Magnetic dispersive micro-solid phase extraction with the CuO/ZnO@Fe3O4-CNTs nanocomposite sorbent for the rapid pre-concentration of chlorogenic acid in the medical extract of plants, food, and water samples.

Herein, the CuO/ZnO@Fe3O4-carbon nanotubes (CNTs)-nanocomposite (NC), as a sorbent for magnetic dispersive micro-solid phase extraction, was developed for the determination of chlorogenic acid (CGA) in the medical extract of plants, food, and water samples in combination with high-performance liquid chromatography. The CuO/ZnO@Fe3O4-CNTs-NC was characterized by FESEM, EDS, XRD, TEM, BET, FT-IR, and VSM. Significant parameters (pH, temperature, eluent volume, vortex time, sonication time, CuO/ZnO@Fe3O4-CNTs-NC mass, and desorption time) that affected the extraction efficiency of CGA were optimized using Plackett-Burman as the screening design and the central composite design as the optimization strategy. Under the optimized conditions, the analytical parameters were obtained. The optimized method showed good linearity and a linear regression coefficient >0.9893. The enrichment factors ranged from 102.43 to 123.76 with the preconcentration factor of 60.0. The limits of detection (LOD) and the limits of quantification (LOQ) were 0.034-0.061 ng mL-1 and 0.114-0.202 ng mL-1, respectively. The method also reflected acceptable accuracy (from 94.07% to 109.7%) and the broad potential applications of CuO/ZnO@Fe3O4-CNTs-NC for the detection of CGA content in the medical extract of plants, food, and water samples.

Dispersive micro-solid phase extraction based on Fe3O4@SiO2@Ti-MOF as a magnetic nanocomposite sorbent for the trace analysis of caffeic acid in the medical extracts of plants and water samples prior to HPLC-UV analysis.

In the present work, a simple and rapid method, namely magnetic dispersive micro-solid phase extraction (MD-µ-SPE), was developed using magnetic Fe3O4@SiO2@Ti-MOF (metal-organic framework)-nanocomposites (NCs) as a viable and efficient sorbent to pre-concentrate and assess caffeic acid (CA) in the medical extracts of plants and water samples. The Fe3O4@SiO2@Ti-MOF-NCs were characterized by various techniques, including FESEM, EDX, FTIR, BET, XRD and VSM. Following the extraction process, HPLC was employed to quantify CA. The effects of different parameters on the MD-µ-SPE method were fully investigated by the Plackett-Burman (PBD) and central composite design (CCD). The highest extraction percentage (99.76%) was obtained under different conditions: pH 4.8, 9 mg of Fe3O4@SiO2@Ti-MOF-NCs, sonication for 5 min, and an eluent solvent of 240 µL. Under optimum conditions, the limits of detection (LODs) and the limits of quantitation (LOQs) were obtained in the range of 0.016-0.021 ng mL-1 and 0.052-0.068 ng mL-1, respectively. The reproducibility and repeatability (RSDs, n = 5) were in the range of 3.65-8.66% and 1.84-5.54%, respectively. Overall, the proposed method was successfully used to determine CA in the medical extracts of plants and water samples with favorable recoveries.

Magnetic nanofluid based on hydrophobic deep eutectic solvent for efficient and rapid enrichment and subsequent determination of cinnamic acid in juice samples: Vortex-assisted liquid-phase microextraction.

A quick, environmentally friendly and easy approach for the determination of cinnamic acid in juice samples based on the creation and usage of a novel magnetic nanofluid (mixture of hydrophobic deep eutectic solvent and magnetic nanoparticles) has been reported. Response surface methodology was applied to justify the contribution of the efficient factors including pH, nanofluid volume, ionic strength and vortex time. Cinnamic acid concentrations were monitored and quantified based on their HPLC peak representing linear correlations under the best operational circumstances showing linearity between 3 and 550 ng mL-1. The LOD, LOQ, and enrichment factor for cinnamic acid were 0.8 ng mL-1, 2.7 ng mL-1 and 57.2, respectively. The proposed method was used for enrichment and subsequent determination of cinnamic acid from juice samples which suggests a potential alternative approach for cinnamic acid analysis in complicated food samples.

A new microfluidic-chip device followed by sensitive image analysis of smart phone for simultaneous determination of dyes with different acidic-basic properties.

In this study, a new microfluidic-chip coupled with micro solid phase extraction (µ-SPE) and a RGB detection system was designed. The method was used for extraction and simultaneous determination of trace amounts of dyes with different acidic-basic properties. Erythrosine (Ery) and Crystal Violet (CV) were selected as acidic and basic model analytes, respectively. The first step of this method is based on the on-chip electromembrane extraction (CEME) of analytes from aqueous solution. The utilized microfluidic system is a single compartment that composed of three polymethyl metacrylate plates (with sandwiched structures) patterned with palm shaped helix channels. The device consisted one pair of platinum electrodes that were embedded in the acceptor phase channels in each side. The middle part was cut and used as the path of the sample. The extracted analytes by CEME were passed through the micro-packed column containing strong cation and anion exchanger sorbents respectively. Two adsorbents were separated by a polypropylene frit and sealed on each side by two polypropylene frites. Following dye adsorption on the sorbents, the colors that emerged were promptly evaluated using RGB colorimetry on a smartphone. Central composite design was used to analyze and optimize the effective parameters on extraction efficiency. The relative standard deviations (RSDs%) based on five replicate measurements were less than 7.8% for RGB and 8.6% for the spectrophotometry technique under ideal conditions. Image analysis using a smartphone yielded LOD values of 15.0 and 10.5 µg L-1 for Ery and CV, respectively. The CEME- µ-SPE -RGB approach produced findings that were equivalent to those obtained by spectrophotometry. Finally, the approach was used to accurately determine Ery and CV in water samples, yielding good relative recoveries (recovery ≥94.0).

Highly selective magnetic dual template molecularly imprinted polymer for simultaneous enrichment of sulfadiazine and sulfathiazole from milk samples based on syringe-to-syringe magnetic solid-phase microextraction.

Antibiotics, such as sulfadiazine and sulfathiazole, are widely used in veterinary applications which can result in remains in edible animal products. Therefore, there is an immense need for a reliable, selective, sensitive, and simple analytical technique for monitoring the concentration of sulfadiazine (SDZ) and sulfathiazole (STZ) in edible animal products. In this regard, we developed a magnetic dual template molecularly imprinted polymer (MMIP) to determine the SDZ and STZ in milk samples. For the sensitive and selective extraction and determination of target analytes, MMIPs have been combined with the syringe-to-syringe magnetic solid-phase microextraction (SS-MSPME) method. In addition, we used central composite design (CCD) for the extraction of SDZ and STZ. With optimum conditions, an efficient, rapid, and convenient technique for the preconcentration and determination of SDZ and STZ in milk samples by SS-MSPME coupling with HPLC-UV was developed. Using our combined approach, the limits of detection are 0.9 and 1.3 ng mL-1 for SDZ and STZ, respectively, along with good linearity and determination coefficients higher than 0.98. Our method demonstrates a practical approach for the deduction of antibiotics in milk samples with high recoveries and selectivity.

Simultaneous selective enrichment of methylparaben, propylparaben, and butylparaben from cosmetics samples based on syringe-to-syringe magnetic fluid phase microextraction.

Present work is the preparation of novel magnetic nanofluids based on deep eutectic solvent and used for the rapid microextraction of methylparaben (MP), propylparaben (PP), and butylparaben (BP) from cosmetics samples using syringe-to-syringe dispersive magnetic nanofluid microextraction procedure (SS-DMNF-ME). The optimization of the extraction of MP, PP, and BP was performed through central composite design (CCD). The optimum extraction conditions were assessed by optimizing pH, nanofluid volume, NaCl concentration, cycle number, and methanol volume. pH 8.0, 200 µL of magnetic nanofluid, 6% w/v of NaCl, eight cycles of injection/back injection, and 80 µL of methanol were the optimum extraction conditions, with the maximum recoveries of 98.62%, 100.92%, and 99.13% for MP, PP, and BP, respectively. The figures of merit calculated under the optimum condition were achieved from the CCD, and the developed method exhibited the low limits of quantitation (4.3, 3.0, and 2.7 ng mL-1) and detection (1.3, 0.9, and 0.8 ng mL-1) for MP, PP, and BP, respectively, as well as excellent linearity with R2 > 0.99. The relative recoveries of three parabens in the actual samples were 85.99-99.07% with relative standard deviations ≤5.52%. In comparison to other extraction methods, SS-DMNF-ME was readily and rapidly determined MP, PP, and BP using HPLC-UV, and experimental data showed the efficiency, robustness, and reliability of the proposed method.

A new approach for microextraction of trace albendazole sulfoxide drug from the samples of human plasma and urine, and water by the molecularly imprinted polymer nanoparticles combined with HPLC.

In this research study, a method of dispersive-micro-solid phase extraction (D-µ-SPE) combined with molecularly imprinted polymer nanoparticles (MIP-NPs) with HPLC-UV was developed for the fast and selective detection of the trace amount of albendazole sulfoxide (ABZSO) in the biological samples. To investigate the effective factors on ABZSO microextraction by the method, central composite design (CCD) was utilized, and the optimum conditions for ABZSO microextraction were sample pH of 8.0, MIP-mass of 15 mg, sonication time of 12 min, and eluent (methanol) volume of 0.25 mL. Under the obtained optimal extraction conditions, the value for the limit of detection (LOD) and limit of quantification (LOQ) was respectively showed to be 0.074 and 0.246 ng mL-1. In addition, the calculated peak areas exhibited a linear relationship with the ABZSO concentration ranging from 0.4 to 4200 ng mL-1. The analyses of the samples including human plasma and urine, and water were successfully performed by the usage of the D-µ-SPE method, which was a simple and sensitive technique and a suitable alternative for the analysis of ABZSO. In the analysis of ABZSO in various samples, the recoveries at various levels of ABZSO concentrations (50, 300, and 500 ng mL-1) were in the range of 95.7-103.0 %, and the relative standard deviations (RSDs; n = 3) varied from 2.2 to 4.4%.

Biocompatible chitosan-zinc oxide nanocomposite based dispersive micro-solid phase extraction coupled with HPLC-UV for the determination of rosmarinic acid in the extracts of medical plants and water sample.

In the present research, a procedure was described for the recovery of rosmarinic acid (RA) from medical extract samples using chitosan­zinc oxide nanoparticles as a biocompatible nanocomposite (CS-ZnO-NC). The dispersive micro-solid phase extraction (D-µ-SPE) of RA from the medical extract samples was investigated by using the prepared biocompatible composite as a solid phase. The HPLC-UV method was used for measuring the extracted RA. The important variables (pH, biocompatible composite mass, contact time, and volume of eluent) associated with the extraction process were analyzed by the application of central composite design (CCD). The achieved optimum values for the mentioned variables were 7.0, 10 mg, 4 min, and 180 µL, respectively. The extraction recovery (99.68%) obtained from the predicted model was in agreement with the experimental data (98.22 ± 1.33%). In addition, under the obtained optimum conditions and over the concentration in the range of 2-3500 ng mL-1, a linear calibration curve was obtained with R2 > 0.993. The limit of detection (LOD) and quantification (LOQ) values were computed, and the obtained ranges were respectively from 0.060 to 0.089 ng mL-1 and 0.201 to 0.297 ng mL-1. In addition, the enrichment factors were obtained in the range of 93.7-110.5 with preconcentration factor of 83.3. Therefore, the D-µ-SPE-HPLC-UV method could be used for analyzing RA in the samples of the extracts obtained from the medical plants and water with the recovery values of the analyte in the range of 96.6%-105.4% and the precision with relative standard deviation <5.7%.

A ferrofluidic hydrophobic deep eutectic solvent for the extraction of doxycycline from urine, blood plasma and milk samples prior to its determination by high-performance liquid chromatography-ultraviolet.

The ferrofluid phase was prepared according to mixing magnetic nanoparticle and the hydrophobic deep eutectic solvent as a green microextraction solvent. This new composite was applied for vortex-assisted dispersive liquid-liquid microextraction (VA-HDES-ferrofluid-DLLME) of doxycycline (DOC) residual extraction and determined through high-performance liquid chromatography-ultraviolet (HPLC-UV). The characterization of magnetic nanoparticle was investigated by XRD, TEM and FESEM. The dependency of DOC microextraction to main variables and their interaction and find optimum points were undertaken using response surface methodology with either central composite design (CCD). Thus, the optimum pH, ionic strength, ferrofluid volume and vortex time for DOC extraction are determined to be 3.0, 4%w/v, 150 µL and 7 min, respectively. According to this condition, linear response is found to be greater than 10-400 ng mL-1, with a correlation coefficient of 0.983. The detection and quantification limits are 3.6 and 8.5 ng mL-1, while the repeatability and reproducibility as precision criteria (RSD%) are 3.74% and 4.15%, respectively. The DOC recoveries in all of the urine, blood plasma and milk samples are between 86.70 and 97.48%, with RSD% lower than 5.72%.

Magnetic dual-template molecularly imprinted polymer based on syringe-to-syringe magnetic solid-phase microextraction for selective enrichment of p-Coumaric acid and ferulic acid from pomegranate, grape, and orange samples.

Magnetic dual-template molecularly imprinted polymer (Fe3O4@SiO2-MDMIP) was prepared to enrich and determine both p-Coumaric acid (p-CA) and ferulic acid (FA) based on syringe-to-syringe magnetic solid-phase microextraction (SS-MSPME). The obtained MDMIP was characterized and recognized, and then its adsorbing performance was studied. Based on the results, the Fe3O4@SiO2-MDMIP indicated selective recognition towards p-CA and FA with large adsorption capacity. The optimization of MDMIP-SS-MSPME conditions (pH, Fe3O4@SiO2-MDMIP mass, NaCl concentration, number of cycle, and elution volume) were conducted using the central composite design (CCD). Under the optimum conditions, an effectual and a convenient method was established to determine p-CA and FA in pomegranate, grapes, and orange samples based on SS-MSPME coupling with high-performance liquid chromatography-ultraviolet (HPLC-UV). Our developed method showed the limit of detection (LOD) of 0.08 ng mL-1 for p-CA and 0.07 ng mL-1 for FA. The method also indicated good linearity with R2 > 0.99 and good recoveries of 85.12-94.96% with RSDs ≤ 5.58% spiked at three various concentration levels in pomegranate, grapes, and orange samples.

Synthesis and application of Ce-doped TiO2 nanoparticles loaded on activated carbon for ultrasound-assisted adsorption of Basic Red 46 dye.

Ce was doped on TiO2 nanoparticles (NPs), and this association was loaded on activated carbon (Ce-TiO2-NPs-AC). The characterization was completed by FE-SEM, TEM, and XRD, and finally these NPs were used for the ultrasonic-assisted adsorption of Basic Red 46 (BR 46) from aqueous solution. An experimental model suggested by the central composite design (CCD)-as a branch of response surface methodology (RSM)-provides insight into the influence of variables, such as BR 46 concentration, pH, adsorbent mass, and sonication time, on BR 46 removal. Experimental results revealed that setting conditions at 25 mg L-1 of BR 46, pH 5.0, 0.02 g of Ce-TiO2-NPs-AC and 4 min sonication resulted in a high coefficient of determination (R2 > 0.99) and low probability values. The difference in the values is likely due to the accumulation of more than 99% of BR 46, while equilibrium data described by Langmuir isotherm model with a high adsorption capacity of 58.61 mg g-1 and adsorption process were successfully correlated with pseudo-second-order kinetics model.

Optimization of process parameters for determination of trace Hazardous dyes from industrial wastewaters based on nanostructures materials under ultrasound energy.

In this study, ultrasound-assisted dispersive solid phase micro-extraction based on nanosorbent namely silver-zinc oxide nanoparticles loaded on activated carbon (Ag-ZnO-NP-AC) combined with derivative spectrophotometry method for the simultaneous pre-concentration and determination of Methyl Green (MG) and Rose Bengal (RB) dyes in water and industrial wastewater. Characterized sorbent by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), particle-size distribution (PSD), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD) and Transmission electron microscopy (TEM) analysis with superior adsorption capacity was applied in ultrasound assisted dispersive-solid-phase micro-extraction (UA-DSPME) methodology. pH, sorbent mass, ultrasonication time, and eluent volume influence and contribution on response correspond to simultaneous pre-concentration and determination of MG and RB were optimized by response surface methodology (RSM) and results were compared with the experimental values. Under the optimal conditions (UA-DSPME), the enrichment factors (EFs) were 93.89 and 97.33 for the MG and RB dyes, respectively. The limits of detection were 2.14 and 2.73ngmL-1 and the limit of quantification were 7.15 and 9.09ngmL-1 for MG and RB, respectively. The analytes can be determined over 10-2000ngmL-1 with recoveries between 90.8% to 97.7% and RSDs less than 3.6%. The developed method due to simplicity and rapidity is able successful for repeatable and accurate monitoring of under study analytes from complicated matrices.

Investigate the ultrasound energy assisted adsorption mechanism of nickel(II) ions onto modified magnetic cobalt ferrite nanoparticles: Multivariate optimization.

In present study, magnetic cobalt ferrite nanoparticles modified with (E)-N-(2-nitrobenzylidene)-2-(2-(2-nitrophenyl)imidazolidine-1-yl) ethaneamine (CoFe2O4-NPs-NBNPIEA) was synthesized and applied as novel adsorbent for ultrasound energy assisted adsorption of nickel(II) ions (Ni2+) from aqueous solution. The prepared adsorbent characterized by Fourier transforms infrared spectroscopy (FT-IR), transmission electron microscope (TEM), vibrating sample magnetometer (VSM) and X-ray diffraction (XRD). The dependency of adsorption percentage to variables such as pH, initial Ni2+ ions concentration, adsorbent mass and ultrasound time were studied with response surface methodology (RSM) by considering the desirable functions. The quadratic model between the dependent and independent variables was built. The proposed method showed good agreement between the experimental data and predictive value, and it has been successfully employed to adsorption of Ni2+ ions from aqueous solution. Subsequently, the experimental equilibrium data at different concentration of Ni2+ ions and 10mg amount of adsorbent mass was fitted to conventional isotherm models like Langmuir, Freundlich, Tempkin, Dubinin-Radushkevich and it was revealed that the Langmuir is best model for explanation of behavior of experimental data. In addition, conventional kinetic models such as pseudo-first and second-order, Elovich and intraparticle diffusion were applied and it was seen that pseudo-second-order equation is suitable to fit the experimental data.

Optimization and modeling of preconcentration and determination of dyes based on ultrasound assisted-dispersive liquid-liquid microextraction coupled with derivative spectrophotometry.

Present study is based on describing an ultrasound-assisted dispersive liquid-liquid microextraction coupled with derivative spectrophotometry (UAS-DLLME-UV-vis) as useful technique for selective determination of crystal violet (CV) and azure b (Az-B). The significant factors like pH, extractor volume, disperser value and extraction time contribution and their numerical coefficient in quadratic model were calculated according to central composite design (CCD). According to desirability function (DF) as good criterion the best experimental conditions was adjusted and selected at pH of 7.0, 170µL of chloroform, 800µL of ethanol that strongly mixed with the aqueous phase via 4min sonication. Additionally, under study system was modeled by trained artificial neural networks (ANNs) as fitness function with acceptable error of MSE 2.97×10-06 and 1.15×10-05 with R2: 0.9999 and 0.9997 for CV and Az-B, respectively. The optimum conditions by using genetic algorithm (GA) method was pH of 6.3, 160µL of chloroform, 740µL of ethanol and 4.5min sonication. Under above specified and optimize conditions, the predicted extraction percentage were 99.80 and 102.20% for CV and Az-B, respectively. The present UAS-DLLME-UV-vis procedure has minimum interference from other substances assign to the matrix, which candidate this method as good alternative to quantify under study dyes content with recoveries in the range of 86-100% for dyes. The detection limits were 2.043ngmL-1 and 1.72ngmL-1, and limits of quantitation were 6.81ngmL-1 and 5.727ngmL-1 for CV and Az-B, respectively. The proposed methodology was successfully applied for quantification of under study analytes at different media.

Comparison between dispersive solid-phase and dispersive liquid-liquid microextraction combined with spectrophotometric determination of malachite green in water samples based on ultrasound-assisted and preconcentration under multi-variable experimental design optimization.

The ultrasound-assisted dispersive solid-phase microextraction (USA-DSPME) and the ultrasound-assisted dispersive liquid-liquid microextraction (USA-DLLME) developed for as an ultra preconcentration and/or technique for the determination of malachite green (MG) in water samples. Central composite design based on analysis of variance and desirability function guide finding best operational conditions and represent dependency of response to variables viz. volume of extraction, eluent and disperser solvent, pH, adsorbent mass and ultrasonication time has significant influence on methods efficiency. Optimum conditions was set for USA-DSPME as: 1mg CNTs/Zn:ZnO@Ni2P-NCs; 4min sonication time and 130µL eluent at pH 6.0. Meanwhile optimum point for USA-DLLME conditions were fixed at pH 6.0; 4min sonication time and 130, 650µL and 10mL of extraction solvent (CHCl3), disperser solvent (ethanol) and sample volume, respectively. Under the above specified best operational conditions, the enrichment factors for the USA-DSPME and USA-DLLME were 88.89 and 147.30, respectively. The methods has linear response in the range of 20.0 to 4000.0ngmL-1 with the correlation coefficients (r) between 0.9980 to 0.9995, while its reasonable detection limits viz. 1.386 to 2.348ngmL-1 and good relative standard deviations varied from 1.1% to 2.8% (n=10) candidate this method for successful monitoring of analyte from various media. The relative recoveries of the MG dye from water samples at spiking level of 500ngmL-1 were in the range between 94.50% and 98.86%. The proposed methods has been successfully applied to the analysis of the MG dye in water samples, and a satisfactory result was obtained.

Ultrasound assisted extraction of Maxilon Red GRL dye from water samples using cobalt ferrite nanoparticles loaded on activated carbon as sorbent: Optimization and modeling.

In this research, a selective, simple and rapid ultrasound assisted dispersive solid-phase micro-microextraction (UA-DSPME) was developed using cobalt ferrite nanoparticles loaded on activated carbon (CoFe2O4-NPs-AC) as an efficient sorbent for the preconcentration and determination of Maxilon Red GRL (MR-GRL) dye. The properties of sorbent are characterized by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Vibrating sample magnetometers (VSM), Fourier transform infrared spectroscopy (FTIR), Particle size distribution (PSD) and Scanning Electron Microscope (SEM) techniques. The factors affecting on the determination of MR-GRL dye were investigated and optimized by central composite design (CCD) and artificial neural networks based on genetic algorithm (ANN-GA). CCD and ANN-GA were used for optimization. Using ANN-GA, optimum conditions were set at 6.70, 1.2mg, 5.5min and 174µL for pH, sorbent amount, sonication time and volume of eluent, respectively. Under the optimized conditions obtained from ANN-GA, the method exhibited a linear dynamic range of 30-3000ngmL-1 with a detection limit of 5.70ngmL-1. The preconcentration factor and enrichment factor were 57.47 and 93.54, respectively with relative standard deviations (RSDs) less than 4.0% (N=6). The interference effect of some ions and dyes was also investigated and the results show a good selectivity for this method. Finally, the method was successfully applied to the preconcentration and determination of Maxilon Red GRL in water and wastewater samples.