Solid Phase Extraction Of Pb Research Articles

Metal organic framework composite (Ti3AlC2 @ZIF-67) for vortex assisted solid phase extraction of lead from water and food samples

A composite of Ti3AlC2 max phase and ZIF-67 metal-organic framework (Ti3AlC2 @ ZIF- 67) was synthesized by mixing Ti3AlC2 and ZIF-67 in dimethyl formamide and used for solid phase extraction of Pb(II). Fourier transformation infrared spectroscopy, scanning electron microscopy, x-ray diffraction, and energy dispersive x-ray were used to find functional group, surface morphology, surface area elemental composition, and crystalline structure of Ti3AlC2 @ ZIF-67. Factors like solution pH (7.0), adsorbent dose (10.0 mg), sample volume, eluent concentration and volume (0.5 M, 1.0 mL), and vortex time (1.0 min) were optimized. The effect of interfering ions has been checked to determine the method's selectivity. Analytical parameters such as limit of detection (LOD) 0.26 µg L−1, limit of quantification (LOQ) 0.86 µg L−1, preconcentration factor (PF) 21, enhancement factor (EF) 20 and relative standard deviation (RSD) 4.6% were calculated under optimized experimental condition. Certified reference materials TMDA-64.3 water samples and INCT-OBTL-5 tobacco leaves were used to validate the accuracy of the proposed method for trace metals detection. The technique was also used for lead determination in food and water samples with satisfactory recovery results.

Fabrication and characterization of MgCo2O4 for solid phase extraction of Pb(II) from environmental samples and its detection with high-resolution continuum source flame atomic absorption spectrometry (HR-CS-FAAS)

Magnesium cobaltite (MgCo2O4) nanosorbent was prepared by hydrothermal synthesis method. It has been characterized by various techniques such as FTIR, XRD and SEM. Enrichment and separation of Pb(II) by using MgCo2O4 on solid phase extraction was investigated. The effects of parameters such as pH of the solutions, amount of adsorbent, vortex time, sample volume, eluent concentration and matrix ions were investigated for optimum recovery of analyte ions. The enrichment factor was 125. The limit of detection (LOD) and limit of quantification (LOQ) under optimal conditions for Pb(II) were determined as 0.39 µg L-1 and 1.30 µg L-1, respectively. The validity of the developed SPE method was obtained by the analysis of certified reference material TMDA-64.3 and IC-INCT-OBTL-5 (Oriental Basma Tobacco Leaves), and when the obtained results were compared with the certified values, acceptable values ​​were obtained. The SPE method under optimized parameters conditions was applied to determination of lead(II) in water and food samples.

Efficient removal of Pb(II) and Hg(II) ions from aqueous solution by amine and thiol modified activated carbon

This study investigates the preparation of a novel chelating adsorbent (AT-MAC), based on the chemical modification of activated carbon (AC) derived from water hyacinth (WH) via functionalization with 2-aminothiazole chelating legend (AT), and then utilizing it for the effective removal of Pb(II) and Hg(II) ions from polluted water. FTIR and XPS spectroscopy confirm the successful incorporation of amine and thiol groups within the porous activated carbon through the amidation reaction between the carboxylic groups of porous activated carbon and 2-aminothiazole legend in presence of DCC as cross coupling agent. The AT-MAC adsorbent exhibited high sorption capacities for the removal of Pb(II) (310.9 mg/g) and Hg(II) (252.5 mg/g) at pH 5.5 and contact time 60 min, which are higher than most previously reported carbon based materials. AT-MAC displayed 100.0% removal for Hg(II) and Pb(II) ions at concentrations up to 50 ppm, thus demonstrating excellent selectivity for Pb(II), and Hg(II) ions. The FTIR before and after adsorption suggested the mechanism of removal based on the complexation between the nitrogen and sulfur atoms on the surface of AT-MAC and Pb(II) forming (C-S-Pb and C-N-Pb). The chemisorption mechanism via the thiol and amine groups grafted onto the surface of AT-MAC was also suggested based on the excellent agreement of the experimental data with a pseudo-second order kinetic model. The AT-MAC also showed high stability over three adsorption–desorption cycles. The results also revealed that AT-MAC is a promising remediation adsorbent for the solid phase extraction of Pb(II) and Hg(II) ions from contaminated water.

Vortex-assisted magnetic solid phase extraction of Pb and Cu in some herb samples on magnetic multiwalled carbon nanotubes.

This study is the development of a new solid phase extraction method based on using magnetic multiwalled carbon nanotubes impregnated with 1-(2-pyridylazo)2-naphthol (PAN) for separation, preconcentration, and flame atomic absorption spectrometric determination of Pb(II) and Cu(II). Optimization of the method was done by investigating pH effect, amount of magnetic multiwalled carbon nanotubes impregnated with PAN, eluent type and volume, matrix effects, and volume of the sample. The optimum adsorbent amount was found to be 75 mg and the optimum pH value was found as 5.5. The detection limits were 16.6 μg L-1 for Pb(II) and 18.9 μg L-1 for Cu(II). The relative standard deviations (RSD%) were less than 4%. Two certified reference materials: SPS-WW2 wastewater and NCS-DC73349 (bush branches and leaves) were used to test the validation of the method. The method was successfully applied to the analysis of Pb(II) and Cu(II) ions in daisy, mint, paprika, sage, rosemary, daphne leaves, heather, green tea, andViburnum opulussamples.

Synthesis and characterisation of new hybrid sorbent, 2,2’- dipyridyl ketone functionalised SBA 15 and its application in solid-phase extraction of Pb(II) & Cd(II) from environmental samples

ABSTRACT The mesoporous silica (SBA-15) was successfully functionalised with 2,2ʹ- dipyridyl ketone by post grafting method. The mesoporous structure and functionalization with organic moiety were examined using different physicochemical techniques such as Low angle X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), 13C NMR Spectroscopy, 29Si NMR Spectroscopy, N2 adsorption/desorption studies and TGA studies. The application of the hybrid material as sorbent in solid-phase extraction of Pb(II) and Cd(II) from environmental samples prior to determination by Flame Atomic Absorption Spectroscopy was studied. The analytical parameters such as pH, eluent type and its volume, sorbent dosage, flow rates, sample volume and effect of co-existing ions were studied and optimised. The prepared sorbent showed the preconcentration factor of 160 for both the metal ions with Limits of Detection of 0.20 µgL−1 and 0.27 µg L−1 and Limits of Quantification of 0.67 µg L−1 and 0.90 µg L−1 for Pb(II) and Cd(II) respectively. The adsorption capacity of the prepared sorbent found as 185.49 mg g−1 and 103.41 mg g−1 for Pb(II) and Cd(II), respectively. The proposed method was validated using a certified reference material NIST SRM-1640a with good agreement values. The proposed solid-phase extraction method was successfully applied to environmental water samples.

A hybrid material composed of multiwalled carbon nanotubes and MoSe2 nanorods as a sorbent for ultrasound-assisted solid-phase extraction of lead(II) and copper(II).

A MWCNT@MoSe2 nanorod hybrid material was synthesized by a hydrothermal method and used as an adsorbent for trace levels of Pb(II) and Cu(II). The material was characterized by Raman spectroscopy, XRD, SEM, SEM-EDX, SEM-mapping and BET methods. The hybrid material is demonstrated to be a viable sorbent for ultrasound-assisted solid phase extraction of Pb(II) and Cu(II) at pH5.5. Following desorption with 3 M HNO3, the two elements were quantified by FAAS. Key parameters affecting the extraction efficiency, including eluent conditions, amount of adsorbent, sample volume were optimized. No significant interference by other ions is observed. The accuracy of the method was evaluated by the analysis of the certified reference materials TMDA-53.3 (lake water) and SPS-WW2 (waste water level 2). The recoveries were in good agreement with certified values. The method was successfully applied to the extraction/preconcentration of Pb(II) and Cu(II) in different real samples. Graphical abstract A hybrid material of type MWCNT@MoSe2 was synthesized, characterized, and used as adsorbent for Pb(II) and Cu(II). Key parameters affecting the extraction efficiency, including eluent conditions, amount of adsorbent, sample volume were optimized. The method was applied to the extraction of analytes in water samples.

Polydopamine-functionalized magnetic iron oxide for the determination of trace levels of lead in bovine milk

In this work, a novel sorbent based on polydopamine-functionalized magnetic ferric oxide (Fe3O4) was synthesized and applied for dispersive solid phase extraction of Pb(II) in bovine milk samples. The extracts were analyzed by flame atomic absorption spectrometry (FAAS). The sorbent was characterized with different analytical techniques (XRD, FT-IR, SEM, TEM, VSM and EDX). To reach the maximum extraction efficiency of Pb(II), some effective parameters on both adsorption and desorption steps were optimized with the aid of central composite design and response surface methodology. Under the optimal conditions, the method provided an enhancement factor of 40.5 corresponding to the absolute recovery of 81%. LOD and LOQ were found as 0.13 and 0.43 ng mL−1, respectively. The calibration curve was linear over the concentration range of 3.0–300 ng mL−1 (R2 = 0.9957). The intra and inter-day precisions (RSD%) of the method were calculated as 3.2% and 5.6%, respectively. Finally, the method was successfully applied for the determination of Pb(II) in different bovine milk samples. The Pb(II) content in one of the investigated milk samples was found to exceed the maximum permissible limit (20 μg L−1) set by Codex Alimentarius Commission. The relative recoveries were obtained within the range of 86.5–93.6.

Highly Selective Solid‐Phase Extraction of Pb(II) by Ion‐Imprinted Superparamagnetic Mesoporous Silica

AbstractPb (II)‐imprinted superparamagnetic mesoporous silica (SPMS) adsorbent has been synthesized and characterized. The thiol functionalized SPMS offered a fast adsorption kinetics for Pb(II) and equilibrium was achieved in just 20 min at pH 8.0. The adsorption isotherm data fits well with Langmuir model with a maximum adsorption capacity of 377.36 mg g−1. The selectivity co‐efficients of imprinted adsorbent for Pb(II)/Cu(II) and Pb(II)/Bi(III) were 3.36 and 3.05 times higher than that of non‐imprinted adsorbent. The imprinted adsorbent was employed for the solid phase extraction of Pb(II) and its detection by graphite furnace atomic absorption spectrometry (GFAAS).The parameters affecting the determination of Pb(II) were also well investigated and optimized. A linear relationship between the Pb(II) concentration and the absorbance was found in the range of 0.8‐500 ng mL−1 with a detection limit of 0.25 ng mL−1. The imprinted adsorbent was applied to the determination of Pb(II) in two certified sediment samples with satisfactory results, which indicates that Pb(II)‐imprinted superparamagnetic mesoporous silica adsorbent possess promising features of a viable adsorbent for the preconcentration of Pb(II) ions in complex matrices.

A hybrid monolithic column based on layered double hydroxide-alginate hydrogel for selective solid phase extraction of lead ions in food and water samples

In order to develop an accurate and precise determination method based on solid phase extraction of Pb(II) in food and water samples, a hybrid monolithic column based on layered double hydroxides (LDHs) nanosheets-alginate hydrogel has been synthesized. Combining the advantages of porous 3D framework of hydrogel with selective adsorption of LDHs toward Pb(II), the hydrogel-based hybrid monolithic column shows enhanced enrichment selectivity and efficiency for target ions. Effects of hydrogel composition, pH, concentration and type of eluent, sample volume, and interfering ions on the recoveries of the analytes were also investigated. Under the optimal experiment conditions of method, the limit of detection, preconcentration factor and precision as RSD% are found to be 0.39 μg L−1, 53.7 and 2.65%, respectively. Trace Pb(II) can be quantitatively preconcentrated at pH 6.0 with recoveries >97%. Finally, the method was successfully verified by analyzing spiked Pb2+ in water and drinking samples.

Solid phase extraction of Pb(II) and Cd(II) using reduced graphene oxide-polychloroprene impregnated with magnetic nanoparticle (MNPs-RGO-PCP)

Solid phase extraction of Pb(II) and Cd(II) using reduced graphene oxide-polychloroprene impregnated with magnetic nanoparticle (MNPs-RGO-PCP)

Vortexing/shaking-free solid phase extraction of lead(II) by using an urchin-like NiCo2O4 hollow microsphere adsorbent

Urchin-like NiCo2O4 hollow microspheres were synthesized by a solvothermal method and characterized by using X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller surface area, and zeta potential measurements. It was used as an adsorbent for the solid phase extraction of Pb(II) from water, food and street dust samples prior to its extraction with dilute HCl and its determination by FAAS. Figures of merit include a preconcentration factor of 30, a detection limit of 5.9 μg L−1 and a relative standard deviation of 2.4%. The major advantage of the method is the fast equilibration during extraction without the need for vortexing or shaking. The method was successfully accurated by analyzing certified reference materials (BCR-482 Lichen, TMDA-70 Lake water and RM 8704 Buffalo River Sediment) and by analyzing spiked sea water, wastewater, well water, apple, eggplant, broccoli, ginger, lentil and street dust samples.

Hybrid nanosheets composed of molybdenum disulfide and reduced graphene oxide for enhanced solid phase extraction of Pb(II) and Ni(II)

Non-modified molybdenum disulfide (MoS2) is known to adsorb heavy metal ions. However, in case of very small particle sizes and high dispersibility, ordinary centrifugation and filtration fail to separate MoS2 from aqueous media, and this limits its applicability to solid-phase extraction. To overcome this shortcoming, the authors have prepared a nanocomposite consisting of MoS2 and sheets of reduced graphene oxide (r–GO). The material was obtained by a hydrothermal reaction between sodium molybdate and L-cysteine in the presence of GO sheets. The results of characterizations show the MoS2 nanosheets to be well dispersed on the surface of r-GO sheets. The nanocomposite was applied to the preconcentration of Pb(II) and Ni(II) ions as representative examples of heavy metal ions. The adsorption capacities are 322 and 294 mg.g−1 for Pb(II) and Ni(II), respectively. The ions were quantified by atomic absorption spectrometry, and the respective detection limits are 0.71 and 0.21 μg⋅L−1, respectively. The relative standard deviations are ±2.2 % for both ions. The method was successfully applied to the preconcentration of the analytes in (spiked) urine, saliva and water samples.

Vortex assisted magnetic solid phase extraction of lead(II) and cobalt(II) on silica coated magnetic multiwalled carbon nanotubes impregnated with 1-(2-pyridylazo)-2-naphthol

In the present study, silica coated magnetic multiwalled carbon nanotubes impregnated with 1-(2-pyridylazo)-2-naphthol was synthesized and characterized by using instrumental techniques such as, Fourier transform infrared spectroscopy (FT-IR), BET surface area analysis, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The novel adsorbent has been used for magnetic solid phase extraction of Pb(II) and Co(II) at trace levels. The parameters including pH of solution, adsorbent dose, sample volume, temperature and matrix effect were optimized. Quantitative recoveries for analytes were obtained at pH6.5 with 100mg of adsorbent. Limit of detection values for lead and cobalt were 1.76μgL−1 and 0.55μgL−1. Preconcentration factor and standard deviation of both metals were 15 and lower than 3.3%. Kinetic data shows that the adsorption process follows pseudo second order kinetic. Positive values of ΔH° and ΔS° show that adsorption of Pb(II) and Co(II) is feasible and endothermic in nature. The validation of the method was carried out to waste water certified water reference materials. The presented separation-preconcentration method was applied to determination of lead and cobalt contents of water samples from Kayseri-Turkey.

Immobilization of the Thenoyltrifluoroacetone on Sodium Dodecyl Sulfate Modified Magnetite Nanoparticles for Magnetic Solid Phase Extraction of Pb (II) from Water Samples

Magnetite nanoparticles (Fe3O4 NPs) were synthesized by co-precipitating method under optimized condition. The Fe3O4 NPs coated with sodium dodecyl sulfate-thenoyltrifluoroacetone (Fe3O4 NPs-SDS-TTFA) were then exerted as the magnetic solid phase extraction (MSPE) adsorbent for the extraction process prior to introducing to a flame atomic adsorption spectrometry (FAAS). The synthesized Fe3O4 NPs-SDS-TTFA were applied for the extraction of Pb(II) ions from different water samples. The characterization studies of nanoparticles were performed via scanning electron microscopy-energy dispersive micro-analysis (SEM-EDAX), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) techniques. The substantial parameters affecting the extraction efficiency were surveyed and optimized. A dynamic linear range (DLR) of 10-400 μg L-1 was obtained and the limit of detection (LOD, n=7) and relative standard deviation (RSD%, n= 6, C=20 μg L-1) were found to be 2.3 μg L-1 and 1.9%, respectively. According to the results, the proposed method successfully applied for the extraction of Pb(II) ions from different environmental water samples and satisfactory results achieved.

Solid phase extraction of Pb(II) and Cd(II) as 2,9 dimethyl-4,7-diphenyl-1,10-phenanthroline chelates on activated carbon cloth in environmental samples and their determination by flame atomic absorption spectrometry

ABSTRACTA solid-phase extraction procedure for Pb(II) and Cd(II) as 2,9 dimethyl-4,7-diphenyl-1,10-phenanthroline complexes on activated carbon cloth (ACC) has been established. In the determination step, flame atomic absorption spectrometry (FAAS) was used. The optimum conditions for pH, type and volume of eluent, volume of sample solution, flow rates of eluent, sample solution and matrix effect were determined. For quantitative recovery of the analyte ions, refereed optimum values are as follows: amount of ACC, 0.4 g; pH, 6.0 and eluent, 10 mL 3 M HNO3. To test the accuracy of the method, a certified reference material (CRM) analysis and add-recovery methods were performed. The developed method was applied for the determination of the analyte elements in water and vegetable samples.

Synthesis of new hybrid sorbent by grafting 2,6-diacetyl pyridine onto microporous β-zeolite and its application in solid phase extraction of heavy metals from environmental samples

The aim of this study was synthesis of a new hybrid material and its application in solid phase extraction of metal ions from environmental samples. The hybrid material was synthesized by grafting 3-aminopropyl trimethoxy silane onto β-zeolite and functionalizing with 2,6-diacetyl pyridine in a stepwise covalent process. This hybrid material was characterized by FT-IR and XRD studies. The hybrid material was used as sorbent in solid phase extraction of Pb(II), Ni(II), Cu(II) and Cd(II). The method is based on the collection of metal ions onto 2,6-DAP-PA- β-zeolite and the sorbed metal ions were eluted with 10 mL of 1 M HNO3. The influences of analytical parameters such as pH of the sample solution, volume of sample, type and volume of eluent, flow rate of the sample and eluent that govern the efficiency and throughput of the method were evaluated. The influence effects of matrix ions (common ions other than the analyte that are present in the sample) on the retentions of the metal ions were also examined. The maximum adsorption capacity values for the metal ions onto 2,6-DAP-PA- β-zeolite, as calculated from the Langmuir model, were 112.7, 94.2, 105, and 102.8 mg g−1, respectively. The relative standard deviation under optimum conditions was lower than 3.10%. The limits of detection were 0.035 for Pb(II), 0.076 for Ni(II), 0.083 for Cu(II) and 0.059 mg L−1 for Cd(II), respectively. The accuracy of the method was estimated by analyzing reference standard materials. The results indicate that the method is efficient for the solid phase extraction of trace levels of Pb(II), Ni(II), Cu(II) and Cd(II) from environmental samples. The hybrid material was synthesized by grafting 3-aminopropyl trimethoxy silane onto β-zeolite and functionalizing with 2,6-diacetyl pyridine. The hybrid material was used for solid phase extraction of Pb(II), Ni(II), Cu(II) and Cd(II) at various analytical parameters. The adsorption capacity values for the Pb(II), Ni(II), Cu(II) and Cd(II) onto 2,6-DAP-PA-β-zeolite were 112.7, 94.2, 105, and 102.8 mg g−1, respectively.

Aspartic acid-modified magnetic nanoparticles as an ideal sorbent for solid phase extraction of Pb in water samples prior to ICP-OES determination

The present study will consider the application of aspartic acid-coated Fe3O4 as a sorbent for solid-phase extraction of trace amounts of Pb using inductively coupled plasma optical emission spectrometry. Magnetic nanoparticles (MNPs) of Fe3O4 possess a high potential for modification with different organic and inorganic compounds. Using an amino acid (in this case, aspartic acid) as a nontoxic modifier, without an organic solvent, could provide a number of environmentally friendly applications in the field of green chemistry. By using modified MNPs as a sorbent, the separation of metal ions from an aqueous sample solution was easily performed by an external magnet without centrifuging or filtering. An elution step was accomplished by using a 2 mol L−1 nitric acid solution for introducing the desorbed analyte to ICP-OES. Different parameters influencing on the extraction efficiency, such as pH, volume of the modifier, extraction and elution time, types and concentrations of eluent were investigated and optimized. Under the optimized conditions, the detection limit for Pb was 0.6 μg L−1 and the calibration curve showed linearity in the range of 1–600 μg L−1. The relative standard deviation (RSD, C = 300 μg L−1, n = 5) was 2.8%. The sorption capacity of the sorbent was found to be 19.9 mg g−1. The sorbent exhibited good stability and high adsorption capacity for lead ions. The applicability of the sorbent was examined by a real sample and the results were satisfactory.

Preparation and characterization of magnetic allylamine modified graphene oxide-poly(vinyl acetate-co-divinylbenzene) nanocomposite for vortex assisted magnetic solid phase extraction of some metal ions

Magnetic allylamine modified graphene oxide-poly(vinyl acetate-co-divinylbenzene) (MGO-DVB-VA) was synthesized and used for magnetic solid phase extraction of Pb(II), Cd(II), Cu(II), Ni(II) and Co(II) prior to their determination by flame atomic absorption spectroscopy. The adsorbent surface functional group was characterized by using FT-IR and Raman spectroscopy. XRD pattern was used to determine the layers of GO. Surface morphology and elemental composition of the adsorbent were evaluated by using SEM and EDX analysis. Various parameters, effecting adsorption efficiency like initial solution pH, adsorbent dose, type and volume of eluent, volume of sample and diverse ions effects were optimized. The preconcentration factor (PF) is 40 for all the metals and the limits of detection for Pb, Cd, Cu, Ni and Co are in the range of 0.37–2.39µgL−1 and relative standard deviation below 3.1%. The method was validated by using the method for certified reference materials (Tobacco Leaves (INCT-OBTL-5), Tomato Leaves (1573a), Certified Water (SPS-ww2) and Certified Water (TMDA 64-2)). The method was successfully applied for natural water and food samples.

Solid phase extraction of Pb(ii) and Cd(ii) ions based on murexide functionalized magnetic nanoparticles with the aid of experimental design methodology

A schematic model for modifying Fe3O4 nanoparticles with Mu.

Solid Phase Extraction of Pb(II) and Cd(II) in Food, Soil, and Water Samples Based on 1-(2-Pyridylazo)-2-Naphthol-Functionalized Organic–Inorganic Mesoporous Material with the aid of Experimental Design Methodology

An effective sorbent of 1-(2-Pyridylazo)-2-naphthol-functionalized mesoporous silica has been prepared to simultaneous separation and preconcentration of lead and cadmium ions in aqueous solution. Structural characterization of 1-(2-Pyridylazo)-2-naphthol-functionalized organic–inorganic hybrid mesoporous materials was conducted by Fourier transform infrared spectroscopy, transmission electron microscopy, N2 adsorption–desorption measurement, X-ray diffraction, and elemental and thermal analysis, which confirmed the successful grafting of organic moiety on mesoporous silica. The affecting parameters on adsorption and desorption steps were optimized by Box-Behnken design through response surface methodology. Three variables (pH value, sorption time, and amount of the sorbent) were selected as the main factors affecting sorption step, while four variables (type of eluent, eluent volume, eluent concentration, and elution time) were selected for desorption step in the optimization study. The optimized values by this optimization method were 10 mg, 8 min, 6.3, HCl, 1.6 mL, 1.2 mol L−l HCl, and 10 min, for amount of sorbent, sorption time, pH of solution, type, volume, and concentration of the eluent, and elution time, respectively. Under the optimized conditions, the detection limits of the proposed method for lead and cadmium ions were found to be 0.9 and 0.04 μg L−1, respectively, while the relative standard deviation (RSD) for five replicate measurements was calculated to be <3 % for both ions. For proving that the proposed method is reliable, a wide range of food, soil, and water samples with different and complex matrixes was used.