State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
Anal Chem. 2011 Sep 1;83(17):6875-82. doi: 10.1021/ac201086a. Epub 2011 Aug 9.
The rapid growth in commercial use of silver nanoparticles (AgNPs) will inevitably increase silver exposure in the environment and the general population. As the fate and toxic effects of AgNPs is related to the Ag(+) released from AgNPs and the transformation of Ag(+) into AgNPs, it is of great importance to develop methods for speciation analysis of AgNPs and Ag(+). This study reports the use of Triton X-114-based cloud point extraction as an efficient separation approach for the speciation analysis of AgNPs and Ag(+) in antibacterial products and environmental waters. AgNPs were quantified by determining the Ag content in the Triton X-114-rich phase with inductively coupled plasma mass spectrometry (ICPMS) after microwave digestion. The concentration of total Ag(+), which consists of the AgNP adsorbed, the matrix associated, and the freely dissolved, was obtained by subtracting the AgNP content from the total silver content that was determined by ICPMS after digestion. The limits of quantification (S/N = 10) for antibacterial products were 0.4 μg/kg and 0.2 μg/kg for AgNPs and total silver, respectively. The reliable quantification limit was 3 μg/kg for total Ag(+). The presence of Ag(+) at concentrations up to 2-fold that of AgNPs caused no effects on the determination of AgNPs. In the cloud point extraction of AgNPs in antibacterial products, the spiked recoveries of AgNPs were in the range of 71.7-103% while the extraction efficiencies of Ag(+) were in the range of 1.2-10%. The possible coextracted other silver containing nanoparticles in the cloud point extraction of AgNPs were distinguished by transmission electron microscopy (TEM), scanning electron microscopy (SEM)- energy dispersive spectroscopy (EDS), and UV-vis spectrum. Real sample analysis indicated that even though the manufacturers claimed nanosilver products, AgNPs were detected only in three of the six tested antibacterial products.
商用纳米银（AgNPs）的快速增长将不可避免地增加环境和普通人群中的银暴露。由于 AgNPs 的命运和毒性效应与 AgNPs 释放的 Ag(+)以及 Ag(+)向 AgNPs 的转化有关，因此开发 AgNPs 和 Ag(+)的形态分析方法非常重要。本研究报告了基于 Triton X-114 的浊点萃取作为一种有效的分离方法，用于抗菌产品和环境水中 AgNPs 和 Ag(+)的形态分析。AgNPs 通过微波消解后用电感耦合等离子体质谱法（ICPMS）测定 Triton X-114 富相中 Ag 的含量进行定量。总银（包括吸附的 AgNP、与基质相关的和自由溶解的）的浓度通过从 ICPMS 消解后测定的总银含量中减去 AgNP 含量来获得。抗菌产品的定量限（S/N=10）分别为 AgNPs 和总银的 0.4 μg/kg 和 0.2 μg/kg。总 Ag(+)的可靠定量限为 3 μg/kg。高达 AgNPs 浓度 2 倍的 Ag(+)浓度对 AgNPs 的测定没有影响。在抗菌产品中 AgNPs 的浊点萃取中，AgNPs 的加标回收率在 71.7-103%之间，而 Ag(+)的萃取效率在 1.2-10%之间。通过透射电子显微镜（TEM）、扫描电子显微镜（SEM）-能谱（EDS）和紫外可见光谱，可以区分在 AgNPs 的浊点萃取中可能共萃取的其他含银纳米粒子。实际样品分析表明，尽管制造商声称纳米银产品，但在测试的六种抗菌产品中，只有三种检测到 AgNPs。
