total Tau (t-Tau), hyperphosphorylated Tau (ptau181), glial fibrillary acidic protein (GFAP) and neurofilament light chain (NfL) in eye fluids relative to blood.MethodsIn this cross-sectional study we collected vitreous humor, aqueous humor, tear fluid and plasma in patients undergoing surgery for eye disease. All six biomarkers were quantitatively measured by digital immunoassay. Spearman and Bland–Altman correlation analyses were performed to assess the agreement of levels between ocular fluids and plasma.ResultsSeventy-nine adults underwent pars-plana vitrectomy in at least one eye. Of the 79, there were 77 vitreous, 67 blood, 56 tear fluid, and 51 aqueous samples. All six biomarkers were quantified in each bio-sample, except GFAP and NfL in tear fluid due to low sample volume. All six biomarkers were elevated in vitreous humor compared to plasma samples. T-Tau, ptau181, GFAP and NfL were higher in aqueous than in plasma, and t-Tau and ptau181 concentrations were higher in tear fluid than in plasma. Significant correlations were found between Aβ40 in plasma and tears (r = 0.5; p = 0.019), t-Tau in plasma and vitreous (r = 0.4; p = 0.004), NfL in plasma and vitreous (r = 0.3; p = 0.006) and plasma and aqueous (r = 0.5; p = 0.004). No significant associations were found for Aβ42, ptau181 and GFAP among ocular fluids relative to plasma. Bland–Altman analysis showed aqueous humor had the closest agreement to plasma across all biomarkers. Biomarker levels in ocular fluids revealed statistically significant associations between vitreous and aqueous for t-Tau (r = 0.5; p = 0.001), GFAP (r = 0.6; p < 0.001) and NfL (r = 0.7; p < 0.001).ConclusionAD biomarkers are detectable in greater quantities in eye fluids than in plasma and show correlations with levels in plasma. Future studies are needed to assess the utility of ocular fluid biomarkers as diagnostic and prognostic markers for AD, especially in those at risk with eye disease.

Determination of aconitum alkaloids in acute poisoning case by electromembrane extraction

In this work, electromembrane extraction (EME) was used for the first time to separate aconitine (AC), mesaconitine (Mes-AC) and hypaconitine (Hyp-AC) from biological samples and Chinese herbal medicines. Efficient EME of polar and high molecular weight aconitine alkaloids from different sample matrices was achieved with the solvent of 1-ethyl-2-nitrobenzene (ENB). Under the optimal EME conditions, EME provided recoveries for all targets in the range of 72%–74 %, 85%–103 % and 92%–94 % for whole blood, urine and aqueous samples. The proposed EME systems combined with LC-MS/MS and HPLC-UV were evaluated using different sample matrices, and the methods displayed satisfactory analytical characteristic including negligible matrix effect. The LOD and LOQ of AC, Mes-AC, and Hyp-AC by EME-LC-MS/MS were in the range of 0.002–0.068 ng/mL and 0.005–0.228 ng/mL respectively. The LOD and LOQ of AC, Mes-AC, and Hyp-AC by EME-HPLC-UV were in the range of 0.06–0.26 μg/mL and 0.20–0.86 μg/mL, respectively. The coefficient of determination, R2-value was ≥0.9926 for all cases, and the accuracy in the linear ranges was in the range of 91%–111 %. Finally, the method was successfully applied for the qualitative and quantitative analysis of AC and Mes-AC in the whole blood and herbal medicine dreg samples from an actual forensic case, and poisoning by aconitum alkaloids was identified as the cause of death. Therefore, we believe that EME could be a powerful tool to identify poisoning, and EME has great potential for efficient separation of polar and high molecular weight substances. These are of great importance in the fields of but not limited to forensic science, Traditional Chinese Medicine and clinics.

Optimization and extraction of annatto pigments obtained from Bixa orellana L. using supercritical fluid extraction

Traditionally, various techniques like water, vegetable oil, and solvent extraction are used to extract annatto pigments, a natural coloring agent derived from the Bixa orellana L. shrub. These traditional extraction methods can be time consuming and yield minimal pigment concentrations. This study explores an innovative approach to extract the maximum pigments from the annatto seed using supercritical fluid extraction (SFE). Fresh, extracted aqueous, and peeled samples of annatto powder were used at different temperatures (40, 45, and 50 °C) using different solvents of ethanol, methanol, and ethyl acetate with 99 % purity. The optimal extraction condition in supercritical fluid extraction is obtained with an aqueous sample treated with methanol solvent at 45 °C that yields 4.62 % norbixin, 2.49 % bixin, and a hue angle of 24.85⁰, achieving a high desirability value (0.949). Response surface method (RSM) was used to optimize the extraction procedure to obtain a higher yield of annatto pigments. In addition, for optimized conditions, the total phenols and antioxidants assay yielded 3.8 mg GAE/g and 51 % inhibition. HPLC analysis confirmed norbixin in the extracts obtained with a retention time of 38.40 min. This method offers a significant boost in pigment extraction efficiency, but also minimizes processing time. These combined advantages position it as a potentially superior approach for producing annatto pigments with enhanced concentration and purity.

Development of dispersive solid phase extraction method for the preconcentration of parathion ethyl as a simulant of nerve agent sarin from soil, plant and water samples prior to GC-MS determination.

In the presented study, an efficient and fast analytical method was developed for the determination of parathion ethyl as sarin simulant by gas chromatography-mass spectrometry (GC-MS). Dispersive solid phase extraction (DSPE) was performed to concentrate parathion ethyl from soil, plant and water samples. Reduced graphene oxide-iron (II, III) oxide (rGO-Fe3O4) nanocomposite was used as an adsorbent to collect the target analyte from the aqueous sample solutions. After the optimization of extraction/preconcentration parameters, optimum conditions for adsorbent amount, eluent type, mixing type/period, eluent volume and initial sample volume were determined as 15mg, acetonitrile, vortex/30s, 100 µL and 10mL, respectively. Under the optimum conditions, analytical performance of the developed DSPE-GC-MS method was evaluated in terms of limit of detection (LOD), limit of quantitation (LOQ) and dynamic range. Dynamic range, LOD and LOQ values were figured out to be 0.94-235.15µg/kg, 0.41µg/kg and 1.36µg/kg (mass based), respectively. Satisfactory percent recovery results (90.3-125% for soil, 93.5-108.7% for plant, 88.5-112.9% for tap water) were achieved for soil, plant and tap water samples which proved the accuracy and applicability of the developed method. It is predicted that the DSPE-GC-MS method can be accurately used for the detection of sarin in soil, plant and water samples taken from war territories.

EVA NEXUS-Phaco performance study.

To investigate a novel phacoemulsification system "EVA NEXUS" (D.O.R.C., Dutch Opthalmic Research Center) in comparison to the existing system "EVA" in clinical use. And to compare both phacoemulsification systems in terms of efficiency, safety and postoperative inflammatory activity. In this study standardized cataract surgery was performed on both eyes of the study participant, using the "EVA system" (control group, n=20) on one eye and the "EVA NEXUS system" (intervention group, n=20) on the other eye. Only patients with cataract LOCS Grading 1-3 and no accompanying eye diseases were included in this study. A total of 20 patients were included in this study, with each treatment arm including 20 eyes. During surgery a 0.1 mL aqueous humor sample was collected 1min after phacoemulsification to measure the total prostaglanin E2 concentrations using an enzyme-linked immunosorbent assay. The endothelial cell count, visual and refractive outcomes, and anterior chamber flare were evaluated preoperatively, and 1d, 1wk, and 3mo postoperatively. There were no statistically significant differences between both groups regarding intraoperative safety parameters including effective phacoemulsification time (P=0.904), balanced saline solution flow (P=0.701) and total surgery time (P=0.565). Postoperative prostaglandin E2 levels, anterior chamber flare as well as endothelial cell loss tended to be lower in the NEXUS-Group, however not being statistically significant (P=0.718; 0.164; 0.486). Both systems provided similar clinical outcomes, regarding best corrected visual acuity and refractive parameters, showing no statistically significant differences between both groups. Both systems show a high level of safety and efficency with similar results in terms of safety parameters including postoperative inflammatory activity and endothelial cell loss as well as visual and refractive outcomes. Although statistically not significant, the EVA NEXUS system tends to cause less postoperative inflammation with lower prostaglandin E2 levels and lower anterior chamber flare values.

Impact of the biogas impurities on the quality of the precipitated calcium carbonate in the regenaration stage of a chemical absorption biogas upgrading unit

Combining Carbon Capture and Storage (CCS) with producing competitive secondary raw materials is key to decarbonizing industry and reducing resource extraction. Biogas upgrading to biomethane stand out as an alternative, but a significant gap remains in integrating this process within a circular economy framework. This issue has been recently addressed by a process that integrates biogas upgrading via caustic absorption with the production of Precipitated Calcium Carbonate (PCC) and the recovery of sodium hydroxide from waste brine solution using membrane technologies. The profitability of this approach depends on the quality of the PCC, a critical factor that this work addresses. By characterizing PCC is determined whether trace compounds in biogas contaminate the PCC and potentially affect its commercial value. It also examines the CO2 absorption process and analyzes the aqueous samples from the filtration phase of the PCC slurry. Results confirm the high purity of PCC obtained from biogas treatment using Raman spectroscopy, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The analyses show that the PCC is pure calcium carbonate, mainly in the stable calcite form, with a typical tetrahedral morphology and no detectable impurities. Characterization of aqueous solutions revealed organic trace compounds from biogas, with TOC concentrations of 9.7 (± 6.4) and 16.0 (± 8) mg C/l. Silicon measurements showed similar concentrations in the absorbent solution and filtrated PCC slurry. Additionally, ammonia escapes as gas, and hydrogen sulfide in the biogas likely contributed to sulfate salt formation. Analysis of the CO₂ absorption shows a first-order reaction with OH-, where the amount of CO₂ absorbed (46.3–50.0 g) closely matches the theoretical value of 48 g. The study reveals that most of the biogas impurities dissolve into the aqueous solution, being crucial for future studies and downstream membrane treatments, and the PCC is unaffected by these impurities with a purity suitable for commercial applications.

Methods for degrading dicloxacillin in water using inorganic peroxides and their combination with UVC- experimental and theoretical aspects

Antibiotics are currently recognized as environmental pollutants. In this work, the methods involved in the degradation of a β-lactam antibiotic (i.e., DXC) by treatments based on inorganic peroxides and UVC (e.g., UVC alone, UV-C/H2O2, UVC/peroxymonosulfate, and UVC/peroxydisulfate) are presented. The methodology of computational calculations to obtain frontier orbitals and Fukui indices for DXC, and elucidate the reactive moieties on the target substance is also shown. Finally, the direct oxidation by peroxides and UV-C/H2O2 action to treat DXC in simulated pharmaceutical wastewater are depicted. The chromatographic and theoretical analyses allowed for determining the degrading performance of inorganic peroxides and UVC-based treatments toward the target pollutant in aqueous samples.•Treatments based on inorganic peroxides and UVC as useful methods for degrading the β-lactam antibiotic dicloxacillin.•Persulfates and UV-C/H2O2 showed high degrading action on the target pharmaceutical.•Methodologies based on theoretical calculations for the identification of reactive moieties on the DXC susceptible to radical attacks are presented.