Silver ion-imprinted magnetic adsorbent hyphenated to single particle-ICP-MS for separation and analysis of dissolved silver and silver nanoparticles in antibacterial gel extracts

Meng Zhang; Han Wang; Yiwei Wu; Xiaoxiao Yu

doi:10.1016/j.aca.2023.341846

Silver ion-imprinted magnetic adsorbent hyphenated to single particle-ICP-MS for separation and analysis of dissolved silver and silver nanoparticles in antibacterial gel extracts

Anal Chim Acta. 2023 Oct 23:1279:341846. doi: 10.1016/j.aca.2023.341846. Epub 2023 Sep 23.

Authors

Meng Zhang¹, Han Wang², Yiwei Wu¹, Xiaoxiao Yu³

Affiliations

¹ Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi, 435002, China.
² Wuhan Customs District of China, Wuhan, 430020, China.
³ Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi, 435002, China. Electronic address: yuxiaoxiao@hbnu.edu.cn.

PMID: 37827657
DOI: 10.1016/j.aca.2023.341846

Abstract

Background: Silver nanoparticles (Ag NPs) are extensively used in various applications, but their reactivity leads to oxidative dissolution into Ag(I). When dealing with real samples involving Ag NPs, it is inevitable to encounter situations where both Ag NPs and Ag(I) coexist. Single particle-inductively coupled plasma mass spectrometry (SP-ICP-MS) is a valuable technique for nanoparticle size characterization. However, the presence of coexisting dissolved ions strongly interferes with the accuracy of particle size analysis using SP-ICP-MS. Therefore, it is crucial to develop a reliable separation analysis method to accurately measure both Ag NPs and Ag(I).

Results: In this study, we synthesized a silver ion-imprinted magnetic adsorbent with high adsorption capacity (149 mg g^-1) and rapid adsorption kinetics (30 min) at both μg L^-1 and mg L^-1 concentration. The adsorbent selectively adsorbs Ag(I) at pH 7 while hardly adsorbing Ag NPs. It is reusable for more than 5 cycles after regeneration. Using this magnetic adsorbent prior to SP-ICP-MS, we accurately determined the sizes of standard Ag NPs in agreement with the size determined by transmission electron microscopy. The detection limit of particle size and number concentrations of Ag NPs was 12.6 nm and 6.3 × 10⁵ particles L^-1. Moreover, we successfully applied the developed method to analyze Ag(I) and Ag NPs in antibacterial gel extracts and validated its accuracy through acid digestion-ICP-MS, TEM, and spiking experiments.

Significance and novelty: Direct SP-ICP-MS analysis in the presence of Ag(I) led to a high baseline, obscuring signals from smaller Ag NPs. Our method of selectively removing Ag(I) substantially improves the accuracy of Ag NPs detection via SP-ICP-MS in the antibacterial gel extracts (e.g. from 48.26 to 35.67 nm). Compared to other approaches used in SP-ICP-MS, our method has a higher adsorption capacity, allowing for better tolerance of coexisting Ag(I).

Keywords: Dissolved silver; Magnetic ion imprinted polymers; Silver nanoparticles; Single particle inductively coupled plasma mass spectrometry.

MeSH terms

Ions
Magnetic Phenomena
Metal Nanoparticles* / chemistry
Particle Size
Silver* / chemistry
Spectrum Analysis

Substances

Silver
Ions