Solid-phase Extraction Process Research Articles

Covalent organic frameworks hybridized polymeric high internal phase emulsions with amphiphilicity for extraction of trace bisamide insecticides in food samples.

Polymeric high internal phase emulsions decorated with covalent organic frameworks (polyHIPEs-COFs) were synthesized and used as the sorbent for cyantraniliprole and chlorantraniliprole. Pickering high internal phase emulsions stabilized by covalent organic frameworks solid particles and liquid surfactants (Span80 and polyvinylpyrrolidone) endow the composites with open-cell structures and superwettability. The amphiphilicity and open-cell structures enable rapid adsorption and desorption for cyantraniliprole and chlorantraniliprole, and the solid-phase extraction process can be completed in 5min. The adsorption efficiencies of polyHIPEs-COFs for cyantraniliprole and chlorantraniliprole are above 85.19%, but lower than 10% for fenvalerate, anti-aphid, and chlorpyrifos, demonstrating the good adsorption selectivity for cyantraniliprole and chlorantraniliprole. The adsorption efficiencies of cyantraniliprole and chlorantraniliprole using a same polyHIPEs-COFs and five different batches of polyHIPEs-COFs range from 94.25 to 100.00%, revealing the good reproducibility of the sorbent. In addition, the polyHIPEs-COF-based solid-phase extraction combined with high-performance liquid chromatography-ultraviolet detector (HPLC-UV) was developed for determination of bisamide insecticides in vegetable (eggplants, tomatoes, and peppers) samples. Results showed that the method was feasible to determinethe cyantraniliprole and chlorantraniliprole in real vegetable samples with a linear range of 0.012-1.2μg/kg and limits of detection of 0.0075-0.0090μg/kg. The recoveries of cyantraniliprole and chlorantraniliprole spiked in vegetable samples ranged from 85.00 to 100.00% with relative standard deviations less than 3.52%. The study indicates the feasibility of amphiphilic polyHIPEs-COFs in extraction and enrichment of bisamide insecticides from vegetable samples for HPLC-UV analysis.

Automated three-step solid-phase extraction of toxicologically relevant psychotropic compounds and metabolites from plasma followed by LC-MS/MS analysis

This study describes a method for the quantification of multiple toxicologically relevant compounds in plasma samples from suicide attempt patients using an automated three-step solid-phase extraction (SPE) with hydrophilic-lipophilic balance (HLB®) sorbent, with subsequent analysis by liquid chromatography-tandem mass spectrometry (LC/MS-MS). This novel approach simplifies the standard five-step SPE process by eliminating the conditioning and equilibration steps. Target analytes included amitriptyline, amphetamine, benzoylecgonine, carbamazepine, cocaethylene, cocaine, codeine, diazepam, fluoxetine, 3,4-methylenedioxymethamphetamine (MDMA), N-methyldiethanolamine (MDEA), methylenedioxyamphetamine (MDA), methamphetamine, morphine, nortriptyline, paroxetine, sertraline, and venlafaxine. Plasma samples (100 µL) were diluted with 4 % phosphoric acid in water, mixed with deuterated internal standards, and subjected to automated SPE using an ASPEC® automation. Analysis was performed using an octadecyl column (1.8 µm, 150 × 2.1 mm) with a 15-minute chromatographic run. The automated SPE took 24 min per sample. Intra-assay precision was 1.6–10.1 %, inter-assay precision was 1.5–5.8 %, and accuracy was 94.4 %–106.6 %. Extraction yields varied from 14.6 % to 78.7 %, with matrix effects ranging from −15.9 % to 13.3 %. The validated method was applied to samples from 50 suicide attempt patients, of which 28 contained quantifiable amounts of the target substances. This study describes the first application of an automated three-step SPE procedure for the extraction of multiple relevant analytes in emergency toxicology

A hierarchical porous Fe3O4-COOH@H-ZIF-67 composite as magnetic solid-phase extraction adsorbent for benzimidazole pesticides

A hierarchical porous structural magnetic zeolite imidazolate framework-67 composite (Fe3O4-COOH@H-ZIF-67) was prepared through directly mixing the H-ZIF-67 and glutaric anhydride functionalized Fe3O4 nanospheres, of which the H-ZIF-67 was synthesized through a double template pore size regulation method. The successful preparation of Fe3O4-COOH@H-ZIF-67 composite was confirmed based on the material characterization using different techniques. The prepared composite was applied in the efficient removal of four benzimidazole pesticides (BZDs) in water using magnetic solid-phase extraction (MSPE) process. The results of static and dynamic adsorption experiments indicate that the adsorption of BZDs on Fe3O4-COOH@H-ZIF-67 follow pseudo-second-order kinetics, the Langmuir model fitted well with the adsorption data (R2 are all higher than 0.9969), and the maximum adsorption capacity for BZDs are 7.44–31.11 mg/g. Meanwhile, the adsorption mechanism study indicate that both hydrogen bonding and coordination play important roles during the adsorption process of BZDs. Finally, the developed MSPE method was combined with HPLC analysis and applied in the removal of BZDs from simulated pesticides wastewater. The removal rate was 82.76–96.18 %, and the treated samples met the requirements of the maximum residue limits of CBZ in the national standard GB 21523–2008. In addition, the adsorbent can be used at least three times and the extraction efficiency changed within 3 % after being stored in dry atmosphere at room temperature for 90 days. The results of this work manifested that Fe3O4-COOH@H-ZIF-67 composite can be used for removal and analysis of BZDs in complex samples.

Preparation of magnetic coconut clothing biochar for extracting neonicotinoid insecticides from environmental water samples

In this study, the magnetic coconut clothing biochar hybrid materials were successfully prepared by in-situ method. The obtained magnetic biochar was characterized in detail by using series of analytical techniques. The results showed that the magnetic hybrid materials presented alveolate network structures with abundant large pores and good magnetic separation ability with Fe3O4 nanoparticles obviously attached on the surface of biochar. The magnetic biochar hybrid materials were used as adsorbents during magnetic solid-phase extraction process for extracting neonicotinoid insecticides from environmental water samples. The adsorption and desorption parameters (adsorption time, elution condition, sample volume, sample pH) affecting magnetic solid-phase extraction efficiency were carefully investigated. Under the optimum conditions (adsorption for 15 min, 5 % formic acid-acetonitrile as elution condition, 50 mL of sample volume, 15 mg of magnetic biochar, pH at 5.0), the magnetic solid-phase extraction process based on magnetic coconut clothing biochar hybrid materials coupled with high performance liquid chromatography tandem mass spectrometry for enriching and detecting neonicotinoid insecticides in environmental water samples was established. The good linear relationship in the range of 0.5–200 ng mL−1 with correlation coefficients greater than 0.9989 and the lower limits of detection (0.0017–0.0069 ng·mL−1) were obtained. The recovery in the spiked water samples was in the range of 68.6 %-104.0 % with relative standard deviation from 0.4 % to 9.3 %. These results demonstrated that the established method was highly sensitive, convenient and repeatable for directly analyzing trace neonicotinoid insecticides in environmental water samples. More importantly, the novel biochar from coconut clothing was introduced into sample pretreatment to enrich trace organic pollutants.

Large-pore covalent organic framework as solid phase extraction absorbentforefficientdetermination of polypeptide antibiotics in animal-derived foods

The precise determination of polypeptide antibiotics (PPTs) in foods has been always challenging because of the interference of various endogenous peptides in complex matrix. Herin, a novel large-pore covalent organic framework (TABPT-SPDA-COF) with accessible pore size of 7.9 nm was synthesized as a solid phase extraction (SPE) absorbent for efficiently enriching four PPTs existed in foods originating from animals. The parameters of SPE process were systematically optimized. Subsequently, four PPTs were determined by UHPLC-MS/MS. Under the optimal conditions, TABPT-SPDA-COF shows outstanding enrichment capacity for PPTs in contrast to commercial absorbents ascribed to size selectivity and multiple interaction effects. The method exhibits excellent linear range (0.005–100 ng mL−1), satisfactory limits of detection (0.1 pg mL–1) as well as relative recoveries (86.2–116 %). This work offers a practicable platform to monitor trace PPTs from complex animal-derived foodstuffs.

The single adsorbent nano-TiO2 modified QuEChERS for simultaneous determination of 18 pyrrolizidine alkaloids in ginseng samples via LC-MS/MS

Pyrrolizidine alkaloids (PAs) are a group of naturally occurring toxins, which have been widely found in herbs. However, the complexity of the herbs made the accurate and simple determination of PAs challenging. Herein, the present work described the development of a simple and effective QuEChERS method for simultaneous determination of 18 PAs in various ginseng samples. The extraction and purification processes were systematically optimized and validated coupled to LC-MS/MS analysis. After intensive screening, a single adsorbent nano-TiO2 was employed as a cleanup adsorbent during the dispersive solid phase extraction process to remove the matrix interferences and retain the target PAs in the sample solution, achieving the simultaneous determination of 18 PAs. The validation results displayed that the PAs had good linearity, sensitivity and satisfactory accuracy by the developed method. The method LODs and LOQs of PAs ranged from 0.05-1.49 μg/kg and 0.17–4.95 µg/kg, respectively. The average recoveries were 70.1 %-111 % with RSD less than 13 % under different spiked concentrations. Compared to the conventional QuEChERS method, this method gave rise to better purification effect and recoveries under the condition of only using one adsorbent nano-TiO2, which obvious improved its simplicity and versatility. Furthermore, this method was used to analyze the real ginseng samples and PAs were detected with concentrations ranging from 1.02 to 139 μg/kg, which further verified the feasibility of the developed method in the PAs analysis from the traditional herbal medicines.

An Eco-Friendly Extraction and Purification Approach for Obtaining Active Ingredients for Cosmetics from Two Marine Brown Seaweeds.

Brown seaweeds are attracting attention due to their richness in bioactive compounds, in particular, their phlorotannins. We present here a case study of two Fucales, Ascophyllum nodosum and Halidrys siliquosa, sustainably collected, to produce active polyphenols for the cosmetics sector. Phenolic contents of crude extracts, obtained by Accelerated Solvent Extraction (ASE), were more elevated in H. siliquosa at 100.05 mg/g dry weight (DW) than in A. nodosum (29.51 mg/g DW), considering 3 cycles with cell inversion. The temperature of extraction for a high phenolic content and high associated antioxidant activities close to positive controls was 150 °C for both algae and the use of only one cycle was enough. A semi-purification process using Solid-phase Extraction (SPE) was carried out on both ASE crude extracts (one per species). The majority of phlorotannins were found in the ethanolic SPE fraction for A. nodosum and the hydroethanolic one for H. siliquosa. The SPE process allowed us to obtain more concentrated fractions of active phenolic compounds (×1.8 and 2 in A. nodosum and H. siliquosa, respectively). Results are discussed in regard to the exploitation of seaweeds in Brittany and to the research of sustainable processes to produce active natural ingredients for cosmetics.

Synthesis of the magnetic composite of Ni-MOF-I in aqueous medium and its application in magnetic dispersive micro solid phase extraction of plasticizers from pharmaceutical samples

For the first time, this research presents the synthesis procedure and analytical application of Ni-MOF-I magnetic composite. The synthesis method was green and done in an aqueous medium. The composite was employed as an adsorbent in a magnetic dispersive solid phase extraction process followed by dispersive liquid–liquid microextraction for the extraction and preconcentration of some plasticizers from pharmaceutical samples stored in plastic containers. The Ni-MOF-I magnetic composite was characterized by applying Fourier transform infrared spectrophotometry, vibrating sample magnetometry, scanning electron microscopy, energy-dispersive X-ray, X-ray diffraction, and nitrogen adsorption/desorption analyses. For operating the extraction procedure, initially, the plasticizers were adsorbed onto the adsorbent particles by vortexing. Then, the plasticizers were desorbed from the adsorbent surface using a mL volume of 2-proponal. Subsequently, the obtained eluate phase was mixed with a mixture of 1,2-dibromoethane and 1,1,2-trichloroethane and then injected into deionized water using a glass syringe. Afterward, centrifugation was done to isolate the extractant from the aqueous phase. Eventually, one microliter of the sedimented phase was injected into gas chromatography-flame ionization detection. Acceptable analytical results such as high enrichment factors (355–415) and extraction recoveries (71–83 %), low limits of quantification (0.76–1.08 μg L−1) and detection (0.23–0.33 μg L−1), wide linear ranges (1.08–300 μg L−1), and satisfactory relative standard deviation values of 4.0–6.3 % (intra-day precision, n = 5) and 4.9–7.4 % (inter-day precision, n = 5) were achieved. The suggested procedure was used as a productive analytical method based on the Ni-MOF-I magnetic composite for the extraction and determination of some plasticizers from different pharmaceutical samples filled in plastic containers. Elimination of centrifugation, using 2-propanol as a green desorption/disperser solvent, detection of di-(2-ethylhexyl) phthalate in boric acid alcohol drop, and applying µL-level of the extraction solvent are the advantages of this proposed method.

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.

A magnetic adsorbent of nitrogen-doped graphene quantum dots, zinc metal-organic framework and molecularly imprinted polymer to extract phenylureas

A highly selective composite nano-sorbent was designed and fabricated for the extraction and enrichment of phenylureas. The nano-sorbent was composed of nitrogen-doped graphene quantum dots (N-GQDs), a zinc metal-organic framework (IRMOF-1) and magnetite nanoparticles incorporated in molecularly imprinted polymer (MIP). The fabricated nano-sorbent was characterized and applied to extract and enrich three phenylureas in a dispersive magnetic solid-phase extraction (d-MSPE) process. The developed method was highly sensitive and detected the target phenylureas at trace levels. The linear range was from 1.0 to 150 µg L−1 and the limit of detection was 1.0 µg L−1. The large specific surface area of the nano-sorbent produced highly efficient adsorption. When applied to extract phenylureas in vegetable samples, recoveries were in the range of 80.2–95.8% with relative standard deviations lower than 8.0%. The developed nano-sorbent not only exhibited highly selective and efficient extraction but also good stability which can be reused four times, and ease of fabrication. The developed strategy can also be modified for the extraction and determination of other organic compounds in various complex samples.

Preparation of metal-organic framework @molecularly imprinted polymers for extracting N-nitrosamines in salted vegetables

In this paper, the novel metal-organic framework @molecularly imprinted polymers were prepared and applied in extracting N-nitrosamines from salted vegetables. The imprinted polymers were coated on the surface of MIL-101 using multi-dummy template molecules (5-nonanol, benzhydrol and N-formylpyrrolidine). The characterization and adsorbing experiments showed that the hybrid imprinted polymers presented spherical particles with typically core-shell structure, and exhibited high adsorption capacity (maximum capacity: 46.85 mg/g) and fast equilibrium rate (only 5 min) for N-nitrosamines. Various parameters (sample loading solvent, pH, washing solvent, elution solvent and elution volume) affecting solid-phase extraction were optimized. Under the optimum conditions, the solid-phase extraction process based on the hybrid polymers combined with high performance liquid chromatography-ultraviolet detection method was established and applied to analyze N-nitrosamines in different salted vegetables. The results showed that the developed method produced the linear relationship between the peak areas versus the N-nitrosamines concentrations of 0.2–10 µg/g with limit of detections from 20.6 to 76.1 ng/g. The spiked recovery of N-nitrosamines in the salted vegetable samples was in the range of 66–100.5 % with relative standard deviation from 0.1 to 3.4 %. Those results demonstrated that the established method was sensitive and efficient for directly enriching and analyzing trace N-nitrosamines in salted vegetables.

In-depth descriptive investigation of composite sorbent based self-assembled magnetic halloysite nanotube-graphene oxide: Actual use case study for rutin

In this study, a three-dimensional nanocomposite with magnetic features made of magnetic iron oxide nanoparticles (Fe3O4), graphene oxide (GO) and halloysite nanotube (Hal) was prepared and introduced for rutin separation from real sample based on magnetic solid phase extraction (MSPE) process. Hal was modified with chitosan (Hal-COS) and showed positive charge, which can combine with GO by electrostatic force self-assembly to fabricate Hal-GO. Based on this, in-situ growth of magnetic sphere on the surface of Hal-GO demonstrated high specific surface area, chemical and thermal stability, water solubility, and capacity of easy separation in aqueous solution. Several characterizations including FT-IR, HRTEM, TGA and XRD evidenced the successful synthesis of the nanocomposite. The results showed that the optimum adsorption pH was 6 and the optimum adsorption temperature was 25 °C. In addition, further experiments showed that the adsorption process conformed to the Langmuir adsorption model and pseudo-second-order kinetic model, which indicated that the maximum equilibrium adsorption capacity was 107.8 mg g−1 and the maximum equilibrium adsorption time was 120 min. With the optimized conditions, the methodological validation experiments showed that the linear range of MSPE based on Fe3O4@(Hal-GO) combined with HPLC was 10–100 μg mL−1, the correlation coefficient of the fitting equation was 0.9991, the LOD and LOQ reached 0.87 μg mL−1 and 2.9 μg mL−1 respectively. It was confirmed that prepared Fe3O4@(Hal-GO) supported efficient enrichment of rutin when the results were compared to those of other studies.

Halüsinasyon yapan yeni tasarım psikoaktif maddelerden biri olan 5-MeO-MiPTin idrarda tayinine yönelik kemometrik yöntem geliştirilmesi

Aim: In this study, a method was developed for analysis and chemometric optimization for 5-methoxy-N-methyl-N-isopropyltryptamine (5-MeO-MiPT).
 Materials and Methods: Our study was carried out in Ege University Institute on Drug Abuse, Toxicology and Pharmaceutical Science, Addiction Toxicology Laboratory.
 Analysis and optimization of the effects of hydrolysis and solid phase extraction processes during the analysis of 5-MeO-MiPT by Gas Chromatography-Mass Spectrometry (GC-MS). For chemometric screenings design, Plackett-Burman was used. The most effective three factors were determined, and a central composite design was applied, and results were evaluated with surface response methodology. The method was validated for selectivity, linearity, the limit of detection, the limit of quantitation, accuracy, intra-day and inter-day repeatability, stability and carry over.
 Results: In the chemometric method, the most effective parameters were found sample volume, hydrolysis temperature, and elution volume for 5-MeO-MiPT in urine analysis. Optimum values for these parameters were calculated by surface response methodology and the results were determined 1ml urine volume, 30°C hydrolysis temperature, 3,5 ml elution volume, respectively. The optimized method was validated for selectivity, linearity (25-500 ng/mL), limit of detection (5 ng/mL), limit of quantitation (18 ng/mL), accuracy (72-101%), intra-day and inter-day precisions were measured, respectively (4,43% RSD),(4,27% CV), stability and carry over parameters.
 Conclusion: With a chemometric approach, quick, practical and accurate method for the detection of 5-MeO-MiPT has been developed with GC-MS. Working of 5-MeO-MiPT without derivatization in GC-MS analysis has shortened the pre-preparation time and is a pioneer for other analogs. It provides an effective method in the analysis of substances such as synthetic analogues from tryptamines which are added every day, with the use of such classical equipment and new methods.

A stable core-shell metal-organic framework@covalent organic framework composite as solid-phase extraction adsorbent for selective enrichment and determination of flavonoids

Hydrophobization and stability is crucial for the practical application of most metal-organic frameworks (MOFs) in extraction technique. In this study, a stable core-shell MOF@COF composite (NH2-MIL-101(Fe)@TAPB-FPBA-COF) was successfully prepared by Schiff base reaction and applied to solid-phase extraction (SPE) of hydrophobic flavonoids. Notably, the TAPB-FPBA-COF shell acts as a hydrophobic "shield", which not only improves the hydrophobicity and stability of hydrophilic NH2-MIL-101(Fe), but also makes the extraction efficiency of flavonoids from MOF@COF composite significantly higher than that of pure NH2-MIL-101(Fe) and TAPB-FPBA-COF. In addition, a sensitive analytical method with excellent linearities (0.1–500 ng mL−1, R2 ≥ 0.9967), low limits of detection (0.02–0.04 ng mL−1 for water; 0.04–0.07 ng mL−1 for grape juice; 0.06–0.08 ng mL−1 for honey), good repeatability (intra-day/inter-day precision are 1.86–5.37%/1.82–7.79%, respectively) and only 5 mg of adsorbent per cartridge was established by optimizing the SPE process combined with high performance liquid chromatography with ultraviolet-visible detector (HPLC-UV). Meanwhile, selectivity study and comparative experiments with the commercial C18 adsorbent showed that the MOF@COF adsorbent exhibited satisfactory extraction efficiency for flavonoids due to multiple interactions such as hydrogen bonding, hydrophobic, and π-π interactions. Finally, the good recoveries in grape juice (84.5–102.5%) and honey (87.5–104.6%) samples further validated the applicability of the proposed method in complex samples.

Development and validation of a multianalyte method for quantification of isoxazolines in animal-derived matrix samples using SPE-HPLC–MS/MS

Isoxazoline drugs, including afoxolaner, fluralaner, lotilaner, and sarolaner, are widely used in veterinary medicine. However, the lack of available analytical methods has made regulatory monitoring of these drugs difficult. Therefore, in this study, we developed an optimized solid phase extraction process using hydrophilic–lipophilic cartridges, and subsequently analyzed the extracts using liquid chromatography–tandem mass spectrometry under optimized conditions. The detection limits for the four isoxazolines were 5.0 μg/kg, while the recoveries in six animal-derived matrices were 71.1–109.2 %, with intra-day and inter-day relative standard deviations below 11.9 % and 11.7 % respectively. Furthermore, an inter-laboratory comparison demonstrated that this method had good recovery (60.3–112.9 %) and acceptable precision (< 11.3 %). Additionally, the developed method exhibited excellent linearity, accuracy, precision, sensitivity, measurement uncertainty and robustness for isoxazoline residue determination in animal-derived samples. It was also successfully applied to determine incurred isoxazoline residues in medicated hens.

Synthesis of a New Molecularly Imprinted Polymer and Optimisation of Phenylglyoxylic Acid Extraction from Human Urine Samples Using a Central Composite Design within the Response Surface Methodology.

Styrene, a chemical widely used in various industries, undergoes metabolic breakdown in the human body, resulting in the production of phenylglyoxylic acid (PGA). A novel molecularly imprinted polymer (MIP) was synthesised for selective extraction and enrichment of PGA in urine samples prior to high-performance liquid chromatography. The MIP employed in this research was a 4-vinylpyridine molecularly imprinted polymer (4-VPMIP) prepared via mass polymerisation using a noncovalent method. The structural and morphological characteristics of the molecularly imprinted polymers (MIPs) and non-imprinted polymers (NIPs) were evaluated using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The efficiency of the molecularly imprinted solid-phase extraction (MISPE) process was optimised by investigating critical variables such as sample pH, sorbent mass, sample flow rate, and volume of the elution solvent. A central composite design (CCD) within the response surface methodology was utilised to develop separate models for the adsorption and desorption steps. Analysis of variance (ANOVA) confirmed the excellent fit of the experimental data to the proposed response models. Under the optimised conditions, the molecularly imprinted polymers exhibited a higher degree of selectivity and affinity for PGA, with a relative selectivity coefficient (α) of 2.79 against hippuric acid. The limits of detection (LOD) and quantification (LOQ) for PGA were determined to be 0.5 mg/L and 1.6 mg/L, respectively. The recoveries of PGA ranged from 97.32% to 99.06%, with a relative standard deviation (RSD) lower than 4.6%. Furthermore, MIP(4VP)SPE demonstrated the potential for recycling up to three times without significant loss in analyte recovery.

Preparation of magnetic molecularly imprinted polymers for the selective extraction of strobilurin fungicides in agricultural products

In this study, the novel magnetic molecularly imprinted polymers were successfully synthesized by surface imprinting technique and used as magnetic adsorbent for extracting six strobilurin fungicides from agricultural products. The magnetic molecularly imprinted polymers showed the typical core-shell structure with high maximum adsorption capacity (42.7 mg/g) and rapid adsorption equilibration (3 min) and specific recognition ability. The parameters (elution solvent, elution time, adsorption time, loading solvent and solution pH) in magnetic solid phase extraction were evaluated. Under the optimum adsorption and desorption condition, the magnetic solid phase extraction process based on magnetic molecularly imprinted polymers coupled with high performance liquid chromatography-tandem mass spectrometry was developed for the sensitive detection of strobilurin fungicides from agricultural products. The developed method presented good linearity (5–200 ng/mL) with correlation coefficients (R2) ≥ 0.9990. The limits of detection and quantification were 0.03–0.49 ng/g and 0.09–1.64 ng/g, respectively. At the three different concentration (20, 50, 100 ng/g) spiked in agricultural products, the good recovery (71.5%−115.8%) was obtained and the relative standard deviations were below 8.3%. These results indicated that this established method was sensitive, accurate, selective and reproducible.

Zinc Oxide Nanomaterial‐Based Dispersive Solid Phase Extraction for the Trace Determination of Gold in Flash Gold Plating Solution Samples using Flame Atomic Absorption Spectrophotometry

AbstractThe noble metal Au is extensively used in jewelry, industry, and medicine. In order to mitigate the low sensitivity of the flame module atomic absorption spectrometer (FAAS) to determine the gold, zinc oxide (ZnO) nanomaterial were synthesized and used to pretreatment of the sample and preconcentrate gold ions in dispersive solid phase extraction (DSPE) process. Enrichment factor of the extraction method was enhanced by performing buffer solution type/volume, nanomaterial amount, mixing type/period, and desorption solvent concentration/volume optimizations. Calibration plot displayed good linearity and percent relative standard deviation recorded for the lowest concentration of the plot was adequately low (&lt;7.0 %). Dynamic dynamic range for the proposed method was calculated between 30–400 μg/L. Regression coefficient (R2) of proposed method was found to be 0.9956. With an enrichment factor of 44.5‐folds, method recorded a detection limit (LOD) of 7.4 μg L−1 and quantification limit (LOQ) of 24.8 μg L−1. Flash gold plating bath solution was used to certify the quantification accuracy/applicability in complex matrix of the method. The obtained results (1.86±0.08 g L−1) were compatible with the results of the reference method (ICP‐OES) (1.87±0.08 g L−1). This is the first study for the extraction/preconcentration of gold using ZnO nanomaterial.

Eco-friendly UV-spectrophotometric methods employing magnetic nano-composite polymer for the extraction and analysis of sexual boosters in adulterated food products: Application of computer-aided design.

Solid phase extraction (SPE) techniques based on computationally designed magnetic-based multi-targeting molecular imprinted polymer (MT-MIP) and combined with UV spectrophotometric approaches provide advantages in the examination of counterfeit samples. The current work describes an innovative and sustainable methodology for the simultaneous determination of tadalafil (TAD) and dapoxetine hydrochloride (DAP) in counterfeited honey and instant coffee aphrodisiac products utilizing a SPE exploiting MT-MIP. Besides, an innovative UV spectrophotometric method capable of resolving TAD in its pharmaceutical binary mixtures with DAP was developed. A novel computational approach was implemented to tailor the synthesis and design of the MT-MIP particles. Herein; we applied a newly developed UV spectrophotometric method which was based on Fourier self-deconvolution (FSD) method coupled with isoabsorptive point for determination of TAD and DAP in pharmaceutical dosage form. Besides we applied a SPE process based on the MT-MIP designed particles, assisting in the analysis of both drugs in counterfeited food samples. The SPE process and the UV spectroscopic methodology were assessed regarding their greenness using the pioneering GAPI, AGREEprep and AGREE greenness assessing tools. The synthesized MT-MIP particles were characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The suggested spectrophotometric methods revealed a wider linear concentration range of 2-50 µg/mL with lower limits of detection in the range of 0.604 -0.994 µg/mL. Additionally, the suggested method demonstrated the utmost sensitivity and eco-friendliness for their target in its mixed dosage form and counterfeited food products. The SPE process and the developed analytical UV spectroscopic methodology were validated as per the ICH guidelines, and were found to be suitable for overseeing some counterfeiting activities in commercially available honey and instant coffee aphrodisiac products. An SPE based on MT-MIP magnetic-based polymer assisted with UV-spectroscopic method was successfully developed for analysis of tadalafil and dapoxetine hydrochloride in different matrices.

Discrimination and quantification of methotrexate in the presence of its metabolites in patient serum using SERS mapping, assisted by multivariate spectral data analysis

Therapeutic drug monitoring (TDM) of methotrexate (MTX), an anticancer drug, is critical since MTX therapy can lead to severe adverse effects if not monitored to ensure clearance. Discriminating and quantifying MTX among its metabolites is challenging, time consuming, and not universally available. Therefore, we propose a surface-enhanced Raman scattering (SERS) based method as a rapid and easy-to-use alternative to complex standard methods. We implemented a solid phase extraction (SPE) process in a syringe filter holder (μ-SPE-SFH), suitable for the extraction of MTX and compatible with nanopillar assisted separation (NPAS) and SERS-based detection. All of the parameters related to the extraction, desorption, and NPAS procedure were investigated and optimized. The SERS spectra from maps were analyzed with partial least squares as regression (PLSR) and as a discrimination analysis (PLS-DA) to enable, for the first time with SERS, the identification and quantification of MTX in the presence of its metabolites (7-hydroxy-methotrexate (7-OH MTX) and 2,4-diamino-N(10)-methylpteroic acid (DAMPA)). PLSR facilitated MTX quantification in patient samples in the presence of drugs that could be co-administered during MTX therapy. We found the detection limit to be 0.15 μM while the limit of quantification was 0.55 μM. In addition, for the PLSR, the accuracy, precision, analytical sensitivity, and inverse of analytical sensitivity were 0.66 μM, 0.5 μM, 10.5 μM−1, and 0.1 μM respectively. Furthermore, when quantifying MTX from patient samples, we found a good agreement between calculated MTX concentration with the developed method and reference assay, showing the potential of the sensor in clinical application.