Sorbent For Micro-solid Phase Extraction Research Articles

Hydrophobic melamine sponge incorporated with carbon dots as a green sorbent for micro-solid phase extraction of triazole fungicide residues in edible fungi samples

Fabrication of hydrophobic melamine sponge incorporated with carbon dots was investigated to extract triazoles prior to HPLC-DAD quantitation. The melamine sponge was simply incorporated with carbon dots via thermal treatment under facile conditions. The optimum conditions were melamine sponge (MeS) (1 × 1 × 1 cm3), 10 mL of standard solution, 0.04 M citric acid, functionalized at 250 °C for 5 h, and the analytes was then eluted from as-prepared material using acetonitrile (200 µL). Operating the best conditions, wide linearity was gained with R2 ≥ 0.99, for all analytes. Detection limits established varied between 3–10 μg L−1. Such approached method demonstrates excellent applicability for accurately and efficiently determining triazole fungicides in edible fungi samples, and a good recovery was also obtained. In addition, the desirable method validation and cost effective, not only its potential for reuse, but also provides it a better alternative for matrix purification. The appraisal estimated by two methods, confirmed its superior environmental friendliness.

Surfactant modified coconut husk fiber as a green alternative sorbent for micro-solid phase extraction of triazole fungicides at trace level in environmental water, soybean milk, fruit juice and alcoholic beverage samples.

In this work, micro-solid phase extraction using surfactant modified biosorbent was investigated for trace level determination of triazole fungicides prior to their analysis by high performance liquid chromatography. Coconut husk fiber (CHF) was selected as an effective biosorbent in the extraction process. Fourier transform infrared spectrometry, scanning electron microscopy and transmission electron microscopy methods were used to characterize the modified biosorbent. Various factors affecting the extraction efficiency of the proposed method were studied including the amount of coconut husk fiber biosorbent (0.1 g), kind and concentration of surfactant as a modifier (sodium dodecyl sulfate, 10 mmol L-1), kind and volume of desorption solvent (methanol, 150 μL), and extraction period (including vortex adsorption time, centrifugation adsorption time, vortex desorption time and centrifugation adsorption time approximately 10 min). Under the selected conditions, the calibration plot was found to be linear in the range of 9-300 μg L-1 with a coefficient for determination of greater than 0.99. The limits of detection and limits of quantification for the studied triazole fungicides were 3.00 and 9.00 μg L-1, respectively. Finally, the proposed method was successfully applied to determine triazole fungicides in environmental water, soybean milk, fruit juice and alcoholic beverage samples with acceptable recoveries obtained in the range of 67.0% to 105.0%.

Cellulose mini-membranes modified with TiO2 for separation, determination, and speciation of arsenates and selenites

Sorptive and selective mini-membranes based on TiO2 directly synthesized onto cellulose filters (TiO2@cellulose) have been developed. The in situ synthesis of TiO2@cellulose applied is simple and economically advantageous. The obtained membranes can be useful for (1) separating arsenic(V) and selenium(IV) from other ions and organic matter, (2) speciation of arsenic and selenium, and (3) determining ulratraces of these ions in water samples. The membranes exhibit good stability and high maximum adsorption capacities for Se(IV) (71 mg g−1) and As(V) (41 mg g−1). A monolayer chemical adsorption of analytes on the membranes was confirmed. The structure of membranes was examined with scanning electron microscopy, x-ray diffractometry, and micro energy-dispersive x-ray fluorescence spectrometry (μ-EDXRF). The membranes were characterized by homogenous distribution of TiO2 onto cellulose. The TiO2@cellulose was used as a new sorbent in micro-solid phase extraction for determination of Se(IV) and As(V) by EDXRF. Using direct analysis of mini-membranes after sorption of analytes avoids the elution step. Thus, the proposed procedure is an attractive and solvent-free option for quantitative monitoring of Se(IV) and As(V) in different materials. Both analytes were quantitatively and simultaneously separated/determined from samples at pH 2 with very good recovery (close to 100%), precision (4.5%), and detection limits (0.4 ng mL−1 Se and 0.25 ng mL−1 As). TiO2@cellulose membranes were applied to water analysis.Graphical-abstractEffective method for determination of ultra trace arsenates and selenites using cellulose-based sorbent

Alginate-Graphene Oxide Biocomposite Sorbent for Rapid and Selective Extraction of Non-Steroidal Anti-Inflammatory Drugs Using Micro-Solid Phase Extraction

In this work, a bio-composite sorbent, alginate incorporated graphene oxide (Alg/GO) is prepared for the micro solid phase extraction of non-steroidal anti-inflammatory drugs (NSAIDs) from water samples. The sorbent was prepared in a suspended solution form at a ratio of 0.3:1 (w/v %) of graphene oxide (GO) and alginate (Alg). The chemical structure, morphology and surface area of the composite beads were characterized using Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and Brunauer–Emmett–Teller (BET). GO showed good miscibility and well dispersion through intermolecular hydrogen bonds and electrostatic interactions within the Alg matrix. The synthesized sorbent was applied for the determination of the selected drugs in a tap water sample using micro-solid phase extraction technique and was analyzed by high-performance liquid chromatography-ultraviolet detector (HPLC-UV). The results showed good linearity in the range of 10–1000 µg L–1 with correlation coefficients (r ≥ 0.9979), low detection limits (LOD) between 3.1–4.6 µg L–1, excellent relative recoveries in the range of 99.6–102.1% and good reproducibility (RSD ≤ 3.9%). Thus, these validated results showed that Alg/GO could be potential and useful as a bio-composite sorbent for micro-solid phase extraction for the analysis of targeted drugs from aqueous matrices.

Covalent triazine-based framework for micro solid-phase extraction of parabens

Herein, nano-sized covalent triazine-based framework grafted magnetic particles were synthesized by a facile Friedel-Crafts reaction between cyanuric chloride as node and biphenyl as linker. The formation of the material has been confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, field emission-scanning electron microscopy, thermogravimetric analysis, and N2 adsorption-desorption measurement. With respect to the material structure, the large number of aromatic rings in the molecular framework provided a bed for extracting aromatic ring-containing compounds through π-π stacking interactions. The applicability of the prepared material as a new sorbent for micro solid-phase extraction of parabens was investigated. The effect of key experimental parameters affecting the extraction efficiency of the analytes including sorbent amount, sample pH, extraction time and desorption conditions were investigated. High-performance liquid chromatography with UV detection was used for determining the enriched analytes. The method was successfully applied for determining parabens in human urine, breast milk, personal care products, and shower wastewater. After optimization, the linearity range of 0.1–500 μg L−1 and detection limit of 0.02 μg L−1 were obtained for all the selected parabens. The relative standard deviations and recoveries for the real sample analysis were in the range of 2.3–5.0% and 86–102%, respectively.

Glycine modified graphene oxide as a novel sorbent for preconcentration of chromium, copper, and zinc ions from water samples prior to energy dispersive X-ray fluorescence spectrometric determination

A novel and selective sorbent for micro-solid phase extraction was synthesized by chemical functionalization of graphene oxide with glycine.

Application of surfactant-templated ordered mesoporous material as sorbent in micro-solid phase extraction followed by liquid chromatography–triple quadrupole mass spectrometry for determination of perfluorinated carboxylic acids in aqueous media

In the present study, micro-solid phase extraction (µ-SPE) followed by liquid chromatography–triple tandem mass spectrometery (LC–MS/MS) was developed for the determination of perfluorocarboxylic acids (PFCAs) at trace levels in water samples. The µ-SPE device comprised of a porous polypropylene membrane bag containing 5mg sorbent. The membrane bag acted as a clean-up filter and prevented matrix compounds from interfering with the extraction process. Analysis was carried out by LC–MS/MS in negative electrospray ionization mode. MS/MS parameters were optimized for multiple reaction monitoring. Calcined and non-calcined MCM-41, as silica-ordered mesoporous materials, were used as sorbents in µ-SPE for the extraction of five PFCAs—perfluoropentanoic acid (PFPA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA)—from aqueous media. The performances of these two sorbents were compared with other sorbents such as octadecylsilane (C18) modified silica, HayeSep-A, HayeSep-B, and Porapak-R. It was found that non-calcined MCM-41 showed better extraction performance for the analytes considered. Parameters influencing extraction efficiency, such as desorption time, extraction time, desorption solvent, and salt concentration, were investigated. The effect of the matrix on MS signals (suppression or enhancement) was also evaluated. Only minor effects on ionization efficiencies were observed. The developed method proved to be convenient and offered good sensitivity and reproducibility. The limits of detection ranged from 0.02 to 0.08ngL−1, with a relative standard deviations between 1.9 and 10.5. It was successfully applied to the extraction of PFCAs in river and rain water samples. As expected from the ubiquitous nature of PFCAs, contamination at low levels was detected for some analytes in the samples (with the highest concentration recorded for PFOA). Satisfactory relative recoveries ranging between 64% and 127% at spiking levels of 10ngL−1 of each analyte were obtained.

Molecularly imprinted polymer as sorbent in micro-solid phase extraction of ochratoxin A in coffee, grape juice and urine

A simple, environmental friendly and selective sample preparation technique employing porous membrane protected micro-solid phase extraction (μ-SPE) loaded with molecularly imprinted polymer (MIP) for the determination of ochratoxin A (OTA) is described. After the extraction, the analyte was desorbed using ultrasonication and was analyzed using high performance liquid chromatography. Under the optimized conditions, the detection limits of OTA for coffee, grape juice and urine were 0.06ngg−1, 0.02 and 0.02ngmL−1, respectively while the quantification limits were 0.19ngg−1, 0.06 and 0.08ngmL−1, respectively. The recoveries of OTA from coffee spiked at 1, 25 and 50ngg−1, grape juice and urine samples at 1, 25 and 50ngmL−1 ranged from 90.6 to 101.5%. The proposed method was applied to thirty-eight samples of coffee, grape juice and urine and the presence of OTA was found in eighteen samples. The levels found, however, were all below the legal limits.

Electrospun composite of polypyrrole-polyamide as a micro-solid phase extraction sorbent

A micro-solid phase extraction technique was developed using a novel polypyrrole-polyamide nanofiber sheet, fabricated by electrospinning method. The applicability of the new nanofiber sheet was examined as an extracting medium to isolate malathion as a model pesticide from aqueous samples. Solvent desorption was subsequently performed in a microvial, and an aliquot of extractant was injected into gas chromatography-mass spectrometry. Various parameters affecting the electrospinning process including monomer concentration, polyamide content, applied voltage, and electrospinning time were examined. After fabricating the most suitable preparation conditions, influential parameters on the extraction and desorption processes were optimized. The developed method proved to be rather convenient and offers sufficient sensitivity and good reproducibility. The limit of detection (S/N = 3) and limit of quantification (S/N = 10) of the method under optimized conditions were 50 and 100 ng L(-1), respectively. The relative standard deviation at concentration level of 1 ng mL(-1) was 2% (n = 3). The calibration curve of analyte showed linearity in the range of 0.1-1 ng mL(-1) (R (2) = 0.9975). The developed method was successfully applied to tap and Zayanderood river water samples, while the relative recovery percentages of 98% and 96% were obtained, respectively. The whole procedure showed to be conveniently applicable and quite easy to be manipulated.

Hybrid organic–inorganic silica monolith with hydrophobic/strong cation-exchange functional groups as a sorbent for micro-solid phase extraction

A hybrid organic–inorganic silica monolith with hydrophobic and strong cation-exchange functional groups was prepared and used as a sorbent for micro-solid phase extraction (micro-SPE). The hybrid silica monolith functionalized with octyl and thiol groups was conveniently synthesized by hydrolysis and polycondensation of a mixture of tetraethoxysilane (TEOS), n-octyltriethoxysilane (C8-TEOS) and 3-mercaptopropyltrimethoxysilane (MPTMS) via a two-step catalytic sol–gel process. Due to the favorable chemical reactivity of mercapto pendant moieties, the obtained hybrid monolith was oxidized using hydrogen peroxide (30%, w/w) to yield sulfonic acid groups, which provided strong cation-exchange sites. The obtained hybrid monolith was characterized by diffused infrared spectroscopy, elemental analysis, scanning electron microscopy and mercury intrusion porosimetry. The results show that the resulting monolith contains much higher carbon (31.6%) and sulfur (4.8%) contents than traditionally bonded silica materials. The extraction performance of the hybrid monolith was evaluated using sulfonamides as testing analytes by micro-SPE on-line coupled to HPLC. The results show that the hybrid monolith with hydrophobic and strong cation-exchange functional groups exhibits high extraction efficiency towards the testing analytes. The column-to-column RSD values were 1.3–9.8% for the extraction of SAs investigated. The extraction performance of the hybrid silica monolith remained practically unchanged after treated with acid (pH 1.0) and basic solutions (pH 10.5). Finally, the application of the hybrid monolith was demonstrated by micro-SPE of sulfonamide residues from milk followed by HPLC–UV analysis. The limits of detection (S/N = 3) for eight SAs were found to be 1.0–3.0 ng/mL in milk. The recoveries of eight SAs spiked in milk sample ranged from 80.2% to 115.6%, with relative standard deviations less than 11.8%.