Ultrasound-assisted Dispersive Solid-phase Research Articles

Are volatile methylsiloxanes in downcycled tire microplastics? Levels and human exposure estimation in synthetic turf football fields

Downcycled rubber, derived from end-of-life tires (ELTs), is frequently applied as crumb rubber (CR) as infill of synthetic turf in sports facilities. This practice has been questioned in recent years as numerous studies have reported the presence of potentially hazardous chemicals in this material. CR particles fall into the category of microplastics (MPs), making them possible vectors for emerging micropollutants. A preliminary study where volatile methylsiloxanes (VMSs) were found in CR originated the hypothesis that VMSs are present in this material worldwide. Consequently, the present work evaluates for the first time the levels and trends of seven VMSs in CR from synthetic turf football fields, while attempting to identify the main sources and impacts of these chemicals. A total of 135 CR samples and 12 other of alternative materials were analyzed, employing an ultrasound-assisted dispersive solid-phase extraction followed by gas chromatography–mass spectrometry (GC–MS), and the presence of VMSs was confirmed in all samples, in total concentrations ranging from 1.60 to 5089 ng.g−1. The levels were higher in commercial CR (before field application), a reflection of the use of VMS-containing additives in tire production and/or the degradation of silicone polymers employed in vehicles. The VMSs generally decreased over time on the turf, as expected given their volatile nature and the wearing of the material. Finally, the human exposure doses to VMSs in CR (by dermal absorption and ingestion) for people in contact with synthetic turf in football fields were negligible (maximum total exposure of 20.5 ng.kgBW−1.year−1) in comparison with the European Chemicals Agency (ECHA) reference doses: 1.35 × 109 ng.kgBW−1.year−1 for D4 and 1.83 × 109 ng.kgBW−1.year−1 for D5. Nevertheless, more knowledge on exposure through inhalation and the combined effects of all substances is necessary to provide further corroboration. This work proved the presence of VMSs in CR from ELTs, another family of chemical of concern to take into account when studying MPs as vectors of other contaminants.

Ultrasound-enhanced dispersive solid phase extraction of Cd (II), Co (II), and Ni (II) using magnetic Pinus pinea

A new ultrasound assisted dispersive solid phase extraction (DSPE) technique has been combined with flame atomic absorption spectrometry (FAAS) to enable the simultaneous preconcentration, determination and removal of cadmium, cobalt and nickel ions from aqueous samples. In this procedure, a magnetic Pinus pinea bio-adsorbent was synthesized and used as bio-adsorbent. The parameters such as solution pH, ultrasound time, analyte concentration and interfering ions were successfully optimized. All three metal ions were extracted within a mere 120 s at pH 6 and the extraction recovery values of the all three analytes were quantitative (˃95%) under the optimal conditions. The adsorption processes of the metal ions were analyzed and adsorption of the metal ions were identified by Energy Dispersive X-Ray Mapping technique. A certified reference material was analyzed for the accuracy of the method. Finally, the developed method was applied for preconcentration and determination of the analytes in real water samples including natural spring water, natural mineral water and factory process water.

One-pot/one-step synthesis of Bi2O3/ZnO/Pd nanocomposite for preconcentration and determination of some heavy metal ions in different samples

ABSTRACT In this contribution, a new green eco-friendly synthesised nanocomposite (Bi2O3/ZnO/Pd) was fabricated by one-pot/one-step method, using ultrasonic waves. The nanocomposite was used for pre-concentration of some heavy metals, i.e. cadmium (II), lead (II), and copper (II), exploiting ultrasound-assisted dispersive micro solid phase extraction (UA-D-μ-SPE) method, before their determination by flame atomic absorption spectroscopy (FAAS). The adsorbent synthesis was confirmed by XRD, SEM, BET, TEM, EDS, and TGA analyses. The central composite design (CCD) method was employed to optimise various parameters affecting the extraction of heavy metals. The effective parameters in the adsorption process, viz. the amount of adsorbent (16 mg), pH of the sample solution (6.2), and adsorption time (4 min), were optimised. The type and the concentration of eluting agent (HCl solution) was investigated as one parameter at a time. Impressive parameters in the desorption stage such as the volume and concentration of eluting solution (400 μL of 0.8 mol L−1 HCl) and desorption time (2.5 min) were optimised. In the best extraction conditions for cadmium (II), lead (II), and copper (II), the limits of detection (LODs) were 0.75, 2.1, and 0.90 ng mL−1; the limits of quantification (LOQs) were 2.5, 7.0, and 3.0 ng mL−1; the linear dynamic ranges (LDRs) were 2.5–100, 7.0–600, and 3.0–250 ng mL−1; preconcentration factors (PF) were 24.10, 25.20, and 25.39; and the relative standard deviations (RSDs%) were 3.7, 4.1, and 3.8 (n = 5), respectively. Additionally, the adsorbent had the ability to extract metals up to 8 times without a significant decrease in the extraction percentages. The adsorbent was successfully used in the determination of cadmium (II), lead (II), and copper (II) ions in different food, biological, cosmetic, and water samples.

Development of microextraction methods for the determination of sulfamethoxazole in water and biological samples: modelling, optimization and verification by central composite design

This study aimed to preconcentration of sulfamethoxazole (SMX) in water and biological samples. Ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) and ultrasound-assisted dispersive solid-phase microextraction (UA-DSPME) methods paired with spectrophotometry were applied to extraction and preconcentration of SMX. ZnFe2O4 nanoparticles were prepared as adsorbent in UA-DSPME method by hydrothermal method. The scanning electron microscopy (SEM) technique showed that the adsorbent had symmetrical, bullet-shaped particles with uniform size. The results of the X-ray diffraction (XRD) showed the successful synthesis of the ZnFe2O4 nanoparticles. Effective parameters in extraction, including ultrasonication time, disperser solvent volume, adsorbent amount, extraction solvent volume, eluent volume, and pH were investigated and optimized. The practical and optimal conditions of the process were determined by the central composite design (CCD). The optimal conditions were 0.024 g of adsorbent, 535 µL of disperser solvent volume, 7.5 min of ultrasonication time, 235 µL of eluent volume, pH of 5, and 185 µL of extraction solvent volume. Linear ranges and detection limits were 20–1,200 μg L−1 and 6 μg L−1 for UA-DSPME and 10–800 μg L−1 and 3 μg L−1 for UA-DLLME. Relative standard deviation (RSD) of less than 4% were obtained for UA-DSPME and UA-DLLME methods. The reusability showed that the ZnFe2O4 adsorbent could extract SMX up to five cycles of adsorption/desorption without significant reduction in its efficiency. Also, interference studies showed that the presence of different cations and anions did not significantly interfere in the extraction of SMX. The outcomes of real-time samples analysis showed that the extraction of SMX for both methods was in the range of 92.44%–99.12%. The results showed the developed methods are simple, sensitive, and suitable for SMX preconcentration in environmental water and biological samples.

Ultrasound-assisted dispersive magnetic solid phase extraction using toner powder for the separation and preconcentration of cobalt in water and food samples and determination by flame atomic absorption spectrometer

In this study, ultrasound-assisted dispersive magnetic solid phase extraction using toner powder (inexpensive and accessible magnetic sorbent) combined with flame atomic absorption spectrophotometry has been developed for the analysis of cobalt (II) in water and food samples. The influence of parameters (amount of toner powder, sample pH, the concentration of the complexing agent, eluent type and volume, and adsorption time) were studied as a function of the extraction recovery. The proposed method, which has been analytically characterized under its optimum operating conditions, allows the detection of cobalt (II) in the samples with method detection limits of 0.7 μg L−1. The method repeatability, expressed as the relative standard deviation (n = 10, Co2+= 50.0 μg L−1), was 3.1%, while the preconcentration factor was 50. Cobalt(II) was determined in water samples (tap water, river water, mineral water, seawater) and food samples (cabbage and cucumber) with good recoveries (96.0–104.0%) using the proposed method.

Ultrasound-assisted dispersive solid-phase extraction for the preconcentration of dyes in water samples

In this research, the magnesium ferrite/zinc oxide (MgFe2O4/ZnO) nanocomposite has been utilized as an effective adsorbent in the ultrasound-assisted dispersive solid-phase extraction (USA-DSPE) coupled to a spectrophotometric method for preconcentration of methylene blue (MB) and safranin O (SO) dyes. X-Ray diffraction (XRD), vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FESEM) analyses were performed to characterize and confirm the properties of the synthesized MgFe2O4/ZnO nanocomposite. Box-Behnken design (BBD) based on response surface methodology (RSM) was utilized to optimize the variables. The results of this research showed that the maximum extraction efficiency was obtained at pH = 7, eluent volume of 140 µL, adsorbent amount of 1.53 mg, and ultrasonic time of 8 min. After optimization by RSM and using the Quadratic model, the extraction efficiency for MB and SO was 98.60% and 97.23%, respectively. The analysis of variance (ANOVA) showed that the data obtained from the experiment were consistent with the predicted model. Under optimal conditions, the calibration curve was linear in the range of 5–1000 µg/L (coefficient of determination of 0.9884) for MB and 10–1100 µg/L (coefficient of determination of 0.9973) for SO. The limit of detections (LOD) of the proposed method for MB and SO were determined as 1.5 µg/L and 3 µg/L, respectively. The relative standard deviations (RSD, n = 5) for MB and SO were obtained as 1.1% and 2.1%, respectively. The results of adsorbent recovery revealed that MgFe2O4/ZnO nanocomposite could be used several times without a significant adsorbent efficiency loss. Furthermore, the findings of interference studies revealed that the presence of different ions does not cause substantial interference with the extraction of dyes. The environmental water samples analysis showed that the extraction efficiency for dyes was in the range of 93.74–99.11%.

Ultrasound assisted dispersive solid phase microextraction using polystyrene-polyoleic acid graft copolymer for determination of Sb(III) in various bottled beverages by HGAAS

A new polyoleic acid-polystyrene (PoleS) block/graft copolymer was synthesized and applied as adsorbent for ultrasound assisted dispersive solid phase microextraction (UA-DSPME) of Sb(III) in different bottled beverages and analysis using hydride generation atomic absorption spectrometry (HGAAS). Adsorption capacity of the PoleS was 150 mg g−1. Several sample preparation parameters such as sorbent amount, solvent type, pH, sample volume and shaking time were optimized (based on central composite design (CCD) approach) and evaluated in respect to the recovery of Sb(III). The method revealed a high tolerance limit of matrix ions presence. Under optimized conditions, linearity range, the limit of detection, the limit of quantitation, extraction recovery, enhancement factor, preconcentration factor were 5–800 ng L−1, 1.5 ng L−1, 5.0 ng L−1, 96%, 82, 90, respectively. Accuracy of the UA-DSPME method was confirmed based on different certified reference materials and standard addition method. Factorial design was utilized to estimate the influences of variables of recovery of Sb(III).

Magnesium ferrite as a dispersive solid-phase extraction sorbent for the determination of organic pollutants using spectrophotometry

This study aimed to determine of malachite green (MG) and auramine O (AO) dyes in different environmental water samples. For this purpose, MG and AO dyes were pre-concentrated by ultrasound-assisted dispersive solid-phase extraction (UA-DSPE) and measured by spectrophotometry. Magnesium ferrite (MgFO) was applied as a magnetic adsorbent in the UA-DSPE-UV/Vis method. The effect of different parameters on the dye extraction efficiency, including pH of the solution, sorbent mass, sample volume, ultrasound frequencies, irradiation time, and type and volume of eluent, were investigated. In addition, response surface methodology (RSM) approach-based central composite design (CCD) was used to design and optimize parameters affecting the process. Analysis of variance (ANOVA) results based on high F-values, low p-values, coefficient of determination (R2 > 0.99), and adjusted-R2 (R2adj > 0.99) revealed that the quadratic model was the best model for defining the interaction of the studied variables. The calibration curve, the limit of detection (LOD), and relative standard deviation (RSD, n = 5) for MG and AO dyes were 1–800 ng mL−1 and 3–1200 ng mL−1, 0.33 ng mL−1 and 1 ng mL−1, and 3.2% and 2.8%, respectively. The effect of some external species (including cations and anions) on the determination of MG and AO dye was investigated. The results revealed that adding different ions does not significantly interfere with determining MG and AO dyes. The reusability of the MgFO adsorbent showed that it could be reused for up to 7 cycles, maintaining its high efficiency in the extraction of MG and AO dyes. Moreover, the proposed method was used for the extraction of MG and AO dyes from different water samples. The obtained extraction efficiency was in the range of 95.37–99.54%.

An immobilization of aminopropyl trimethoxysilane-phenanthrene carbaldehyde on graphene oxide for toluene extraction and separation in water samples

A new functionalized Nano graphene with aminopropyl trimethoxysilane-phenanthrene-4-carbaldehyde (NGO@APTMS-PNTCA) as a novel adsorbent was used to extract toluene from water samples by the ultrasound-assisted dispersive solid-phase microextraction procedure (USA-D-SPME). So, 50 mg of NGO@APTMS-PNTCA adsorbent was added to water samples and sonicated for 20 min. After toluene extraction, the NGO@APTMS-PNTCA adsorbent separated from the liquid phase with a Whatman membrane filter (200 nm). Then, the toluene was back-extracted from the adsorbent by 2.0 mL of the acetone/ethanol (1:1, eluent) at 25 °C. Due to the physical properties and structure of toluene, fluorobenzene was used as an internal standard. Finally, the toluene values were measured by a gas chromatography-flame ionization detector (GC-FID). In optimized conditions, the limit of detection (LOD), the working range (WR), and the enrichment factor (EF) were obtained at 2.5 μg L−1, 0.01–1.2 mg L−1, and 9.63, respectively (MRSD% = 3.38). Also, the limit of quantification (LOQ) 10 μg L−1 and extraction recovery of more than 95% was efficiently achieved for toluene. Standard additions of toluene to blank solutions had high recoveries between 95.2% and 104.5% with a relative standard deviation (RSD%) of 0.27–5.2. The absorption capacities of NGO and NGO@APTMS-PNTCA adsorbents for toluene extraction were obtained at 32.8 mg g−1 and 154.9 mg g−1, respectively. The USA-D-SPME method was validated by spiking the standard concentrations of toluene. The proposed method demonstrated relevant and suitable statistical results with high accuracy and precision for toluene extraction by a novel adsorbent synthesis.

Nanostructured magnetic graphene oxide/UIO-66 sorbent for ultrasound-assisted dispersive solid-phase microextraction of food colorants in soft drinks, candies, and pastilles prior to HPLC analysis

Direct quantitative determination of food colorants in commercial food products is challenging due to their trace concentration. In this work, the magnetic graphene oxide/UIO-66 sorbent was used in an ultrasound-assisted dispersive solid-phase micro-extraction (UA-DSPME) process for the pre-concentration of Tartrazine (TA), Sunset Yellow (SY), and Allura Red (AR) food colorants prior to their quantitative determination using high-performance liquid chromatography (HPLC) analysis. Plackett-Burman design (PBD) was used to statistically explore all extract independent variables, and response surface methodology (RSM) was used to optimize the key variables. Under ideal circumstances, the method showed superior analytical performance with limits of detection (LOD) less than 0.070, 0.281, and 0.150 ng mL−1, and limits of quantitation (LOQ) less than 2.318, 9.368, and 4.988 ng mL−1 for TA, SY, and AR colorants, respectively. Furthermore, the procedure was effectively implemented with an extraction time of 15 min per sample with recoveries ranging from 95.01 to 106.33 %. Analysis of the standard reference material and recovery trials (>95 % relative recovery with lower than 6 % relative standard deviations) after spiking a known quantity of analyte in actual samples were used to evaluate the developed method's accuracy. The current method's distinctive benefits include minimal extraction time, high recovery, acceptable limit of detection, high accuracy, and good reusability in the development of pre-concentration and quantitative measurement of food colorants at trace levels in commercial food items.

Cellulose-based nanocomposite for ultrasonic assisted dispersive solid phase microextraction of triazole fungicides from water, fruits, and vegetables samples

Herein, an ultrasound-assisted dispersive solid phase microextraction (UA-DSPME) approach has been described for trace level analysis of triazole fungicides in real samples. For this purpose, a new nanosorbent was prepared through modification of carboxymethylcellulose biopolymer with zinc-based metal–organic framework and graphene oxide, and fully characterized. Then, the effect of extraction parameters on extraction efficiency was optimized for the microextraction process. Finally, desorbed triazole fungicides with ethanol were determined using gas chromatography equipped with flame ionization detector. This technique provided good linearity (R2 > 0.99), low detection limits (0.3–1.5 ng mL−1), high preconcentration factors (419–426), good relative recoveries (91.6–102 %), and high repeatability (RSD < 4.1 %) at optimized conditions (amount of sorbent: 15 mg; pH of solution: 7.0; and extraction time; 4 min). Ultimately, this approach was applied to determine triazole fungicides in different water and food samples.

Effect of Storage Temperature and Time on Biogenic Amines in Canned Seafood.

Biogenic amines in canned seafood are associated with food quality and human health. In this study, a total of nine biogenic amines (histamine (HIS), phenylethylamine (PHE), tyramine (TYM), putrescine (PUT), cadaverine (CAD), tryptamine (TRY), spermine (SPM), spermidine (SPD), and octopamine (OCT)) were used as standards. The biogenic amines of five canned seafood species (canned mud carp, canned sardine, canned mantis shrimp, canned scallop, and canned oyster) were investigated every three months for 12 months at different storage temperatures (4, 10, 25, and 30 °C). The biogenic amine contents were determined by the ultrasound-assisted dispersive solid-phase extraction method combined with reversed-phase high-performance liquid chromatography-photodiode array detection (UADSPE-RPLC-PDA). These results showed a detection rate of 100, 60, and 40% for HIS, PHE, PUT, and TYM; CAD, SPM, and SPD; OCT in all the samples, respectively. The contents of histamine and tyramine exceeded the recommended maximum limits (50 and 100 mg kg−1) in the canned mud carp and canned scallop when stored at 30 °C, indicating their potential health risks (p < 0.05). This result also indicates that low temperatures could inhibit the BAs content of canned seafood during storage. Overall, storage temperature and time can be used as the primary means to monitor and control the quality and safety of canned seafood.

Ultrasound assisted dispersive solid-phase extraction coupled with high-performance liquid chromatography-diode array detector for determination of caffeine and carbamazepine in environmental samples using exfoliated graphite/chitosan hydrogel

Ultrasound assisted dispersive solid-phase extraction coupled with high-performance liquid chromatography-diode array detector for determination of caffeine and carbamazepine in environmental samples using exfoliated graphite/chitosan hydrogel

Covalent organic framework as adsorbent for ultrasound-assisted dispersive (micro)solid phase extraction of polycyclic synthetic fragrances from seawater followed by fluorescent determination

In this work, a new analytical approach based on ultrasound-assisted dispersive (micro)solid phase extraction (US-D-μSPE) using TpBD-Me2 covalent organic framework (COF) as adsorbent for simple, rapid and selective fluorescent determination of two polycyclic synthetic fragrances in seawater, i.e., 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta-(γ)-2-benzopyran (HHCB), branded galaxolide®, and 7-acetyl-1,1,3,4,4,6-hexamethyltetralin (AHTN), branded tonalide®, is proposed. Different parameters involved in both adsorption and desorption steps were optimized in order to obtain the best results. High adsorption efficiencies in the range of 91.2–97.8% were achieved for both analytes. Desorption efficiencies of ∼98% for AHTN and HHCB were obtained using methanol as solvent, rendering the material recyclable with merely minor losses in adsorption efficiency after five consecutive cycles of adsorption/desorption. Limits of detection (LODs) were 0.082 μg L−1 and 0.070 μg L−1 for AHTN and HHCB, respectively. The proposed method was successfully applied for the analysis of seawater without the need for a previous sample treatment, e.g., pH adjustment. Recoveries in the range of 90.4–101.2% with a relative standard deviation of 5.8% were obtained for both fragrances. The results proved the great capacity of TpBD-Me2 COF for the selective sorption of polycyclic fragrances in combination with fluorescent detection, being highly promising for application to environmental monitoring of other emerging organic pollutants.

Ultrasound-assisted dispersive solid phase extraction for promoting enrichment of ng L−1 level Hg2+ on ionic liquid coated magnetic materials

Herein, we investigated the enrichment behavior of inorganic mercury (Hg2+) on magnetic adsorbent with different ultrasound (US) energy field input. The enrichment rate of 0.10 μg L−1 mercury is increased by 4.5 times after US instead of stirring as dispersion mode. The input of higher frequency and power ultrasound can accelerate the enrichment of magnetic ionic liquid adsorbent and reduce the Hg2+ residue, importantly, which has not been reported. The positive correlation between cavitation effect and acoustic frequency and power in imaging experiments documents that US parameters are the key factors affecting the magnetic solid phase extraction. In addition, in-situ desorption and detection of adsorbate and recovery of adsorbent can be realized by slurry vapor generation (SVG) technology. The recovery of Hg2+ in four cycles is more than 90%, which indicates that the structure and properties of the material are not affected by the application of US. Hence, the degradation of adsorption properties caused by agglomeration of magnetic materials can be improved by introducing dispersion methods such as US. At the same time, 95% enrichment efficiency and 0.01–1.0 μg L−1 linear calibration range corresponding to 150 mL sample documents that magnetic ionic liquid adsorbent combined with US and sensitive spectral detector can meet the needs of ng L−1 level Hg2+ analysis in natural water samples.

Synthesis and Characterization of Poly(pyrrole-1-carboxylic acid) for Preconcentration and Determination of Rare Earth Elements and Heavy Metals in Water Matrices.

Pyrrole was N-functionalized with solid carbon dioxide followed by chemical polymerization to create a new air-stable, granular, and water-insoluble sorbent, poly(pyrrole-1-carboxylic acid) (PPy-CO2). PPy-CO2 exhibited enhanced affinity for the sorption of metal ions compared to unfunctionalized PPy due to the incorporation of carboxylate functional groups directly onto the polymer backbone. As a freestanding sorbent material, immobilization to an additional solid support is not needed. Sorption, and therefore preconcentration, occurs simultaneously to achieve efficient removal and recovery of metal ions by a pH-dependent sorption-desorption mechanism. PPy-CO2 was evaluated on the analytical scale for the solid-phase extraction of a range of metal ions and found to efficiently preconcentrate rare earth elements (REEs), Th, and heavy metals (Cr, Fe, Cd, and Pb), which allowed quantitation by inductively coupled plasma mass spectrometry (ICP-MS). The impact of sorption parameters, such as solution pH, amount of sorbent, and sorption time, and the effect of desorption flow rate for recovery were investigated and optimized using ultrasound-assisted dispersive solid-phase extraction (UAD-SPE) with ICP-MS analysis. Maximum efficiency for sorption and recovery of most metal ions was achieved at a solution pH of 6.0, 10 mg of sorbent, a sorption time of 5 min, and desorption conditions of 1 mL of 2 M nitric acid applied at a flow rate of 0.25 mL min-1. Detection limits for REEs and Th ranged from 0.2-3.4 ng L-1 for REEs and Th and 0.9-5.7 ng L-1 for heavy metals. Linear ranges from 0.1-1000 μg L-1 for REEs and 0.1-500 μg L-1 for heavy metals and Th were also observed. PPy-CO2 successfully preconcentrated and facilitated the determination of the targeted metal ions in water matrices of varying complexity, including tap water, well water, river water, and produced water samples. These results indicate the potential application of PPy-CO2 for larger-scale recovery and removal of valuable or hazardous metal ions.

Multi-ion imprinted polymers (MIIPs) for simultaneous extraction and preconcentration of Sb(III), Te(IV), Pb(II) and Cd(II) ions from drinking water sources

Simultaneous extraction and preconcentration of several potentially toxic metal ions have received great attention because of their toxicological effects on aquatic life and human beings. Multi-ion imprinted polymers (MIIP) have proved to be promising adsorbents with excellent specific recognition performance than single-ion imprinted polymer. Therefore, in this study, the MIIP strategy was employed for simultaneous extraction and enrichment of Sb(III), Cd(II), Pb(II) and Te(IV) ions from drinking water sources. MIIPs was used as a sorbent material in ultrasound-assisted dispersive solid phase extraction combined with inductively coupled plasma optical emission spectrometry (UA-DSPE/ICP-OES). The experimental parameters that affect the extraction efficiency and recovery of Sb(III), Cd(II), Pb(II) and Te(IV) were investigated using response surface methodology. Under optimum conditions, the enhancement factors, linear range, limit of detection (LOD) and limit of quantification (LOQ) were 37.7–51.1, 0.04–100 µg L-1, 0.011–0.28 µg L-1, 0.037–093 µg L-1, respectively. The intra-day (n = 10) and inter-day (n = 5) precision expressed as relative standard deviations (%RSDs,) were 3% and 5%, respectively. The proposed UA-DSPE/ICP-OES method was applied for preconcentration and determination of the trace metal ions in environmental samples. Furthermore, the accuracy of the method was evaluated using spiked recovery experiments and the percentage recoveries ranged from 95% to 99.3%.

Development of ultrasound assisted dispersive micro solid phase extraction based on CuO nanoplate-polyaniline composite as a new sorbent for insecticides analysis in wheat samples

A simple, fast and highly sensitive preconcentration method based on dispersive micro-solid phase extraction (D-µSPE) was developed using CuO nano plate-polyaniline composite (CNPC). The method was applied for the determination of diazinon and imidacloprid insecticides followed by high performance liquid chromatography (HPLC) analysis. The sorbent was characterized by scanning electron microscopy (SEM), Fourier transform- infrared (FT-IR) and x-ray detection (XRD). Experimental design was applied for optimization of the effective parameters on the extraction efficiency such as sample pH, extraction and desorption times, ionic strength and eluent volume. Optimized conditions were obtained as sample pH of 8.0, 100 µl of eluent, adsorption and desorption times of 12.5 and 23 min, respectively and 30% (w/v) of NaCl when 11 mg of the sorbent was applied. The adsorption isotherms were investigated for diazinon and imidacloprid and the results showed better fitness with the Langmuir model. The adsorption capacity of CNPC for diazinon and imidacloprid were calculated 12.18 and 2.58 mg g−1, respectively. Under the optimized conditions, limits of detection of 3 and 0.056 µg Kg−1 and relative standard deviations of 1.7% and 3.7% were obtained for diazinon and imidacloprid, respectively. Relative recoveries up to 99% were achieved indicating good adsorption efficiency of the sorbent. Finally, the developed method was successfully applied for the determination of trace amount of the target analytes in grain samples.

Fabrication of ZIF-71/Fe3O4/polythionine nanoarray-functionalized carbon cotton cloth for simultaneous extraction and quantitation of febuxostat and diclofenac

A sustainable hybrid material based on carbonized cotton cloth/zeolite imidazolate framework-71/Fe3O4/polythionine (CC/ZIF-71/Fe3O4/PTh) was synthesized and applied in ultrasound-assisted dispersive magnetic solid-phase extraction (USA-DMSPE) followed with high performance liquid chromatography-ultraviolet detection (HPLC-UV) for simultaneous quantitation of diclofenac (DIC) and febuxostat (FEB) in human plasma. The surface of CC was modified with nanoarrays of zeolite imidazolate framework-71/Fe3O4/Polythionine. At first, an in situ synthesis of ZIF-71 in the presence of CC was carried out, and followed with magnetization process and oxidative polymerization of thionine. The nano-modifier agents improved the merits of the sorbent involving stability, porosity, mast transfer, π–π interactions and selectivity of CC. Characterizations of the hybrid sorbent were examined with different instrumental techniques. The limits of detection (LODs, S/N = 3) were recognized 2.1 ng mL−1 for DIC and 3.7 ng mL−1 for FEB. Acceptable linearity (0.992 ≤ r2 ≤0.996) and relatively broad dynamic ranges of 10.0–1800.0 ng mL−1 and 15.0–2500.0 ng mL−1 were achieved for DIC and FEB, respectively. Reasonable intra-assay (≤7.2%, n = 9) and inter-assay (≤7.5%, n = 9) precisions as well as appropriate accuracies (≤8.0%) were provided illustrating applicability of the current approach for analytical purposes. Eventually, CC/ZIF-71/Fe3O4/PTh was employed as four-part sorbent for the assessment of DIC and FEB in human plasma at trace levels and subsequently main pharmacokinetic data such as T1/2, Tmax,Cmax, and AUC0–24 of these drugs were comprehensively investigated.

Reduced Graphene Oxide-Cadmium Sulfide Quantum Dots Nanocomposite Based Dispersive Solid Phase Microextraction for Ultra-Trace Determination of Carbamazepine and Phenobarbital

This research presents a fast, sensitive, and selective ultrasound-assisted dispersive solid phase microextraction technique for simultaneous preconcentration and determination of ultra-trace amount of carbamazepine and phenobarbital. Reduced graphene oxide sheets decorated with cadmium sulfide quantum dots was synthesized, characterized, and used as a high capacity adsorbent. A high performance liquid chromatography with UV detector (HPLC-UV) instrument with 58:42 composition of methanol:acetic acid/acetate buffer (pH = 5; 0.05 mol L-1) as the mobile phase and set on the wavelength of 230 nm was used to separate and quantify the analytes. In this regard, different parameters affecting adsorption and desorption of the analytes on the surface of the nanocomposite were studied and optimized to maximize the efficiency of the method. The method was linear in the ranges of 0.5-180 and 0.5-140 ng mL−1 (correlation coefficient (r) &gt; 0.999) with limits of detection of 0.19 and 0.24 ng mL−1 for carbamazepine and phenobarbital, respectively. Eventually, to evaluate the efficiency of the proposed method for the determination of pharmaceuticals in biological samples, different real samples including breast milk, urine and human plasma were tested. Obtained recoveries values were within the range of 96.3 ± 2 to 103.7 ± 3.3% which showed satisfactory efficiency.