Novel ferrofluid based on hydrophobic deep eutectic solvents for separation and analysis of trace estrogens in environmental water and urine samples.

A novel ferrofluid prepared from a hydrophobic deep eutectic solvent (DES) and Fe3O4@graphite composite materials was introduced as a green microextraction medium for the separation and enrichment of trace estrogens in real samples. It was found that the ferrofluid greatly improved the capacity and selectivity of target analytes, benefiting from the enrichment of both DES and Fe3O4@graphite composite materials. Using a combination of high-performance liquid chromatography-fluorescence detection (HPLC-FLD) and vortex-assisted liquid-liquid microextraction (VALLME), a new method was established for simultaneous rapid processing and accurate determination of three estrogens (estradiol [E2], estriol [E3], and ethinyl estradiol [EE2]) in environmental water and urine samples. Key parameters affecting the extraction efficiency were optimized using a single-factor approach and response surface methodology. Under optimal conditions, this method yielded a low limit of detection (1.01 ng L-1, 3.03 ng L-1, and 25.0 ng L-1 for EE2, E2, and E3, respectively), wide linear range (3-200,000 ng L-1), high enrichment factors (9.81-47.2), and satisfactory recovery (73.8-129.0%). Compared with traditional analytical techniques, this method avoids the use of volatile toxic organic extraction solvents and cumbersome phase separation operations.

3D flower-liked Fe3O4/C for highly sensitive magnetic dispersive solid-phase extraction of four trace non-steroidal anti-inflammatory drugs.

A low cost-effective and simple synthesis method was adopted to acquire three-dimensional flower-like structure Fe3O4/C that has large specific area, suitable pore structure and sufficient saturation magnetism. The obtained Fe3O4/C exhibits outstanding preconcentration ability and was applied to extracting non-steroidal anti-inflammatory drugs from complex environmental and biological samples. The parameters of magnetic solid-phase extraction were optimized by univariate and multivariate methods (Box-Behnken design). The high degree of linearity from 2.5 to 1000.0 ng mL-1 (R2 ≥ 0.9976), the limits of detection from 0.25 to 0.5 ng mL- 1 (S/N = 3), and the limits of quantitation from 1.0 to 2.0 ng mL- 1 (S/N = 10) were yielded by adopting this novel method after the optimization. Moreover, the recoveries of non-steroidal anti-inflammatory drugs from 89.6 to 107.0% were acquired in spiked plasma, urine and lake samples. In addition, the adsorption of non-steroidal anti-inflammatory drugs on Fe3O4/C was explored by adsorption isotherms and kinetic studies. Furthermore, the adsorption mechanism for non-steroidal anti-inflammatory drugs by Fe3O4/C was proposed, which was hydrogen bonding and π-π interaction between non-steroidal anti-inflammatory drugs and Fe3O4/C. Graphical abstract.

The Influence of Ionic Liquids on the Effectiveness of Analytical Methods Used in the Monitoring of Human and Veterinary Pharmaceuticals in Biological and Environmental Samples-Trends and Perspectives.

Recent years have seen the increased utilization of ionic liquids (ILs) in the development and optimization of analytical methods. Their unique and eco-friendly properties and the ability to modify their structure allows them to be useful both at the sample preparation stage and at the separation stage of the analytes. The use of ILs for the analysis of pharmaceuticals seems particularly interesting because of their systematic delivery to the environment. Nowadays, they are commonly detected in many countries at very low concentration levels. However, due to their specific physiological activity, pharmaceuticals are responsible for bioaccumulation and toxic effects in aquatic and terrestrial ecosystems as well as possibly upsetting the body's equilibrium, leading to the dangerous phenomenon of drug resistance. This review will provide a comprehensive summary of the use of ILs in various sample preparation procedures and separation methods for the determination of pharmaceuticals in environmental and biological matrices based on liquid-based chromatography (LC, SFC, TLC), gas chromatography (GC) and electromigration techniques (e.g., capillary electrophoresis (CE)). Moreover, the advantages and disadvantages of ILs, which can appear during extraction and separation, will be presented and attention will be given to the criteria to be followed during the selection of ILs for specific applications.

Ion-pair switchable-hydrophilicity solvent-based homogeneous liquid-liquid microextraction for the determination of paraquat in environmental and biological samples before high-performance liquid chromatography.

An approach involving ion-pair switchable-hydrophilicity solvent-based homogeneous liquid-liquid microextraction coupled to high-performance liquid chromatography has been applied for the preconcentration and separation of paraquat in a real sample. A mixture of triethylamine and water was used as the switchable-hydrophilicity solvent. The pH was regulated using carbon dioxide; hence the ratio of the ionized and non-ionized form of triethylamine could control the optimum conditions. Sodium dodecyl sulfate was utilized as an ion-pairing agent. The ion-associate complex formed between the cationic paraquat and sodium dodecyl sulfate was extracted into triethylamine. The separation of the two phases was carried out by the addition of sodium hydroxide, which changed the ionization state of triethylamine. The effects of some important parameters on the extraction recovery were investigated. Under the optimum conditions (500 µL of the extraction solvent, 1 mg sodium dodecyl sulfate, 2.0 mL of 10 mol/L sodium hydroxide, and pH 4), the limit of detection and the limit of quantification were 0.2 and 0.5 µg/L, respectively, with preconcentration factor of 74. The precision (RSD, n = 10) was  <5%. The recovery of the analyte in environmental and biological samples was in the range of 90.0-92.3%.

Synergistic optical sensing: Selective colorimetric analysis of copper in environmental and biological samples.

A groundbreaking optical sensing membrane has been engineered for the accurate assessment of copper ions. The pliable poly(vinyl chloride) membrane is formulated through the integration of sodium tetraphenylborate (Na-TPB), 4-(2-hydroxy-4-nitro azobenzene)-2-methyl-quinoline (HNAMQ), and tri-n-octyl phosphine oxide (TOPO), in conjunction with o-nitrophenyl octyl ether (o-NPOE). The sensor membrane undergoes a thorough investigation of its composition to optimize performance, revealing that HNAMQ serves a dual role as both an ionophore and a chromoionophore. Simultaneously, TOPO contributes to enhancing the complexation of HNAMQ with copper ions. Demonstrating a linear range for Cu2+ ions spanning from 5.0 × 10-9 to 7.5 × 10-6 M, the proposed sensor membrane showcases detection and quantification limits of 1.5 × 10-9 and 5.0 × 10-9 M, respectively. Rigorous assessments of potential interferences from other cations and anions revealed no observable disruptions in the detection of Cu2+. With no discernible HNAMQ leaching, the membrane demonstrates rapid response times and excellent durability. The sensor exhibits remarkable selectivity for Cu2+ ions and can be regenerated through exposure to 0.05 M EDTA. Successful application of the sensor in determining the presence of Cu2+ in biological (blood, liver and meat), soil, food (coffee, black tea, sour cherry juice, black currant, and milk powder) and environmental water samples underscores its efficacy.

Assessment of microplastics pollution in aquatic species (fish, crab, and snail), water, and sediment from the Buriganga River, Bangladesh: An ecological risk appraisals.

Current work focus on microplastic (MPs) occurrence in the water, sediment, and aquatic species (fish, crab, and snail) of the Buriganga River, Bangladesh, with an ecological risk assessment perspective. It also includes the distribution of MPs in different river ecosystem segments and the presence of heavy metal (loid)s (HMs) in water, sediments, and MPs surface. The MPs were inspected by stereomicroscope to identify the shapes, color, and size, and Fourier transform infrared (FTIR) spectroscopy was used to characterize polymer types. The samples concentration of four HMs viz., As, Cd, Cr, and Pb were determined by atomic absorption spectrometry (AAS). The possible MPs content in water, sediment, fish, crab, and snail were varied from 0.250 to 0.117 MPs/mL, 3.5-8.17 MPs/g, 0.65-3.82 MPs/g, 3.75-4.28 MPs/g, and 0.84-1.12 MPs/g, respectively. Fibers and fragments were the most dominant shape, less than 0.5 mm was dominant in size, and blue was the dominant color. In the evaluation of the chemical composition of MPs in water, sediment, fish, snail, and crab samples, Polyethylene terephthalate (PETE), Ethylene-vinyl acetate (EVA), High-density polyethylene (HDPE), Acrylonitrile butadiene styrene (ABS), Cellulose acetate (CA), and Nylon were identified. Regarding HMs load, the river demonstrated a highly polluted environment following the abundance pattern Cr > Pb > As>Cd. SEM-EDAX of MPs was conducted to investigate the surface MP's surface and elemental composition. It reveals that the MPs surface has characteristic flakes, cracks, and adhering particles along with Si, K, Au, C, and O on the surface studied MPs. There is no significant relationship found among the ecosystem segments. However, Ompok bimaculatus species show a negative relationship of MPs distribution with water and sediment. Moreover, according to the ecological risk of MPs pollution in the Buriganga River, it was in category-I, indicating considerable pollution load due to the presence of MPs.

Colorimetric sensing of cephradine through polypropylene glycol functionalized gold nanoparticles.

The development of metal nanoparticle-based facile colorimetric assays for drugs and insecticides is an emerging area of current scientific research. In the present work, polypropylene glycol was used for stabilization of gold nanoparticles (AuNPs) in a simple one-pot two-phase process and subsequently employed it for the specific detection of cephradine (CPH). The characterization of the prepared PPG-AuNPs was conducted through various analytical techniques such as UV-visible spectrophotometry, Fourier transform infrared spectroscopy, atomic force microscopy (AFM), zeta potential and zetasizer techniques. As the major target of the study, the stabilized PPG-AuNPs were employed for colorimetric detection of CPH and other drugs. Typical wine-red colour of PPG-AuNPs disappeared immediately and surface plasmon resonance band quenched by addition of CPH in the presence of several other interferents (drugs and salts) and in real samples. PPG-AuNPs permitted efficient, selective, reliable and rapid determination in a concentration range of 0.01-120 mM with a detection limit (LoD) of 11.0 mM. The developed sensor has the potential to be used for fast scanning of pharmaceutical formulations for quantification of CPH at production facilities.

3-Aminophenylboronic acid-mediated aggregation of gold nanoparticles for colorimetric sensing of iohexol in environmental and biological samples.

Iohexol (IHO), as one of iodinated X-ray contrast, is often used as not only a chemical marker for tracking wastewater contamination in aquatic environment, but also an ideal glomerular filtration rate marker for explorating kidney disease. To these aims, it is important to establish reliable, fast, and cheap methods to detect IHO in environmental and biological samples. This work describes for the first time the development of a selective, sensitive and reliable colorimetric sensing assay for the fast determination of IHO in environmental and biological samples based on 3-aminophenylboronic acid (3-APBA) mediated aggregation of gold nanoparticles (AuNPs). In this approach, 3-APBA can assemble on the AuNPs surface through electrostatic interaction between its amino groups with the negatively charged citrate stabilizer of AuNPs to form AuNP@3-APBA. Subsequently, the aggregation and visual color change of the assembled AuNP@3-APBA are induced by the covalent reaction between boronic acid ligands of 3-APBA and cis-diols of IHO. The developed assay presented a very simple operating procedure and a rapid analysis time of around 10 min. The developed assay also exhibited good selectivity and a low limit of detection (LOD) of 0.005 mM for detecting IHO. Moreover, the developed assay showed comparable accuracy and precision to the high-performance liquid chromatography-diode array detector (HPLC-DAD) method when used for the rapid determination of IHO in river water and human urine samples. The recoveries of IHO at three spiking levels were in the range of 91.5-106.3% with relative standard deviation (RSD) values below 6.39%.

A novel fluorescence immunoassay based on AgNCs and ALP for ultrasensitive detection of sulfamethazine (SMZ) in environmental and biological samples.

A novel indirect competitive fluorescence immunoassay based on the quenching of I- to silver clusters (AgNCs) was developed for the highly selective and ultrasensitive detection of sulfamethazine (SMZ). In this system, alkaline phosphatase (ALP) was labeled on the secondary antibody (Ab2). And after a competition step, magnesium ascorbyl phosphate could be catalyzed to produce ascorbic acid under the catalysis of ALP. Subsequently, I2 was introduced and further reduced to I- in the presence of ascorbic acid, triggering the fluorescence quenching of AgNCs dispersed in isopropanol (IPA) buffer. More importantly, trace I- could lead to an obvious reduction in fluorescence signal, indicating the sensitivity of this method would be greatly improved. Under the optimal condition, this improved method for the SMZ detection has a lower detection of limit (LOD, 0.05000 µg/L) with a wider range (0.1400-71.71 µg/L). After an evaluation, the fluorescence ELISA proposed in this work has satisfactory accuracy and reliability (recoveries, 84.18-118.6%; CV, 2.03-7.64%), illustrating good performance and great potential for the detection of trace SMZ in environmental and biological samples.

Bar adsorptive microextraction (BAµE) coated with mixed sorbent phases-Enhanced selectivity for the determination of non-steroidal anti-inflammatory drugs in real matrices in combination with capillary electrophoresis.

The present work proposes the application of bar adsorptive microextraction coated with mixed sorbent phases (n-vinylpyrrolidone and divinylbenzene polymers with strong and weak anion exchangers), combined with liquid desorption followed by capillary electrophoresis with diode array detection (BAµE(PMIX)-LD/CE-DAD) for the determination of trace levels of non-steroidal anti-inflammatory drugs (NSAIDs: salicylic acid, mefenamic acid, diclofenac and naproxen as model compounds) in urine and water matrices. Assays performed on 25mL of water samples spiked at the 80.0µg/L level, yielded average recoveries between 86.6 and 104.% for all the NSAIDs under study using optimized experimental conditions. The proposed analytical methodology demonstrated suitable detection limits (0.3µg/L) and good linear dynamic ranges (2.5-320.0µg/L) with determination coefficients higher than 0.9981. By using the standard addition methodology, the present analytical approach was applied on urine and water samples, where good selectivity and sensitivity were achieved. The proposed method, which operated under the floating sampling technology, proved to be a suitable sorption-based static microextraction alternative for monitoring trace levels of NSAIDs in urine and water samples. The methodology showed to be easy to implement, demonstrating good reproducibility and robustness, allowing the possibility to choose the most selective sorbent, or mixed sorbent phases, according to the compounds of interest.

Determination of trace heavy metals in environmental and biological samples by solution cathode glow discharge-atomic emission spectrometry and addition of ionic surfactants for improved sensitivity.

Solution cathode glow discharge-atomic emission spectrometry (SCGD-AES) was evaluated for its ability to determine toxic heavy metals, including cadmium (Cd), mercury (Hg), lead (Pb), and chromium (Cr), in environmental and biological samples. A significant enhancement in heavy metal signal was observed by addition of a small amount of cetyltrimethylammoniumchloride (CTAC, C16H33 (CH3)3NCl) to the samples. The net intensity of atomic emission lines of Cd, Hg, Pb, and Cr increased by 2.1-, 4.8-, 6.6-, and 2.6-fold, respectively, after addition of 0.15% CTAC to the test solutions. The effects of ionic surfactants (CTAC) compared with non-ionic surfactants, e.g., Triton x-45 and Triton x-100, on the sensitivity of Cd, Hg, Pb, and Cr were also investigated in the present study. The enhancement effect is in the order Triton x-45

Hollow fiber liquid-liquid-liquid microextraction combined with high performance liquid chromatography-ultraviolet detection for the determination of various environmental estrogens in environmental and biological samples.

A new method of hollow fiber liquid-liquid-liquid microextraction (HF-LLLME) combined with high performance liquid chromatography-ultraviolet detection (HPLC-UV) was developed for simultaneous analysis of various environmental estrogens. Taking eight environmental estrogens (17ß-estradiol (E2), estrone (E1), estriol (E3), 17α-ethynylestradiol (EE), diethylstilbestrol (DES), dienestrol (DIS), bisphenol-A (BPA) and 4-t-octylphenol (OP)) as the target analytes, the factors affecting HF-LLLME-HPLC-UV were investigated in detail. Under the optimized experimental conditions, the extraction efficiency of HF-LLLME for eight target estrogens was in the range of 13.9-62.8%, and the enrichment factor was 88-376-fold. The limits of detection (LODs) of the proposed method for eight target estrogens of ES, BPA, E2, EE, E1, DES, DIS and OP were 0.11, 0.055, 0.66, 0.55, 0.51, 0.20, 0.11 and 1.46ng/mL, respectively, which are lower than that obtained by some other sample pretreatment methods followed by HPLC-UV analysis. The relative standard deviations of the method (RSDs, cE3, BPA, DIS=5ng/mL, cE1, E2, EE, OP=40ng/mL, cDES=15ng/mL, n=7) are in the range of 5.5-8.4%. The developed method was applied for the determination of environmental estrogens in environmental and biological samples (sediment and fish), and none of the eight target estrogens was detected. The recoveries for the spiking samples with low, medium and high spiking levels were in the range of 73.2-117.5%. The proposed method has been demonstrated to be suitable for simultaneous determination of multiple environmental estrogens with high sensitivity, high enrichment factors, good sample clean-up ability and no derivatization required.