基于银纳米片表面增强拉曼光谱的变压器油中溶解糠醛原位检测

In-situ Detection of Furfural Dissolved in Transformer Oil Based on Silver Nano-plates Surface Enhanced Raman Scattering

实现变压器油中溶解糠醛含量的准确检测,对评估运行变压器油纸绝缘的老化状态具有重要意义。表面增强拉曼光谱技术(surface enhanced Raman scattering,SERS)作为检测微量物质的有效手段,已广泛应用于生物医药、食品安全以及环境监测等诸多领域的检测分析。该文应用置换法制备了正六边形银纳米片,并以此作为SERS基片对不同糠醛含量的变压器油样进行了拉曼光谱原位检测;研究了糠醛分子在-SERS基片上的拉曼信号增强效应,选取756cm1作为油中溶解糠醛分子的定性分析依据;结合最小二乘法,以756和-853cm1两处拉曼信号的强度比为指标,建立了变压器油中溶解糠醛含量的定量分析方法。试验结果表明:以正六边形银纳米片为SERS基片,表面增强拉曼光谱技术能有效地对变压器油中溶解微量糠醛进行原位检测分析,其最小检测浓度极限约为0.5mg/L。理论与试验结果为拉曼光谱应用于变压器油中溶解微量糠醛的原位检测奠定了基础。

For the investigation of transformer oil-paper insulating aging state, it is of great significance in realizing the accurate detection of furfural dissolved in power transformer oil. As an effective means for detecting trace materials, surface enhanced Raman scattering （SERS） has already been applied in many analysis fields, such as biological medicine, food safety, and environment monitoring. In this paper, hexagon silver nano-plates were prepared by Applying galvanic displacement. And these silver nano-plates were used as SERS substrate to detect transformer oil samples with different furfural concentrations by the Raman spectroscopy test platform. The enhancement effect of furfural Raman signals on the SERS substrate was studied, and the Raman signal at 756cm-1 was selected as characteristic peak for qualitative analysis. Utilizing the Raman peak intensity ratio between 756 and 853cm-1, the quantitative analysis method was built based on the least squares method. The comparison results show that SERS can quantitatively analyze the furfural dissolved in transformer oil effectively （with the detection limit reached 0.5 mg/L）. The theoretical and experimental results lay the foundation for the in-situ detection of furfural dissolved in transformer oil by Raman spectroscopy method.