Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, 20224, Taiwan, ROC.
Department of Biomedical Engineering and Environmental Sciences, National Tsing-Hua University, Hsinchu, 30013, Taiwan, ROC.
Anal Chim Acta. 2016 Mar 31;914:110-6. doi: 10.1016/j.aca.2016.01.057. Epub 2016 Feb 3.
Whether silver nanoparticles (AgNPs) persist or release silver ions (Ag(+)) when discharged into a natural environment has remained an unresolved issue. In this study, we employed a low-cost stereolithographic three-dimensional printing (3DP) technology to fabricate the angle-defined knotted reactors (KRs) to construct a simple differentiation scheme for quantitative assessment of Ag(+) ions and AgNPs in municipal wastewater samples. We chose xanthan/phosphate-buffered saline as a dispersion medium for in situ stabilization of the two silver species, while also facilitating their extraction from complicated wastewater matrices. After method optimization, we measured extraction efficiencies of 54.5 and 32.3% for retaining Ag(+) ions and AgNPs, respectively, in the printed KR (768-turn), with detection limits (DLs) of 0.86 and 0.52 ng L(-1) when determining Ag(+) ions and AgNPs, respectively (sample run at pH 11 without a rinse solution), and 0.86 ng L(-1) when determining Ag(+) ions alone (sample run at pH 12 with a 1.5-mL rinse solution). The proposed scheme is tolerant of the wastewater matrix and provides more reliable differentiation between Ag(+)/AgNPs than does a conventional filtration method. The concept and applicability of adopting 3DP technology to renew traditional KR devices were evidently proven by means of these significantly improved analytical performance. Our analytical data suggested that the concentrations of Ag(+) ions and AgNPs in the tested industrial wastewater sample were both higher than those in domestic wastewater, implying that industrial activity might be a main source of environmental silver species, rather than domestic discharge from AgNP-containing products.
当银纳米粒子（AgNPs）排放到自然环境中时，它们是否会持续释放银离子（Ag(+)），这一问题一直悬而未决。在本研究中，我们采用了一种低成本的立体光刻三维打印（3DP）技术来制造角度定义的打结反应器（KR），以构建一种简单的分化方案，用于定量评估市政废水中的 Ag(+)离子和 AgNPs。我们选择黄原胶/磷酸盐缓冲盐水作为两种银物种的原位稳定分散介质，同时也有利于它们从复杂的废水基质中提取。经过方法优化，我们在打印的 KR（768 匝）中分别测量了 Ag(+)离子和 AgNPs 的提取效率，分别为 54.5%和 32.3%，检测限（DL）分别为 0.86 和 0.52ng/L（在 pH 11 下测定 Ag(+)离子和 AgNPs 时，无需冲洗溶液），单独测定 Ag(+)离子时的检测限为 0.86ng/L（在 pH 12 下测定 Ag(+)离子时，使用 1.5mL 冲洗溶液）。该方案对废水基质具有较强的耐受性，并提供了比传统过滤方法更可靠的 Ag(+)/AgNPs 分化。通过这些明显改善的分析性能，显然证明了采用 3DP 技术更新传统 KR 设备的概念和适用性。我们的分析数据表明，在测试的工业废水中 Ag(+)离子和 AgNPs 的浓度均高于生活污水，这表明工业活动可能是环境银物种的主要来源，而不是含 AgNP 产品的家庭排放。
