Electronic waste (e-waste) is attracting increasing interest in industry, politics, academic centers, and initiatives worldwide. Because of its complex composition of precious and hazardous substances, new technologies are often required to process e-waste in order to maximize resource recovery and minimize possible harm to humans and the environment. Printed circuit boards (PCBs) are present in most electronic products and currently comprise a significant fraction of e-waste. In this study, a reference material (RM) for inorganic constituents in PCB samples was prepared and leaching procedures for its characterization were developed. Full factorial design and principal component analysis (PCA) were applied to evaluate five different types of acidic solvents (aqua regia, inverted aqua regia, aqua regia 50% v/v, 7 mol L⁻¹ HNO₃ + H₂O₂, and 14 mol L⁻¹ HNO₃) in sample leaching by microwave radiation and inductively coupled plasma optical emission spectrometry (ICP OES) for the determination of Ag, Al, As, Au, Ba, Cr, Cu, Fe, Ni, Pb, Sb, Si, Sn, and Zn. Diluted aqua regia provided high leaching efficiency and the best results for these elements. The optimal conditions for further experiments were fixed for 0.1 g of sample and 10 mL of acid mixture. The PCB material was also submitted to nondestructive testing by instrumental neutron activation analysis (INAA) and a paired t-test was applied to compare the results obtained by microwave radiation and INAA. A minimum mass study was carried out and 100 mg was established as the minimum sample mass for further studies in agreement with the optimal conditions fixed for the sample mass after optimization.

中文翻译：

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建议将电子废物作为参考材料–第1部分：样品制备，表征和化学计量评估

电子废物（电子废物）在全球的工业，政治，学术中心和计划中引起了越来越多的兴趣。由于贵重和有害物质的组成复杂，通常需要使用新技术来处理电子废物，以最大程度地回收资源并最大程度地减少对人类和环境的危害。印刷电路板（PCB）存在于大多数电子产品中，目前占很大一部分电子废物。在这项研究中，制备了用于PCB样品中无机成分的参考材料（RM），并开发了用于表征的浸出程序。应用全因子设计和主成分分析（PCA）评估五种不同类型的酸性溶剂（王水，倒王水，王水50％v / v，7 mol L ^-1HNO ₃ + H ₂ O ₂和14 mol L ^-1 HNO ₃）的微波辐射浸出和电感耦合等离子体发射光谱法（ICP OES）用于测定Ag，Al，As，Au，Ba，Cr，铜，铁，镍，铅，锑，硅，锡和锌。稀释的王水为这些元素提供了高浸出效率和最佳效果。进一步实验的最佳条件是固定0.1 g样品和10 mL酸混合物。PCB材料还通过仪器中子活化分析（INAA）和成对的t进行了无损检测。-检验用于比较通过微波辐射和INAA获得的结果。进行了最小质量研究，并确定了100 mg作为最小样品质量，以供进一步研究，并与优化后为样品质量确定的最佳条件相一致。