Conventional Solid-phase Extraction Research Articles

Evaluation of lignin and dip coating for elemental analysis by thin film microextraction followed by laser-induced breakdown spectroscopy

Separation and preconcentration procedures are often necessary to eliminate interferents, enhance sensitivity, and improve detection limits. Conventional solid-phase extraction (batch) finds extensive applications in the determination of various analytes, particularly in low concentrations and complex matrices such as environmental, food, and biological samples. However, drawbacks include high reagent consumption, time-consuming sample processing and low analytical throughput. To address these issues and promote Green Analytical Chemistry (GAC), novel methods have emerged, with solid-phase and liquid-phase microextraction being notable examples. Thin Film Microextraction (TFME) represents an innovative approach involving a solid support coated with a thin layer of adsorbent material, attached to a rod and immersed in the sample solution. Extracted analytes can be quantified either after desorption (elution) or directly on the thin film. This article aims to explore TFME's potential when combined with Laser-Induced Breakdown Spectroscopy (LIBS) for Cd, Cr and Ni determination using lignin as adsorbent material deposited on a solid substrate by dip coating. Under optimized conditions, limits of detection obtained were 1.76 μg kg−1 (Cd), 5.72 μg kg−1 (Cr), and 3.27 μg kg−1 (Ni). The accuracy of the proposed method was evaluated through the analysis of a certified reference material (ERM® CA713), drinking and tap water.

Techno-Economic analysis of an efficient anthocyanin extraction process from grape pomace using eutectic solvents ─ A critical panorama regarding drying techniques and reusability of solvents

A techno-economic analysis of a novel eutectic solvent-based platform useful to recover anthocyanins from grape pomace was performed. The study addressed the economic impact of conventional drying methods and explored the economic implications of purification strategies to separate the extract from the eutectic solvent. This was exemplified by employing solid-phase extraction (SPE) with C18-based adsorbent material. An alternative low-energy demanding approach using SiO2 particles was also assessed for profitability as a freeze-drying replacement strategy. The results highlighted challenges in the economic feasibility of eutectic solvent reusability when conventional SPE is applied, highlighting the need to obtain new and inexpensive bio-based adsorbents. Moreover, it was uncovered that the SiO2-based drying strategy presents itself as a financially viable alternative, effectively addressing the elevated energy requirements associated with conventional drying methods. The findings highlight the potential of alternative solvents-based processes, particularly towards challenges related to the circularity of raw materials.

4D-Printed Elution-Peak-Guided Dual-Responsive Monolithic Packing for the Solid-Phase Extraction of Metal Ions.

Four-dimensional printing (4DP) technologies are revolutionizing the fabrication of stimuli-responsive devices. To advance the analytical performance of conventional solid-phase extraction (SPE) devices using 4DP technology, in this study, we employed N-isopropylacrylamide (NIPAM)-incorporated photocurable resins and digital light processing three-dimensional printing to fabricate an SPE column with a [H+]/temperature dual-responsive monolithic packing stacked as interlacing cuboids to extract Mn, Co, Ni, Cu, Zn, Cd, and Pb ions. When these metal ions were eluted using 0.5% HNO3 solution as the eluent at a temperature below the lower critical solution temperature of polyNIPAM, the monolithic packing swelled owing to its hydrophilic/hydrophobic transition and electrostatic repulsion among the protonated units of polyNIPAM. These effects resulted in smaller interstitial volumes among these interlacing cuboids and improvements in the elution peak profiles of the metal ions, which, in turn, demonstrated the reduced method detection limits (MDLs; range, 0.2-7.2 ng L-1) during analysis using inductively coupled plasma mass spectrometry. We studied the effects of optimizing the elution peak profiles of the metal ions on the analytical performance of this method and validated its reliability and applicability by analyzing the metal ions in reference materials (CASS-4, SLRS-5, 1643f, and Seronorm Trace Elements Urine L-2) and performing spike analyses of seawater, groundwater, river water, and human urine samples. Our results suggest that this 4D-printed elution-peak-guided dual-responsive monolithic packing enables lower MDLs when packed in an SPE column to facilitate the analyses of the metal ions in complex real samples.

Synthesis of in-situ magnetized MOF-cellulose membranes for high-efficiency enrichment of diamide insecticides in vegetables and determination by LC-MS/MS

This study presents a novel, eco-friendly composite adsorbent material designed for the magnetic solid-phase extraction of diamide insecticides from vegetable samples. The membrane, denoted as Fe-MMm, was incorporated with a cellulose framework embedded with Metal-Organic Frameworks (MOFs) and Multi-Walled Carbon Nanotubes (MWCNTs) magnetized with Fe3O4. This innovative material streamlined the conventional solid-phase extraction process, simplifying the sample pre-treatment. By combining it with liquid chromatography tandem mass spectrometry (LC-MS/MS), the method achieves significantly enhanced extraction efficiency through systematic optimization of experimental parameters, including adsorbent selection, pH, ionic strength, adsorption time, and elution time. The method had a wide linear range of 0.1–1000 ng/mL and an exceptionally low detection limit ranging from 0.023 to 0.035 ng/mL. The successful identification of diamide insecticides in vegetable samples underscores the potential of Fe-MMm as a robust material for sample pretreatment in analytical applications.

Preparation of amphiphilic poly(divinylbenzene-co-N-vinylpyrrolidone)-functionalized polydopamine magnetic nanoadsorbents for enrichment of synthetic cannabinoids in wastewater.

Concerns have been raised about synthetic cannabinoids (SCs), which are among the most often trafficked and used illegal substances. An analytical method that holds promise for determining illicit drug use in the general population is wastewater-based epidemiology (WBE). Unfortunately, the concentration of SCs in wastewater is often extremely low on account of their hydrophobic nature, thus presenting a significant obstacle to the accurate detection and quantification of SCs using WBE. In this study, we present novel magnetic nanomaterials as amphiphilic adsorbents for pretreatment of wastewater using magnetic solid phase extraction (MSPE). Polydopamine-modified Fe3O4 nanoparticles were used as the magnetic core and further functionalized with poly(divinylbenzene-N-vinylpyrrolidone). Coupled with UHPLC-MS/MS analysis, an analytical method to simultaneously detect nine SCs at trace-levels in wastewater was developed and validated, enriching 50 mL wastewater to 100 μL with limits of detection (LOD) being 0.005-0.5 ng L-1, limits of quantification (LOQ) being 0.01-1.0 ng L-1, recoveries ranging from 73.99 to 110.72%, and the intra- and inter-day precision's relative standard deviations less than 15%. In comparison to the time-consuming conventional column-based solid phase extraction, the entire MSPE procedure from sample pre-treatment to data acquisition could be finished in one hour, thus largely facilitating the WBE method for drug surveillance and control.

Novel capsule phase microextraction - Gas chromatography - Mass spectrometry for analysis of pheniramine in a case of its fatal intoxication

In forensic toxicology, the extraction and purification of analytes from complex biological matrices heavily rely on the effectiveness of sample preparation methods. However, existing methods often face inherent challenges such as interfering substances and limited sample quantities, which can compromise the accuracy and efficiency of toxicological analyses. In the present work, for the first time, capsule phase microextraction (CPME) was implemented in forensic toxicology casework for the straightforward, affordable and sustainable extraction of the pheniramine (PHN) drug from human autopsy samples (whole blood and liver) and determined by GC-MS. A systematic investigation was conducted to optimize the extraction efficiency of CPME by examining and optimizing significant variables such as pH and volume of sample, adsorption time, desorption time and volume. The optimized method demonstrated linearity, covering a range of 0.1–10 μg mL−1 for blood samples and 0.1–10 μg g−1 for liver samples. The limit of quantification (LOQ) of the method for PHN in blood and liver samples was determined to be 0.063 μg mL−1 and 0.076 μg g−1, respectively. Repeatability and reproducibility of the method were less than 3.2% and 9.2%, respectively. The method demonstrated accuracy and recovery within the ranges of 94%–101.3%, and 67.4%–82%, respectively. The method was applied for analysis of autopsy samples from a case of fatal PHN intoxication and results were compared to those obtained using the conventional solid-phase extraction (SPE) method. Further, the competence of the proposed method has been judged by White Analytical Chemistry (WAC) RGB12 algorithm. CPME-GC-MS method demonstrates notable performance and significant stride in the domain of postmortem toxicology sample preparation. It is superior to traditional methods in several ways such as simpler, more sustainable, affordable and overcome the challenges of interfering substances and limited sample quantity.

Determination of 10 carbamate pesticide residues in liquid milk by ultra performance liquid chromatography-tandem mass spectrometry with pass-through solid-phase extraction purification

Carbamates are used in broad-spectrum insecticides and herbicides, and have highly efficient, low-residue, and long-lasting characteristics. However, this type of pesticide exerts mutagenic, teratogenic, carcinogenic, and other adverse effects, and its frequent use can exceed the recommended scope and limits. Research on the determination of carbamate pesticides mainly focuses on foods of plant origin and pays less attention to foods of animal origin. The methods for carbamate determination described in the current national standards have complicated operating procedures and low efficiency. Therefore, highly efficient and accurate methods for carbamate detection in milk must be established. In this work, a rapid method based on pass-through solid-phase extraction (SPE) purification coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of 10 carbamate pesticides in liquid milk. The pretreatment and instrument methods were systematically optimized. The milk sample was extracted with acetonitrile, and then purified using a Captiva EMR-Lipid filtration kit. The purified extract was separated on an ACQUITY UPLC BEH C18 column with mobile phase of methanol and 0.1% formic acid aqueous solution in gradient elution. The flow rate was 0.3 mL/min. Column temperature was 35 ℃. Quantitative analysis was performed using the external standard method with matrix matching curves. The 10 carbamate pesticides showed good linear relationships in the mass concentration range of 2-200 μg/L, with correlation coefficients greater than 0.999. The limits of detection (LODs) and quantification (LOQs) for the 10 carbamate pesticides were 0.045-0.23 and 0.15-0.77 μg/kg, respectively. Recovery tests were conducted using the blank-matrix method at three spiked levels of 15, 50, and 100 μg/kg, and good recoveries for the 10 carbamate pesticides were obtained. In particular, the recoveries for the three spiked levels of 15, 50, and 100 μg/kg were 68.7%-93.3% with relative standard deviations (RSDs) of 1.8%-8.0%. The proposed method is efficient, convenient, accurate, and suitable for the rapid detection of the 10 carbamate pesticides in liquid milk. Compared with the conventional NH2 and ENVITM-18 SPE columns used in the national standard determination method, the proposed method demonstrated better purification effects. The recoveries for aldicarb sulfoxide, aldicarb sulfone, methomyl, and carbaryl after purification using the Captiva EMR-Lipid kit increased from 60% to 80%. Thus, the proposed method is suitable for targets with strong polarity and gives measurement results with good repeatability and accuracy.

Exploring the potential of fabric phase sorptive extraction in postmortem toxicology: Green analysis of pheniramine in a forensic case of its fatal intoxication

Sample preparation is vital in postmortem toxicology to extract and purify analytes from complex matrices. Challenges like interfering substances and limited sample quantity can be overcome with effective preparation, ensuring accurate results. Hence, a simple, sustainable, affordable, and high-throughput method using fabric phase sorptive extraction (FPSE) - gas chromatography - mass spectrometry (GC–MS) was developed for pheniramine (PHN) analysis in postmortem biological samples (blood and liver). FPSE extraction efficiency was optimized by studying factors like membrane type, stirring time and speed, back-extraction solvent, sample pH, and ionic strength. The optimized method was validated following SWGTOX guidelines for linearity, precision, sensitivity, recovery, matrix effect, stability, and other relevant parameters. The method exhibited linearity in the range of 0.1–10 µg mL−1 for blood and 0.1–10 µg g−1 for liver samples under optimal conditions. The limit of quantification (LOQ) was 0.066 µg mL−1 and 0.073 µg g−1 for PHN in blood and liver, respectively. Intra-day and inter-day precision were < 5.8% and < 9.8%, respectively. Recovery and accuracy ranged from 74 to 80% and 95–100%, respectively. Real autopsy samples were analyzed using this method, compared to conventional solid-phase extraction (SPE), demonstrating its effectiveness. Additionally, the environmental impact and sustainability were assessed using ComplexGAPI and Analytical Eco-Scale tools. The FPSE-GC–MS method showed superior performance, marking a notable advancement in postmortem toxicology sample preparation. To the best of our knowledge, this is the first application of FPSE in the analysis of postmortem tissue samples. In conclusion, FPSE-GC–MS method offers a simple, sustainable, and affordable approach to sample preparation for postmortem forensic samples, overcoming challenges such as interfering substances and limited sample quantity. These advantages of FPSE make it a promising alternative to traditional methods, positions it as a significant advancement in the field, poised to shape the future of sample preparation in forensic toxicology.

Effect of salinity on molecular characterization of dissolved organic matter using ESI FT-ICR MS

Solid-phase extraction (SPE) coupled with negative-ion Electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has been widely used for molecular characterization of dissolved organic matter (DOM). However, little attention has paid to test whether the salinity of the sample and the presence of chloride ions in water samples affect the molecular composition of DOM extracted by SPE (SPE-DOM). In this study, one natural organic matter standard and several natural waters were selected to investigate how salinity affects the molecular composition of SPE-DOM and the selectivity of chloride ion adducts formation with respect to the molecular structure of SPE-DOM in negative ion ESI FT-ICR MS analysis. The results show that the molecular composition of SPE-DOM varied in a sample made by different salinity; and the variation pattern of DOM composition was different among different water samples under the treatment of consistent salinity gradients. The chloride ions can't be completely removed from cartridges in conventional SPE, thus leading organic compounds in SPE-DOM to form [M+Cl]‾ adducts when performing ESI FT-ICR MS analysis. In addition, the molecules with high H/C and low O/C ratios were likely to form [M+Cl]‾ ions. The relative abundance of [M+Cl]‾ ions could increase with the increase of salinity. These results are instructive to guide the pretreatment and molecular characterization of DOM in water samples with different salinity. Overall, we proposed a modification to the SPE to minimum reduce the formation of chloride ion adducts during the isolation of DOM.

Determination of Ethylene Glycol Dinitrate in Environmental and Forensic Water Samples Using Microextraction by Packed Sorbent Followed by Gas Chromatography

Ethylene glycol dinitrate (EGDN) is a liquid nitrate ester, a secondary explosive. In the past, it was used as an explosive ingredient in dynamite along with nitroglycerine. Due to its various applications, the reliable detection of EGDN in the environment is a key issue for both forensic and environmental applications. In these areas, sensitive and reliable methods for determining the concentration of nitro compounds are needed. Microextraction by packed sorbent (MEPS) is an innovative approach to green technology in the sample preparation field. Compared to conventional solid-phase extraction (SPE), MEPS uses a smaller sample volume and can be easily combined with various chromatographic techniques. An important benefit is the reduction of sorbent amount and up to 100-times repeatable use compared to disposable SPE columns, thus reducing the costs of analysis as well as waste production. Optimal extraction parameters for isolating EGDN from water, e.g., 30 µL of toluene as extraction agent, working in one cycle and in draw/discard mode, were selected. Method validation was performed, obtaining a limit of detection and a limit of quantification of 0.45 pg/μL and 1.34 pg/μL, respectively. Accuracy in terms of recovery rates was evaluated over a wide concentration range, obtaining values from 83.7 to 90.0%. The satisfactory linearity expressed by the coefficient of determination was 0.9914. A matrix factor of −9.3% indicates a weak matrix effect. The application to real environmental water samples and a forensic post-blast wash water sample was realized. EGDN detection in the post-blast samples provides valuable information for forensic technicians.

Preconcentration and Removal of Pb(II) Ions from Aqueous Solutions Using Graphene-Based Nanomaterials.

Direct determination of lead trace concentration in the presence of relatively complex matrices is often a problem. Thus, its preconcentration and separation are necessary in the analytical procedures. Graphene-based nanomaterials have attracted significant interest as potential adsorbents for Pb(II) preconcentration and removal due to their high specific surface area, exceptional porosities, numerous adsorption sites and functionalization ease. Particularly, incorporation of magnetic particles with graphene adsorbents offers an effective approach to overcome the separation problems after a lead enrichment step. This paper summarizes the developments in the applications of graphene-based adsorbents in conventional solid-phase extraction column packing and its alternative approaches in the past 5 years.

Polyaniline and Polyaniline-Based Materials as Sorbents in Solid-Phase Extraction Techniques.

Polyaniline (PANI) is one of the best known and widely studied conducting polymers with multiple applications and unique physicochemical properties. Due to its porous structure and relatively high surface area as well as the affinity toward many analytes related to the ability to establish different types of interactions, PANI has a great potential as a sorbent in sample pretreatment before instrumental analyses. This study provides an overview of the applications of polyaniline and polyaniline composites as sorbents in sample preparation techniques based on solid-phase extraction, including conventional solid-phase extraction (SPE) and its modifications, solid-phase microextraction (SPME), dispersive solid-phase extraction (dSPE), magnetic solid-phase extraction (MSPE) and stir-bar sorptive extraction (SBSE). The utility of PANI-based sorbents in chromatography was also summarized. It has been shown that polyaniline is willingly combined with other components and PANI-based materials may be formed in a variety of shapes. Polyaniline alone and PANI-based composites were successfully applied for sample preparation before determination of various analytes, both metal ions and organic compounds, in different matrices such as environmental samples, food, human plasma, urine, and blood.

Comparison of conventional and dispersive solid phase extraction clean-up approaches for the simultaneous analysis of tetracyclines and sulfonamides in a variety of fresh vegetables

The extensive use of antibiotics in agriculture has led to the occurrence of residual drugs in different vegetables frequently consumed by humans. This could pose a potential threat to human health, not only because of the possible effects after ingestion but also because the transmission of antibiotic-resistant genes could occur. In this work, two accurate sample preparation procedures were developed and validated for the simultaneous analysis of sulfonamides (SAs) and tetracyclines (TCs) in four of the most widely consumed vegetables (lettuce, onion, tomato, and carrot) in Europe. The evaluated protocols were based on QuECHERS for extraction and subsequent clean-up by SPE (solid phase extraction) or dispersive SPE. Parameters affecting both extraction and clean-up were carefully evaluated and selected for accuracy of results and minimal matrix effect. Overall, apparent recoveries were above 70% for most of the target analytes with both analytical procedures, and adequate precision (RSD<30%) was obtained for all the matrices. The procedural limits of quantification (LOQPRO) values for SPE clean-up remained below 4.4 μg kg−1 for TCs in all vegetables except for chlortetracycline (CTC) in lettuce (11.3 μg kg−1) and 3.0 μg kg−1 for SAs, with the exception of sulfadiazine (SDZ) in onion (3.9 μg kg−1) and sulfathiazole (STZ) in carrot (5.0 μg kg−1). Lower LOQPRO values (0.1–3.7 μg kg−1) were obtained, in general, when dSPE clean-up was employed. Both methods were applied to twenty-five market vegetable samples from ecological and conventional agriculture and only sulfamethazine (SMZ) and sulfapyridine (SPD) were detected in lettuce at 1.2 μg kg−1 and 0.5 μg kg−1, respectively.

Disposable, pressure-driven, and self-contained cartridge with pre-stored reagents for automated nucleic acid extraction

Nucleic acid extraction is vital in many applications such as molecular diagnostics, genetic engineering, and deoxyribonucleic acid (DNA) sequencing. Although recent advances in nucleic acid extraction have been made to improve the process using microfluidics, it is still necessary to make it easy for end-users by having pre-loaded reagents, eliminating pipetting between steps, and automating the process for point-of-care (POC) testing. Herein, we present a pressure-driven and self-contained cartridge with pre-stored reagents for automating nucleic acid purification. To reduce operational complexity, reagents were transferred through a microfluidic chip using pressurized air stored inside the cartridge instead of an external pump or valving system. After performing cell lysis, the cartridge was inserted into the device, and the nucleic acid was purified automatically within 3 min Escherichia coli (E. coli) O157:H7 DNA extracted by our device showed similar concentration, purity, and real-time polymerase chain reaction (qPCR) results as the conventional column-based nucleic acid extraction method. Our device achieved a detection limit of 103 CFU for E. coli DNA, which is the same as that obtained using the conventional solid-phase extraction method. This study introduces a novel approach for automating the sample preparation process, which can help in facilitating POC molecular diagnostics.

Solid-Phase Extraction Approaches for Improving Oligosaccharide and Small Peptide Identification with Liquid Chromatography-High-Resolution Mass Spectrometry: A Case Study on Proteolyzed Almond Extract.

Reverse-phase solid-phase extraction (SPE) is regularly used for separating and purifying food-derived oligosaccharides and peptides prior to liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. However, the diversity in physicochemical properties of peptides may prevent the complete separation of the two types of analytes. Peptides present in the oligosaccharide fraction not only interfere with glycomics analysis but also escape peptidomics analysis. This work evaluated different SPE approaches for improving LC-MS/MS analysis of both oligosaccharides and peptides through testing on peptide standards and a food sample of commercial interest (proteolyzed almond extract). Compared with conventional reverse-phase SPE, mixed-mode SPE (reverse-phase/strong cation exchange) was more effective in retaining small/hydrophilic peptides and capturing them in the high-organic fraction and thus allowed the identification of more oligosaccharides and dipeptides in the proteolyzed almond extract, with satisfactory MS/MS confirmation. Overall, mixed-mode SPE emerged as the ideal method for simultaneously improving the identification of food-derived oligosaccharides and small peptides using LC-MS/MS analysis.

Screening of new psychoactive substances in human plasma by magnetic solid phase extraction and LC-QTOF-MS

The emergence of new psychoactive substances (NPSs) is an increasing challenge in forensic toxicology. There are many extraction methods in use to isolate NPSs in biological fluids, including protein precipitation (PPT), liquid-liquid extraction (LLE), and solid phase extraction (SPE). However, there is a need to develop an effective extraction method with a short extraction time and low consumption of solvent. To meet these requirements, magnetic solid phase extraction (m-SPE) was attempted to isolate 40 NPSs in human plasma in this study. Forty NPSs (13 synthetic cannabinoids, 13 phenethylamines, 4 tryptamines, 4 other substances, 3 aminoindanes, 2 piperazines, 1 phencyclidine-type substance) were spiked in plasma and analyzed by m-SPE using COOH-functionalized multi-walled carbon nanotubes with magnetic nanoparticles (COOH-mMWCNTs). A liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) method was used for screening and identification of 40 target compounds. Method validation including limits of detection, recovery, matrix effect, and precision was performed for all 40 -target compounds. The limits of detection (LOD) of the 40 analytes were between 0.002 and 0.084 mg/L. Extraction recovery ranged from 36.9% to 110.6% (average 87%). Matrix effects ranged from –29.0% (ion suppression) to 9.8% (ion enhancement). Both intra- and inter-day precision values were less than 27.5% (RSD%). The accurate mass of QTOF-MS enabled the identification of analytes by exact monoisotopic mass and isotopic pattern. m-SPE was applied to extract 40 NPSs, and revealed less time-consuming and laborious than conventional SPE. This method proved to be an advantageous procedure to extract NPSs from biological fluids.

Porous electrospun microfibers for low flow-resistant solid phase extraction of fluoroquinolones in tap water, egg and milk samples

In this work, porous electrospun microfibers (PEMFs) were prepared using a polyimide/polyvinylpyrrolidone/polyethylene glycol (PI/PVP/PEG) solution mixture with coaxial ultrasonic water vapor spraying. After removing PVP and PEG by ultrasonic water washing, the PEMFs were successfully demonstrated as adsorbents for solid phase extraction (SPE). Most non-porous electrospun nanofibers are hundreds of nanometers in diameter, with a specific surface area of dozens of square meters per gram. In contrast, the diameter of the as-prepared PEMFs was tuned between 3 and 8μm, the specific surface area was 76 m2g-1 and the pore size was ca 25nm. Therefore, the flow resistance of the PEMF-SPE cartridges was similar to those of conventional commercial SPE cartridges, and much lower than those of SPE cartridges packed with electrospun nanofibers. Using the PEMF-SPE cartridges with ultra-performance liquid chromatography-fluorescence detector (UPLC-FLD), five fluoroquinolones (FQs) in tap water, egg and milk samples were extracted and quantified successfully. After optimizing the extraction conditions, FQs in water samples were extracted and eluted with high recoveries of 84.8-114.8%. The inter-batch and intra-batch relative standard deviation (RSD) values for the FQs were in the range of 1.9-9.5% (n=3), and the limits of detection were between 0.0024-0.014μg L-1. The method was linear in the concentration range of 0.005-10μg L-1. The reliability of the developed method was validated by analyzing tap water, egg and milk samples, and the recovery values were found to be in the range of 74.8-116.6% under the optimized conditions.

Novel fructooligosaccharides of Dioscorea alata L. tuber have prebiotic potentialities

Dioscorea alata L. (Dioscoreaceae), commonly known as water yam, is a popular tuber crop vegetable used across the globe. It is mainly composed of starch (75–84% of the dry weight) with a small amount of proteins, lipids, and vitamins and is very rich in minerals. It has nutritional superiority compared with other tropical root crops. The main aim of the study was to extract and characterize the fructooligosaccharides (FOSs) fractions from the tuber of this plant and evaluate their prebiotic properties. The soluble FOSs were fractionated by the conventional solid-phase extraction method and were characterized by FT-IR, HPTLC, and ESI–MS analyses. In addition, the beneficial health attributes of these fractions were checked for in vitro and in vivo prebiotic properties in Swiss albino mice. The FT-IR, HPTLC, and ESI–MS analyses of the FOSs from the hot water and 80% ethanol fractions showed that both are rich in inulin-like prebiotics. Furthermore, these FOSs showed an excellent prebiotic activity score and had enhanced in vitro cholesterol-binding activities in the presence of probiotic lactic acid bacteria (LAB) strains. Moreover, these had good antioxidant efficacies with IC50 values of 36.51 µg/ml and 33.12 µg/ml. In vivo treatment in Swiss albino mice, these FOSs had significantly lowered serum cholesterol (df = 6, p value < 2.2e−16), serum HDL (df = 6, p value = 3.68e−11), serum LDL (df = 6, p value < 2e−16), serum VLDL (df = 6, p value = 2.2e−13), serum triglycerides (df = 6, p value < 2e−16), blood sugar (df = 6, p value = 0.01857), serum glutamic pyruvic transaminase (S.G.P.T., df = 6, p value = 0.01189), serum glutamic oxaloacetic transaminase (S.G.O.T., df = 6, p value = 0.01239) but no significant difference found in weight gain (df = 6, p value = 0.166) and serum creatinine (df = 6, p value = 0.987). Furthermore, they enhanced IgA-mediated immunomodulation and influenced the gut colonization of probiotic LAB strains than the standard prebiotics, inulin. Thus, the study revealed that the FOSs from the storage tuber of D. alata possess some novel prebiotic that could contribute to human nutrition. This is the first report of the prebiotic FOS characterization from this plant.

Recent Advances in Molecular-Imprinting-Based Solid-Phase Extraction of Antibiotics Residues Coupled With Chromatographic Analysis

Abuse and residues of antibiotics cause great harm to organisms and the environment. Appropriate sample pretreatment is usually required for sensitive determination, because of the low content presence of a variety of antibiotics in complicated matrices. Molecular-imprinting-based solid-phase extraction (MISPE) has been widely used for sample pretreatment of antibiotics, using molecularly imprinted polymers (MIPs) as adsorbents. Herein, we comprehensively review the recent advances of MISPE of antibiotics, followed by chromatographic analysis. Various solid-phase extraction (SPE) modes based on MIPs are briefly introduced, such as conventional SPE, dispersive SPE, magnetic SPE, matrix solid-phase dispersion, and pipette-tip SPE. Then, several emerging preparation techniques for antibiotics MIPs are summarized including surface imprinting, nanoimprinting, living/controlled radical polymerization, multitemplate imprinting, multifunctional monomer imprinting, and dummy template imprinting. Subsequently, applications of MISPE to analysis of a variety of antibiotics residues since 2018 are overviewed, including sulfonamides, quinolones, tetracycline, and others. Finally, the preparation and application of antibiotics MIPs are prospected.

Application of a fast and sensitive method for the determination of contaminants of emerging concern in wastewater using a quick, easy, cheap, effective, rugged and safe-based extraction and liquid chromatography coupled to mass spectrometry

The inefficiency of wastewater treatment plants (WWTPs) to remove contaminants of emerging concern (CECs) leads to their continuous release to the environment. Consequently, CECs are present at low concentrations in the treated wastewater (TWW), producing unpredicted and unwanted effects on living organisms as they are discharged into water receiving bodies. This work presents a fast and reliable method for the determination of CECs in TWW based on the innovative application of a QuEChERS (quick, easy, cheap, effective, rugged and safe) method for water extraction and determination by sensitive liquid chromatography coupled to quadrupole-linear ion trap tandem mass spectrometry (LC-QqLIT-MS/MS). The scope of the proposed QuEChERS-based method allows the monitoring of 107 CECs, including pharmaceuticals (58), antibiotics (16) and pesticides (33). The proposed method was successfully validated in urban TWW at two concentration levels (50 and 500 ng L−1) and it is a feasible alternative to conventional and time-consuming solid-phase extraction (SPE) methodologies. 89% of the CECs presented mean recovery values in the 70–120% range with relative standard deviations (RSDs) always < 20% (intra and inter-day precision), and limits of quantification (LOQs) in the range 5–500 ng L−1 (89% of the compounds showed a LOQ ≤ 50 ng L−1). The applicability of the method was demonstrated by the analysis of urban TWW samples (7 sampling events). In total, 35 CECs (23 pharmaceuticals, 2 antibiotics and 10 pesticides) were detected in the monitored samples with concentrations ranging from 5 to 677 ng L−1.