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.
Wuhan Customs District of China, Wuhan, 430020, China.
Anal Chim Acta. 2023 Oct 23;1279:341846. doi: 10.1016/j.aca.2023.341846. Epub 2023 Sep 23.
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).
In this study, we synthesized a silver ion-imprinted magnetic adsorbent with high adsorption capacity (149 mg g) and rapid adsorption kinetics (30 min) at both μg L and mg L 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 × 10 particles L. 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.
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).
银纳米粒子（Ag NPs）在各种应用中广泛使用，但由于其反应性，会氧化溶解为 Ag(I)。在处理涉及 Ag NPs 的实际样品时，不可避免地会遇到 Ag NPs 和 Ag(I)共存的情况。单颗粒电感耦合等离子体质谱（SP-ICP-MS）是一种用于纳米颗粒尺寸表征的有价值技术。然而，共存溶解离子的存在会强烈干扰 SP-ICP-MS 进行颗粒尺寸分析的准确性。因此，开发一种可靠的分离分析方法来准确测量 Ag NPs 和 Ag(I)至关重要。
在这项研究中，我们合成了一种具有高吸附容量（在μg L 和 mg L 浓度下分别为 149 mg g）和快速吸附动力学（30 min）的银离子印迹磁性吸附剂。该吸附剂在 pH 7 下选择性吸附 Ag(I)，而几乎不吸附 Ag NPs。在再生后可重复使用超过 5 次。在 SP-ICP-MS 之前使用这种磁性吸附剂，我们准确地确定了标准 Ag NPs 的尺寸，与透射电子显微镜确定的尺寸一致。Ag NPs 的粒径和数浓度检测限分别为 12.6 nm 和 6.3×10 个粒子 L。此外，我们成功地将开发的方法应用于分析抗菌凝胶提取物中的 Ag(I)和 Ag NPs，并通过酸消解-ICP-MS、TEM 和加标实验验证了其准确性。
在存在 Ag(I)的情况下直接进行 SP-ICP-MS 分析会导致基线升高，从而掩盖来自较小 Ag NPs 的信号。我们选择性去除 Ag(I)的方法大大提高了抗菌凝胶提取物中通过 SP-ICP-MS 检测 Ag NPs 的准确性（例如，从 48.26 到 35.67 nm）。与 SP-ICP-MS 中使用的其他方法相比，我们的方法具有更高的吸附容量，能够更好地容忍共存的 Ag(I)。
