Preconcentration Of Lead Research Articles

Ionic Liquid-Solidified Floating Organic Drop Microextraction for the Preconcentration of Lead in Environmental Water Samples Prior to Its Determination with Electrothermal Atomic Absorption Spectrometry.

This research investigates the utilization of an ionic liquid combination of solidified floating organic drop micro-extraction (IL-SFODME) to augment the concentration of trace amounts of lead, working as a preliminary stage before electrothermal atomic absorption spectrometry (ETAAS) analysis without the use of chelating agents. Key parameters impacting the microextraction efficiency-including pH, the volume of the ionic liquid (1-Hexyl-3-methylimidazolium hexafluorophosphate, HMIMPF6), temperature, extraction time, and stirring speed-were methodically examined to determine optimal conditions. Under detected optimized conditions, an enhancement factor of 71.2 was obtained for a 15 mL sample solution. The calibration curve exhibited linearity within the concentration range of 0.2-2.5 µg/L, with a detection limit (3σ) of 0.054 µg/L and a quantification limit (10σ) of 0.18 µg/L. For seven replicate measurements of 0.5 µg/L lead, the relative standard deviation (RSD) was ±2.30%. This method was effectively implemented to extract and quantify lead in both reference water and different real water samples, showcasing significantly efficient extraction performance.

Development of liquid phase microextraction-based deep eutectic solvent for the extraction and determination of toxic metal ions in herbal medicines

Herein, an eco-friendly, simple, and inexpensive procedure was developed using vortex-assisted combined with deep eutectic solvent-based liquid phase microextraction (VA-LPME-DES) followed by graphite furnace atomic absorption spectrometry. In the present procedure, DES was first synthesized from the combination of l-menthol and (1S)-(+)-camphor-10-sulfonic acid (CSA) in a molar ratio of 5:1, and then it was used as a green and safe extractant instead of common toxic organic solvents. The ability of the presented method was applied for the separation and preconcentration of lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As) in herbal medicines. After optimizing all the parameters of the experiment, the linear ranges were 0.10–200 µg kg−1 with coefficient of determination (r 2) better than 0.985. The limits of detection were in the ranges of 0.03–0.15 µg kg−1. Relative standard deviation values for intra-day and inter-day of the method based on 7 replicate measurements were in the range of 1.8%–3.6% and 3.1%–7.3%, respectively. The relative recoveries of herbal medicines which have been spiked with different concentrations of metal ions were 91.5%–109.8%. The method was successfully used to analyze the heavy and toxic metals in herbal medicine samples.

Extraction and preconcentration of lead (II) in various water and food samples by orbital shaker-assisted magnetic solid phase extraction method using a new magnetic poly linoleic acid-polystyrene-PDMS block copolymer

The aim of this study was to develop a practical orbital shaker-assisted magnetic solid phase extraction (OSA-MSPE) method for the determination of lead by FAAS. A new magnetic poly linoleic acid-polystyrene-polydimethylsiloxane (PSt-PLina-PDMS) hydrophobic graft copolymer was synthesized and characterized by NMR, FT-IR, SEM-EDX, DSC, TGA, BET and used as adsorbent for the extraction of Pb (II). This adsorbent can be used at least 50 times without any decrease of its adsorption properties for the adsorption and elution of analyte ions. Several analytical parameters including pH, adsorbent amount, sample volume, shaking time, etc. were optimized. Multivariate optimization was used for the investigation of different parameters. The linear range at optimum operating condition was 1.7–84 μg L−1. The limit of detection (LOD) and limit of quantification (LOQ) were 0.5 μg L−1, 1.7 μg L−1, respectively. Intraday and interday relative standard deviation (RSD %), enhancement factor (EF) and adsorbent capacity were found as 1.9%, 3.3%, 166.7, 50 mg g−1, respectively. OSA-MSPE method was tested with certified reference materials including LGC-6010 (Hard Drinking Water), NCS ZC73032 Celery and CS-M-3 Control Sample Microelements in Mushroom Powder for the accuracy. Experimental results for lead were confirmed with certified values. Present method was successfully applied to various liquid and solid food samples. The OSA-MSPE method has some important features such as selective, sensitive, low LOD, LOQ and RSD, pre-concentration factor (PF) and high enhancement factor (EF). High tolerance limits against matrix ions were achieved.

Green Surfactant Assisted-Solidified Floating Organic Drop Micro-Extraction (SA-SFODME) for the Preconcentration of Trace Lead with Determination by Flame Atomic Absorption Spectrometry (FAAS)

Determination of trace lead from environmental samples was carried out by solidified floating organic drop microextraction for preconcentration before analysis by flame atomic absorption spectrometry. The determination of lead from environmental samples, even at trace levels, was possible with an ordinary flame atomic absorption spectrometer (FAAS). The lead formed a hydrophobic complex with the anionic surfactant sodium dodecyl benzene sulfonate (SDBS), and this hydrophobic complex was extracted into the 1-dodecanol drop. Parameters affecting analytical performance have been studied. The optimum pH value was 3.5. The optimum sample volume, SDBS concentration, and extraction solvent volume were 75 mL, 50 mM in dodecanol, and 75 µL, respectively. The optimum extraction time was determined as 30 min, the optimum extraction temperature was 45 °C, the optimum mixing speed was 650 rpm and the ideal extraction phase volume was 0.50 mL. Methanol has been shown to be effective when used as a diluent. Using the optimum conditions, the enhancement factor was 106, and the limit of detection (3s) and precision were 3.3 ng/mL and 2.3% (n = 9,15 ng/mL), respectively. The limit of quantification (LOQ) (10s) was 10 ng/mL and the linear working range was 15-100 ng/mL. The accuracy was evaluated by certified reference material analysis. The optimized method was applied to the determination of Pb(II) from environmental water samples. This method follows the principles of green analytical chemistry.

Preconcentration and Removal of Lead From Water Samples Using Magnetic Copper Ferrite Nanoparticles

The presence of lead and its compounds is extremely dangerous to various forms of life. Therefore, exploring effective treatments that can reduce the presence of lead ions around us becomes crucial, thereby averting lead toxicity. A magnetic solid phase extraction (MSPE) procedure for the removal and preconcentration of trace amounts of Pb(II) using copper ferrite nanoparticles (CuFe2O4 NPs) prior to their determination by flame atomic absorption spectrometry (FAAS) has been proposed. CuFe2O4 as solid-phase extraction adsorbent was synthesized via co-precipitation and characterized by attenuated total reflection–infrared spectroscopy (ATR–IR), x-ray diffraction spectrometry (XRD), and scanning electron microscopy (SEM). These magnetic CuFe2O4 carrying the Pb(II) could be easily separated from the aqueous solution by applying an external magnetic field; no filtration or centrifugation was necessary. Various analytical parameters, including pH, eluent type/concentration, adsorbent mass, sample volume, adsorption/desorption time, mixing, and interfering ions, were systematically studied and optimized for the recovery of Pb(II). A sample volume of 20 mL achieved a preconcentration factor of 20. The method effectively determined Pb(II) in water samples, with recovery values exceeding 95% using the optimal conditions.

Synthesis of Nanocube‐Shaped Cobalt Tin Hydroxides for the Preconcentration of Lead in Environmental Seawater Collected from Antarctic Region

AbstractHere, a simple/efficient analytical strategy based on dispersive solid phase extraction was developed using CoSn(OH)6 nanocubes for lead ions from environmental water samples by FAAS (flame atomic absorption spectrometry). CoSn(OH)6 was synthesized as an adsorbent using the co‐precipitation method and characterized. The characterization studies proved the cube‐shaped morphology and uniform size distribution. The optimal experimental conditions were found by optimization studies and, the limit of quantification (LOQ), limit of detection (LOD), linear dynamic range were recorded as 37.6 μg/L, 11.3 μg/L, and 40–600 μg/L, respectively. The enhancement factor of the presented method was calculated as 158.7‐folds compared to the LOD of the conventional FAAS system. Recovery experiments were performed to check the method's applicability/accuracy and the percent recovery results varied from 89.0 % to 112.9 %. According to these findings, the developed method was successfully applied for the quantitative determination of the target analyte in a seawater sample matrix.

Univariate optimization of dispersive liquid-liquid microextraction for preconcentration of lead from environmental matrices, Samawah region prior to quantification using flame atomic absorption spectroscopy

Univariate optimization of dispersive liquid-liquid microextraction for preconcentration of lead from environmental matrices, Samawah region prior to quantification using flame atomic absorption spectroscopy

Cysteine-functionalized selenium nanoparticles for efficient extraction and preconcentration of cadmium, copper, lead, and zinc ions from environmental water samples

This study aimed to develop cysteine-functionalized selenium nanoparticles (SeNPs) supported by γ-alumina (Al2O3@Se@Cys) for the effective extraction and preconcentration of cadmium, copper, lead, and zinc ions from river water and seawater samples. This one-pot synthesis method produced and functionalized SeNPs using L-cysteine as a green reducing agent. The different properties of Al2O3@Se@Cys were analyzed using various techniques, including Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD). Several experiments were conducted to identify and optimize the key variables influencing extraction efficiencies, such as the pH, ascorbic acid concentration, Al2O3@Se@Cys amount, solution volume, salinity, and elution and matrix clean-up conditions. The results showed that the proposed method provided detection limits ranging from 0.25 to 1.00 µg/L, relative standard deviations (RSDs, n = 5) between 1.1 % and 4.5 %, dynamic linear ranges within 10–200 µg/L (R2 ≥ 0.995), and enrichment factors >85. Moreover, the recoveries of the spiked standard solutions in river water and seawater samples were at least 94.0 %, with negligible interference from most major and minor ions commonly found in environmental water samples. The study demonstrated the successful development and application of Al2O3@Se@Cys, which exhibits a sustainable and eco-friendly approach to addressing environmental contamination challenges and highlights the expanding utility of SeNPs.

Utilization of Multivariate Optimization for Preconcentration and Determination of Lead in Different Water and Food Samples Using Functionalized Activated Carbon

In this study, apricot-pit-based activated carbon was functionalized and used as a sorbent for the preconcentration of lead (Pb2+) in different water and food samples. The activated sorbent was modified with ethylenediaminetetraacetic acid (EDTA) to enhance its selectivity for the efficient removal of Pb2+ ions. The modified activated sorbent was characterized using FTIR, an SEM, BET, and TGA. The column adsorption method was used to study the adsorption capacity of synthesized and modified activated carbon and analyzed using atomic absorption spectrophotometry. A multivariate procedure, i.e., Plackett–Burman design (PBD) and central composite design (CCD), was studied for optimizing the adsorption process, which allows the optimization of multiple variables at the same time. An interference study was conducted to ascertain the selectivity of the developed method. The developed method was validated by assessing certified reference materials and additional standards for Pb2+ detection in real samples. To assess the precision of the proposed procedure, repeatability (RSDr) and reproducibility (RSDR) were calculated, which were determined to be <3.0 (n = 7) and <7.5 (n = 15), respectively. The obtained results revealed that the modified AC is a suitable and efficient sorbent for the preconcentration of Pb2+ in real water and food samples.

Electric field-enabled aptasensing interfacial engineering to simultaneously enhance specific preconcentration and electrochemical detection of mercury and lead ions

Aptamers with strong affinity to heavy metal ions (HMIs) allow fabrication of electrochemical sensors with high selectivity and sensitivity, while controllable regulation of aptamer-HMI recognition at the sensing interface, which is vital for better analytical performance, remains challenging. Here, an electric field-based strategy for engineering an aptasensing interface was proposed to realize the specific preconcentration and accurate detection of mercury (Hg2+) and lead (Pb2+) ions with a ratiometric electrochemical sensor. The working principle is to apply an electric field to drive HMIs to approach the aptamer and retain the orientation of the DNA structure. Anthraquinone-2-carboxylic acid (AQ)-labeled complementary DNA was designed to simultaneously bind a ferrocene (Fc)-labeled aptamer for Hg2+ and a methylene blue (MB)-labeled aptamer for Pb2+, and the sensing interface was fabricated with this presynthesized DNA structure. For preconcentration, an electric field of 3.0 V pushed HMIs to approach the aptamer and retained the orientation of DNA to favor the following recognition; for detection, the oriented DNA in 2.5 V electric field offered a stable current of AQ as a reference. In this way, currents of AQ, Fc and MB were used to produce ratiometric signals of IAQ/IFc and IAQ/IMB for Hg2+ and Pb2+, respectively. Such a strategy allowed the simultaneous detection of Hg2+ and Pb2+ within 30 min with detection limits of 0.69 pM and 0.093 pM, respectively. The aptasensor was applied for soil, water, and crayfish analysis in paddy fields. The electric field-enabled strategy offers a new way to fabricate high-performance electrochemical aptasensor for HMIs detection.

Modified Polysulfone Nanofibers for the Extraction and Preconcentration of Lead from Aqueous Solutions.

Since lead is a highly toxic metal, it is necessary to detect its presence in different samples; unfortunately, analysis can be complicated if the samples contain concentrations below the detection limit of conventional analytical techniques. Solid phase extraction is a technique that allows the carrying out of a pre-concentration process and thus makes it easy to quantify analytes. This work studied the efficiency of sorption and preconcentration of lead utilizing polysulfone (PSf) fibers grafted with acrylic acid (AA). The best conditions for Pb(II) extraction were: pH 5, 0.1 mol L-1 of ionic strength, and 40 mg of sorbent (70% of removal). The sorbed Pb(II) was pre-concentrated by using an HNO3 solution and quantified using flame atomic absorption spectrometry. The described procedure was used to obtain a correlation curve between initial concentrations and those obtained after the preconcentration process. This curve and the developed methodology were applied to the determination of Pb(II) concentration in a water sample contained in a handmade glazed clay vessel. With the implementation of the developed method, it was possible to pre-concentrate and determine a leached Pb(II) concentration of 258 µg L-1.

Increase the Efficiency of Dispersive Liquid-Liquid Microextraction (DLLME) and its Use for the Determination of Lead (II) in Aqueous Solutions

A simple, sensitive, and greener method for green extraction and preconcentration of lead from aqueous media and further assay by UV-Vis spectrophotometer has been developed using 1,5 diphenylthiocarbazone (dithizone). Several factors of dispersive liquid-liquid microextraction (DLLME) including the type and volume of extraction and dispersive solvents, shaking time, the concentration of dithizone as a complexing agent, and pH were optimized. Under optimum selected conditions, the limit of detection (LOD), the limit of quantification (LOQ), the linearity range, the relative standard deviation (RSD), and the Enrichment factor (EF) of the proposed method were obtained at 0.007 ppm, 0.025 ppm, 0.01-0.1 ppm, 4.3% (n = 3) and 40, respectively. This proposed method was successfully applied in the analysis of three synthetic water samples and good spiked recoveries over the range of 96.0–98.5% were obtained.

Biohybrid adsorbent for the preconcentration of lead and its determination in fruit juices by electrothermal atomic absorption spectrometry.

Fruit juices are one of the most non-alcoholic beverages consumed in the world. Essential elements and other nutrients present in fruit juices play an important role in human well-being. However, fruit juices may also contain potentially toxic elements at trace levels, causing health risks. The objective of this work was to develop an analytical methodology based on the preconcentration of lead using a new biodegradable hybrid material composed of Rhodococcus erythropolis AW3 bacteria and Brassica napus hairy roots. The biodegradable hybrid material was implemented in an online solid phase extraction system for the determination of lead in fruit juices by electrothermal atomic absorption spectrometry. Effects of critical parameters on lead retention were studied. Under optimal experimental conditions, extraction efficiency higher than 99.9% and an enrichment factor of 62.5 were achieved. The dynamic capacity of the biodegradable hybrid material was 36 mg/g, which favored the reuse of the column to at least 8 biosorption-desorption cycles. The limit of detection and quantification for preconcentration of 5 mL of sample were 5.0 and 16.5 ng/L lead, respectively. The relative standard deviation was 4.8% (at 1 µg/L lead and n = 10). The developed method was suitable to be applied for lead determination in different types of fruit juices.

Construction of 1, 10-phenanthroline functionalized magnetic starch as a lead (II) tagged surface imprinted biopolymer for highly selective targeting of toxic lead ions

In this research 1, 10 - phenanthroline functionalized CaFe2O4 - starch was employed as a magnetic ion-imprinted polymer (IIP) for highly selective targeting toxic Pb2+ ions from aqueous media. VSM analysis revealed that the sorbent has magnetic saturation of 10 emu g−1 which is appropriate for magnetic separation. Moreover, TEM analysis confirmed that the adsorbent is composed of particles with a mean diameter of 10 nm. According to XPS analysis, lead coordination with phenanthroline is the main adsorption mechanism that is along with electrostatic interaction. A maximum adsorption capacity of 120 mg g−1 was obtained within 10 min at a pH of 6 and an adsorbent dosage of 20 mg. Kinetic and isotherm studies showed that lead adsorption followed the pseudo-second–order and Freundlich models, respectively. The selectivity coefficient of Pb (II) relative to Cu(II), Co(II), Ni(II), Zn(II), Mn(II), and Cd(II) was 4.7, 14, 20, 36, 13 and 25, respectively. Moreover, the IIP represents the imprinting factor of 1.32. The sorbent showed good regeneration after five cycles of the sorption/desorption process with an efficiency of >93 %. Finally represented IIP was used for lead preconcentration from various matrices i.e., water, vegetable, and fish samples.

Simultaneous preconcentration and determination of trace metals in edible plants and water samples by a novel solvent bar microextraction using a meltblown layer of facemask as the extractant phase holder combined with FAAS

A new microextraction method as a facile, efficient, and safe intermediate sample preparation procedure was developed for simultaneous extraction and preconcentration of nickel (II), cobalt (II), and lead (II) in some vegetables and water samples. The new method uses a novel deep eutectic solvent as an extractant on the surface of a meltblown layer of a facemask with an iron wire inside of it. 2-(5-Bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) was used as a chelating reagent. The concentrations of the enriched ions were measured using a flame atomic absorption spectrophotometer (FAAS). The introduced method underwent significant parameter optimization, which may influence the extraction process efficiency. Under the best situations, the calibration curve of the method showed excellent linearity over the concentration range 2–150 μg L−1, 3–150 μg L−1, and 7–500 μg L−1 have satisfactory coefficients of determination (R2 ≥ 0.998) for nickel (II), cobalt (II), and lead (II), respectively. Detection limits were within 0.61 – 2.30 μg L−1, and the relative standard deviation values were fewer than 2.6 % (n = 10). Experimental results indicated that the presented method has a high ability to cleanly and enrich metal ions in several samples, including natural water, dill, coriander, and spinach leaves, with limited solvent consumption and low operating costs.

Optimization and modeling of preconcentration of lead in rice samples by organic gas steam–liquid extraction

Optimization and modeling of preconcentration of lead in rice samples by organic gas steam–liquid extraction

Facile green synthesis of magnetic porous organic polymers for fast preconcentration of trace lead and mercury from environmental water followed by graphite furnace atomic absorption spectrometry detection

Magnetic porous organic polymers (MPOPs) was synthesized in aqueous phase under mild condition by using Fe3O4@SiO2 nanoparticles as magnetic core, 1,3,5-tris-(4-aminophenyl) benzene (TAPB) and 4-(2-pyridylazo) resorcinol (PAR) as two building blocks. The resultant materials (denoted as TAPB-PAR-MPOPs) have the features of good magnetism, high porosity and large surface area, and fast adsorption kinetic (8 min) as well as high adsorption capacities (319 and 374 mg g−1, respectively) toward lead and mercury ions. With the prepared TAPB-PAR-MPOPs as sorbent, a method of magnetic solid phase extraction coupled with graphite furnace atomic absorption spectrometry was developed for the determination of trace lead and mercury in environmental water samples. Under the optimal conditions, the detection limits were 0.009 and 0.017 μg L−1 for lead and mercury, respectively. The developed method was successfully applied to the analysis of trace lead and mercury in tap water, lake water and river water samples with satisfactory recoveries (88.3–107%), demonstrating a good potential of TAPB-PAR-MPOPs in extraction of trace lead and mercury in environmental waters.

A novel thiourea derivative for preconcentration of copper(II), nickel(II), cadmium(II), lead(II) and iron(II) from seawater samples for Flame Atomic Absorption Spectrophotometry

A novel adsorbent, 3-phenyl-1-(2-pyridyl)thiourea (PPTU) was synthesized and its adsorption capabilities were studied for Cu(II), Cd(II), Ni(II), Pb(II) and Fe(II) cations in the waters such as tap and polluted seawaters. The kinetics, Langmuir and Freundlich isotherms were discussed related to the adsorptions. The adsorption capacities of PPTU were found 9.4; 12.6; 90.9; 57.1 and 30.4 mg g−1 and preconcentration with PPTU including the FAAS step yielded the LOQ values 0.46; 2.65; 1.12; 2.65 and 1.72 ng mL−1 for Cu(II), Cd(II), Ni(II), Pb(II) and Fe(II), respectively. The adsorbent after the elutions and washings could be reused three times in the next adsorptions. The interferences on the adsorptions arising from the major cations of the seawater and the usability of PPTU for interested metals in the seawater were discussed. The proposed method is simple with highly efficient and green preconcentration procedure for trace analysis of the target metal ions.

Separation, Preconcentration, and Determination of Lead, Cadmium, and Iron Using Cloud Point Extraction with Flame Atomic Absorption Spectrometry

Separation, Preconcentration, and Determination of Lead, Cadmium, and Iron Using Cloud Point Extraction with Flame Atomic Absorption Spectrometry

Synthesis and comparison of two different morphologies of graphitic carbon nitride as adsorbent for preconcentration of heavy metal ions by effervescent salt-assisted dispersive micro solid phase extraction method

The g-C3N4 (GCN) adsorbent with two different morphologies, coral (CGCN) and nano fiber (GCNNF), was synthesized and recruited for extraction and preconcentration of lead and copper metal ions by effervescent salt-assisted dispersive micro solid phase extraction procedure. The structures of the two adsorbents were affirmed by Fourier-transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy and Brunauer–Emmett–Teller analyses. The factors affecting the extraction efficiency were carefully studied and the optimum values of the parameters for both adsorbents were pH 6.5, adsorbent dosage 8 mg, desorption time 3 min, and the elution solvent 300 μL of 2 mol L−1 of HNO3. The detection limits of Pb(II (and Cu(II) ions for CGCN were 0.9 and 0.3 μgL−1 and for GCNNF were 1.56 and 0.7 μgL−1, respectively. The percent relative standard deviations were obtained to be 1.32% and 2.23% for CGCN (n = 3) and 1.24% and 2.29% for GCNNF (n = 3), respectively for the lead and copper metal ions. In addition, the adsorbents could be used up to 7 times without an imperative reduction in the percentages of analytes recovery. Finally, the performance of CGCN and GCNNF were used for preconcentrate of lead and copper ions in honey, canned fish, and human hair samples.