Magnetic Dispersive Micro-solid Phase Extraction Research Articles

Integration of Magnetic Dispersive Solid-Phase Micro-extraction with HPLC for Precise Detection of Tumor Markers 1-Methyladenosine and 1-Methylinosine in Urine Samples from Breast Cancer Patients

Integration of Magnetic Dispersive Solid-Phase Micro-extraction with HPLC for Precise Detection of Tumor Markers 1-Methyladenosine and 1-Methylinosine in Urine Samples from Breast Cancer Patients

Application of magnetic nanoparticles modified with poly(8-hydroxyquinoline) as a nanosorbent for magnetic dispersive micro-solid phase extraction of copper in vegetable, water, and soil samples

In this study, a novel nanosorbent, namely F3O4@SiO2 modified with poly(8-hydroxyquinoline) (Fe3O4@SiO2@PHQ), was synthesized and employed for magnetic dispersive micro-solid phase extraction of Cu(II) followed by flame atomic absorption spectrometry detection in water, vegetables, and soil samples. This nanosorbent was characterized using FT-IR, XRD, VSM, FE-SEM, and EDS. To attain the best extraction recovery, effective parameters were studied and optimized. Under the optimal experimental conditions, the extraction recovery was 92%. The limits of detection and quantification were determined to be 0.64ngmL-1 and 2.13ngmL-1, respectively. The preconcentration factor was 92, and relative standard deviations for intra-day and inter-day measurements were 1.6%, and 2.5%, respectively. The linearity ranged from 2 to 200ngmL−1 with an R2 value greater than 0.998 and relative recoveries in the range of 90% to 96% in real sample analysis.

A novel deep eutectic solvent modified magnetic covalent organic framework for the selective separation and determination of trace copper ion in medicinal plants and environmental samples

BackgroundPretreatment techniques should be introduced before metal ion determination because there is very low content of heavy metals in Chinese medicinal plants and environmental samples. Magnetic dispersive micro solid phase extraction (MDMSPE) has been widely used for the separation and adsorption of heavy metal pollutants in medicinal plants and environmental samples. However, the majority of MDMSPE adsorbents have certain drawbacks, including low selectivity, poor anti-interference ability, and small adsorption capacity. Therefore, modifying currently available adsorption materials has gained attention in research. ResultsIn this study, a novel adsorbent MCOF-DES based on a magnetic covalent organic framework (MCOF) modified by a new deep eutectic solvent (DES) was synthesized for the first time and used as an adsorbent of MDMSPE. The MDMSPE was combined with inductively coupled plasma optical emission spectrometry (ICP-OES) for selective separation, enrichment, and accurate determination of trace copper ion (Cu2+) in medicinal plants and environmental samples. Various characterization results show the successful preparation of new MCOF-DES. Under the optimal conditions, the enrichment factor (EF) of Cu2+ was 30, the limit of detection (LOD) was 0.16 μg L−1, and the limit of quantitation (LOQ) was 0.54 μg L−1. The results for the determination of Cu2+ were highly consistent with those of inductively coupled plasma mass spectrometry (ICP-MS), which verified the accuracy and reliability of the method. SignificanceThe established method based on a new adsorption material MCOF-DES has achieved the selective separation and determination of trace Cu2+ in medicinal and edible homologous medicinal materials (Phyllanthus emblica Linn.) and environmental samples (soil and water), which provides a promising, selective, and sensitive approach for the determination of trace Cu2+ in other real samples.

Fe3O4-SiO2-MIL-53 (Fe) nanocomposite for magnetic dispersive micro-solid phase extraction of cadmium (II) at trace levels prior to HR-CS-FAAS detection.

A magnetic metal-organic framework Fe3O4-SiO2-MIL-53 (Fe) nanocomposite was synthesized for magnetic dispersion micro-solid phase extraction (M-d-µSPE) of cadmium in water, spice, chocolate, tea, and tobacco samples prior to the detection by flame atomic absorption spectrometry. Fe3O4-SiO2-MIL-53 (Fe) nanocomposite fabricated using the solvothermal technique was characterized using a field emission scanning electron microscope and X-ray diffraction. The extraction efficiency of the method was improved by optimizing the experimental factors. After optimization, the linearity range for Cd (II) was 4.3-500µgL-1. The limits of detection and quantification were 1.3 and 4.3µgL-1, respectively. The presented magnetic dispersion-micro solid phase extraction method was applied to Cd (II) analysis in food and some environmental samples.

Efficient extraction of heavy metals from aqueous environments using magnetic effervescent Tablet-Assisted ionic Liquid-Based dispersive Solid-Phase microextraction

In this study, we successfully developed an effervescent tablet-assisted dispersive solid-phase microextraction approach using sulfanilic acid-modified magnetic graphene oxide (MGO@SA-DSPM) for the efficient removal of heavy metals (Pb(II), Cd(II), Zn(II), and Cr(II)). The study systematically investigated the impact of different variables on the extraction efficiency of heavy metals. Results demonstrated that the MGO@SA nanocomposite exhibited superior extraction yields for all four metals, with recovery rates of 100.6 % for Cd(II), 103.6 % for Zn(II), 99.39 % for Cr(III), and 87.08 % for Pb(II), surpassing those of the MGO composite (81.08 % for Cd(II), 101.5 % for Zn(II), 54.35 % for Cr(III), and 80.48 % for Pb(II)). The enhanced extraction efficiencies due to the introduction of additional functional moieties, such as sulphonyl (-SO3-) and amid (NH-CO) moieties, onto the surface of MGO through its modification with SA. This led to a significantly improved extraction process. Under optimized conditions, the MGO@SA-DSPM method achieved low limits of detection (LOD) ranging from 0.204 to 299 μg/L, and limits of quantification (LOQ) between 0.68 and 0.99 μg/L, along with satisfactory extraction recoveries (87.08 % − 103.6 %) and relative standard deviations of 1.36–1.99 % for all four heavy metals. In summary, the proposed MGO@SA-DSPM approach demonstrates promising potential for routine water quality monitoring.

A sustainable magnetic γ-Fe2O3@Escherichia coli (E. coli) bio-sorbent for determination trace amounts of thymol in pharmaceutical, food and cosmetic samples

Due to the need for environmentally friendly technologies, using microorganisms such as bacteria as a biosorbent for the solid phase extraction (SPE) technique has paid attention. These biosorbents have advantages, such as good performance, abundance and accessibility, operation over a wide range of environmental conditions, regeneration, and not producing secondary contaminations. This study examines a biotechnological application using Escherichia coli (E. coli), as a highly efficient adsorbent for separation, preconcentration, and determination of thymol. The E. coli was immobilized to γ-Fe2O3 magnetic nanoparticles, as a solid-phase biosorbent, for magnetic dispersive micro-solid phase extraction (MDμ-SPE) to provide an efficient and rapid recovery after the sorption process. Characterization of the prepared biosorbent was carried out using the Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscope (FE-SEM), and vibrating sample magnetometer (VSM). The MDμ-SPE as a green and sensitive method proposed for the separation and determination of trace quantities of thymol. Some experimental factors, such as sample pH, amount of sorbent, adsorption time, and temperature affecting the MDμ-SPE efficiency, were tested by the experimental design method. Under optimal conditions, linear range, detection limit, and the relative standard deviation for extraction and preconcentration of thymol were obtained; 30–500, 9.1 ng mL−1, and 1.4 %, respectively. Finally, the proposed method was successfully applied to the preconcentration and determination of target analyte in pharmaceutical, food, and cosmetic samples.

Determination of organochlorine pesticides from juice samples using magnetic biochar-based dispersive micro-solid phase extraction in combination with dispersive liquid-liquid microextraction

Analysis of pesticide residue levels in juice beverages is important to ensure safe consumption and avoid global trade concerns associated to pesticide contaminations. A simple, inexpensive and effective method was developed for the determination of organochlorine pesticides (OCPs) in bottled juice drinks using GC-MS. Sample pretreatment was performed using dispersive solid-phase microextraction (D-μ-SPE) for matrix desorption and dispersive liquid-liquid microextraction (DLLME) for analyte enrichment. In this study, an affordable and effective sorbent for the adsorption of OCPs from juice samples was synthesized from avocado seeds mixed with magnetic precursors for D-μSPE. The ground avocado seeds combined with a magnetic precursor nanocomposite were characterized using various instruments including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) analysis. The solution obtained from D-μ-SPE desorption was used as a dispersant for the subsequent DLLME, which made the combination of D-μ-SPE with DLLME much easier. The effectiveness of the method was enhanced by optimizing the influential parameters in both D-μ-SPE and DLLME. Then after, the optimal values were determined for the real sample analysis. Accordingly, there was good linear dynamic range with a coefficient of determination (r2) ≥ 0.9989. The limit of detection and quantification were 0.02–0.69 and 0.06–2.10 ng/L respectively. The method showed high enrichment factors ranging from 96 to 313 with recoveries of 87–100 %. Intraday and interday precisions were ≤4 %. Compared with other reported methods, this method is a one-step, simple, cheap, fast, and environmentally friendly alternative and straightforward method for adsorbing organochlorine pesticides from sample solutions. These results demonstrates the high potential of the proposed method for the extraction and cleanup of contaminants in selected juices and other related samples.

Using Fe3O4-graphene oxide-modified chitosan with melamine magnetic nanocomposite in the removal and magnetic dispersive solid-phase microextraction of Cr (VI) ion in aquatic samples

Using Fe3O4-graphene oxide-modified chitosan with melamine magnetic nanocomposite in the removal and magnetic dispersive solid-phase microextraction of Cr (VI) ion in aquatic samples

Selective and fast magnetic dispersive solid phase micro-extraction of copper and lead in water and vegetables after synthesis of magnetic mesoporous carbon

Magnetic mesoporous carbon (Fe3O4@C, MMC) was synthesized and characterized. It was used for the first time as a sorbent for the magnetic dispersive solid phase microextraction (M-dSPμE) of copper and lead in water and vegetables. FAAS was used to determine the analyte concentrations after elution. The MMC was found to be have surface area of 145.9 m2 g−1 and average pore diameter of 15 nm. The analytical parameters affecting M-dSPμE of copper and lead were optimized. They were pH of sample, 6; eluent, 2 mol L−1 HCl (3 mL); and sample volume, 250 mL. The MMC reaches equilibrium very fast without vortexing for adsorption and only 5 s for elution. The LOD and PF of the M-dSPμE method for copper and lead were found to be 0.87 μg L−1 and 83 for Cu(II) and 2.8 μg L−1 and 167 for Pb(II), respectively. The precision of the M-dSPμE method was found to be ≤ 3.2%. The M-dSPμE method was verified by certificate reference materials (TMDA-53.3 Fortified Lake water and NIST SRM 1573a Tomato Leaves). It was successfully applied to the determination of copper and lead in lake water, wastewaters, sea water, radish, spinach, lettuce, and celery samples.

Carbon nanotubes/metal-organic framework based magnetic dispersive micro-solid phase extraction for the determination of triazole fungicides in wastewater and soil samples

In this research, the magnetic dispersive micro solid phase extraction (M−D-µ-SPE) method was used for pre-concentration and trace detection of triazole fungicides in agricultural wastewater and soil samples. The nano sorbent used for M−D-µ-SPE is based on a magnetic carbon nanotubes/Cu-based MOF (M−MWCNT−Cu−BDC) nanocomposite, which was synthesized and characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, vibrating-sample magnetometer, and Nitrogen adsorption-desorption analysis. The effective parameters on the extraction performance were optimized, and under the optimized conditions (pH value: 7.0; the amount of sorbent: 30 mg; extraction time: 30 min; desorbing agent: ethanol; the volume of desorbing solvent: 500 μL and desorption time: 5 min), the limits of detection (LOD) was 0.45 ng mL−1, and the linear range was 1.50 to 750 ng mL−1 with a correlation coefficient higher than 0.993. The repeatability (RSD%) of the method for five replicates ranged from 2.8 to 5.5%. High recoveries (91–94%) and excellent preconcentration factor (PF = 91–94) were also obtained. Finally, this method was applied to determine triazole fungicides in agricultural wastewater and soil samples.

Simultaneous and rapid determination of three organophosphorus pesticides from vegetable and cereal samples with a magnetic dispersive solid-phase microextraction method by gas chromatography-mass spectrometry

ABSTRACT A straightforward and fast magnetic dispersive solid-phase microextraction method (MDSPME) as a sample preparation procedure coupled with gas chromatography/mass spectroscopy (GC/MS) was developed to measure three organophosphorus pesticides (OPPs), including ethion, diazinon, and chlorpyrifos, from fruit and cereal samples. Magnetic Fe3O4@ reduced graphene oxide nanocomposites as an excellent sorbent were synthesised based on several steps such as graphite oxide preparation, graphite oxide exfoliation, graphene oxide reduction, and chemical co-precipitation of magnetic Fe3O4 methods. Nine factors affected in the MDSPME procedure were thoroughly optimised using the design of experiment approach. The Plackett-Burman design and central composite design were utilised for screening the significant factors and for optimising the factors, respectively. The calibration curves of ethion, diazinon, and chlorpyrifos were linear in the ranges of 0.008–4.5, 0.01–4.0, and 0.01–4.5 ng ml−1 with R-squared of 0.9953, 0.9923, and 0.9981, respectively. The proposed method has high preconcentration factors (PF ≥ 220), low sample solution consumption (5.0 ml), and fast extraction time (5.0 min) for the OPPs determination. Analysis of real samples, including rice and cucumber samples, was shown that the proposed procedure is the suitable sample preparation and determination method for the measurement of OPPs with a recovery percentage in the range of 91.3%-102.2% and RSDs lower than 7.2%. The method has great advantages including low desorption solvent consumption, simple operation, and suitable RSDs for the OPPs determination in the fruit and cereal samples with complex matrices.

Use of a simple magnetic material for the determination and speciation of very low amounts of silver and gold

Silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) can be separated of their ions by a magnetic dispersive micro-solid phase extraction procedure using non-functionalised ferrite particles. The separation and speciation are based on careful control of the acidity of the medium, without involving oxidation-reduction processes. Thus, using a small amount of ferrite particles (2 mg for a typical 10 mL sample) which is added to the sample as a suspension, Ag(I) as well as both gold species are retained in the sorbent at pH 4, while AgNPs are retained at pH 8. For the selective retention of AuNPs, ammonium diethyl dithiophosphate is added to the medium and the extraction process is repeated at pH 4. In all cases, the analytes are desorbed by treating the solid phase separated by the magnet with 0.1 mL of a thiourea solution at pH 3 and determined by electrothermal atomization atomic absorption spectrometry. For the measurement of silver, a palladium salt is used as a chemical modifier. This is not required for the determination of gold. The enrichment factor is 97 and the detection limits are 12 and 4 ng L−1 for gold and silver, respectively. The reproducibility is close to 5% for the four analytes studied. The reliability of the procedures is checked by standard additions and by the use of four standard reference materials with certified total silver content. Several water samples are analysed, and speciation results are given.

Development of magnetic dispersive micro-solid phase extraction of four phenolic compounds from food samples based on magnetic chitosan nanoparticles and a deep eutectic supramolecular solvent

A magnetic dispersive micro-solid phase extraction technique (CS@Fe3O4-MD-μSPE-DESP) based on magnetic chitosan nanoparticles and a deep eutectic supramolecular solvent was developed and applied to determinations of four phenolic compounds in food samples. To prevent environmental pollution and the introduction of toxic substances, deep eutectic supramolecular solvents (DESPs), which exhibited greater desorption capacities than conventional organic solvents and deep eutectic solvents, were used as novel green eluents for the first time. Some important parameters were screened by the Plackett–Burman method and then further optimized with response surface methodology (RSM). Under the optimal conditions, the proposed method showed excellent methodological indices with linearity over the range 0.1–200.0 µg·mL-1, R2 > 0.9988, extraction recoveries above 94.8 %, and precision (RSD%) below 2.9 %. The established method finishes the process of adsorption and desorption in approximately 3 min and enhances the efficiency for determination of phenolic compounds.

Magnetic molecularly imprinted polymers based on eco-friendly deep eutectic solvent for recognition and extraction of three glucocorticoids in lotion

In this study, a magnetic dispersive micro-solid phase extraction (MD-μ-SPE) pretreatment method assisted by deep eutectic solvent-magnetic molecularly imprinted polymers (DES-MMIPs) was established in combination with UHPLC-UV analysis method for extraction and determination of Hydrocortisone (HC), cortisone (COR) and dexamethasone (DEX) in lotion. The prepared DES-MMIPs were characterized by FT-IR, SEM and VSM, showing the successful synthesis DES-MMIPs. Then, a series of adsorption affinity tests indicated the prepared material had excellent adsorption capacity, specific recognition performance (IF = 1.33–1.44) and satisfactory reusability (four times). The DES-MMIPs combine the low toxicity of DES, selectivity of MIPs and the convenience of recovery offered by magnetism. Furthermore, the adsorption and desorption conditions were investigated. Under the optimum conditions, the method detection limits (MDLs) of HC, COR and DEX were 0.6, 0.6 and 0.9 ng mL−1, respectively. And the method linear ranges of HC, COR and DEX were 1.8–115.2, 1.8–115.2 and 3.5–224.0 ng mL−1, respectively, which showed a good correlation (r > 0.9997). The extraction recovery ranged from 81.2 % to 96.7 %. Finally, three glucocorticoids were not detected in some lotion samples. Therefore, the established MD-μ-SPE-UHPLC-UV method provides a promising strategy to the selective extraction and determination of three GCs in lotion.

Potential of sodium dodecyl sulfate micellar solutions as eluents in magnetic dispersive micro-solid phase extraction with polydopamine-coated magnetite nanoparticles. Application to antidepressant drugs

In this paper, the potential of micellar solutions of the anionic surfactant sodium dodecyl sulfate (SDS) as eluents in dispersive micro-solid phase extraction (D-μSPE) using polydopamine-coated magnetite nanoparticles (Fe3O4@PDA NPs) for the extraction and preconcentration of seven basic drugs (bupropion, citalopram, fluoxetine, mianserin, nomifensine, trimipramine, and viloxazine) is explored for the first time (to the best to our knowledge) and compared with conventional hydro-organic eluents. The impact of the sample solution pH, Fe3O4@PDA NPs and PDA coating amounts and extraction time on the extraction efficiency (EE), as well as the composition of the eluent on the overall efficiency (OE) are studied. Under the selected experimental conditions (50 mg of Fe3O4@PDA NPs, 100 μL of 1 M NH3, 5 min of extraction time and 0.15 M SDS at pH 2.6 as eluent), EE and OE values were higher than 90% for all compounds and for the most hydrophobic compounds (trimipramine, fluoxetine and mianserin), respectively. The results shown in this paper demonstrate the suitability of Fe3O4@PDA NPs as a sorbent for the extraction of antidepressants as well as the advantages of using SDS micellar solutions over classic hydro-organic eluents containing methanol, acetonitrile or tetrahydrofuran. Finally, the stability and reusability of the Fe3O4@PDA NPs is proven.

Sensitive and selective magnetic dispersive microextraction of diazinon from urine samples by molecularly imprinted polymer based on core–shell metal–organic frameworks

A core–shell magnetic metal–organic framework (Fe3O4 SiO2/ PAEDTC@ MIL- 101 (Fe)) was synthesized as the substrate and then covered with a surface molecularly imprinted polymer (MIP) layer. Next, Fe3O4 SiO2/ PAEDTC@ MIL- 101 (Fe) @ MIP was characterized by XRD, FT-IR, BET, VSM, TEM, and FE-SEM techniques and applied for selective, fast, and sensitive magnetic dispersive solid-phase microextraction (M-DµSPE) of diazinon from urine samples by the GC- FID detection method. The key experimental variables affecting M-DµSPE were studied and optimized by central composite design (CCD). Under optimum conditions (5 mL; sample at pH: 7.0, the mass of solid sorbent; 6 mg, extraction time; 4 min, acetonitrile as an eluent solvent; 1.5 mL, and desorption time; 3 min, and then reconstituted with 100 µL of methanol), the proposed method exhibits high sensitivity with limits of detection and quantification of 0.005 and 0.017 ng mL−1, respectively. Excellent extraction recovery (98.5 %), wide linearity range (0.02–200000 ng mL−1, R2 > 0.992), high enrichment factors (47–53), and satisfactory precision (<6.3 % RSD) were achieved. The MIP- MOF@ M-DµSPE -GC-FID method can be used with high precision and wide linearity to extract and analyze trace levels of diazinon in real urine samples.

Magnetic Nanoparticle-Based Dispersive Solid-Phase Microextraction of Three UV Blockers Prior to Their Determination by HPLC-DAD.

The need for proper handling of environmental samples is significant, owing to their environmental effects on both humans and animals, as well as their immediate surroundings. In the current study, magnetic nanoparticle-based dispersive solid-phase microextraction was combined with high-performance liquid chromatography using a diode array as the detector (HPLC-DAD) for both the separation and determination of three different UV blockers, namely octocrylene, ethylhexyl methoxycinnamate, and avobenzone. The optimum conditions for the extraction were found to be as follows: Stearic acid magnetic nanoparticles (20 mg) as the sorbent, acetonitrile (100 µL) as the eluent, as well as a sample pH of 2.50, adsorption and desorption time of 1.0 min, with a 3.0 mL sample volume. The limits of detection were as low as 0.05 µg mL−1. The coefficient of determination (R2) was above 0.9950, while the percentages of relative recoveries (%RR) were between 81.2 and 112% for the three UV blockers from the environmental water samples and sunscreen products.

Renewable sorbent dispersive solid phase extraction automated by Lab-In-Syringe using magnetite-functionalized hydrophilic-lipophilic balanced sorbent coupled online to HPLC for determination of surface water contaminants

An automated methodology for magnetic dispersive solid phase microextraction integrating bead injection approach for renewable sorbent introduction is presented for the first time and was successfully applied to the enrichment of water contaminants. For this purpose, a simple procedure was developed for the functionalization of commercial SupelTM-Select HLB (Hydrophilic modified styrene polymer) sorbent beads that allowed embedding magnetite nanoparticles (Fe3O4). The sorbent was then used in a dispersive solid phase extraction procedure that was carried out entirely inside the void of an automatic syringe pump following the flow-batch concept of Lab-In-Syringe including automated renewal of the sorbent for each analysis. Mixing processes, sorbent dispersion, and sorbent recovery were enabled by using a strong magnetic stirring bar, fabricated from a 3D printed polypropylene casing and neodymium magnets, inside the syringe. The final extract was submitted to online coupled liquid chromatography with spectrometric detection. System and methodology were applied to determine mebendazole, bisphenol A, benzyl 4-hydroxybenzoate, diclofenac, and triclosan selected as models from different groups of environmental contaminants of current concern. Experimental parameters including extraction and elution times, composition and volume of eluent, and bead recollection were optimized. Required system elements were produced by 3D printing. Enlarging the sample volume by repeated extraction to enhance the sensitivity of the method was studied. Using double extraction from 3.5 mL, limits of detection ranged from 1.2 μg L−1 to 6.5 μg L−1 with an RSD (n = 6) value less than 7% for all the analytes at 25 μg L−1 level. The method was linear in the range of 5–200 μg L−1 and was successfully implemented for the analysis of surface waters with analyte recoveries ranging from 78.4% to 105.6%.

Development of magnetic dispersive micro-solid phase extraction based on magnetic adipic acid nanoparticles and deep eutectic solvents for the isolation and pre-concentration of phenolic compounds in fruit juice samples prior to determination by HPLC-UV

In this research, novel magnetic nanoparticles based on ultrasonic-assisted magnetic dispersive micro-solid phase extraction and deep eutectic solvent have been developed for the determination of phenolic compounds (naringenin, hesperetin, gallic acid) in fruit juice samples. For this purpose, for the first time, adipic acid-coated magnetic nanoparticles (AD@Fe3O4) as an efficient sorbent were synthesized and identified. In this study, deep eutectic solvents were prepared with available and less-toxic compounds and used as eluent solvent in the desorption step. These solvents are good options instead of conventional organic solvents to reduce hazardous waste products and improve the adsorption capacity. In addition, the extracted analytes were easily isolated from the media by an external magnet, and no special devices were required for phase separation. The screening of some important parameters on the extraction procedure was examined by fractional factorial design. Then, the central composite design was applied to optimize the effective parameters. The optimum conditions for the developed method were obtained as pH: 3.7, the amount of salt: 5% (w/v), the amount of adsorbent: 2 mg, and extraction time: 2 min. Under the optimal conditions, the proposed method demonstrated excellent linearity in the range of 1.0–500.0 µg L−1 for hesperetin and 5.0–500.0 µg L−1 for naringenin and gallic acid (R2 > 0.997). The extraction recoveries were obtained above 91.0%, and the intra-day and inter-day precision (RSD%) lower than 4.8%. Limit of detections (LODs) were in the range of 0.3–2.0 µg L−1. The results indicated that the suggested method is simple, fast, and eco-friendly. At the end, the new method was effectively applied for the determination of phenolic compounds in fruit juice samples.

Sensitive, Accurate and Selective Determination of Cd(II) Using Anodic Stripping Voltammetry with in‐situ Hg‐Bi Film Modified Pencil Graphite Electrode After Magnetic Dispersive Solid Phase Microextraction

AbstractThis paper describes a novel approach to detect Cd(II) using the combination of the differential pulse anodic stripping voltammetry and magnetic nanoparticle based dispersive solid phase microextraction as an efficient, green and accurate method. Currents of Cd(II) increased linearly in the range from 75 to 2000 ng L−1 Cd(II) with a detection limit of 21.6 ng L−1. The RSD values of 2.6 and 6.0 % for 1.00 and 0.10 μg L−1 respectively showed that proposed method has an acceptable repeatability. Recovery values between 92.3 and 98.6 % showed that this approach can be successfully used for determination of Cd(II) in water samples.