Mikhail S. Ermolin

Examples of applications of single particle quadrupole and time-of-flight mass spectrometry (SP-ICP-MS) to the study of natural and incidental nanoparticles in various samples: volcanic ash and fumarole condensates, aerosol and settled urban dust, indoor dust, ice cores, river colloids, bottom sediments, soils and rock dumps are considered. It is shown that quadrupole and time-of-flight SP-ICP-MS should be considered complementary analytical methods, which, despite their limitations, are indispensable in nanogeochemistry and provide unique information on the elemental composition of nanoparticles, their numerical and mass concentrations, as well as mass and size distribution. The capabilities of the single- and multi-collector magnetic sector SP-ICP-MS are also mentioned. Particular attention is paid to sample preparation, which in some cases is critically important for obtaining correct results in the study of nanoparticles by SP-ICP-MS.

Urban dust nanoparticles, which are extremely mobile in the environment and easily penetrate into living organisms, are important samples of ecoanalytical research. Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) is an effective method for studying anthropogenic nanoparticles. A critical step in an SP-ICP-MS analysis of environmental nanoparticles is sample preparation, which typically involves the preparation of suspensions and the extraction of nanoparticles from a polydisperse sample. This paper shows that the optimal ratio of dust sample to the extractant (water) for the separation of nanoparticles by centrifugation is 1 : 500. It was found that, for a study, it is advisable to take a 20-mg dust sample in 10 mL of water, at which the time spent for the extraction of nanoparticles is reduced and their mass concentrations can be determined with an average relative standard deviation no more than 34%. Using a standard sample of gold nanoparticles, the completeness of the extraction of nanoparticles from a polydisperse dust sample was estimated at 102 ± 4%. The optimized sample preparation method was tested using samples of urban dust from the city of Krasnoyarsk; the mass concentrations and median diameter of Cr-, Cu-, Zn-, Sn-, Sb-, W-, Pb-, and Bi-containing nanoparticles were determined.

Nanoparticles (NPs) of urban dust can be hazardous to human health due to the possibility of a high accumulation of potentially toxic elements (PTEs), high penetration ability into organisms, and their ability to cause injury to cells, tissues, and organs. The composition of NPs of urban dust may vary during the year; however, there are so far no studies on the seasonal changes in their elemental composition and related ecological and health risks. The current work was carried out using samples of urban dust from Moscow, the largest megacity in Europe, collected in spring, summer, and autumn. It was found that NPs of urban dust are polluted by PTEs, namely W, Bi, Hg, P, S, Sn, Mo, Cu, Cd, Pb, Sb, and Zn. The highest pollution and ecological risks were found in NPs of urban dust collected in summer (RI = 592) as compared to autumn (RI = 399) and spring (RI = 231). The same regularity was observed for health risks. The highest possible cancerogenic risk was found in summer NPs (CTCR = 3.0 × 10⁻⁴) followed by autumn NPs (CTCR = 2.5 × 10⁻⁴) and spring NPs (CTCR = 3.5 × 10⁻⁵). However, the difference between mean values obtained for the three seasons was not statistically significant. Additionally, it was demonstrated that vehicle emissions are one of the main sources of pollution of NPs, and their intensity does not significantly change throughout the year in Moscow. The results obtained offer new insights into the regularities of seasonal variations in elemental composition, pollution, and related ecological and health risks of NPs of urban dust.

Development of novel methods for the separation, characterization, and analysis of microplastics is an urgent task. Countercurrent chromatography (CCC) has been proven to be an efficient method for the separation and preconcentration of microplastics from aqueous samples using two-phase water–oil systems. However, the efficiency of separation of microplastics from natural seawater by CCC has not been studied so far. Here we demonstrate the high efficiency of separation of microplastics from Black Sea water samples by CCC. The separation efficiency of PE, PP, PS, PVC, PET microparticles of different size (<63, 63–100, 100–250 μm) from spiked seawater samples is about 100%. The method enables the separation of microplastics with size at least down to 1 μm to be performed. The combination of CCC and pyro-GC-MS was applied to the quantification of microplastics in Black Sea water samples. Seven microplastics (μPE, μPP, μSBR, μPVC, μPET) were determined in the seawater samples under study. The total concentration of determined microplastics was about 6.5 μg/L. It was shown that the combination of CCC and pyro-GC-MS enabled robust analytical data to be obtained and hence can be applied to an accurate quantification of microplastics in seawater.

An Erratum to this paper has been published: https://doi.org/10.1134/S1061934825020042

Microplastic emissions to the environment increase every year. Over the past twenty years after the first publication on the study of microplastics, the problem of the global environmental pollution by synthetic materials has been confirmed, its toxicological effect has been proven at all levels of the organization of biosystems, including human health. Spectral, chromatographic, microscopic, and thermal methods of analysis are used to study microplastics. This review considers these groups of methods in the context of their application to the identification of microplastics and the determination of toxic substances associated with them.

Microplastic pollution in aquatic environments requires special attention. In current study, a novel method based on dynamic liquid–liquid extraction in a rotating coiled column for the removal of microplastics from aqueous samples was developed.

Determination of the microplastics content of natural waters is an important task in assessing the degree of water body pollution, identifying pollution sources, and evaluating potential risks for aquatic ecosystem inhabitants and water consumers. Solving this problem primarily falls within the realm of analytical chemistry, with separation methods for particles playing a crucial role. This work for the first time presents a potential application of the method of continuous-flow microplastic separation in a rotating coiled column using a water–oil system for assessing the microplastics content in river water. Microplastics in the extracted particle samples were determined by pyrolytic gas chromatography with mass spectrometric detection (pyro-GC–MS). A water sample from the Moskva River was analyzed. Using a water–castor oil system, 1.8 mg/L of suspended particles were extracted from the river water. A procedure for the digestion of the organic matter of the sample (30% H ₂ O ₂ ) reduced the mass of the extracted particles to 0.4 mg/L. The residual fraction was analyzed by optical microscopy. According to the pyro-GC–MS data, the total microplastics content in the test water sample was 109 µg/L, accounting for 1.4% of the total suspended particle content of the sample. Five types of microplastics were identified: polyethylene, polypropylene, acrylonitrile butadiene styrene, acryl–butadiene rubber, and polyethylene terephthalate, with polyethylene being the predominant type (97 µg/L). The proposed method offers promise for assessing the microplastics content in natural waters.

Urban dust particles are a major pathogenic factor in respiratory diseases such as asthma and chronic obstructive pulmonary disease, and also increase the