Target Analytes Research Articles

Secondary metabolites of soybean seeds variety locus and their spatial arrangement, represented by laser microscopy

The purpose of this study is a detailed metabolomic analysis using tandem mass spectrometry of the soybean variety Locus, selected from the collection of the Federal Scientific Center for Agrobiotechnologies of the Far East named after A. K. Chaika», to identify both the polyphenolic composition of seeds and the determination of other chemical groups in the composition of the seed. Tandem mass spectrometry studies were further supported by visual data obtained for the first time using laser microscopy. The object of the study is the seeds of the soybean variety Locus, grown in 2022 at the field site of the soybean breeding laboratory of the Federal Scientific Center for Agrobiotechnologies of the Far East named after A. K. Chaika», located in the village of Timiryazevsky (near the city of Ussuriysk). Experiments were carried out on a CLSM-800 laser confocal microscope and mass spectrometry of biologically active substances on an amaZon SL ion trap. Laser microscopy made it possible to clarify in detail the spatial distribution of the content of phenolic acids, flavonols and anthocyanins in soybean seeds. The studies were able to convincingly show that soybean polyphenolic substances and, in particular, anthocyanins are spatially localized mainly in the soybean seed coat. High-performance liquid chromatography coupled with ion trap (tandem mass spectrometry) was used to identify target analytes in soybean seed extracts. Using tandem mass spectrometry, the presence of 59 compounds was identified, of which 35 compounds represent the group of polyphenolic compounds. 15 compounds were identified for the first time in soybean extracts of the Locus variety. These are flavones: apigenin, acacetin, cirsimaritin; tetrahydroxyflavone aromadendrin 7-O-rhamnoside; lignan medioresinol; coumarin tomentin and other polyphenolic compounds. The data obtained will help intensify future research on the development and production of new drugs, dietary supplements, food additives and various functional and specialized products containing targeted soybean extracts.

A Label-Free Sensor Array Based on Carbon Quantum Dots for Detection of α-Synuclein Oligomers in Saliva.

Salivary oligomeric α-synuclein (α-Syn) has been introduced as a promising biomarker for the diagnosis of Parkinson's disease. Herein, a fluorescence sensor array based on three carbon quantum dots (CQDs) with different surface functional groups was developed for the identification and quantification of salivary α-Syn oligomers. Each of the CQDs generated a different fluorescence response to the target analyte, and the responses were analyzed by NPLS-DA to create a unique response pattern for the target analyte. The developed three-element sensor array showed a linear response to α-Syn oligomers in the range of 0.5-32 μg/mL and a detection limit (LOD) of 0.5 μg/mL, with a cross-validation accuracy of 92% in aqueous solution. The sensor array could detect the analyte in a mixture of different proteins and in the complex medium of saliva, with the LOD of 0.3 μg/mL indicating the massive potential of CQD arrays for developing sensitive, simple, inexpensive, and label-free sensing platforms.

A facile lyophilisation-based sample preparation approach for the determination of selected wastewater-borne antiretroviral drugs and metabolites by SFC-MS/MS

The presence of pharmaceuticals in aquatic ecosystems is at the centre-stage of research after the realization that wastewater treatment processes are generally ineffective in the removal of these entities in wastewater given the high likelihood of effluent reuse after disposal. In addition, the continued efforts to scout for new and emerging aquatic contaminants has until recently elicited proliferation of numerous analytical methods for the determination of various (un)known contaminants, since emphasis is now placed in the development of environmentally benign approaches. Herein, we propose and discuss a novel and relatively eco-friendly analytical method based on lyophilization for sample preparation and SFC-MS/MS for the determination of eight (8) antiretroviral drugs (ARVDs) and three (3) metabolites in wastewater samples. This method proved useful in the improvement for the recoveries of lamivudine (3TC) and emtricitabine (FTC) by up to 99% compared to as low as 23% with solid phase extraction (SPE) method. Indeed, previous literature reports has reported poor recoveries for the polar ARVDs, especially on reversed phase (RP) SPE. In contrast, lyophilization promoted matrix effects as evidenced by ion suppression of up to 50% experienced on late eluting compounds. Despite this, lyophilization-SFC-MS/MS method was successfully validated for the quantification of all target analytes, partial exceptions were for ritonavir metabolite (RTVM) which could not be quantified using lyophilization possibly due to lyophilization-induced losses. Generally, the obtained data has proved that lyophilization is an alternative to SPE and SFC is a suitable alternative to LC.

Electrochemical sensing platform for anticonvulsant drug carbamazepine detection based on graphitic carbon nitride and tetrabutylammonium chloride ionic liquid

The development of a rapid and straightforward electrochemical approach for the quantification of the anticonvulsant drug carbamazepine (CBZ) is herein presented. Carbon paste electrode (CPE) was bulk modified with a type of two-dimensional conjugated polymer, i.e., graphitic carbon nitride (g-C3N4), and additionally with an ionic liquid tetrabutylammonium chloride (TBACl) to obtain advanced electrochemical sensor for CBZ. Synthesized g-C3N4 material was structurally and morphologically characterized by Raman spectroscopic, FTIR, and SEM/EDX methods. CV experiments showed that the resulting electrode (TBACl-g-C3N4-CPE) has an improved electrochemical response compared to unmodified CPE and g-C3N4-CPE due to the synergistic effect of electrode modifiers, as well as that the CBZ oxidation process is irreversible and diffusion-controlled. After optimization steps concerning the amount of electrode modifiers and the selection of pH of the supporting electrolyte, the analytical performance of TBACl-g-C3N4-CPE was investigated by direct anodic square-wave voltammetry (SWV). The most intensive peak of the target analyte was obtained in Britton-Robinson buffer solution at pH 7.0, whereby the developed SWV method was characterized by a linear concentration range of CBZ from 0.42 to 9.31 µmoL L−1, limit of detection (LOD) of 0.13 µmoL L−1, and relative standard deviation lower than 3 %. The interference study showed that TBACl-g-C3N4-CPE exhibits adequate selectivity for CBZ in the presence of ions/compounds commonly present in the urine matrix. The developed sensor was utilized to determine CBZ in pharmaceuticals and spiked human urine sample with excellent recovery and reproducibility, indicating a good application capability of TBACl-g-C3N4-CPE for monitoring CBZ in different matrices.

Determination of Rare Earth Elements, Zirconium, Hafnium, Thorium and Uranium in Ultramafic Rocks by ICP‐MS after RE‐UTEVA Resin Columns for Separation and Pre‐Concentration

A simple method was developed for the determination of REEs, Zr, Hf, Th and U in ultramafic rocks by inductively coupled plasma‐mass spectrometry with a combination of RE and UTEVA extraction resins for their separation and pre‐concentration. Ultramafic rocks were digested with HNO3‐HF‐HClO4 and finally turned into 11 mol l−1 HCl solutions together with H3BO3 to remove insoluble fluorides. The removal of matrix elements was achieved during the loading procedure. Following this, REEs on RE resin, and Zr, Hf, Th and U on UTEVA resin were eluted with 10 ml of 0.24 mol l−1 HCl, with recoveries better than 94.4%. This method was validated using reference materials JP‐1, DTS‐2B, OKUM, UB‐N, MUH‐1 and DZΣ‐2, and the measurement results for target analytes were comparable to literature values, indicating its applicability to the determination of REEs, Zr, Hf, Th and U at ultra‐trace level in ultramafic rocks.

An orange light emitting 'off–on-off' fluorogenic probe for consecutive detection of Al3+ ions and 2,4,6-trinitrophenol

A simple, orange light emitting 'off–on-off' fluorogenic sensor, (E)-4-(((2-hydroxy-4-nitrophenyl) imino) methyl) naphthalene-3-ol (HNMN), has been introduced for the successive recognition of Al3+ ions and 2, 4, 6-trinitrophenol respectively, utilizing the photoluminescence 'off–on-off' mechanism. A significant enhancement in the photoluminescence of HNMN is found at 558 nm, attributed to the chelation of Al3+ ions, resulting in a visible orange-colored photoluminescence under a handy 365 nm UV light illumination. Among the different tested nitroaromatic compounds (NACs), 2, 4, 6-trinitrophenol, namely picric acid (PA), selectively quenches the orange photoluminescence caused by Al3+ on the HNMN complex. The stoichiometric ratio for the complex formation between HNMN and aluminum ion is determined to be 1:1, with an estimated limit of detection (LOD) and quantification (LOQ) found to be 8.6 nM and 28.4 nM respectively in DMF medium. Different spectroscopic analyses have elucidated the mechanistic features of identifying Al3+ ions. A test kit–based experiment is performed with the HNMN-coated filter paper to detect Al3+ ions and PA sequentially & selectively. Based on the chemical inputs and optical output, we have framed the INHIBIT molecular logic circuit. The present report evokes a facile approach for the design and molecular development of highly red-shifting fluorosensors from the non-fluorophore moieties to avoid false signaling during the detection of target analytes.

Application of MoS42−intercalated magnetic layered double hydroxide for preconcentration of cadmium and lead from water samples

A MoS42−-intercalated magnetic FeMgAl layered double hydroxide (Fe3O4@MoS42−-FeMgAl LDH) nanocomposite was synthesised via hydrothermal assisted exfoliation. The material was applied as the adsorbent for extraction, preconcentration and removal of cadmium ions (Cd2+) and lead ions Pb2+ from wastewater and river water. The structural properties and morphologies of the adsorbent were determined by transmission electron microscopy (TEM), scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS), Fourier transform infrared spectroscopy (FTIR), zeta potential and X-ray diffraction (XRD). The parameters influencing preconcentration and the adsorptive removal process were optimised using the central composite design (CCD) method. The concentration of Cd2+ and Pb2+ in the samples was determined using inductively coupled plasma optical emission spectrometry (ICP-OES). The preconcentration method developed in the study was ultrasound-assisted magnetic solid phase extraction (UA-MSPE). Under optimum conditions, linearity was 0.1-800 µg/L with a correlation of determination (R2) of 0.9987. The uncertainty of the slope and the uncertainty of the intercept were both lower than the uncertainty of the calibration indicating good precision, selection of standards closest to a blank and wide range. Precision expressed as %RSD for both intra-day (n = 27) and inter-day (n = 9) were found to be 3.3 % and 7.0 % respectively. The limit of detection (n = 10) and limit of quantification (n = 10) of the UA-MSPE/ICP-OES were 0.03 µg/L and 0.10 µg/L. The developed method was applied for real sample analysis. Herein, influent wastewater was reported as 1.77 ± 0.14 and 6.53 ± 0.33 ug/L for Cd2+ and Pb2+, respectively while the effluent was reported at 0.96 ± 0.07 and 2.57 ± 0.13 ug/L, respectively. River water samples were found to be 0.45 ± 0.01 and 1.23 ± 0.04 ug/L, respectively proving that the adsorbent is capable of preconcentrating the target analytes.

A Clinically Feasible Diagnostic Electrochemical Micronano Motors Biosensor Built on Miniature Swimmer for Multiplex Detection and Grading of Breast Cancer Biomarkers.

Estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER2), and Ki67 are four crucial biomarkers used in the clinical diagnosis of breast cancer. Accurate detection of these biomarkers is essential for an effective diagnosis and treatment. MOF-based micronano motors (MOFtors) are promising for various applications, including environmental remediation, targeted nanosurgery, and biomarker detection. This paper presents a clinically feasible diagnostic electrochemical micronano motor biosensor, built on a miniature swimmer, for the multiplex detection and grading of breast cancer biomarkers. We designed a biosensor, named MOFtor-MSEM, incorporating aptamers and antibodies functionalized on SiO2@Co-Fe-MOF, which acts as a miniature swimmer in solution. The SiO2@Co-Fe-MOF serves as the body, while complementary double-chain-linked antibodies function as paddles. In a homogeneous solution, when a positive voltage is applied to the working electrode, the electrostatic interaction between the neutral SiO2@Co-Fe-MOF and the negatively charged complementary double-linked antibody causes the antibody to move toward the electrode and then regress due to water resistance. This back-and-forth motion propels the miniature swimmer, enabling it to move the target analyte through the solution. The sensor features an automatic "sample-amplifying signal-output" process, achieving simultaneous signal amplification and output of four electrochemical signals on a single nanomaterial, a significant challenge in electrochemical sensing. The biosensor boasts a short detection time of 40 min, compared to approximately 1 week for current clinical tissue testing. Additionally, the bioplatform selectively detects HER2, ER, Ki67, and PR in the range of 0-1500 pg/mL, with detection limits of 0.01420, 0.03201, 0.01430, and 0.01229 pg/mL, respectively.

Occurrence and environmental risk assessment of pharmaceuticals in the Mondego river (Portugal)

In this case study pharmaceuticals were analysed in the Mondego river (Portugal) and their environmental risk assessed by means of risk quotients based on an extensive retrieval of ecotoxicological data for freshwater and saltwater species. The Mondego river crosses Coimbra, the most populated city in the Portuguese Centro Region hosting a complex of regional hospitals. Environmentally relevant and prioritised pharmaceuticals were investigated in this study and their potential hazards were evaluated by conducting a separate risk assessment for the freshwater and estuary parts of the examined river section.A target analysis approach with method detection limits down to 0.01 ng L−1 was used to determine pharmaceuticals. Twenty-one prioritised target analytes out of seven therapeutical classes (antibiotics, iodinated X-ray contrast media (ICM), analgesics, lipid reducers, antiepileptics, anticonvulsants, beta-blockers) were investigated by applying ultra-high pressure liquid chromatography coupled to a triple quadrupole mass spectrometer equipped with an electrospray ionisation source.The relative pattern of pharmaceuticals along the middle to the lower Mondego showed a quite uniform picture while an approximately 40fold increase of absolute concentrations was observed downstream of the wastewater treatment plant (WWTP) discharge of Coimbra. The most frequently measured substance groups were the ICM, represented by the non-ionic ICM iopromide (βmin: 3.03 ng L−1 - βmax: 2,810 ng L−1). Environmentally more critical substances such as carbamazepine, diclofenac, and bezafibrate, with concentrations up to and 52.6 ng L−1, 59.8 ng L−1, and 10.2 ng L−1 respectively, may potentially affect aquatic wildlife. Carbamazepine revealed elevated risk quotients (RQs >1) along the middle and lower Mondego with a maximum RQ of 53 downstream of Coimbra. Especially for saltwater species, carbamazepine and clarithromycin pose high potential risks.Especially in periods of low water discharge of the Mondego river, other pharmaceuticals as diclofenac and bezafibrate may pose additional risks downstream of the WWTP.

Paper-Based Electrochemical (Bio)Sensors for the Detection of Target Analytes in Liquid, Aerosol, and Solid Samples.

The last decade has been incredibly fruitful in proving the multifunctionality of paper for delivering innovative electrochemical (bio)sensors. The paper material exhibits unprecedented versatility to deal with complex liquid matrices and facilitate analytical detection in aerosol and solid phases. Such remarkable capabilities are feasible by exploiting the intrinsic features of paper, including porosity, capillary forces, and its easy modification, which allow for the fine designing of a paper device. In this review, we shed light on the most relevant paper-based electrochemical (bio)sensors published in the literature so far to identify the smart functional roles that paper can play to bridge the gap between academic research and real-world applications in the biomedical, environmental, agrifood, and security fields. Our analysis aims to highlight how paper's multifarious properties can be artfully harnessed for breaking the boundaries of the most classical applications of electrochemical (bio)sensors.

A Piezoelectric Nanogenerator-Driven Dual-Mode Platform for Visualization and Impedance Sensing.

Traditional visual biosensing platforms rely on color to display detection results, which can be influenced by individual visual abilities, equipment, parameters, and lighting conditions during photo capture. This limitation significantly impedes the advancement of next-generation portable electrochemical biosensors. Therefore, we propose a visual biosensing device that utilizes distance as an indicator, enabling the facile determination of the length of discoloration, which is inversely proportional to the concentration of the target analyte. The separation of the Signal Generation (SG) and Signal Output (SO) regions effectively mitigates potential interference from the sample color. Additionally, the SG region can be disassembled to facilitate electrochemical impedance spectroscopy (EIS) detection in laboratory settings, enabling dual-mode detection. Meanwhile, the utilization of piezoelectric nanogenerators (PENG) empowers the entire point-of-care testing (POCT) sensing device, effectively addressing the issue of a limited battery life. The biosensing device exhibited a satisfactory linear range (EIS mode, 5 pg/L to 5 mg/L; visual mode, 0.5 ng/L to 5 mg/L) and a low limit of detection (EIS mode, 2.3 pg/L; visual mode, 0.14 ng/L) with S/N = 3 for ochratoxin A (OTA) under optimized conditions. The self-powered and cost-effective dual-mode biosensing platform developed for OTA detection offers clear and easily interpretable results, demonstrating a high accuracy in laboratory settings.

Detection of nonsteroidal and steroidal selective androgen receptor modulators in equine hair after oral administrations.

This paper describes the detections of nonsteroidal and steroidal selective androgen receptor modulators (SARMs), namely, RAD140 and YK-11, in mane hair collected from horses having been orally administered with the respective drugs. SARMs are potent anabolic agents with a high potential of misuse in horseracing and equestrian sports, and the misuses of RAD140 and YK-11 in human sports have been reported. To better control the misuse of RAD140 and YK-11 in horses, two separate oral administration studies of RAD140 (0.3mg/kg daily for 3days) and YK-11 (0.2mg/kg daily for 3days) were previously conducted to investigate their metabolism and to identify target analyte(s) with the longest detection time in urine and plasma for doping control. In this work, segmental analyses of post-administration hair samples have revealed that (i) RAD140 and YK-11 could be detected in horse mane after oral administration and (ii) internal incorporation of RAD140 into hair via bloodstream and external incorporation through sweat or sebum were both observed, whereas YK-11 was primarily incorporated into hair via sweat or sebum.

Stability of new psychoactive substances in crude wastewater.

Those involved in drug testing continue to grapple with the dynamic nature of emerging psychoactive substances (NPS) and their rapid infiltration into society. The challenge extends beyond merely detecting and measuring NPS using analytical tools; it also encompasses the complexities arising from the formation and presence of metabolites and degradation products. This study utilises liquid chromatography time-of-flight mass spectrometry to investigate the stability of new psychoactive substances in wastewater. Seven NPS compounds including 25C-NBOMe, 5F-APINACA 4-hydroxyphenyl, AB-PINACA, APINACA 4-hydroxyphenyl, fentanyl, norfentanyl and MDPV, along with their corresponding internal standard, were examined. Reference material for each NPS compound was introduced into a wastewater sample from a Wessex water treatment plant. The sample was then exposed to four different environments: room temperature, refrigerator temperature, acidification to pH 2, and the introduction of sodium metabisulfite. The findings highlight the critical dependence of storage conditions on target analytes, emphasizing the paramount importance of the time elapsed between collection and analysis for NPS wastewater analysis. Notably, synthetic cannabinoids exhibit limited stability in wastewater whereas cathinone-like substances demonstrate greater stability. Furthermore, metabolites prove to be more stable in wastewater than the parent drug, suggesting that focusing on metabolite detection may be more favourable for future analysis.

Strontium Oxide Functionalized Chitosan as Novel Bioaffinity Layer for Construction of Multipurpose Biosensor Platform

The wet chemical technique was used to create a biofriendly composite consisting of Strontium Oxide hybridized chitosan (SrO-CS). A spectroscopic analysis revealed that the CS amine group is mostly hybridized with the SrO nanoparticle. The crystalline phases of the nanoparticle are visible in the as prepared SrO-CS. Morphological studies show that the SrO nanorods are covered in CS flakes. The greater electron transfer rate is demonstrated by the SrO-CS modified GCE, which follows a surface confined mechanism at the interface. The SrO-CS modified screen-printed electrode was used to immobilize miRNA sequences in order to selectively detect exosomal CD24 oligonucleotides that are suitable for a broad spectrum of target analyte detection. For biosensor applications, the created SrO-CS functions as a useful bio-affinity layer for biomolecule attachment.

Ionic-liquid/Carbowax 20 M functionalized capsule phase microextraction platform for the extraction of phosphodiesterase-5 inhibitors from human serum and urine prior to their determination by LC–MS

Capsule phase microextraction (CPME) is an efficient bioanalytical technique that streamlines the sample preparation by integrating the filtration and stirring mechanism directly into the device. A novel composite sorbent designed to be selective towards the target analytes consisting of mixed-mode sorbent chemistry synthesized by sol–gel technology is found promising and superior to the conventional C18 sorbents. Herein we describe the encapsulation of an ionic liquid (IL)/Carbowax 20M-functionalized sol–gel sorbent (sol–gel IL/Carbowax 20 M) in the lumen of porous polypropylene tubes for the capsule phase microextraction of three phosphodiesterase-5 inhibitors namely avanafil, sildenafil, and tadalafil in human serum and urine samples. The CPME device was characterized by Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FT-IR). The experimental parameters of CPME procedure (e.g. sample pH and ionic strength, extraction time, stirring rate, elution solvent and volume) were carefully optimized to achieve the highest possible extraction efficiency for the analytes. Method validation was conducted in terms of precision, linearity, accuracy, matrix effect, lower limits of quantification, and limits of detection (LOD). The method linearity was investigated in the range of 50–1000 ng mL−1 for all analytes while the precision was less than 11.8 % in all cases. For all analytes, the LOD values were 17 ng mL−1. The IL/CW 20M-functionalized microextraction capsules could be reused at least 25 times both for urine and serum samples. The green character and the applicability of the proposed method were evaluated using the ComplexGAPI and BAGI indexes. The optimized CPME protocol exhibited reduced consumption of organic solvent and generation of waste, cost-effectiveness, and simplicity. Finally, the proposed method was successfully applied to the analysis of sildenafil in human urine after administration of drug-containing formulation.

Detection of the selective androgen receptor modulator S-23 and its metabolites in equine urine and plasma following oral administration.

S-23 is an arylpropionamide selective androgen receptor modulator that has been investigated in animal models for use as a male hormonal contraceptive but is not yet available therapeutically. S-23 is available alongside other selective androgen receptor modulators (SARMs) to purchase online via uncontrolled sites, sold as supplement products. It has been detected in several human doping cases, highlighting the importance of identifying the best analytical targets for equine doping control. The purpose of this study was to investigate the detection of S-23 and its phase I metabolites in equine urine and plasma following a multiple dose oral administration to two Thoroughbred racehorses. Liquid chromatography-high resolution mass spectrometry was used for metabolite identification, and liquid chromatography-tandem mass spectrometry was used for full sample analysis and generation of urine and plasma profiles. S-23 and seven phase I metabolites were observed in urine following enzyme hydrolysis and solvolysis. The most abundant analyte detected was the hydroxylated 4-amino-2-(trifluoromethyl)benzonitrile metabolite, which also allowed the longest duration of detection in urine from both horses, for up to 360 h following administration. The data suggest that this metabolite was likely to be highly conjugated with both sulphate and glucuronide moieties. In plasma, S-23 and two phase I metabolites were observed. S-23 was the most abundant analyte detected for both horses, allowing detection for up to 143 h post-administration. To the best of the authors' knowledge, this is the first report of S-23 and metabolites in equine urine and plasma samples.

A portable and versatile fluorescent platform for high-throughput screening of toxic phosgene, diethyl chlorophosphate and volatile acyl chlorides

Highly toxic phosgene, diethyl chlorophosphate (DCP) and volatile acyl chlorides endanger our life and public security. To achieve facile sensing and discrimination of multiple target analytes, herein, we presented a single fluorescent probe (BDP-CHD) for high-throughput screening of phosgene, DCP and volatile acyl chlorides. The probe underwent a covalent cascade reaction with phosgene to form boron dipyrromethene (BODIPY) with bright green fluorescence. By contrast, DCP, diphosgene and acyl chlorides can covalently assembled with the probe, giving rise to strong blue fluorescence. The probe has demonstrated high-throughput detection capability, high sensitivity, fast response (within 3 s) and parts per trillion (ppt) level detection limit. Furthermore, a portable platform based on BDP-CHD was constructed, which has achieved high-throughput discrimination of 16 analytes through linear discriminant analysis (LDA). Moreover, a smartphone adaptable RGB recognition pattern was established for the quantitative detection of multi-analytes. Therefore, this portable fluorescence sensing platform can serve as a versatile tool for rapid and high-throughput detection of toxic phosgene, DCP and volatile acyl chlorides. The proposed “one for more” strategy simplifies multi-target discrimination procedures and holds great promise for various sensing applications.

A Novel Apparatus for the Fully Automated Extraction and Online Liquid Chromatographic Analysis of Solid Environmental Samples: Application to the Pressurized Hot Water Extraction of Pharmaceuticals in Soil.

A new self-assembled apparatus for the extraction of solid samples was designed and implemented to perform a recirculated pressurized hot water extraction (R-PHWE) directly coupled to liquid chromatography-tandem mass spectrometry. To investigate the potential of this new extraction apparatus, 34 target pharmaceutical compounds were analyzed in loam, silt-loam, and silty-clay-loam soils. The target analytes were characterized by heterogeneous physicochemical properties (e.g., -1.60 ≤ log D ≤ 5.91 at pH = 7.2, i.e., at the mean pH values of the three soils). Design of experiments (DoE) was used to identify the best extraction conditions for the target analytes by studying temperature, pressure, and number of extraction cycles. The results of DoE optimization pointed out the significant influence of the number of cycles on recovery. The application of DoE set point to the three reference soils provided recoveries ≥60% for 21-25 out the 34 target analytes, depending on soil. Good recovery precision (<25%) and moderate suppressive matrix effect (≤40%) were found for most target analytes, regardless of the soil considered. The optimized R-PHWE procedure evidenced statistically higher recoveries for 16 out of 34 target analytes when compared to conventional off-line dynamic PHWE.

Recent Progress in Organic Electrochemical Transistor-Structured Biosensors.

The continued advancement of organic electronic technology will establish organic electrochemical transistors as pivotal instruments in the field of biological detection. Here, we present a comprehensive review of the state-of-the-art technology and advancements in the use of organic electrochemical transistors as biosensors. This review provides an in-depth analysis of the diverse modification materials, methods, and mechanisms utilized in organic electrochemical transistor-structured biosensors (OETBs) for the selective detection of a wide range of target analyte encompassing electroactive species, electro-inactive species, and cancer cells. Recent advances in OETBs for use in sensing systems and wearable and implantable applications are also briefly introduced. Finally, challenges and opportunities in the field are discussed.

Enantiomeric separation of nefopam and cathinone derivatives using a supramolecular deep eutectic solvent as a chiral selector in capillary electrophoresis.

The present study investigates the utilization of a supramolecular deep eutectic solvent (SUPRADES), consisting of sulfated-β-cyclodextrin (S-β-CD) and citric acid (CA), as a chiral selector (CS) in capillary electrophoresis for the enantiomeric separation of nefopam (NEF) and five cathinone derivatives (3-methylmethcathinone [3-MMC], 4-methylmethcathinone [4-MMC], 3,4-dimethylmethcathinone [3,4-DMMC], 4-methylethcathinone [4-MEC], and 3,4-methylendioxycathinone [MDMC]). A significant improvement in enantiomeric separation of the target analytes was observed upon the addition of S-β-CD-CA to the background electrolyte (BGE), leading to a baseline separation of all analytes. In particular, the optimum percentage of S-β-CD-CA, added to the BGE, was determined to be 0.075% v/v for NEF (Rs=1.5) and 0.050% v/v for three out of five cathinone derivatives (Rs=1.5, 1.6, and 2.4 for 3-MMC, 4-MEC, and 3,4-DMMC, respectively). In the case of 4-MMC and MDMC, a higher percentage of the CS, equal to 0.075% and 0.10% v/v, respectively, was required to achieve baseline separation (Rs=1.5, 1.9 for MDMC and 4-MMC, respectively). The outcomes of the present study highlight the potential effectiveness of using SUPRADES as a CS in electrophoretic enantioseparations.