Solid-phase Extraction Technique Research Articles

Thiourea-functionalized magnetic coffee residue for adsorption and magnetic solid-phase extraction of selected toxic metals in water

Herein, a recyclable thiourea-modified magnetic coffee residue was prepared, characterized, and investigated for Cd(II) and Pb(II) adsorption and magnetic solid-phase extraction in aqueous solutions. Optimal conditions of the adsorption parameters were found to be initial Cd(II) and Pb(II) concentrations of 4 and 20 mg/L, respectively, sample solution pH of 7, adsorbent amount of 50 mg, agitation rate of 150 rpm, and adsorption period of 30 min. The adsorption isotherm and kinetics aligned well with the Langmuir and the pseudo-second-order models, respectively. The modified magnetic coffee residue demonstrated a high uptake potential (mg/g), 8.9 for Cd(II) and 40 for Pb(II). The results indicate that chemosorption is the rate-limiting and that temperature influences the process. The elution procedure was performed by 5 mL 0.5 M thiourea in 2 % HCl and the developed magnetic solid-phase extraction technique presented excellent linearity (R2 ≥0.998), sensitivity (LOD (µg/L), 0.18 and 0.93 respectively for Cd(II) and Pb(II)), and precision (%RSD, ≤2.7 %). Compared to the reported techniques, the method is highly effective, environmentally friendly, and easily accessible. It also demonstrated good potential (%R, 92.5–99.0 %) when applied to real-world water samples. In conclusion, the developed techniques are recommended for the adsorption and magnetic solid-phase extraction of toxic metals in water systems.

Comprehensive undergraduate experiment: determination of phenylurea herbicide in tea by magnetic solid-phase extraction-high performance liquid chromatography

Against the backdrop of the Ministry of Education's promotion of new agricultural science construction and interdisciplinary integration, a comprehensive chemistry experiment to enhance the practical skills of students in preparing biomass functional materials and detecting pesticide residues was designed. Natural loofah was utilized as a precursor in synthesizing nitrogen-doped magnetic porous carbon materials, which were then applied in a magnetic solid-phase extraction (MSPE) technique. Subsequently, high performance liquid chromatography (HPLC) was employed to analyze and detect the phenylurea herbicide monuron in tea. The experimental process included material synthesis, characterization, optimization of the MSPE conditions, adsorption performance studies, and HPLC, reflecting its scientific, systematic nature and providing a comprehensive learning platform for students. It not only deepens student understanding of the relationship between material characterization and application, but also improves their experimental design and problem-solving capacities. Moreover, by integrating cutting-edge science, ideological and political education, and experimental training, it not only stimulates student interest in scientific research and cultivates innovative thinking and practical skills, but also strengthens their feelings of social responsibility and historical mission. This approach realizes the comprehensive educational goals of experimental training and lays the foundation for nurturing high-quality talent with a global perspective and sense of social responsibility.

Evaluation of in-house-built pipette-tip micro-solid-phase extraction devices for sample preparation in the analysis of amino compounds by liquid chromatography-tandem mass spectrometry

Amino compounds are of significant interest in dietary, clinical, and quality control fields. Efficient extraction is crucial for comprehensive metabolomics, especially for amino acids and biogenic amines, but traditional solid-phase extraction (SPE) methods are costly and require large solvent volumes. Miniaturized SPE techniques, like pipette-tip micro-solid-phase extraction (PT-µ-SPE), offer promising alternatives by improving throughput and reducing solvent and sorbent usage. This study presents PT-µ-SPE for the screening and quantification of amino compounds in bee products, particularly honey. The method involves derivatization with diethyl ethoxymethylenemalonate (DEEMM) and analysis using liquid chromatography-triple quadrupole mass spectrometry. Silica-based SCX sorbents were effective for a broad range of amino compounds, while WCX sorbents were better for aliphatic amines. The method's extraction efficiency was assessed across sample loading, washing, and elution solution, with recovery rates of 70 - 120% in oat bran, sea buckthorn leaves, and honey extracts. Matrix effects were observed for four amino compounds in honey. Limits of detection (LoD) and quantification (LoQ) ranged from 0.37 to 57 µg L⁻¹ and 1.13 to 174 µg L⁻¹, respectively. Covering 48 amino compounds under different PT-µ-SPE conditions, this method has been applied to several samples, demonstrating accuracy, environmental sustainability, cost-effectiveness, portability, and versatility in amino compound analysis.

Comparative evaluation of DNA synthesis for qPCR analysis from oral squamous cell carcinoma tissues - A rapid and robust isolation technique for gene expression studies

BackgroundDNA isolation from biological materials is the initial step in several bioanalytical processes, including the polymerase chain reaction (PCR). This procedure works best with pure DNA devoid of potential amplification reaction inhibitors. Since the quantity and quality of biological samples are limited, it is essential to extract as much DNA as possible from the original sample. The solid-phase extraction technique is frequently used to purify DNA. In this process, the DNA is adsorbed onto a solid support, any contaminants from the reaction are eliminated by washing, and the purified DNA is then eluted from the support. The quality and concentration of DNA have a direct effect on the gene analysis procedure. Therefore, before interpreting the results of PCR-based diagnostic assays, it is imperative to confirm the DNA preparation and integrity, particularly if no pathogenic DNA is identified. MethodsA comparative study was carried out using two standardized protocols for DNA synthesis in comparison with a test protocol incorporating carrier RNA and proteinase K from a viral detection kit. The quality and quantity of the synthesized DNA are assessed by qPCR analysis for gene amplification of metastasis suppressor genes NDRG1, RhoGDI, and KISS 1. Results and conclusionThe test protocol showed higher yields of DNA in comparison to the standard protocol. The concentration of DNA obtained was validated by the concentration of gene expressed from q PCR analysis. The gene expression was significantly higher when the test protocol method was followed for DNA synthesis. Thus the study validates the potential of nucleic acid carrier RNA molecules to improve DNA extraction processes used in tissue samples for gene analysis procedures.

Magnetic solid-phase extraction of trace elements in water and fish using greenly synthesized MnFe2O4 @ cabbage hydrochar/chitosan ternary composite

A new analytical method for determining lead, cadmium, and copper in water and fish was established employing a novel synthesized magnetic eco-friendly ternary nano-composite adsorbent of manganese ferrite@cabbage hydrochar/chitosan (MnFe2O4@CBH/CTS). Cabbage leaves were employed as a green fuel, acting as a reducing and capping agent in the green manufacture of manganese-ferrite nanoparticles, and then hydrothermally carbonized to form hydrochar. The novel material underwent FT-IR, XRD, SEM, EDX, and BET investigation, revealing a micro-porous surface. The magnetic solid-phase extraction (MSPE) technique was used to enrich the samples and separate the matrix for GFAAS analysis. The impact of adsorption factors such as pH, extraction duration, metal ion concentration, and interference from coexisting ions were examined. Based on a preconcentration factor of 50, the method demonstrated LOD (3σ/m) ranging from 6 to 18 ng L−1, linearity (ng L−1) from 48 to 450 (Pb), 20–180 (Cd) and 59–300 (Cu), and precision (RSD, n=3) of 1.8–3.9 % (1.0 μg L−1) and 3.0–4.6 % (10 μg L−1). The approach was effectively applied to the analysis of tested elements in water and marine fish samples, with spiked sample recoveries above 95 % and an RSD of less than 5.4 %.

Comparative study of bisphenols in e-cigarette liquids: Evaluating fabric phase sorptive extraction, ultrasound-assisted membrane extraction, and solid phase extraction techniques

To address the under-researched risk of bisphenols (BPs) in e-cigarette liquids, comprehensive studies have been conducted to propose optimum sample preparation and analysis methods. To determine twelve BPs in refill liquids for e-cigarettes, three sample preparation methods based on distinct operational and working principles were employed. These included fabric phase sorptive extraction (FPSE), ultrasound-assisted solvent extraction of porous membrane-packed samples (UASE-PMS) and solid phase extraction (SPE) utilizing molecularly imprinted polymers (MIPs) technology. Each extraction method was combined with ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). Key parameters of FPSE and UASE-PMS procedures were optimized. This optimization included selection of the FPSE membrane types, durations of extraction and the choice solvents. Comprehensive validation was conducted, demonstrating linearity across a range from 2 to 60 ng/mL for all BPs (BPS, BPA, BPF, BPE, BPB, BPC, BPZ, BPFL, BPBP, BPP, BPG and BPM). Determination coefficients were above 0.9913, signifying linear relationship. The limits of detection (LODs) were established below 0.90 ng/mL, while the limits of quantification (LOQs) were lower than 2.5 ng/mL. Notably, the method based on UASE-PMS was successfully applied to the analysis of refill liquids for e-cigarettes samples. A comparative analysis of the methods highlighted variances in precision, accuracy, and applicable aspects, such as adjustment of parameters, sample preparation time, cost, handling, availability and possible limitations. Three methods have been identified as suitable for analysing BPs in e-cigarette refill liquids, highlighting the necessity to examine their presence in these products.

Evaluating the reliability of solid phase extraction techniques for hydrocarbon analysis by GC–MS

Saturate and aromatic compounds are essential in the petroleum industry for assessing the thermal maturity of source rocks and oils, which is critical for basin modeling and sweet-spot mapping. These compounds also play a role in environmental applications, such as oil spill fingerprinting and biogeochemistry. However, the analysis of these compounds by gas chromatography-mass spectrometry (GC–MS) requires meticulous and time-consuming separation processes. Traditional methods like normal-phase liquid column chromatography (LCC) involve large volumes of harmful solvents. This study evaluates the effectiveness of five different sorbents using solid-phase extraction (SPE) techniques—neutral Si, SiOH, Ag-ion, neutral Al, and Ag-ion mixed with activated silica—compared to LCC. The goal was to discern differences in peak resolution, concentration, and isomer ratios of saturate and aromatic compounds for thermal maturity and source rock assessments. The results show that SiOH, neutral Si, and neutral Al do not fully separate aromatic compounds from the saturate fraction, sometimes leaving 40–100% of aromatics within the saturate fraction. Ag-ion mixed with activated silica provided the best separation, resulting in up to 23 times higher aromatic concentration than SiOH. This method is more reliable for quantifying both saturate and aromatic compounds, increases the efficiency of hydrocarbon evaluations, and reduces solvent consumption by 63%, offering a more sustainable approach to hydrocarbon analysis.

Application of a laccase-catalyzed oxidative coupling for the removal and detoxification of typical flotation reagent salicylhydroxamic acid

Residual organic flotation reagents in mineral processing wastewater (MPW) can pose environmental hazards and hinder the sustainable development of the mining industry. Laccase as a versatile biocatalyst can eliminate various recalcitrant contaminants from the environment, but its potential applications for the removal and detoxification of organic flotation reagents have until now been overlooked. Herein, the influence of superparamagnetic immobilized laccase (SPM-IMLac) on the enzymatic removal of salicylhydroxamic acid (SHA), a typical mineral flotation reagent, as well as the mechanism of this process have been explored for the first time. The results indicated that SPM-IMLac can effectively remove SHA over a broad pH range and this process follows the pseudo-first-order reaction kinetics. A methodology which combined high resolution mass spectrometry (HRMS) and a solid phase extraction (SPE) technique revealed that SPM-IMLac could catalyze a single-electron oxidation of SHA to generate self/cross-oligomers via radical-driven C-C and/or C-O-C covalent coupling pathways. The Vibrio fischeri bioluminescence inhibition assay and a total organic carbon (TOC) analysis corroborated that the SHA transformation was accompanied by detoxification and by a reduction in TOC of the reaction solution, the extent of which correlated with the extent of the oxidative coupling. Moreover, SPM-IMLac could be easily recovered and reused, while keeping its high removal efficiency of SHA in the actual MPW matrices. This study not only provides fascinating insights into the transformation mechanisms and environmental fate of SHA mediated by SPM-IMLac, but it also exploits a viable and sustainable approach for the remediation of organic flotation reagents-contaminated MPW.

Contamination of Phthalic Acid Esters (PAEs) in Surface Sediment Samples Collected from Rao Cai River in Ha Tinh, Vietnam

In this report, the solid phase extraction technique combined with the gas chromatography-mass spectrometry method (GC-MS) was optimized to determine the contamination of nine phthalic acid esters (PAEs) in the surface sediment samples collected from Rao Cai River in Ha Tinh, Vietnam. The method detection limits (MDLs) were from 2.0 to 6.0 ng/g-dry weight (ng/g-dw). The recoveries of surrogate standards (PAE-d4) in both blank and real samples ranged from 79.6 to 94.3% (RSD < 8.7%). The total concentration of PAEs in the surface sediment samples was in the range of 72.4-1390 ng/g-dw (mean/median: 561/552 ng/g-dw). Among PAEs, di-(2-ethyl)hexyl phthalate (DEHP) was detected at the highest level in all samples. In contrast, dimethyl phthalate (DMP), diethyl phthalate (DEP), and dipropyl phthalate (DPP) were found at low frequency and concentration. Moreover, the risk quotient of PAEs in sediments was estimated based on the measured concentrations. Diisobutyl phthalate (DiBP) posed a medium risk for fish.

Novel Triton X-114 coated Fe3O4 magnetic nanoparticle adsorbent for Cd(II) and Co(II) ions preconcentration in honey samples using magnetic solid-phase extraction: Determination by ICP-OES

This work focuses on creating and studying the effectiveness of Fe3O4 nanoparticles coated with (3-aminopropyl)triethoxysilane (APTES) and polyethylene glycol tert-octylphenyl ether (TX-114), respectively, as adsorbent. Fe3O4@APTES@TX-114 adsorbent extracts heavy metal cations Cd2+ and Co2+ using a magnetic solid phase extraction technique. The synthesized magnetic nanoparticles (MNPs) were characterized by Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-Ray Analysis (EDX), Fourier Transform Infrared Spectroscopy (FT-IR), and Thermogravimetric Analysis (TGA). After this stage, Cd2+ and Co2+ determinations were made with the ICP-OES device. The optimum conditions for recovering Cd2+ and Co2+ cations were pH 7, an adsorbent dosage of 2 g/L, and a contact time of 120 min. While the method was compatible with Langmuir and Freundlich isotherm models, the pseudo-second-order kinetic equation was more compatible than the pseudo-first-order. Acidic and basic media were investigated for the desorption of Cd2+ and Co2+ ions from the adsorbent. At the same time, maximum recovery was achieved for both cations at a concentration of 1.5 mol/L HCl, but no significant recovery was obtained in the NaOH medium. The common ion study observed that Cd2+ and Co2+ cations were recovered over 95 % in the presence of many cations and anions at different concentrations. The relative standard deviation (RSD), limit of quantification (LOQ), limit of detection (LOD), and enrichment factor (EF) were calculated as 1.40 %, 2.963 µg/L, 0.889 µg/L, 20.99 for Cd2+ and 3.05 %, 1.88 µg/L, 0.564 µg/L, 109.41 for Co2+, respectively. The magnetic solid phase extraction method realized quantitative recovery of Cd2+ and Co2+ cations in different honey samples. It was found that the heavy metal contents in honey samples from the Sakarya region are below permissible levels.

Analytical advances in the determinations of dietary sphingolipids in milk, dairy products, and infant formula and impacts on human health

SummarySphingolipids (SL) are bioactive compounds in milk, dairy products, and infant formula. SL has been found to have different health benefits, such as anti‐inflammatory, antimicrobial, anticancer, and cholesterol‐lowering characteristics. SL requires careful extraction, separation, and identification due to their unique characteristics. This review discusses the importance of extracting, purifying, and analysing SL from milk and dairy products. OE (Organic extraction), SPE (solid‐phase extraction), and SFE (supercritical CO2) techniques, as well as dispersive OE and SPE, are the most common methods. In addition, this review discussed various analytical techniques that can be used to determine and quantify SL classes, including TLC (thin‐layer chromatography), HPLC (high‐performance liquid chromatography), nuclear magnetic resonance spectroscopy, and mass spectrometry. These techniques are crucial for understanding the amounts of SL dairy products and infant formula. The paper also focuses on the different types of SL present in milk, dairy products, and infant formula and their concentrations. SL has the potential to be applied to the development of functional foods, and further research in this area is needed. This article sheds light on the extract, purification, and analysis of SL dairy products and infant formula, as well as their potential health benefits.

Magnetic solid-phase extraction technique based on Fe3O4@coPPy-PTH nanocomposite for extraction of cobalt, chromium, and nickel prior to determination by microsample injection system-flame atomic absorption spectrometry in alcoholic and nonalcoholic beverages.

A novel Fe3O4@coPPy-PTH nanocomposite-based sorbent was prepared via in situ oxidative polymerization using Fe3O4 nanoparticles with spherical and flower-like morphologies of thiophene and pyrrole as the feedstocks. The synthesized nanocomposite displayed sensitive extraction and determination of metal ions Co(II), Cr(III), and Ni(II) without a chelating agent, followed by microsample injection system-flame atomic absorption spectrometry. Advanced spectroscopic and imaging techniques including scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy were used to characterize the composition and morphology of the Fe3O4@coPPy-PTH nanocomposite. SEM observations showed that the size of the Fe3O4 nanoparticles changed from 30 nm to 120 nm in diameter after copolymer (PPy-PTH) coating. The Fe3O4@coPPy-PTH nanocomposite has good dispersion properties and stability in strong acid solutions. For effective extraction of the studied analytes, the influence of sample pH, volume of sample solution and eluent, amount of adsorbent, and interference of coexisting metal ions were optimized. Under the optimum conditions, preconcentration factors were obtained as 25 for all analytes. The calibration curves were linear in the range of 0.0-10.0 μg L-1 with coefficients of determination (R2) greater than 0.9957 for all three analytes. Limits of detection (S/N = 3) were calculated in the range of 0.17-0.23 μg L-1. Precision values, expressed as relative standard deviations, were lower than 3.0%, and relative recoveries were obtained in the range of 88.6%-103.6%. The proposed method (Fe3O4@coPPy-PTH/MSPE/MIS-FAAS) was successfully applied to extract and determine the studied metal ions in beer, wine, and nonalcoholic beverage samples.

Development of LC–MS/MS Method for the Simultaneous Detection of Emerging Contaminants in Aquatic Matrices

Emerging contaminants (ECs) are substances that have no defined environmental quality standards or regulations, and have the potential to pose major adverse impacts on the environment and human health. The detection of contaminants in the natural environment is the key step for establishing precise environmental risk assessment approach for ECs. However, ECs come from different origins with various physicochemical properties, making their detection a complicated process. Moreover, their presence in the aquatic environment at trace concentration range (ng/L-µg/L), requires an accurate detection at low concentration levels. This study aims to develop an efficient analytical method for simultaneous determination of 5 different ECs in aqueous solution based on solid phase extraction technique (SPE) followed by liquid chromatography-mass spectrometry (LC–MS/MS). High recovery rates (72% to 114%) were achieved for all targeted compounds. Ciprofloxacin (CIP), diuron (DIU), terbutryn (TER) and diclofenac (DIC) had a limit of detection (LOD) of 5 µg/L and a limit of quantification (LOQ) of 10 ng/L, while LOD and LOQ for EE2 were 25 µg/L and 50 ng/L, respectively. These results confirm that the optimized method can be applied for extraction and analysis of ECs from different classes in the aquatic environment.

Fe3O4@PS-DVB microspheres modified with urea functional groups for rapid and green extraction of fluorinated aromatic carboxylic acids from tap and formation water

The present study describes the trace analysis of 23 fluorinated aromatic carboxylic acids based on the dispersive magnetic solid phase extraction (m-SPE) technique coupled with the gas chromatography coupled with mass spectrometry (GC–MS) electron ionization (EI) technique. A commercial hydrophilic-lipophilic balanced (HLB) material polystyrene divinyl benzene having urea functional groups was modified with magnetite nanoparticles and employed as a sorbent for dispersive m-SPE of fluorobenzoic acids (FBAs) from the tap and formation water samples. The extraction occurred due to π- π interaction between the aromatic ring of synthesized sorbent and the aromatic ring of FBAs, the hydrogen bond formation between the urea functional group of the sorbent and carbonyl oxygen, fluorine of the FBAs. As a result, the method was precise, rapid, reproducible, and calibrated with the coefficient of variation (R2) greater than 0.98 for all 23 compounds. The instrument detection limit (IDL) and method detection limit (MDL) were found in the range of 2.60 – 8.25 ng/mL and 0.08 – 0.28 ng/mL respectively. Extraction efficiencies were found in the range of 83.80–100 % for tap water samples and 78.41–98.92 % for formation water samples, respectively, with an enrichment factor of 33.33–66.66 and a maximum RSD of 7.07 %. The recyclability and magnetic properties of the synthesized material were also investigated, resulting in the material being reused for six cycles without impacting its performance; hence, the method offers rapid determination and high throughput analysis of FBAs. In addition, simulation studies were performed using the adsorption location tool of Material Studio, confirming the interaction sites of sorbent with FBAs. AGREE evaluated the analytical greenness of the method, and the score was found to be 0.51.

Novel Application of Metal-Organic Frameworks as Efficient Sorbents for Solid-Phase Extraction of Chemical Warfare Agents and Related Compounds in Water Samples.

In this work, we test metal-organic frameworks (MOFs) as sorbents in the solid-phase extraction (SPE) technique to determine chemical warfare agents (CWAs) and their related compounds in water samples. During this study, we used 13 target compounds to test the selectivity of MOFs thoroughly. Three MOFs were used: MIL-100(Fe), ZIF-8(Zn), and UiO-66(Zr). The obtained materials were characterized using FT-IR/ATR, SEM, and XRD. CWA's and related compounds were analyzed using gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). The effect of the type of elution solvent and the amount of sorbent (MOFs) in the column on the efficiency of the conducted extraction were verified. The LOD ranged from 0.04 to 7.54 ng mL-1, and the linearity range for the analytes tested extended from 0.11/22.62 (depending on the compound) to 1000 ng mL-1. It was found that MOFs showed the most excellent selectivity to compounds having aromatic rings in their structure or a "spread" spatial structure. The best recoveries were obtained for DPAA, CAP, and malathion. Environmental water samples collected from the Baltic Sea were analyzed using an optimized procedure to verify the developed method's usefulness.

Environmental Pollution Monitoring via Capillary Zone Electrophoresis and UHPLC Simultaneous Quantification of Some Antipsychotic Drug Residues in Industrial Wastewater Effluents

Monitoring and measuring pharmaceutical pollutants in environmental samples is a vital and complex task due to their potential detrimental effects on human health, even at low levels. Using capillary zone electrophoresis (CZE) and ultra-high-performance liquid chromatography (UHPLC), it was possible to separate and measure three commonly used antipsychotic drugs, chlorpromazine (CPZ), haloperidol (HAL), and risperidone (RIS), in wastewater of the pharmaceutical industry. The technique of solid-phase extraction (SPE) was developed and implemented as a very effective method for preparing samples prior to analysis. The settings of the capillary electrophoretic and chromatographic techniques were adjusted to obtain the most efficient separation profile for the medications being studied. The concentration of all the medicines being investigated ranged from 0.5 to 50 µg/mL. SPE was used to treat real wastewater samples after a thorough validation process that followed the rules set by ICH-Q2B. The developed assays were then effectively employed to identify the tested antipsychotic substances in the real wastewater samples. The provided methodologies may be efficiently utilized to monitor the extent of environmental contamination caused by the investigated pharmaceuticals.

Natural Occurrence and Co-Occurrence of Beauvericin and Enniatins in Wheat Kernels from China.

A total of 769 wheat kernels collected from six provinces in China were analyzed for beauvericin (BEA) and four enniatins (ENNs), namely, ENA, ENA1, ENB and ENB1, using a solid phase extraction (SPE) technique with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results show that the predominant toxin was BEA, which had a maximum of 387.67 μg/kg and an average of 37.69 μg/kg. With regard to ENNs, the prevalence and average concentrations of ENB and ENB1 were higher than those of ENA and ENA1. The geographical distribution of BEA and ENNs varied. Hubei and Shandong exhibited the highest and lowest positive rates of BEA and ENNs (13.46% and 87.5%, respectively). However, no significant difference was observed among these six provinces. There was a co-occurrence of BEA and ENNs, and 42.26% of samples were simultaneously detected with two or more toxins. Moreover, a significant linear correlation in concentrations was observed between the four ENN analogs (r range: 0.75~0.96, p < 0.05). This survey reveals that the contamination and co-contamination of BEA and ENNs in Chinese wheat kernels were very common.

Residues of veterinary antibiotics in solid natural and organic fertilizers-method development and sample analysis.

Livestock excrement is used around the world as natural fertilizers or, after processing, as organic fertilizers for crops and grasslands. But due to the presence of veterinary antibiotics in them, they may pose a threat not only to the natural environment, mainly to soil microorganisms, but also to human and animal health. This article describes a method for detecting 21 antibacterial substances in solid natural and organic fertilizers. Antibiotics from fertilizers were extracted with a mixture of acetonitrile and McIlvain-Na2EDTA buffer, twice. The extracts were purified by solid phase extraction technique on Strata-X cartridges and analyzed with the use UHPLC-MS/MS technique. The method was validated in accordance with EU Commission Implementing Regulation 2021/808; the obtained recovery ranged from 93.6 to 116.6% (depending on the analytes), and the linearity ranged from 50 to 1000µg/kg. The developed method was used to analyze 73 samples of solid natural and organic fertilizers. Our research has shown that over 38% of natural fertilizers were contaminated with antibiotics, mainly doxycycline in concentrations reaching several dozen milligrams per kilogram of fertilizers. In the case of processed organic fertilizers, the presence of antibiotics was found in over 37% of the analyzed samples. The research results showed that the developed and validated analytical method may be useful for assessing the presence and content of antibacterial substances in solid natural and organic fertilizers.

The distribution and fate of pesticides in full-scale drinking water treatment plants

This study utilized HPLC-MS/MS combined with improved solid-phase extraction techniques to investigate the distribution and fate of 31 pesticides in three drinking water treatment plants (DWTPs), which source their water from the Yangtze River, the Yellow River, and Taihu Lake. The total concentration of pesticides in the raw water of the three water treatment plants ranged from 145.4 to 257.1 ng/L, while in the treated water it ranged from 22.8 to 59.0 ng/L, with an average removal efficiency of 78.3 %. Atrazine emerges as the predominant pesticide substance in the raw water of all three plants, indicating its continued widespread use. In the conventional treatment process, sand filtration and disinfection can remove a small amount of pesticides, while coagulation and sedimentation are ineffective. However, adding a pre-ozonation step before coagulation and sedimentation can enhance the removal efficiency of pesticides. Ozone and BAC are the most effective removal processes, with pesticide removal rates ranging from 31.8 % to 64.6 % for ozone and from 20.9 % to 47.7 % for BAC. The combination of ozone and H2O2 (64.6 %) has a higher pesticide removal efficiency compared to the ozone process alone (31.8 % and 50.7 %), especially for substances that are resistant to degradation by ozone. However, BAC's effectiveness in pesticide removal decreases significantly with increasing years of usage. After 2 years of use, the removal rate of BAC is 83.3 %, whereas after 4 years, it decreases to only 26.6 %. This study contributes to the understanding of the fate of pesticides in the drinking water treatment process.

Recovery of an Antioxidant Derived from a Phenolic Diphosphite from Wastewater during the Production of a Polypropylene Compound: A Step towards Sustainable Management.

Organic phosphoester (OPE) antioxidants are currently required due to their contribution to enhancing the quality of polymers, including polypropylene (PP). In this research, an integral methodology is presented for the efficient extraction of bis(2,4-dicumylphenyl) pentaerythritol diphosphite from industrial wastewater. Upon employing the solid-phase extraction (SPE) technique, the recovered compound is subjected to a comprehensive analysis of the recovered compound using high-performance liquid chromatography (HPLC), mass spectrometry (MS), thermal analysis (TGA), Fourier transforms infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Subsequently, purified Bis(2,4-dicumylphenyl) pentaerythritol diphosphite was evaluated as a thermo-oxidative stabilizer after incorporation into PP resins. The relative standard deviation (RSD), Error (Er), linearity (R2), and percentage (%) recovery were less than 2.6, 2.5, more significant than 0.9995, and greater than 96%, respectively, for the inter-day and intra-day tests of the chromatographic method and the SPE. Except for chloroform, which was necessary due to the solubility properties of the investigated analyte, the use of environmentally friendly solvents, such as methanol and acetonitrile, was considered during the development of this research. The OPE extracted from industrial wastewater was characterized by FTIR, UV-Vis, DSC, TGA, and MS, allowing the elucidation of the structure of Bis(2,4-dicumylphenyl) pentaerythritol diphosphite (BDPD). The recovered OPE was mixed with PP resins, allowing it to improve its thermal properties and minimize its thermo-oxidative degradation. Organophosphorus flame retardant (OPE)' concentration in wastewater is alarming, ranging from 1179.0 to 4709.6 mg L-1. These exceed toxicity thresholds for aquatic organisms, emphasizing global environmental risks. Using a validated solid-phase extraction (SPE) technique with over 94% recovery, the study addresses concerns by removing organic contaminants and supporting circular economy principles. The high economic and environmental significance of recovering BDPD underscores the need for urgent global attention and intervention.