Preconcentration and Separation of Gold Nanoparticles from Environmental Waters Using Extraction Techniques Followed by Spectrometric Quantification

Abstract

The quantification of gold nanoparticles (AuNP) in environmental samples at ultratrace concentrations can be accurately performed by sophisticated and pricey analytical methods. This paper aims to challenge the analytical potential and advantages of cheaper and equally reliable alternatives that couple the well-established extraction procedures with common spectrometric methods. We discuss several combinations of techniques that are suitable for separation/preconcentration and quantification of AuNP in complex and challenging aqueous matrices, such as tap, river, lake, brook, mineral, and sea waters, as well as wastewaters. Cloud point extraction (CPE) has been successfully combined with electrothermal atomic absorption spectrometry (ETAAS), inductively coupled plasma mass spectrometry (ICP-MS), chemiluminescence (CL), and total reflection X-ray fluorescence spectrometry (TXRF). The major advantage of this approach is the ability to quantify AuNP of different sizes and coatings in a sample with a volume in the order of milliliters. Small volumes of sample (5 mL), dispersive solvent (50 µL), and extraction agent (70 µL) were reported also for surfactant-assisted dispersive liquid–liquid microextraction (SA-DLLME) coupled with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS). The limits of detection (LOD) achieved using different combinations of methods as well as enrichment factors (EF) varied greatly, being 0.004–200 ng L−1 and 8–250, respectively.

Prospects of surfactant assisted dispersive liquid–liquid microextraction for the selective extraction of silver and titanium dioxide nanoparticles from tap water and determination by spICP-MS

“…Surfactants (triton X-100, triton X-114, and tween 80) have been used as dispersing agents in dispersive liquid-liquid microextraction (DLLME) procedures due to their dissolution capacity in polar and non-polar media (the extractant in DLLME is an organic solvent) leading to the so-called surfactant assisted dispersive liquid-liquid microextraction (SA-DLLME). As reviewed, applications have been mainly focused on preconcentrating/isolating organic compounds and metallic ions; [30][31][32] although some developments have been made for gold nanoparticles (Au NPs) in water 33 and TiO 2 NPs and zinc oxide nanoparticles (ZnO NPs) in wastewater. 34 Analytical techniques such as inductively coupled plasma optical emission spectroscopy (ICP-OES) 34 and electrothermal vaporizationinductively coupled plasma-mass spectrometry (ETV-ICP-MS) 33 have been proposed for assessing the metal amount of the isolated NPs.…”

Investigation of Chemical Constituents and Antioxidant Activity of Biologically Active Plant-Derived Natural Products

“…Generally, isolation is carried out in accordance with widely recognised techniques concerning complete extraction (e.g., maceration, steam- or hydro-distillation, pressing, boiling, infusion, percolation, Soxhlet extraction, microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), accelerated solvent extraction (ASE), supercritical fluid extraction (SFE), pressurised fluid extraction (PFE), enzyme-assisted extraction (EAE), subcritical water extraction (SWE), ionic liquid extraction (ILE), pulse electric field extraction (PEFE)), preferably with nontoxic solvents (e.g., water, carbon dioxide, ethanol, ionic liquids) [ 7 , 8 , 10 , 11 , 12 , 19 , 20 , 21 , 22 ]. The biomass extract preparation includes general pre-treatment (e.g., liquid-liquid extraction, solid-phase extraction, gel filtration) and pre-concentration (e.g., gel filtration, solid-phase extraction, molecularly imprinted polymers, microporous absorption resin) [ 7 , 23 , 24 ]. Depending on the intended application of the obtained extracts, the biological assays (e.g., antibacterial, antifungal) can also be performed [ 7 , 25 , 26 ].…”