Simultaneous preconcentrations of Cu(II), Ni(II), and Pb(II) by SPE using E. profundum loaded onto Amberlite XAD-4

Switchable metal extractant integrated miniaturized 3D-printed device: A semi-online multi-metal separation system for matrix-free ICP-MS analysis

BACKGROUND

This study tackles the critical challenges in metal analysis by presenting an innovative miniaturized metal extraction device prototype. This device features a functional nanocomposite (FNC) enhanced 3D-printed polylactic acid (PLA) metal extractant (FNC@3D PLA). The research is motivated by the constraints of traditional solid-phase extraction (SPE) methods, specifically their limitations in handling competitive metal ion environments and matrix interference during inductively coupled plasma mass spectrometry (ICP-MS) analysis. The designed prototype aims to overcome these challenges and enhance the extraction efficiency of diverse metals.

RESULTS

The FNC, designed to incorporate various functional groups critical for metal ion extraction efficiency, was meticulously engineered through the reaction of acid-treated and delaminated graphitic carbon nitride nanosheets (Thiol-gCN NSs) with 3-mercaptopropyl trimethoxysilane (MPTMS). The competitive metal ion extraction efficiency of FNC@3D PLA was demonstrated, showcasing notable limit of detection values of 3.2 ± 0.7 ng mL-1 and 8.57 ± 3.05 ng mL-1 for Cu and Ag, respectively. Furthermore, the miniaturized 3D-printed metal-preconcentration setup incorporating FNC@3D PLA exhibited favorable intraday relative standard deviation (RSD) percentage (%) values ranging from 1.23 to 8.6 for both Cu and Ag. Interday RSD % between 1.41 and 8.14 were observed under spiked real urine sample conditions. The sustainability and robustness of the proposed approach were underscored by substantial recovery % values exhibited by FNC@3D PLA, even after eight consecutive regeneration processes.

SIGNIFICANCE

This study significantly contributes to the advancement of analytical methodologies by providing a reliable and efficient platform for metal extraction and preconcentration in practical metal analysis applications. Developed FNC@3D PLA system demonstrates its potential to address the challenges associated with SPE in metal analysis, especially in complex sample matrices. We believe implications of this research can be extended to various fields, from environmental monitoring to clinical diagnostics, where accurate and reliable metal analysis is paramount.

Hybrid biomaterials to preconcentrate and determine toxic metals and metalloids: a review

Toxic elements represent a serious threat to the environment and cause harmful effects on different environmental components, even at trace levels. These toxic elements are often difficult to detect through the typical instrumentation of an analytical laboratory because they are found at very low concentrations in matrices such as food and water. Therefore, preconcentration plays a fundamental role since it allows the effects of the matrix to be minimized, thus reaching lower detection limits and greater sensitivity of detection techniques. In recent years, solid-phase extraction has been successfully used for the preconcentration of metals as an environmentally friendly technique due to the fact that it eliminates or minimizes the use of reagents and solvents and offers reduced analysis times and low generation of waste in the laboratory. Hybrid biomaterials are low-cost, eco-friendly, and useful as efficient solid phases for the preconcentration of elements. In this review, recent investigations based on the use of hybrid biomaterials for the preconcentration and determination of toxic metals are presented and discussed, given special attention to bionanomaterials. A brief description of hybrid biomaterials often used for analytical purposes, as well as analytical techniques mostly used to characterize the hybrid biomaterials, is explained. Finally, the future prospects that encourage the search for new hybrid biomaterials are commented upon.

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.

Determination of some heavy metals from aqueous solutions using modified Amberlite XAD-4 resin by selective solid-phase extraction

The adsorption efficiency of Pb(II) and Cd(II) from aqueous solutions on m-phenylenediamine-modified Amberlite XAD-4 resin was investigated. The effects of pH, adsorbent amount, initial metal concentration, eluent type and volume and flow rate on the retention of the metal ions have been studied on column studies. The optimum parameters were determined as pH 5, concentration 10 mg/L, stirring time 30 min and 0.2 g adsorbent amount and flow rate 2.5 mL/min for a quantitative adsorption. Sorption data were interpreted in terms of Langmuir and Freundlich equations, and both models were found to be fully appropriate. Each column can be used up to 10 sequential analyses without considerable change. The results indicate high metal adsorption capacity and satisfactory recovery of Pb(II) and Cd(II).

Modeling and Optimization of Heavy Metals Biosorption by Low-Cost Sorbents Using Response Surface Methodology

This paper exploits, through modeling and optimization, the experimental laboratory data on the biosorption of heavy metal ions Pb(II), Cd(II), and Zn(II) from aqueous media using soybean and soybean waste biomasses. The biosorption modeling was performed using the Response Surface Methodology, followed by optimization based on numerical methods. The aim of the modeling was to establish the most probable mathematical relationship between the dependent variables (the biosorption efficiency of the biosorbents when adsorbing metal ions, R(%), and the biosorption capacity of sorbents, q(mg/g)) and the process parameters (pH; sorbent dose, DS (g/L); initial metal ion concentration in solution, c0 (mg/L); contact time, tc (min); temperature, T (°C)), validated by methodologies specific to the multiple regression analysis. Afterward, sets of solutions were obtained through optimization that correlate various values of the process parameters to maximize the objective function. These solutions also confirmed the performance of soybean waste biomass in the removal of heavy metal ions from polluted aqueous effluents. The results were validated experimentally.