Rapid In-situ Analysis for Methyl Ethyl Ketone Dissolved in Transformer Oil Using Surface Enhanced Raman Scattering

Methyl ethyl ketone dissolved in transformer oil is a new chemical mark of thermal insulation degradation. As an effective detection method, Surface-enhanced Raman scattering (SERS) could directly perform rapid detection for methyl ethyl ketone in transformer oil without complex preprocessing steps, which can provide in-situ capability to overcome the shortcomings of traditional method. First, sliver nano-bulks were synthesized on the copper foil surface by the galvanic displacement. silver nanobulks were used as the SERS substrate to detect standard transformer oil samples with different methyl ethyl ketone concentrations. The SERS peak at 763 cm^-1 was selected as the characteristic SERS peak for qualitative and quantitative analyses. In addition, the quantitative analysis model was built between the Raman intensity at 763 cm^-1 and methyl ethyl ketone concentrations by applying the least square method. Experimental results showed that SERS method could be used to analyze methyl ethyl ketone dissolved in transformer oil quantitatively and effectively. With further improvements of the detection limit, the SERS method will provide a useful approach to achieving rapid in-situ analysis for methyl ethyl ketone dissolved in transformer oil. (paper)