Determination Of Lead In Water Research Articles (Page 1)

A simple procedure for determination of lead in water and food samples using cloud point microextraction based on switchable-hydrophilicity solvents

The toxicity of metal ions, such as lead (Pb2+) and cadmium (Cd2+), has been a worldwide issue since the 1970s. For Pb2+ specifically, chronic exposure via drinking water can have lasting health effects. While inductively coupled plasma‐mass spectrometry (ICP‐MS) and atomic absorption spectroscopy (AAS) are the most common instruments used for the detection of Pb2+, electrochemical methods like square wave anodic stripping voltammetry (SWASV) have classically shown promise. However, the determination of metals in a real sample matrix typically requires pretreatment and/or extraction of the analyte from the sample itself. Cloud point extraction (CPE) is a sustainable technique that can be used as a solventless substitute for liquid–liquid or solid‐phase extraction. While typically coupled to AAS detection, the applicability of CPE to electroanalysis is still not well understood, nor fully optimized. In this work, CPE was used to isolate Pb2+ from water samples for analysis by SWASV with a bismuth‐coated glassy carbon (Bi‐GC) electrode. This is the first report coupling CPE to electroanalytical detection of trace metals in the absence of mercury (Hg). In addition, a back extraction (BE) step was incorporated to recover Pb2+ from the surfactant‐rich phase, which resulted in a more sensitive and accurate method. High extraction efficiency was achieved and theoretical limits of detection (LOD) of 2.6, 0.81, and 1.7 μgL−1 were obtained with deposition times (tdep) of 1, 2, and 3 min, respectively. The optimized CPE‐SWASV procedure for Pb2+ was selective; only manganese (Mn2+) was identified as an interferant. Measurements in more complex water samples were also completed. Overall, this innovative CPE‐SWASV approach offers a sensitive, cost‐effective, and sustainable alternative to Hg‐based electrochemical quantification of Pb2+.

Starch-modified nickel ferrite nanoparticles as a magnetic nano-bio adsorbent for the extraction and determination of lead in water and Moringa oleifera samples

Determination of lead in water from reservoirs for human supply using atomic absorption spectrometry

Today, the safety of water resource is the most important challenges which was reported by health and environment organizations. Water pollution can be created by hazardous contaminants of environmental pollutions. Lead as a heavy metal has carcinogenic effects in humans. Metal organic framework (MOF) is a highly porous material with different application. The Zn2(BDC)2(DABCO) is a good candidate of MOF based on zinc metal (Zn-MOF) with potential adsorption/extraction. In this work, Zn2(BDC)2(DABCO) MOF as polycaprolactone (PCL) nanocomposite were applied for lead adsorption/extraction from 50 mL of aqueous solution by ultra-assisted dispersive suspension-micro-solid phase extraction procedure (USA-S- µ-SPE) at pH=8. The samples were characterized by the FTIR, the XRD analysis, the FE-SEM and the BET surface area. The effect of parameters was investigated on lead absorption before determined by UV–VIS spectroscopy. The linear range, the detection limit (LOD) and enrichment factor of adsorbent were obtained 0.05-1 mg L-1, 0.25 μg L-1 and 48.7, respectively (r = 0.9992, RSD%=3.65). The absorption capacity of Zn2(BDC)2(DABCO) MOF for 50 mg L-1 of standard lead solution were obtained 133.8 mg g-1 for 0.25 g of adsorbent. The results indicate that this nanocomposite can have a good potential to develop different adsorbents.

Air-assisted solvent terminated dispersive liquid–liquid microextraction (AA-ST-DLLME) for the determination of lead in water and beverage samples by graphite furnace atomic absorption spectrometry

Determining uncertainty in a simple UV–Vis spectrometry method employing dimethyl carbonate as green solvent for lead determination in water

Utility of solid phase extraction for colorimetric determination of lead in waters, vegetables, biological and soil samples

In this paper, we present novel developments to our recently developed method so-called “continuous sample drop flow microextraction (CSDF-ME)” technique. Previously, we showed that the CSDF-ME technique offers several advantages, including stability of extraction solvent, no need for holder device, and easy to operate. The merit of current study is to make the extraction steps faster with sample required for the analysis. The key novelty of proposed method includes usage of a solvent mixture (i.e., methanol and carbon disulfide), allowing to pump aqueous samples with a higher flow rate than the former technique which led to reduce the extraction time. Results show that the technique is cable to become faster by five times with an enrichment factor of 93 for 4.0 mL of aqueous sample. The linear range and limit of detection for Pb are found to be 0.1–6.0 and 0.03 µg L−1, respectively. The relative standard deviation for determination of 1.0 µg L−1 of Pb in a sample is 2.9% (n = 5). Furthermore, the relative recoveries of the developed CSDF-ME method for Pb in tap water, mineral water, and Standard Reference Material for apple leaves (1515) are shown to be 98, 100, and 94%, respectively.

A simple and green deep eutectic solvent based air assisted liquid phase microextraction for separation, preconcentration and determination of lead in water and food samples by graphite furnace atomic absorption spectrometry

This study presents the elaboration of a simple and cheap electrode made by carbon paste introduced into a cavity of electrode body, and used for the lead traces determination in tap water. A potentiostatic pre-electrolysis at constant voltage enables the reduction of the lead (Pb2+) and the accumulation of the metallic lead at and into the carbon paste; the reoxidation of the Pb (Linear sweep voltammetry) leads to the anodic striping peak. The effect of the main operating parameters on the shape of the peak and the magnitude of the current was examined and their optimal values were determined. Then calibration was achieved and the method was successfully applied (using all the optimized parameters) to the determination of lead in water, with a detection limit of 0.138 μg·L-1. Compared to other methods (ICP-AES for example), the proposed method offers a satisfactory detection limit of the Pb2+ (0.138 μg·L-1) because of the important specific area of the carbon paste electrode, for a significantly lower cost. Besides, there is no observed loss in the electrode answer in terms of peak current, which means that there is no any irreversible steps nor deactivation of the electrode, even after ten successive measurements; only reduction of the lead followed by the deposit oxidation was observed at the electrode.

In the present paper, a Cuban clinoptilolite-type zeolite was used as lead sorbent. The effect of chemical conditioning with 1 mol L−1 NaCl, NaOH and NH3 solutions at room temperature on the ion exchange capacity for lead uptake by clinoptilolite has been investigated. According to the batch experiments, NH3-treated clinoptilolite exhibited the highest sorption capacity. For this material, the effect that contact time, solid-to-liquid ratio and pH have on the removal of lead from aqueous solutions was comprehensively analyzed, and the most suitable values for these parameters were selected afterward. The pseudo-second-order kinetic model was appropriate for the description of the kinetic performance of the sorption. The Langmuir and Freundlich isotherm models were applied to describe sorption process, and the best fit was reached by using the Freundlich model. The nondestructive techniques, namely particle-induced X-ray emission and X-ray fluorescence, have successfully been evaluated for determining lead concentration in water by its concentration in zeolite. In addition, the more traditional flame atomic absorption spectrometry determination of lead in water was also improved.

Ionic liquid-linked dual magnetic microextraction of lead(II) from environmental samples prior to its micro-sampling flame atomic absorption spectrometric determination

A simple on-line separation/preconcentration procedure is described for the determination of trace levels of Pb(II) by flame atomic absorption spectrometry (FAAS). A mini-column packed with Dowex Marathon C (DMC) ion-exchange resin was used for the on-line preconcentration of Pb(II) at pH 3.5. Pb(II) was sorbed on the resin, from which it could be eluted with 3 mol L−1 HCl and then introduced directly to the nebulizer–burner system of FAAS. The parameters influential on the determination of Pb(II) ions such as the pH of sample solution, eluent type, interfering ions and flow variables were studied. Under the optimum conditions, the calibration graph obtained was linear over the concentration range of 0.01–0.1 mg L−1. The detection limit of the method was 1.3 μg L−1 while precision was 1.1% (n = 15) at a 0.05 mg L−1 Pb(II) level. The accuracy of the method was proven using standard reference materials. The developed method has been applied successfully to the determination of lead in water and various environmental samples with satisfactory results.

Preconcentration of lead using solidification of floating organic drop and its determination by electrothermal atomic absorption spectrometry

Determination of Lead in Water Using Amberlite XAD-2 Functionalized With Xylenol Orange Resin as Column Material for On-line Flow Injection- Flame Atomic Absorption Spectrometry Analysis

A microfluidic device equipped for in situ fluorescence detection and combined with an off-line microcolumn adsorption is proposed for the determination of lead in natural water. The precolumn adsorption is based on a microcapillary filled with aminopropyl silica. An efficient Pb2+ adsorption on aminopropyl silica was proved by Langmuir isotherm adsorption experiments. The maximum adsorption capacity was found to be 5.7 × 10−4 mol g−1. By using this solid phase extraction procedure (SPE), a 100-fold specific lead concentration was obtained. The concentrated solution was then run into a microfluidic device equipped for fluorescence detection and the complete procedure allows lead determination with a detection limit of 2 μg L−1. Furthermore, it was found that these measurements are not disrupted by the addition of a large excess of other interfering cations.

In this work, we present the design, fabrication and characterization of a novel micro-extractor that performs on-line extraction–concentration–detection (ECD) of target molecules flowing in a carrier liquid. The system comprises a primary microchannel containing a flowing aqueous carrier liquid and a secondary organic storage fluid circulating in an adjacent channel. The interfaces between the two immiscible fluids are stabilized by vertical micro-pillars. The system encompasses three functions: (i) extraction of the target molecules from the carrier fluid through the pillar-stabilized interfaces, (ii) concentration of the targets in the secondary organic solvent due to its very low—or zero—velocity and (iii) on-line detection via optical spectrometry. We successively present the analysis of the physics of the system, which has led us to a specific design, then the microfabrication of the chip, and finally we demonstrate the extraction, concentration and detection of lead ions (Pb 2+) from a water flow.

Determination of lead in environmental waters with dispersive liquid–liquid microextraction prior to atomic fluorescence spectrometry

Abstract Interest in preconcentration techniques for the determination of metals at ultratrace levels still continues increasingly because of some disadvantages of flameless atomic absorption spectrometry and the high costs of other sensitive methods in compared to flame atomic absorption spectrometry (FAAS). Among preconcentration techniques, solid‐phase extraction is the most popular because of a number of advantages. In this work, thiol‐containing sulfonamide resin was synthesized, characterized, and applied as a new sorption material for solid phase extraction and determination of lead in natural water samples. The optimization of experimental conditions was performed using the parameters including pH, contact time, and volumes of initial and elution solutions. After preconcentration procedure, FAAS was used for determinations. The synthesized resin exhibits the superiority in compared to the other adsorption reagents because of the fact that there is no necessity of any complexing reagent as well as high sorption capacity. Consequently, 280‐fold improvement in the sensitivity of analytical scheme was achieved by combining the slotted tube atom trap‐atomic absorption spectrometry (STAT‐FAAS) and the developed preconcentration method. The limit of detection was found to be 0.15 ng mL−1. The Pb2+ concentrations in the studied water samples were found to be in the range of 0.9–6.7 ng mL−1.