Application Of Solid-phase Extraction Research Articles

Enhancing Solid-Phase Extraction of Tamoxifen and Its Metabolites from Human Plasma Using MOF-Integrated Polyacrylonitrile Composites: A Study on CuBTC and ZIF-8 Efficacy.

This study investigates electrospun fibers of metal-organic frameworks (MOFs), particularly CuBTC and ZIF-8, in polyacrylonitrile (PAN) for the solid-phase extraction (SPE) of Tamoxifen (TAM) and its metabolites (NDTAM, ENDO, and 4OHT) from human blood plasma. The focus is on the isolation, pre-concentration, and extraction of the analytes, aiming to provide a more accessible and affordable breast cancer patient-monitoring technology. The unique physicochemical properties of MOFs, such as high porosity and surface area, combined with PAN's stability and low density, are leveraged to improve SPE efficiency. The study meticulously examines the interactions of these MOFs with the analytes under various conditions, including elution solvents and protein precipitators. Results reveal that ZIF-8/PAN composites outperform CuBTC/PAN and PAN alone, especially when methanol is used as the protein precipitator. This superior performance is attributed to the physicochemical compatibility between the analytes' properties, like solubility and polarity, and the MOFs' structural features, including pore flexibility, active site availability, surface polarity, and surface area. The findings underscore MOFs' potential in SPE applications and provide valuable insights into the selectivity and sensitivity of different MOFs towards specific analytes, advancing more efficient targeted extraction methods in biomedical analysis.

Preparation of a novel polymer microspheres and application in solid phase extraction combined with hollow fiber membrane system for capturing lactic acid from simulated fermentation broth

To separate the fermentation products in real time and improve the fermentation yield, a novel poly-4-vinylpyridine-vinylbenzeneboronic acid polymer microspheres (p4VP-VPBA) with bifunctional groups was prepared by suspension polymerization. The spherical p4VP-VPBA was 5–20 μm and thermally stable below 355.4 °C. The elemental contents of N and O were 1.36% and 5.72%, respectively, and the content of boronic acid was 0.1357 mmol/g. Its adsorption performance to lactic acid was satisfactory. Under pH 4 and 20 °C, the maximum static adsorption of p4VP-VPBA was up to 185.31 mg/g in 3 h. Its selectivity on lactic acid to glucose was 70.05 at pH 2, 7.71 at pH 4, and only 0.81 at pH 10, which indicated a good selectivity to lactic acid at low pH fitting to fermentation process. Furthermore, a p4VP-VPBA-combined with hollow fiber membrane (HFM) separation system was proposed and the removal rate of 5 mg/mL lactic acid was maintained at about 90% after 5 consecutive cycles. These data showed a huge potential for future real-time capturing lactic acid from fermentation, which also was a reference for other fermentation inhibited by product concentration.

Miniaturized 3D printed solid-phase extraction cartridges with integrated porous frits

Here we have studied the effect of the thickness and printing orientation using PolyJet 3D printing to fabricate single-material cartridges with built-in porous frits enabling solid-phase extraction (SPE) by packing commercial sorbents. This is achieved by tuning the degree of interpenetration of the building material and the water-soluble support material used in PolyJet 3D printing by modifying the orientation of the print head respective to the frit. SPE cartridges printed at an orientation of 30° with a 150 μm thick integrated frit were selected for the SPE experiments in a compromise between frit permeability to flow and stability to retain commercial sorbents for SPE.The performance of the 3D printed cartridges was evaluated for the SPE of the endocrine-disrupting phenols 4-tert-octylphenol (4-tOP) and 4-nonylphenol (4-NP), comparing three commercial SPE sorbents (Evolute Express ABN, Bond Elut PPL, and Silica-C18). The best overall extraction performance was obtained using Silica-C18, and the main extraction parameters were optimized. Detection limits of 0.3 μg L−1 for 4-tOP and 1.1 μg L−1 for 4-NP were achieved using HPLC-DAD for analyte separation and quantification. Enrichment factors of 30.1 (4-tOP) and 16.2 (4-NP) were obtained under the selected conditions. The developed method was applied to water and milk powder samples obtaining satisfactory recoveries ranging from 97% to 103%. These results demonstrate the suitability of PolyJet 3D printing for the fabrication of miniaturized cartridges with integrated frits for SPE applications.

Development trend and prospect of solid phase extraction technology

Solid phase extraction is widely used in sample pretreatment, concentration and analysis processes due to high selectivity and suitability for low concentration sample system. In this review, we systematically summarized and discussed the development trends of solid phase extraction by bibliometrics method. By analyzing papers output scale, the research and development direction of solid phase extraction technology is prospected. We also give an overview on current strategies of novel solid phase extraction from the separation medium and separation technology. The paper aims to describe the global research profile and the development trends of solid phase extraction, to help researchers to accurately grasp the research trend and to provide support for scientific research institutions to formulate scientific policies and strategic plans. Furthermore, the prospect of the development and application of solid phase extraction is also discussed.

Sample preparation and antibiotic quantification in vinasse generated from sugarcane ethanol fuel production

Vinasse - liquid organic residue derived from the production of sugarcane ethanol fuel, has been applied as soil amendment via fertigation for decades in Brazil. This organic residue is an important source of nutrients and water for sugarcane crops. Through fertigation, approximately 400 billion liters of vinasse are recycled annually. Despite the economic and agronomic importance of this practice, vinasse-based fertigation can be a source of antibiotic contamination in the environment. The present work reports the application of solid phase extraction (SPE), salting-out liquid-liquid extraction (SALLE), and on-line solid phase extraction (on-line SPE) as sample preparation techniques for the analysis of the following antibiotics (contaminants) in vinasse sample: monensin, penicillin G, virginiamycin M1, virginiamycin S1, tetracycline and erythromycin. The study also employed a totally automated quantitative method based on on-line SPE and liquid chromatography coupled to quadrupole linear ion trap tandem mass spectrometry (LC-QqLIT-MS/MS) for the analysis of these contaminants in vinasse. The application of the aforementioned sample preparation techniques led to the successful extraction of the analytes, and a comparative analysis of the techniques showed that the on-line SPE technique was the most advantageous among the techniques investigated. The quantitative analytical method applied yielded well-defined chromatographic peaks, working range of 1.0–370.0 ng·mL−1, apparent recovery ranging from 80 to 110% for most compounds, repeatability between 3 and 16%, and limits of detection ranging from1.0 to 10 ng·mL−1. The analysis of six vinasse samples from different ethanol producing plants led to the detection of monensin at the concentration of 14.3 ng·mL−1 in their compositions. The results obtained show that fertigation with vinasse is a source of antibiotic contamination in the environment.

Application of Solid Phase Extraction (SPE) Media Rods to Assess Degree of NAPL Encapsulation in In Situ Deposited NAPL Sediments

ABSTRACT Oil-particle aggregates (OPAs) develop from solid particles attaching to and/or penetrating into the surface of a non-aqueous phase liquid (NAPL) bead suspended in the water column. In situ deposited NAPL (IDN) sediments result from the deposition of OPAs on the sediment bed at the bottom of the water body. The extent of solid particle coverage on the surface of the oil bead defines the degree of encapsulation of the OPA (i.e., fully or partially encapsulated). Since important properties such as NAPL mobility and contaminant flux are controlled by the degree of OPA encapsulation, the ability to measure this physical property is critical in characterizing NAPL fate and transport in IDN sediments. This paper describes a semi-quantitative method to measure the degree of encapsulation within IDN sediment using the fluorescence response from rods coated with solid phase extraction (SPE) media. Specifically, Direct Analysis in Real Time (DART®) technology, which was developed and is distributed by Dakota Technologies, was applied to measure the amount of contact between the SPE material coated on a vertical rod and the PAHs contained in the NAPL found in the surrounding IDN sediment. Based on laboratory results in this paper, the magnitude of the fluorescence response correlates with the degree of encapsulation. For the single NAPL and various sediment combinations prepared in the laboratory for this study, fully (or nearly fully) encapsulated IDN sediments produced a DART® response below 15% reference emitter (%RE), a defined internal standard, whereas partially encapsulated IDN sediments produced a DART® response that was generally above 30%RE and as high as several thousand %RE. This difference in fluorescence response enables DART® technology to be applied as a line of evidence to determine the degree of NAPL encapsulation in an IDN sediment in field screening programs.

Application of Solid Phase Extraction and High-Performance Liquid Chromatography with Fluorescence Detection to Analyze Bisphenol A Bis (2,3-Dihydroxypropyl) Ether (BADGE 2H2O), Bisphenol F (BPF), and Bisphenol E (BPE) in Human Urine Samples.

In this study, we propose a simple, cost-effective, and sensitive high-performance liquid chromatography method with fluorescence detection (HPLC-FLD) for the simultaneous determination of the three bisphenols (BPs): bisphenol A bis (2,3-dihydroxypropyl) ether (BADGE 2H2O), bisphenol F (BPF), and bisphenol E (BPE) in human urine samples. The dispersive solid phase extraction (d-SPE) coupled with solid phase extraction (SPE) procedure performed well for the analytes with recoveries in the range of 74.3–86.5% and relative standard deviations (RSD%) less than 10%. The limits of quantification (LOQs) for all investigated analytes were in the range of 11.42–22.35 ng mL−1. The method was validated at three concentration levels (1 × LOQ, 1.5 × LOQ, and 3 LOQ). During the bisphenols HPLC-FLD analysis, from 6 min a reinforcement (10 or 12) was used, therefore analytes might be identified in the small volume human urine samples. The results demonstrated clearly that the approach developed provides reliable, simple, and rapid quantification and identification of three bisphenols in a urine matrix and could be used for monitoring these analytes.

Selective Recognition and Separation of Ubiquitin by Nanoparticle Embedded Cryogel Traps with Ubiquitin Memories Based on Photosensitive Covalent Imprinting

Recognition and determination of ubiquitin (Ubq) is very important since it affects the enzymatic mechanisms, which causes damages in the living organisms. This can lead to diseases especially in neuronal system. Molecularly imprinted polymers (MIPs) are selective resins that exhibit high affinity toward target compounds. MIPs have attracted significicant research interest because of their various applications in solid phase extraction, biosensors and drug delivery, etc. Various MIP types can be used such as thermo-sensitive, pH-sensitive, biomolecule-sensitive, ion-sensitive and photo-sensitive in these applications. Photosensitive MIPs can be used to increase the selectivity and binding efficiency to decrease denaturation of target biomolecules. The aim of this study is to prepare photosensitive cross-linked p(Ubq-co-MACys-Ru(bipyr)2-MACys) polymeric nanoparticles (UbqINPs) and leach with 0.5 M HCl to create Ubq memories onto nanoparticles (UbqINPs) and optimize their binding parameters in cryogel based column system. For this purpose, different factors such as pH, flow rate, ionic strength and temperature were investigated, and maximum ubiquitin binding capacity was found to be 25 mg/g at pH 7. The results showed that the UbqINPs can be considered as a good binding material for recognition and separation of Ubq.

Synthesis and characterization of α-mangostin imprinted polymers and its application for solid phase extraction

α-mangostin imprinted polymers have been synthesized by a non-covalent imprinting approach with α-mangostin as a template molecule. The α-mangostin molecularly imprinted polymers (MIPs) prepared by radical polymerization using methacrylic acid, ethlylene glycol dimethacrylate, benzoyl peroxide, and acetonitrile, as a monomer, crosslinker, initiator, and porogen, respectively. The template was removed by using methanol:acetic acid 90:10 (v/v). The physical characteristics of the polymers were investigated by Fourier Transform Infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The rebinding studies were carried out by batch methods. The results exhibited that the MIPs was able to adsorb the α-mangostin at pH 2 and the contact time of 180 min. The kinetic adsorption data of α-mangostin performed the pseudo-second order model and followed the Langmuir isotherm model with the adsorption capacity of 16.19 mg.g-1. MIPs applied as a sorbent material in solid-phase extraction, namely molecularly imprinted solid-phase extraction (MISPE) and it shows the ability for enrichment and clean-up of α-mangostin from the complex matrix in medicinal herbal product and crude extract of mangosteen (Garcinia mangostana L.) pericarp. Both samples, respectively, which were spiked with α-mangostin gives recovery more than 90% after through by MISPE in all concentration ranges.

SINTESIS DAN KARAKTERISASI MAGNETIT (Fe3O4): STUDI KOMPARASI METODE KONVENSIONAL DAN METODE SONOKIMIA

Magnetite (Fe 3 O 4 ) is one of the iron oxide compounds which has strong magnetic properties so that it is widely modified with other materials for application in solid phase extraction. This study aims to compare the physical and chemical properties of magnetite synthesized by conventional methods and magnetite synthesized by sonochemical methods. The physical and chemical properties of magnetite were studied using Fourier Transform Infrared (FTIR) and X-Ray Difraction spectrophotometry. Magnetite saturation magnetization (Ms) was measured using a Vibrating Sample Magnetometer (VSM). The results of FTIR characterization showed that the absorption at a wave number of 780 cm -1 was a typical absorption of magnetite Fe-O bonds both on magnetite synthesized through sonochemical and conventional methods. The difference in crystallinity of magnetite synthesized by the two methods was not significant. The Ms magnetite value synthesized by sonochemical method was higher than the Ms magnetite value synthesized by conventional method. Keywords: magnetite, Fe 3 O 4 , synthesis, conventional, sonochemical

Multidimensional separation schemes enhance the identification and molecular characterization of low molecular weight proteomes and short open reading frame-encoded peptides in top-down proteomics

Short open reading frame-encoded peptides (SEP) represent a widely undiscovered part of the proteome. The detailed analysis of SEP has, despite inherent limitations such as incomplete sequence coverage, challenges encountered with protein inference, the identification of posttranslational modifications and the assignment of potential N- and C-terminal truncations, predominantly been assessed using bottom-up proteomic workflows. The use of top-down based proteomic workflows is capable of providing an unparalleled level of characterization information, which is of increased importance in the case of alternatively encoded protein products. However, top-down based analysis is not without its own limitations, for which efficient separation prior to MS analysis is a major issue.We established a sample preparation approach for the combined bottom-up and top-down proteomic analysis of SEP. Key improvements were made by the application of solid phase extraction (SPE), which supported enrichment of proteins below ca. 20 kDa, followed by 2D-LC-MS top-down analysis encompassing both HCD and EThcD ion activation. Bottom-up experiments were used to support and confirm top-down data interpretation. This strategy allowed for the top-down characterization of 36 proteoforms mapping to 12 SEP from the archaeon Methanosarcina mazei strain Gö1, with the concurrent detection and identification of several posttranslational modifications in SEP. Biological significanceSmall or short open reading frames (sORF) have been widely neglected in genome research in the past. With their increasing discovery, the question about the presence and molecular function of their translation products, the short open reading frame-encoded peptides (SEP), arises. As these small proteins are usually below the 10 kDa range, the number of peptides identifiable by bottom-up proteomics is limited which hampers both the identification and the recognition of potential posttranslational modifications. The presented top-down approach allowed for the detection of full length SEP, as well as of terminally truncated proteoforms, and further enabled the identification of disulfide bonds in these small proteins. This demonstrates, that this yet widely undiscovered part of the proteome undergoes the same modifications as classical proteins which is an essential step for future understanding of the biological functions of these molecules.

Functionalization of Amberlite XAD-4 with 8-hydroxyquinoline chelator using aryldiazonium radical reaction and its application for solid phase extraction of trace metals from groundwater samples

<p>In this work, the aryldiazonium salts radical addition method has been used successfully to anchor 8-hydroxyquinoline (8-HQ) moieties onto the surface of Amberlite XAD-4 beads. The nitroaniline aryldiazonium salt was generated (in-situ) and covalently grafted onto Amberlite XAD-4 by aid of hypophosphorous acid as a catalyst to facilitate the anchorage of 8-HQ chelator making use of the conventional diazo coupling. The successfulness of the synthesized chelating resin was confirmed by (ATR-IR), (TGA) and (XPS). The risen was packed into cartridges and used with standard solid phase extraction (SPE) apparatus for the extraction of trace metals; Co (II), Ni (II) and Cu (II) from groundwater samples prior to their measurement by (ICP-MS). The resin exhibited more than 90% enhancement in capacity exchange relative to the plain Amberlite XAD-4. Under the optimum conditions the sorption capacity of the sorbent was 0.366, 0.265 and 0.328 (mM/g) for Co (II), Ni (II) and Cu (II) respectively. The sorbent showed efficient performance when applied for SPE of trace metals from groundwater real samples from AlMadinah AlMumnawarah, Saudi Arabia.</p>

Application of solid phase extraction (SPE) coupled to dispersive liquid–liquid micro-extraction (DLLME) and sensory evaluation technique for the study of taste and odor active compounds in water

Abstract Short-chain carbonyls could cause taste and odor issues in drinking water due to their very low odour threshold concentrations (OTCs). Several techniques such as 2,4-dinitrophenylhydrazine (DNPH) derivatization-HPLC and solid-phase micro-extraction (SPME) have been applied for trace short-chain aldehydes analysis in water. However, to study the taste and odor contributors in drinking water, it would be helpful to obtain an extract with representative odor from water samples for further studies, such as GC-olfactometry analysis or sensory test. Therefore, the above techniques still have some constraints due to the derivatization process or complex operating procedures. In this work, we developed a solid-phase extraction (SPE) coupled to dispersive liquid–liquid micro-extraction (DLLME) method to study short-chain aldehydes in ozonated water samples (LOQ = 1 ppb, RSD% = 12–45%). This method enables us to obtain an extract with representative odor from water for further volatile components analysis and sensory evaluation. Pair-wise nose clip sensory evaluation on the taste and odor of ozonated water indicated a high correlation between odor and taste of ozonated water. The SPE-DLLME method enabled a reliable study, for the first time, on correlations of volatile carbonyls and taste & odor performance for ozonated water by applying a series of statistical models.

A 3D-polyphenylalanine network inside porous alumina: Synthesis and characterization of an inorganic-organic composite membrane.

Surface functionalization of porous materials allows for the introduction of additional functionality coupled with high mechanical stability of functionalized inner pores. Herein, we investigate the surface-initiated ring-opening polymerization (SI-ROP) of phenylalanine-N-carboxyanhydride (PA-NCA) in porous alumina membranes (ALOX-membranes) with respect to different solvent mixtures (tetrahydrofuran (THF) and dichloromethane (DCM)). It was found that increasing the volume fraction of DCM leads to an increasing amount of fibrillar polymer structures within the porous ALOX-membrane. A three-dimensional fibrillar network with intrinsic porosity was formed in DCM, whereas in THF, a dense and smooth polypeptide film was observed. A post-treatment with a mixture of chloroform and dichloroacetic acid leads to rearrangement of the morphology of the grafted polymer films. The analysis by scanning electron microscopy (SEM), near-infrared spectroscopy (NIR) and contact angle measurements (CA) reveals a change in morphology of the grafted polymer films, which is due to the rearrangement of the secondary structure of the polypeptides. No significant loss of the surface-grafted polypeptides was determined by thermogravimetric (TG) measurements, which indicates that the change in morphology of the polymer films is solely a result of a conformational change of the surface-grafted polypeptides. Furthermore, adsorption of a test analyte (chloroanilic acid) was investigated with respect to different polymer functionalization schemes for reversed-phase solid phase extraction applications. The adsorption capability of the functionalized composite membrane was increased from 16.7% to 38.1% compared to the native ALOX-membrane.

Synthesis and structural properties of carbon/alumina composites: Practical application in solid phase extraction of explosives

Abstract Carbon-inorganic composites belong to group of modern nanomaterials possessing high potential in many applications. Such adsorbents combine characteristics of nonpolar carbon phase and polar inorganic matrix. Both porosity and texture of composites substantially depend on applied carbon precursor, inorganic component and pyrolysis conditions. Novel carbon/alumina composites were prepared using co-polymerization of resorcinol-formaldehyde polymer with fumed Al2O3 and subsequent pyrolysis of derived materials in inert atmosphere at 800 °C. Morphological and structural characteristics of as-obtained initial polymeric and carbon-inorganic nanocomposites were studied using powder X-ray diffraction, scanning electron microscopy, Raman spectroscopy, nitrogen adsorption methods, and temperature-programmed desorption mass spectrometry. The experimental results showed that filler Al2O3 acting as catalyst has significant influence on the resorcinol-formaldehyde polycondensation reaction and further pyrolysis step, therefore affects the structure of carbon-inorganic composites that is evidenced by the changes of specific surface area and porosity. It was shown that the porosity and texture of prepared composites substantially influenced the adsorption/desorption steps of explosives from aqueous samples. The results provide new ideas on the hybrid composites synthesis as well allow one to elucidate the effect of synthesis method on the structural characteristics of materials which can be used as high quality adsorbents in water treatment.

Multiresidue Determination of Endocrine Disrupting Compounds in Sewage Treatment Plants (SPE-HPLC-DAD)

This work focuses on the validation and application of solid phase extraction followed by high-performance liquid chromatography (SPE-HPLC) analysis of important endocrine disruptors compounds (EDC) from different classes in highly complex wastewater matrix. The endocrine disruptors investigated included three different categories: pharmaceuticals (sulfamethoxazole (SMZ), trimethoprim (TMP) and diclofenac (DCF)), hormones (estrone (E1), 17α-ethinylestradiol (EE2) and 17β-estradiol (E2)) and plastic materials (bisphenol A (BPA)). The method involves pre-concentration by SPE using Strata-X extraction cartridges followed by HPLC coupled with diode array detector (DAD). As the assumption of homoscedasticity was met for analytical data, ordinary linear regression procedure was applied to the data. The method was considered validated for 7 EDC after consistent evaluation of the key analytical parameters. Recoveries were ranged from 52.3 to 179.6%. Limits of quantification were in the range 6.0-0.4 µg L−1. The described method was applied to evaluate the occurrence and removal efficiency of EDC in two biological sewage treatment plants (STPs). The influent mean concentrations of E1, E2 and EE2 hormones were 79.54; 175.09 and 102.19 µg L−1, respectively, while for SMZ, TMP, DCF and BPA were 215.17; 187.01; 218.97 and 87.12 µg L−1 for STP A, respectively. The efficiencies for the removal of EDCs ranged from 0 to 79.4%.

Incorporating solid-phase extraction into compendial procedures for the determination of dexamethasone and impurities in low-dose drug products

A low-dose drug product is characterized by extremely low concentrations of analytes and a high ratio of excipients to the drug substance; the analysis of these drug products presents a number of analytical challenges for detection and quantitation, which in turn could impact potency, purity, and uniformity of the dosage units. In this work solid-phase extraction (SPE) was used to enrich analytes and minimize the interference of excipients, despite the fact that the application of SPE to pharmaceutical dosage forms is surprisingly uncommon. Specifically, in the development of compendial procedures for two dexamethasone (DEX) low-dose drug products, elixir 0.1 mg/mL and oral solution 0.1 mg/mL, a SPE protocol using Oasis HLB cartridges was developed for sample preconcentration and clean-up. The protocol was rigorously evaluated to ensure high recoveries and repeatability for DEX and its eight impurities (100 ± 2% and RSD ≤ 2.0% for DEX; 100 ± 5% and RSD ≤ 2.0% for impurities). In addition, Strata and Strata X cartridges were identified as an alternative cartridge for the elixir and oral solution, respectively. Furthermore, the extraction efficiency of the SPE protocol was evaluated by comparing the sample preparations with and without SPE using a regular-dose product (DEX Intensol oral solution 1 mg/mL). The SPE-based HPLC method was validated as an effective procedure for the determination of DEX and impurities in DEX elixir and oral solution. The case study demonstrated that incorporation of SPE into USP monographs could significantly strengthen compendial procedures for quality control.

Method development and application for triazine herbicides analysis in water, soil and sediment samples from KwaZulu-Natal

This study reports on the development and application of solid phase extraction (SPE) and ultrasonic extraction (UE) methods for the analysis of triazine herbicides in water, soil and sediment samples. The extraction parameters such as conditioning solvent, sample loading volume, eluting solvent, extraction time and sample mass were optimized due to their influence on the extraction efficiency of the analytes. To assess the applicability of the SPE and UE methods, spiked distilled water or soil samples were extracted and analyzed using an LC-PDA instrument. The recoveries obtained under optimum conditions were between 65–94% and 75–100% for SPE and UE, respectively. The relative standard deviations obtained were less than 0.36% for SPE and less than 4.6% for UE. The limit of detection (LOD) ranged from 0.026–0.084 µg/L for SPE and 0.0028–0.0083 mg/kg for UE. The limit of quantification (LOQ) was between 0.088–0.28 µg/L for SPE and 0.0089–0.028 mg/kg for UE. The concentrations of triazines were found to be between 0.96–7.4 µg/L and 0.79–15 µg/L in river water and wastewater effluent samples, respectively. In sediment samples, the triazine concentrations were found to be between 0.032–0.93 mg/kg, while in soil samples they were between 0.12–1.03 mg/kg.

A new hybrid sorbent 2,2’-pyridil functionalized SBA-15 (Pyl-SBA-15) synthesis and its applications in solid phase extraction of Cu(II) from water samples

A mesoporous hybrid material, 2,2’-Pyridil-SBA-15 (Pyl-SBA-15) was synthesized by anchoring 2,2’-Pyridil onto the surface of SBA-15. The application of Pyl-SBA-15 as a sorbent in separation and preconcentration of Cu(II) ions in water samples was studied. Effect of different parameters like pH, volume of eluent, sample flow rate and interfering ions was investigated. The preconcentration capacity value of the prepared material under optimized conditions for Cu(II) was 0.88 ± 0.01 mmol g−1. The Cu(II) ions collected onto the sorbent were eluted out with 6 mL of 1 M HNO3 and determined by atomic absorption spectroscopy (AAS). The enrichment factor and detection limit of Cu(II) were found to be 66.6 and 0.38 μg L-1 respectively.

Synthesis of silver nanoparticles by pistachio skin extract and its application for solid phase extraction of Bi(III) followed by electrothermal atomic absorption spectrometry

The aim of this paper is to synthesize of Ag-nanoparticles (Ag-NPs) by the pistachio skin extract followed by its application for preconcentration and measurement of ultra-trace levels of Bi(III) by electrothermal atomic absorption spectrometry. Pistachios skin extract was used as a green reducing agent to produce Ag-NPs from silver ion solution. The results of the FT-IR spectroscopy, UV–Vis spectrophotometry, Scanning electron microscopy, Transmission electron microscopy (TEM) and X-ray diffraction spectroscopy show that Ag-NPs with uniform size of 25–40 nm in diameter were synthesized successfully. In order to optimize different parameters affecting the extraction efficiency, Response surface methodology-Box Behnken optimization technique was used. Under the optimum conditions, the calibration curve was linear in the range of 0.5–8 µg L−1 of Bi(III) with a correlation coefficient of 0.9993. The relative standard deviation (%) was 3.5% for five replicate analysis of 1 µg L−1 Bi(III). Also, the limit of detection was 0.09 µg L−1 Bi(III), and the preconcentration factor calculated from the ratio of the volume of sample solution to the desorbent solvent volume after preconcentration step was 100. The accuracy of the method was evaluated by the analysis of certified reference material and spike methods. Finally, this technique was successfully applied for determination of ultra-trace levels of Bi(III) in water, food, human serum and hair samples.