Ligandless temperature-controlled ionic liquid-phase microextraction of lead(II) ion prior to its determination by FAAS

An eco-friendly and sensitive deep eutectic solvent-based liquid-phase microextraction procedure for extraction preconcentration of Pb (II) ions

In recent years, interest in green solvents, which are environmentally friendly, easy to prepare and biodegradable, and in their applications in chemistry has considerably increased. In the current study, a new and easy deep eutectic solvent-based liquid-phase microextraction method compatible with green chemistry principles was developed for preconcentration of Pb (II) ions. The amount of Pb (II) ions was determined with graphite furnace atomic absorption spectrometry (GFAAS). Various analytical parameters such as deep eutectic solvent (DES) ratio and amount, ligand amount, pH, sample volume were optimized and the effects of potential matrix ions on the method were investigated. The preconcentration factor of the method was found to be 160, while the limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.071 µg L^-1 and 0.236 µg L^-1, respectively. The developed procedure was performed to determine Pb (II) ions in lake and river waters, and the accuracy of the procedure was determined with certified reference wastewater (SPS-WW1) analysis.

Ionic liquid solvent bar micro-extraction of CdCln(n-2)- species for ultra-trace Cd determination in seawater

Water analysis of trace metals has been benefited by recent studies on sample preparation by liquid micro-extraction. However, there are still limitations for its application to seawater, such as the need of additives to preserve the sample or the availability of chemical extractants for the selective extraction from highly saline samples. In this work, a three phase solvent bar micro-extraction (3SBME) system containing the ionic liquid trioctylmethylammonium chloride (Aliquat^® 336) has been used for isolation and pre-concentration of Cd from seawater samples, due to its ability for ionic exchange of CdCl_n^(n-2)-. The system was optimized to work at the natural pH of seawater, and conditions for application to real samples were 0.18 M Aliquat^® 336 dissolved in kerosene with 0.25 M dodecan-1-ol as organic solution, 1.5 M HNO₃ as acceptor solution, 60 min extraction time, and 800 rpm stirring speed in the sample. Loss of organic solution into the sample during extraction was evaluated and revealed its dependence on stirring rate and extraction time. Under optimum conditions samples containing Cd 0.09-0.90 nM were pre-concentrated 65 times. GF-AAS was used for metal quantification with a limit of detection of 0.04 nM. Accuracy was successfully evaluated measuring Cd in a seawater certified reference material BCR-403.

Bovine serum albumin-Cu(II) hybrid nanoflowers: An effective adsorbent for solid phase extraction and slurry sampling flame atomic absorption spectrometric analysis of cadmium and lead in water, hair, food and cigarette samples

Herein, the synthesis of bovine serum albumin-Cu(II) hybrid nanoflowers (BSA-NFs) through the building blocks of bovine serum albumin (BSA) and copper(II) ions in phosphate buffered saline (PBS) and their use as adsorbent for cadmium and lead ions are reported. The BSA-NFs, for the first time, were efficiently utilized as novel adsorbent for solid phase extraction (SPE) of cadmium and lead ions in water, food, cigarette and hair samples. The method is based on the separation and pre-concentration of Cd(II) and Pb(II) by BSA-NFs prior to determination by slurry analysis via flame atomic absorption spectrometry (FAAS). The analytes were adsorbed on BSA-NFs under the vortex mixing and then the ion-loaded slurry was separated and directly introduced into the flame AAS nebulizer by using a hand-made micro sample introduction system to eliminate a number of drawbacks. The effects of analytical key parameters, such as pH, amount of BSA-NFs, vortexing time, sample volume, and matrix effect of foreign ions on adsorbing of Cd(II) and Pb(II) were systematically investigated and optimized. The limits of detection (LODs) for Cd(II) and Pb(II) were calculated as 0.37 μg L(-)(1) and 8.8 μg L(-)(1), respectively. The relative standard deviation percentages (RSDs) (N = 5) for Cd(II) and Pb(II) were 7.2%, and 5.0%, respectively. The accuracy of the developed procedure was validated by the analysis of certified reference materials (TMDA-53.3 Fortified Water, TMDA-70 Fortified Water, SPS-WW2 Waste Water, NCSDC-73349 Bush Branches and Leaves) and by addition/recovery analysis. The quantitative recoveries were obtained for the analysis of certified reference materials and addition/recovery tests. The method was successfully applied to the analysis of cadmium and lead in water, food, cigarette and hair samples.

Switchable solvent based liquid phase microextraction of mercury from environmental samples: a green aspect

A novel and environmental friendly approach using switchable solvent based liquid phase microextraction (SPS-LPME), followed by UV-vis-spectrophotometric determination has been developed for the preconcentration and determination of mercury.

Ionic-liquid-micelle-functionalized mesoporous Fe3O4 microspheres for ultraperformance liquid chromatography determination of anthraquinones in dietary supplements

A magnetic solid-phase extraction method using ionic liquid (IL)-micelle-functionalized mesoporous Fe3O4 microspheres (MFMs) was proposed for the preconcentration of anthraquinones in dietary supplements. The analytes were then determined by ultraperformance liquid chromatography combined with an ultraviolet detector. The extraction parameters, such as the choice of ILs, the concentrations of ILs and MFMs, the pH of diluent, and the concentration of acetic acid in the eluent, were presented. Under the optimized conditions, the limits of detection and limits of quantitation were 0.4-2.8 ng mL(-1) and 1.4-9.4 ng mL(-1), respectively. The accuracy of the proposed method was investigated by recovery in herb and granules of Radix et Rhizoma Rhei, yielding values between 89.25% and 96.48%. The use of the proposed method in the sample pretreatment of complex dietary supplements is feasible due to the high surface area and excellent adsorption capacity of MFMs after modification with IL.

Low voltage electrically stimulated lab-on-a-chip device followed by red-green-blue analysis: a simple and efficient design for complicated matrices

An electrical field-induced lab-on-a-chip design followed by RGB analysis is introduced to develop a portable device for analysis of Pb²⁺.

Fe3O4nanoparticles and ultrasound assisted dispersive liquid–liquid microextraction of lead(ii) for its microsampling flame atomic absorption spectrometric determination in food and environmental samples

A method for the isolation of lead from aqueous samples as a Chicago sky blue 6B chelate, based on the combination of Fe₃O₄nanoparticles and ultrasound assisted dispersive liquid–liquid microextraction (NPU-DLLME) prior to flame atomic absorption spectrometry, was developed.