Current Methods and Prospects for Analysis and Characterization of Nanomaterials in the Environment

Abstract

Analysis and characterization of naturally occurring and engineered nanomaterials in the environment are critical for understanding their environmental behaviors and defining real exposure scenarios for environmental risk assessment. However, this is challenging primarily due to the low concentration, structural heterogeneity, and dynamic transformation of nanomaterials in complex environmental matrices. In this critical review, we first summarize sample pretreatment methods developed for separation and preconcentration of nanomaterials from environmental samples, including natural waters, wastewater, soils, sediments, and biological media. Then, we review the state-of-the-art microscopic, spectroscopic, mass spectrometric, electrochemical, and size-fractionation methods for determination of mass and number abundance, as well as the morphological, compositional, and structural properties of nanomaterials, with discussion on their advantages and limitations. Despite recent advances in detecting and characterizing nanomaterials in the environment, challenges remain to improve the analytical sensitivity and resolution and to expand the method applications. It is important to develop methods for simultaneous determination of multifaceted nanomaterial properties for in situ analysis and characterization of nanomaterials under dynamic environmental conditions and for detection of nanoscale contaminants of emerging concern (e.g., nanoplastics and biological nanoparticles), which will greatly facilitate the standardization of nanomaterial analysis and characterization methods for environmental samples.

Unveiling Fragmentation of Plastic Particles during Biodegradation of Polystyrene and Polyethylene Foams in Mealworms: Highly Sensitive Detection and Digestive Modeling Prediction

“…We used the mealworm frass at the end of the 6-week experiment for analysis because the mealworms have reached the stabilization phase of PS and PE biodegradation since Week 4. After the supernatant became clear, the solution containing residual plastic particles was allowed to stand for 1 h. ,, The solution containing residual plastic particles underwent filtration using a polyamide (PA) membrane filter (porosity: 100 nm, Yibo Filter Material Co., Zhejiang, China), which was the most suitable filter with the smallest available pore size. The micro- and submicroplastic particles with a size exceeding 100 nm on the filter membrane were meticulously collected and observed under high vacuum conditions using a scanning electron microscope (SEM; Phenom Pro, Phenom World Inc., Netherlands).…”

Atomic spectrometry update – a review of advances in environmental analysis

“…A review (291 references) on the characterisation of nanomaterials in the environment covered, 57 amongst other topics, the preconcentration of nanomaterials from aqueous samples, their quantification by sp-ICP-MS and XRFS and their characterisation by techniques such as FFF-ICP-MS and LA-ICP-MS. A more specific review (74 references) on the trends and challenges in determining engineered NPs in seawater drew 58 the reader’s attention to the important fact that the main limitation of many studies is the use of spiked samples at concentrations much higher than those found in real samples. Of note was the table on atomic spectrometric methods used and the sample preparation procedures required prior to analysis.…”

“…Nanoparticles were the topic of a comprehensive review (290 references) that covered 57 advances in methods for determination of their abundance, morphology, composition and structure in water, soil, sediment and biological samples. Laser- and plasma-based approaches for NP characterisation were included 117 in a broader review (596 references) that also covered monitoring of NP synthesis and the use of NPs for signal enhancement.…”

“…Several reviews covered separation and preconcentration techniques . Methods for the extraction, preconcentration and analysis of a range of nanomaterials in natural waters, waste waters, soils and sediments and biological samples were critically reviewed (291 references) by Jiang et al 57 The review (146 references) of Viana et al 60 on extraction from waters, soils and sediments for metal speciation included techniques such as MAE, UAE, SPE, SPME and LPME. Jalili et al 152 reviewed (113 references) supramolecular solvent-based microextraction techniques, primarily for the analysis of waters but also for the analysis of soils.…”

Selection of chromatographic separation conditions for reliable monitoring of the transformation of AgNPs/Ag(i) species by HPLC-ICP-MS in surface water and green algae cells

“…Characterisation of the physico-chemical properties of nanoparticles requires application of various methods, such as microscopic, spectroscopic, mass spectrometric, and sizefractionation, which provide complementary information about nanoparticles. 5,6 Among them, inductively coupled plasma-mass spectrometry (ICP-MS) has sufficiently low detection limits and selectivity for the analysis of trace levels of metallic nanoparticles in complex environmental and biological samples. However, this requires operation of ICP-MS in single particle mode or in combination with a separation technique, such as eld ow fractionation (FFF), capillary electrophoresis (CE) or high performance liquid chromatography (HPLC).…”